Move With Freedom Project Blog

2016-07-29 First Test Ride of the Electric Handcycle

2016-06-30T18:59:46Z

Ted Wojcik is seen here with the beta version of the Electric Handcycle. He calls this a “mule.” It’s a version of the bike that lets you test out the key features without putting any effort on finishing touches. It uses a plastic car seat, and has one simple hand brake (not a backpedal brake that I’ve been used to)

The electric motor is just behind the chain ring. The battery hangs below that. Eventually we might move the battery further back. For now, this puts about 15 pounds up high on what Ted calls the “power pylon.” I need to do more test riding to understand what this means for stability. My initial rides weren’t bad, but I need to see how it feels in real riding.

The motor controller is off in this photo. But it shows speed, and you can set the assist from 1-5. I rode it on 1 and then 2, and it was really powerful.

There are three important controls here. The top one is the electronic Shimano Alfine shifter. Hit the button to up. The left side to shift down. It’s a nice shifter, and has 11 speeds and a 4.09 ratio on high to low gear. But there is no backpedal brake. I think we’ll try the Shimano 8 speed with internal coaster brake. That’s what I use on the travel bike, and it works great. But the ratio is much lower…around 2.5.

It was really hot and I had to take my shirt off for test riding.

Here’s some of the stats of the battery: 36V, 12A max current, 6A nominal.

The racing seat includes an integral headrest. Hmmm, that means it doesn’t fit in the car. Not to worry, nothing a hack saw can’t fix.

Sometimes hardware can be modified almost as easily as software. Fits perfectly now.

Download IMG_2843_copy.mov

This video shows my first test ride, with out the assist motor. I mainly wanted to see how it handles as a handcycle, before I try out the motor. It feels good, it turns out, and the 11 speed Shimano Alfine hub seems to be very smooth. It has an electronic shifter that's very cool. But the motor and the battery are both mounted up high, so that will take some getting used to as far as stability goes.

Download IMG_2844.mov

This video has the momentous turning on of the power. I took it out for a test ride, but I really needed both hands and couldn't take and videos. The assist motor is powerful and quiet. It has assist levels from 1 to 5. The device has a display that says how much power its putting out. On level 1, that's about 75 watts. Even at this level, the assist was significant.

2016-02-06 Building the "Mule" - A quick test of a drastically simplified Electric Bike - and a look at the Shimano Di2 11-speed internal hub and controls

2016-02-06T22:51:48Z

Above is the part of the Electric Handcycle that Ted Wojcik has dubbed the "power pylon." It's a good name because there's a 500 watt Bofeili electric motor mounted at the very top. Because Ted has already been building a range of electric bikes, this is a motor and a controller that he's familiar with. The controller provides assist-based power. The harder you pedal, the more power the motor adds.

We had thought of mounting the motor half way down the pylon. This would lower the center of gravity. But it would also mean we would need to put our intermediate cassette onto the square taper pedal mounts on the motor.

So we decided to skip the intermediate drive for now and have a single chain going to an 11 Speed Shimano Alfine Di2 Electronic Shifting Internal Hub. With a gear ratio range of 4.09, the Alfine might just give us enough gear range when coupled with a strong motor. The power pylon approach is much different than the original design, which planned a Bionx direct drive motor in the front hub. This new design will give the rider and the motor the same thing - a nice 11-speed range of gears that is over 4x from low to high

The "Mule" will tell us. It's not meant to be fancy or beautiful, but it's meant to get the job done. We can learn and modify from there, since the mule will be made entirely of steel. Later we will substitute some of it for titanium.

This is the clamp for the Bofeili motor. Just built by Ted at the shop this Saturday, February 6, 2016

This is a Fifield Electric Bike made by Ted, using the same mid drive motor, controller, and battery that we're using on the mule.

Below is a nice video from Fifield. It gives you a good introduction to Ted, and there are lots of shots of the bike above.

We will use an internal 11 speed hub with a disc brake.

Gearing

Chainring: 25 t

Drive Gear: 23 t

Front Low Ratio: 0.57 - yields an 11.5 gear inch low

Front High Ratio: 2.34 - yields a 46.8 gear inch high

100 RPM Speed: 13.9 mph

Overall Ratio: 4.09

Speeds: 11

Shifting: Shimano Di2 electric shifting

The Shimano Di2 System has a paddle shifter for the derailleur (or the 11 speed internal). Also you can see the display mounted near the center of the handlebars.

More details about Di2 shifting here

Here's more details about the Shimano XTR Di2 M9050 System Display. This unit shows the battery condition, what gear is selected. It also provides a connection point for the control cables.

Shifting for the Di2 hub is by push button. It's supposed to be fast and smooth. Battery lasts about 1000 km before recharging. That's plenty.

This is the SM-BTR1 battery pack.

Internal Diagram of the Shimano Alfine 11-Speed Internal Hub

2016-02-01 Moving to Mid-Drive Design - Online Design Session #2 With Cody Wojcik

2016-02-02T00:20:59Z

Cody and I got together today via Skype and began to flesh out the Solidworks model using a mid-drive motor approach. It appears that mid drive is the way to go.

The plan is to place the motor at the same location as the intermediate cluster. It will drive down to the front derailleur which will be a VERY wide range cluster.

This side view shows the chain line in orange, going to the largest cog. (Not showing a 45t cog here.)

One Up Components makes a 45t modification http://www.oneupcomponents.com/products/45t-sprocket-18t to the Shimano CS-M9000 cassette that we plan to use.

This is the Shimano 11 speed CS-M9000 cassette - http://www.ridextr.com/en/productdetail/sku,CS-M9000.html

It is a really light weight design that includes some titanium cogs, as well as a carbon fiber body.

Shimano XTR M9000 Long Cage SGS Rear Derailleur is a great choice for the front derailleur. It can handle the 11-45 range, which gives the motor the most help. It also has advanced ways to maintain chain tension, which is helpful to keep the chain from falling off.

The bottom line taken from the spreadsheet shows the 11/45 cassette. The cool thing is that this gives a low gear ratio of .44, or 8.8 gear inches in low gear, as seen by the mid drive motor. This is a very low gear. Lower than what we have on either the New England Handcycle or Travel bike. It should mean that the mid drive motor can easily power the bike up even steep hills.

This chart shows that in low gear, each crank of the pedals moves you 27 inches. At 50 rpm, the bike is only going 1.3 mph. But at least it’s moving! With a hub drive, the motor would have to put out more than twice the torque because it has a 20 inch direct drive wheel vs a virtual 8.8 inches wheel with the gearing.

Now what about at high gear? Now we use the 1.82 ratio, and at 100 rpm, we get 10.8 MPH.

Can the mid drive motor go up to 150 rpm? That would about do it for speed. I wouldn’t be pedaling at 150 cadence, because of the intermediate derailleur.

Below is a confusing Excel file viewer (I don’t know how to get rid of it.)

Ignore that and go right for the Excel file download at the end.

Download Electric_Handcycle_Gearing_11-45.xlsx

Cody Wojcik - Analysis of Electric Handcycle Stability (Word file)

2016-01-31T00:07:32Z

I asked Cody to write up an analysis of stability for the three different handcycles. Part of the goal of this blog is to provide some of the basic building blocks for others that might make new designs. Cody provides a detailed way of looking at stability for these three-wheeled vehicles.

Here is Cody’s analysis in a Word viewer. After this is a link to download the Word file.

Download Design_of_electric_hand_cycle_geometry.docx

Who is Jim Turner and has he convinced me that the Electric Handcycle design is wrong? Should we switch to mid-drive?

2016-01-30T00:56:25Z

Jim Turner is an electric bike designer and founder of https://optibike.com/ Optibike in Longmont, Colorado, just north of Boulder. I just happened upon his tutorial about electric bike motors. Our initial design of the Electric Handcycle contemplated using a Bionx hub motor in the front 20 inch wheel. Everyone said it would work fine. Just one problem. Watch the tutorial, and you’ll realize that as soon as the hub motor design hits a hill, the motor will become more stressed. It will have to put out more torque at a lower rpm than its sweet spot. This will increase current draw, increase heat, and heat up the battery, all leading to a big drop in range.

In an handcycle, it’s even worse. If you start to go too slow, the electric motor will stop helping at all. The Bionx motor requires a certain amount of wheel rpm in order to add power. So you could quickly get to a point where you’re pedaling up the hill with no electric assist at all.

Watch the full tutorial here:

This is a kid’s toy called the Huffy Green Machine. The pedals directly drive the 20” wheel. This is the same condition we have with our Bionx front wheel hub motor. It is built into the wheel, and and it has no mechanical advantage — it just drives the wheel directly.

A measure of bike gearing is called “gear inches.” It goes back to the old big wheel bikes. Anatomically, a person couldn’t ride a bike much bigger than a 60” wheel diameter. Later, when geared bikes came along, they used the gear inches term to say what virtual wheel size the rider was pedaling. Usually bigger would be better, at least for level ground speed.

So our Electric Handcycle starts out by offering the Bionx the equivalent of a direct drive 20” wheel. (um, wait, its ACTUALLY a direct drive of a 20” wheel)

Gear	Gear inches	Metre development	Gain ratio	Front/ rear	60 rpm	80 rpm	100 rpm	120 rpm
mph	km/h	mph	km/h	mph	km/h	mph	km/h
Very high	125	10	9.4	53/11	22.3	36	29.7	47.8	37.1	59.7	44.5	72
High	100	8	7.5	53/14	18	29	24	38.6	30	48.3	36	57.9
Medium	70	5.6	5.2	53/19 or 39/14	12.5	20	16.6	26.7	21	33.6	25	40
Low	40	3.2	3.0	34/23	7.2	11.6	9.6	15.4	11.9	19.2	14.3	23
Very low	20	1.6	1.5	32/42	3.5	5.6	4.7	7.6	5.9	9.5	7.1	11.4

This chart from Wikipedia shows a range of gear inches for regular bikes with 700c (almost 27”) wheels. Note that the very high range is 125 gear inches, or a the equivalent of a penny farthing bike with a massive 10 foot high wheel.

At the very low end in this chart we have 20 gear inches. This is very low for a rider using their legs. But when you pedal with your arms, you have about 1/4 the available power. This usually means you need a lower gear ratio.

	Chainring	Int Small	Int Big	Int Drive	Front Small	Front Big	Full Low Gear In	Full High Gear In
New England Handcycle	25	13	38	28	13	38	9.7	82.8
Travel Bike	25	0	0	0	0	0	9.7	25.3
Electric Bike	26	11	36	24	11	42	8.3	103.1

Here we see that the New England Handcycle and the Travel Bike have a low gear of 9.7 inches.

This John Deere kids tractor has a front wheel that’s about 12 inches. In my case we have a 220 lb adult and a 50 lb bike, or 270 pounds to climb the hill. The Electric bike gets a 8.3 inch equivalent wheel to give you a really low gear.

With two derailleurs - one on the front wheel, and one half way up the to the pedals, we get a wide range of gearing. But its interesting — the overall ratio of 12.5 is used to make 20” wheel become an 8.3 inch wheel for climbing. And then for speed, those gears turn the 20” wheel into a 103” wheel - equivalent of a 8.6 foot penny farthing direct drive wheel. So, most of gearing is used for speed, and just a bit to make the hill climbing easier.

To use Jim Turner’s mid drive suggestion — which certainly does seem like a good idea — we need to mount a 7.9 lb electric motor somewhere along the drive train. We have two main options. One is to mount it at the pedals. This gives us the benefit of both derailleurs and will let the electric motor see that tiny 8.3 in front wheel on the hills, and then see a nice big 103” wheel for speed on level ground and down hill. I’ve simulated the rough size of the motor in the model above. Gosh, it seems really big there, and a shame to have a really heavy device perched at the end of a long tube.

A better alternative is to mount the motor as part of the intermediate derailleur. This would mean that the electric mid drive motor would only see the benefit of the front derailleur, which in our current design is an 11-42 large range cassette.

Drive Gear: 24 t (mounted to mid drive)

Low Gear: 42 t (24/42 * 20 = 11.4 gear inches)

High Gear: 11 t (24/11 * 20 = 43.6 gear inches)

Low Ratio: 0.57

High Ratio: 2.18

I can’t imagine mounting this big motor up by the pedals.

So this begs these questions:

Question 1: How big a deal is it to give the motor a 11.4” (virtual) front wheel vs a 20” front wheel for Bionx?

Question 2: How big a deal is it to give the motor an equivalent 43” front wheel for speed, vs a fixed 20” wheel?

Hmmmm… Maybe Jim Turner himself will provide some expert guidance. Stay tuned.

Sketchup Models (Sketchup 15 or higher)

Download Electric_Handcycle_showing_motor_positions.skp

Download Electric_Handcycle_seat_and_battery_FINAL_geoff.skp

Here is the gearing spreadsheet used in this post:

Download Electric_Handcycle_Gearing_11-42.xlsx

2016-01-13 Proposed Location and Mounting of Bionx Battery for the Electric Handcycle

2016-01-13T05:26:42Z

The Bionx motor system has a lithium-ion battery that needs to be mounted somewhere. I propose to mount it under where the basket will go.

Bionx makes a removable battery that fits in a special double level rear rack. We might get a rack and cut it up and use it to mount the battery below the main tube.

Here’s a look at the Bionx battery carrier rack.

Here is the connector that mounts inside the rack.

With one wheel removed, you can see the battery more clearly. I don’t want the battery under the seat, as there is some remote chance of fire, and better to have flames behind you than under you!

You can download the Sketchup model below. (Uses Sketchup 2015 or 2016)

Download Electric_Handcycle_seat_and_battery_FINAL_geoff.skp

2016-01-13 Proposed Seat Design for the Electric Handcycle - A Modified Version of a 1980 Design

2016-01-13T05:24:12Z

Working with Geoff Bostwick SketchupTutors@gmail.com we were able to add a proposed seat design to the Electric Handcycle design. The Sketchup model is available at the end of the post. You can download it and play around for yourself.

This 1982 photo shows me on the first handcycle I designed. It was based on my 1980 undergraduate thesis at MIT. We’re stealing part of the seat design for the Electric Handcycle, some 36 years later.

In this scale model made of brass (I was very proud of that), I proposed a square main tube and two sliding seat supports which would clamp to the main tube. In the end we used round tube, and round clamps. It worked fine, and I rode that bike for years.

If you feel like it, here is a whole bunch of photos of the brass model and photos of the actual thesis handcycle before painting.

The proposed seat will use round clamps over the 2” metal tube. The seat will be able to move from to back. But that’s not really the point because the front end isn’t adjustable, and the seat will end up where it due to the geometry we pick on the front end. We may have an adjustable reclining angle for the seat, and that would mean moving it front to back.

The Travel Bike uses steel clamps over a titanium tube. It works great. Titanium is like gold — it doesn’t corrode at all. We may use titanium for the main frame, which will make clamping very easy, whether the seat is also in titanium, or if we use chrome-moly.

The first prototype will be all chrome-moly. The clamps should work fine. Yes, clamping will scratch the paint, but if we go with titanium, no pain on the main tube (or that part of it) is required.

Here’s the clamp, but with no bolts or anything. When finished, there will be a top piece and a bottom piece. They’ll bolt together.

NOTE: This is far from a finished design. This is meant to get the concept going.

Here we see the current Sketchup model with the Solidworks model dimensions overlayed. The seat is positioned correctly, but you can see that front end is about 1 inch further back than the Solidworks model calls for. Not a big issue right now, but we’ll need to sync up with Solidworks once we finalize the geometry. For example, or recent work has the head tube angle at 54 degrees, and the pedal offset at about 5”.

You can download the Sketchup Model below. (Uses Sketchup 2015 or later)

Download Electric_Handcycle_seat_and_battery_FINAL_geoff.skp

2016-01-08 Thinking of Using the Shimano SLX Components

2016-01-09T04:09:54Z

The Shimano SLX 10-speed mountain bike drive system provides all the components for a mountain bike. We will use the derailleur, the cassette, and the shifter. For cranks we need a square taper approach (see an upcoming post). We have no front derailleur. Not sure if we'll use their disc brake. SRAM has one made by Avid. I kinda like that name.

The most crucial component is the derailleur. The Shimano SLX RD-M675 10-speed SGS Rear Derailleur offers much of the features of the fancier XLR line. This includes some clever techniques that make sure the chain always has tension. This is key as a mountain bike jumps over rough terrain. In the handcycle, this will be a useful feature because you often turn the steering 90 degrees, which puts the chain sideways over the cogs which are now in a horizontal rather than vertical position. On my older bikes, if you backpedal in this situation, you will likely have a chain come off. And that's a pain. But with this derailler, maybe the tensioner will help avoid the situation.

The Shimano XTR CS-M980 10-Speed 11-36 Dyna-Sys Cassette X is ten speeds and should fit on the Bionx front wheel, as well as in the intermediate derailleur position.

The M980 is a premium product, selling retail for about $200. The M980’s largest three cogs are made from titanium. This saves 3.5 oz over the less expensive cassette. Taken together, the two more expensive cassettes add about $250 to the retail parts cost, but they save about half a pound, and they reduce the rotating mass. This seems like quite a nice win for the money.

The Shimano SLX SL-M670 Shifters - 2x10 trigger shifter looks like it will work for the front derailleur which has an unmodified cassette. It won't work on the intermediate derailleur once we're done mucking with the cogs. We'll be taking a ten speed and making it 8 speeds or even 7. (The same thing on the New England Handcycle is 4 speeds.

Here's how it looks on the New England Handcycle (circa 1982!). Note 4 speeds and one drive cog.

The shifter controls on the New England Handcycle is a click shifter on the left side running a derailleur, and the right side is just friction and it runs the intermediate derailluer.

So lets look at what we might do with 2 times as many cogs as we used to have!

In the intermediate position, the cogs would be arranged as follows:

ORIGINAL: 11, 13, 15, 17, 19, 21, 24, 28, 32, 36T

Modification:

Remove the 28-32-36 titanium grouping

Remove the 24 and save it as a drive gear by putting at the end when done.

Remove the 19 to create additional space.

Rearrange with proper spacing

Replace the 28-32-36.

Add the 24 on the end.

MODIFIED: 11, 13, 15, 17, __, 21, __, 28, 32, 36T, 24

This rearrangement will mean we can’t use the trigger shifter. Will need to find a regular friction shifter for the intermediate derailleur. That’s the way we do it now. The front one uses a click shifter.

Comparing the original and the modified:

ORIGINAL: 11, 13, 15, 17, 19, 21, 24, 28, 32, 36T

MODIFIED: 11, 13, 15, 17, 21, 28, 32, 36T, 24T

(bold sprockets are one unit)

From our parts database: (Click on the underlined part to find out much more.)


	BK3-1067		Shimano XTR CS-M980 10-Speed 11-36 Dyna-Sys Cassette
	BK4-1068		Shimano SLX RD-M675 10-speed SGS Rear Derailleur
	BK5-1072		Shimano SLX SL-M670 Shifters - 2x10

2016-01-02 Design Session #1 - Choosing the frame geometry (and other stuff too) [Includes live capture screen recording of Solidworks]

2016-01-09T01:20:27Z

Cody and I did an online design session to review the geometry of three handcycles. The New England Handcycle (NEH), which uses a 20” wheel and a 24.5” track, and has the rider sitting further back and higher up. Then the Travel Bike which is 2” narrower, has a steeper head tube angle by 6 degrees, and the rider sits further forward and a bit lower.

The screen image above shows the Electric Handcycle’s initial choice of geometry, with the same 20” wheel as the NEH. The Electric Handcycle (EHC) pushes the head tube angle to 55 degrees. This moves the pedals forward quite a bit. It moves the rider forward also. The EHC seat is a bit lower for better stability, even though it uses the 24.5” track of the NEH bike, and might be stable enough with a littler higher (and more fun and more visible) seat.

Here is the same illustration, but with a range of useful dimensions, including trail (0.981 for both) and wheelbase at 50.375 for the EHC. Note that the EHC is a bit longer overall than the New England Handcycle. This isn’t a great thing, because overall length matters a lot for small elevators when you get inside. Inches count. Later, we’ll reduce the overall length.

Here is a dimensioned illustration for the NEH bike taken from Solidworks. Note the 49 degree head tube angle, the 49.344 wheelbase (a bit shorter than the initial EHC bike)

We then began to investigate stability for the three bikes. Cody drew in the stability triangle for each bike, and we made guesstimate of the center of gravity of the bike with a rider. Check out this tutorial on stability triangle.

Here you can see the (estimated) CG points in the respective triangles for the Travel bike (narrower with a little longer wheelbase) and the NEH (wider, with a bit shorter wheelbase)

The NEH bike is much more stable and forgiving when riding. But the extra two inches of narrowness on the Travel Bike is a great win indoors. The Electric Bike will spend more time outside, going fast, so we’ll probably go with a wider track. The steeper head tube angle of the Travel Bike puts so much more weight on the front wheel. The Travel Bike can climb steep roads straight up without drive wheel slippage. The NEH bike wheel slips often. So we’ll probably stay with the 55 degree head tube angle.

We did some editing of the design and made the Electric Handcycle match the Travel Bike length. So now you can see the EHC and the Travel Bike. The CG points are coincident. But the EHC bike is 2 inches wider than the Travel Bike

We then played around with the frame design of the Electric Handcycle. The bent (mitered) frame is mounted below the cross axle and gives us a few inches of extra clearance to bring one’s legs over when getting in. That can make a big difference.

Tools for following and learning from the design process

One of the goals of Move With Freedom is to spread knowledge of design of handcycles and other special vehicles. Towards that end, we will be publishing quite a bit of design detail as we figure out the Electric Handcycle. Please feel free to download tools and to give feedback along with way. Bill is at bill@warnerresearch.com Cody is at wojcik.cody@gmail.com

Session Screen Recording with Audio and Webcam

I recorded the interactive design session with Cody. He was on Skype from New Hampshire. I was at my office at www.greentownlabs.org in Somerville, MA. A few other people joined in at times. One is my friend Jim Gregoric, and the other is Blake Sessions (www.riserobotics.com

You will notice one edit. That's when we went off on too much of a tangent for even an unedited video. So we spared you that one, but you'll be subjected all the rest! Seriously though, I do hope its useful to be a fly on the wall during some pretty interesting and nitty gritty design work.

Solidworks Model

You can follow along in Solidworks by downloading the model below. This is the model used during the sessio

Download Travel_Bike.SLDPRT

Download NEH.SLDPRT

Download Electric_Handcycle.SLDPRT

E-Drawings File

By using the E-viewer file below, you can see but not edit the files.

Download New_Handcycle_and_Travel_Bike.SLDASM

Solidworks E-Drawings Viewer

Download the free Solidworks E-Drawings viewer here:

Windows: http://www.solidworks.com/sw/support/edrawings/e2_downloadcheck.htm

Mac: (click starts download) http://www.solidworks.com/plugins/edrawings/download.cfm?Release=REL&Type=MAC

2016-01-07 A survey of planned front end components on the Electric Handcycle - including new throttle and display from Bionx

2016-01-08T02:32:29Z

I’m working on a basic model that shows all the key components in place. This model (attached at the end) is pretty close.

Here we see two bar end shifters. One will drive a 10-speed Shimano cassette that is compatible with the Bionx electric motor hub. The left one will control the front derailed and will be used as an index shifter. The right one will control the intermediate drive, which will have fewer than ten gears. The shifter will need to be used without the detents.

The model has a hidden geometry that shows the sweep of the pedals. Generally we like to keep the controls outside of the sweep of the pedals.

The shifters fit between the pedal sweeps, but we need room there for the caliper brake. We’ll have to play with the fact placement of the shifters, which will probably be a clamp-on weldment that will move up and down the pedal tube.

From this side we can see the two clusters and the two derailleurs. This gives us a wide range of gearing, which is key for up and down hills. Even though the bike as an electric assist, we’re designing it to work well with no power at all.

The front wheel showing the Bionx electric motor mounted in a 20” wheel. A Shimano 10 speed cluster will probably go 12 to 36.

The intermediate derailleur.

We will re-order the cogs in a cluster. We’ll keep the largest and the smallest. A smaller cog (shown in the lighter color) will be used to drive the chain to the front derailleur.

The front wheel showing the two brake. A cable-operated disc brake, and a V-brake caliper.

Front end showing the disc. The disc brake caliper is not in the model. The disc itself is shown here at about 125 mm diameter.

V-brake shown without brake pads. This is a nice solution because we don’t have to worry about mounting a caliper brake close to the tire.

The pedals will be old-fashioned square taper mount. This is because we need a smooth axle for the backpedal brake (see later in this post) The model is showing a bottom bracket that is probably different than what we will use, but you get the idea.

We need a small drive cog, about 25 t. We’d probably machine off the rest of the spider.

The v-brake will be run by some handle mounted as shown.

The Bionx comes with a display and controller. I think this will mount between the pedals for good visibility. We’ll have to see if that works to get to the controls, especially while pedaling.

The Bionx comes with a throttle when you want power without pedaling. I assume the red button is stop (at least stop the power)

A closeup because I’m proud of my 3d modeling of the device.

Here’s what the actual Bionx throttle looks like.

Bionx has a cool new controller called the RC3 http://ridebionx.com/technology/console-technology-2/

Looks like it allows you to control everything without pecking at the screen buttons. That would be great for the Electric Handcycle.

Their new display is much smaller.

Looks more like a regular bike cyclometer, with more of the controls on the throttle (on the far right of the photo)

The red handle here is normally folded up along the pedal upright tube. When backing up, for example, to get out of an elevator, the backpedal brake will engage and stop you. So flip down the red handle, and it will eliminate the cable tension in the brake. Back up while holding this lever down. When you let go, it springs up, and cable tension is restored. (Note the older display is still shown in the model)

The backup release shown in the stowed position. The brake cable will pass by the base of this, which will be have a cam or an off center element. Rotating the lever detentions the cable that is running by. (not in the housing, and not shown)

The backup brake shown from the New England Handcycle, with the pedal removed.

Front view.

The yoke shown removed with its cam follower attached. Note the brake cord where it inserts into the bottom of the yoke.

This is the roller clutch. This is why we need a smooth axle that we can get by using square taper pedals. When the crank moves forward, this clutch does nothing. But as soon as you backpedal, the clutch engages, which make the cam (that it’s pressed into) rotate. The follower rolls up the cam, and that pulls the brake cable.

Just for the heck of it, here’s how to buy one of those roller clutches.

Click below to download the model. You’ll need Sketchup 2015 or higher.

Download Electric_Handcycle_with_backup_release_and_end_shifters_edited_by_Bill.skp

2016-01-02 First Frame Design from Cody

2016-01-02T20:58:33Z

Cody provided the first pass at the Electric Handcycle, as shown in his email below. It is interesting to see how he approached, which I think is better than what I did in my Sketchup experiment with Geoffrey. While we both used a 55 degree head angle, Cody fixed the trail at the same as the Travel Bike. In my Sketchup model, we used 55 degrees, but also set the pedal offset at 4”. Cody let the pedal offset float as needed. See the end of this blog post to see why Cody’s method is better.

Hey Bill,

I was able to spend a little time today on the handcycle.

Anyway, I set out to start to get the geometry of the electric handcycle to start to make sense and see how everything fits together and relates. I started with the travel bike and started with adjusting the geometry for a 20" wheel. I decided to keep the following constant:

- Head tube angle (55 degrees)

- Amount of trail (.981 inches)

- Wheelbase (50.375 inches)

- The position of the pedals in relation to the position of the seat

- Seat height off of the ground

Everything else was up for adjustment.

I found that as I moved the front axle up (necessitated by the larger front wheel) the pedals moved forward. So, the seat moves forward as well to maintain the same relationship. This has the added benefit of putting more weight over the front wheels which should help with traction.

To maintain the same amount of trail, the headtube/steerer offset changes to a little under 5 inches.

You will also notice a little L-shape near the bottom, these are the footrests. Since we didn't take this geometry from the travel bike, I took it from the NEH. I think it will be important to have that in the model to determine how to place the miter in the main tube.

Moving forward a little bit I roughed in some tubes, using the same diameters as the travel bike.

I found that the miter in the main tube is probably going to be a requirement. Since the increased front tire diameter would otherwise increase the height of the main tube by almost two inches, it would be very difficult to get your leg over the main tube if it were not mitered. I just kept the main tube horizontal in this version which works well aesthetically I think.

If we were to use a continuous main tube, rather than a mitered one, this is what it would look like.I would imagine this gives it more of a rakish look than you were going for.

I also know you didn't want a bent main tube for aesthetic reasons, but it was easy enough to model it, so I made a quick version like that

Probably difficult to get a good idea at this point but as we get more detail in there with wheels, crank, etc. we can play with these things some more.

Next up, I'll be going to the shop tomorrow so I can get some good fork dimensions and start to design the whole pedal/steerer assembly in a bit more detail.

Let me know what you think so far.

Cody

I went into the Sketchup model from the prior post, and extended the head tube axis to the ground. Somehow I thought we’d have very little trail, but in fact with the Sketchup model we have 2.2 inches of trail, which is becoming more than we want. Even as much as I’ve been thinking about this, my mental picture was 180 degrees off. Having a smaller pedal offset will INCREASE trail because it pulls the head tube up, and thus makes the extension of the steering axis hit further ahead of the contact patch, thus increasing trail.

Requires Sketchup 15. Download here: http://www.sketchup.com/download

Download Electric_Hand_Cycle_With_basic_parts_-_added_trail_dimension.skp

2015-12-31 Parts and Assembly Database Using Quickbase

2015-12-31T20:55:15Z

We're still at an early stage of the design for the Electric Handcycle. Many design choices depend on the components being used. So I started a database of components being used, and how these components fit together into assemblies. The fabricated components will eventually get drawings, and these will be accessible in the database as well.

Click here to see the live status of the Parts table in the database. It will open in a new window. Note that these parts are only an intial cut at selections. Ted and Cody and I are going to take a new pass through the components soon.

Note that you can click around the database all you want, but even if presented with a button like "Add Part" it won't let you. It might say to ask for permission, but we have to restrict editing of the database to those on the team. So view all you want, but please leave any editing buttons as they are (strangely, Quickbase doesn't let us take away all the buttons that Web viewers should avoid.)

This a screenshot of the Assemblies table in the database. Again, as of this post, these are preliminary. But if you click on this link much later than this post, the state of the database might be more reflecting of the actual plan (or even the reality.)

And here is the Vendors table from the database.

This is a look at a Part Record for the Front End Assembly. Parts and assemblies are handled the same. Parts can contain other parts, and then we call them assemblies. This screen shot shows some of the parts in the Front End Assembly AS2-1032

2015-12-29 Initial Sketchup Model for the Electric Handcycle

2015-12-29T19:32:27Z

This post will review an initial Sketchup model for the Electric Handcycle. It is based on measurements made at our kickoff meeting. Mostly, we'll use the design parameters of the Travel Bike, but with a 20" instead of a 16" wheel.

This model was made using my instructions by:

Geoff Bostwick

sketchuptutors@gmail.com

303 919 8131

Note that the real design is being done by Cody Wojcik using Solidworks. This model is for visualizing the machine. It's reasonably accurate, but not at all suitable for dimensioning parts like the Solidworks model will be. Still, it is efficient, because Geoff made the model in 90 minutes based on my instructions over a Skype screen share. I had previously searched for lots of bike components, so we were ready to move quickly.

Key parameters for the Electric Handcycle:

Overall length: 72"

Front wheel: 20"

Head tube angle: 55 degrees

Pedal height: 39 inches

Pedal tube offset from head tube: 4 inches

Rear track between tire centers: 24.5 inches

With these parameters, Geoff and I were able to collaborate (with him driving Sketchup) to make the model

Side view. Overall length, tip of front wheel to tip of back wheel is 72"

Front view. Width is 24.5" to the center of the wheels. Overall width including the hubs will be a few inches wider. This width is from the NEH bike, which has a wider track. That bike is 28" wide overall, compared to 25" wide overall for the Travel Bike. But the travel bike has a major focus of indoor use, and those extra 3" matter a lot. The Electric Bike will also go indoors, but will be focused more on outdoors and speed. So an extra few inches of track width gives better stability.

The electric motor will be supplied by Bionx This is a 350 watt motor that runs at 48 V. It is supposed to perform well without much drag if you are paddling on your own. It is an assist-based motor system that multiplies your own energy.

The Bionx kit shown with a 26" wheel. It can also be mounted in a 20" wheel.

An earlier post showed the gearing range of the NEH vs Travel Bike. The NEH has a much wider gear range due to an intermediate derailleur. The Electric Handcycle will also have an intermediate derailleur. We're hoping to use a 9 to 44 tooth derailleur used on mountain bikes that use a single chainring.

Click the link below to download the Sketchup Model. It was made using Sketchup 2015.

Download Electric_Hand_Cycle_With_basic_parts.skp

Click on the link above to open the Sketchup model (made with Sketchup 2015)

2015-12-27 Electric Handcycle Gearing - Excel Spreadsheet

2015-12-28T04:50:55Z

The New England Handcycle (NEH) is on the left, and the Travel Bike on the right. The NEH bike shown here was built in about 1982 by my company, New England Handcycles. It built handcycles in the basement of my house in Brookline, from 1980 to 1990 when Chris Hager, my frame builder and partner, moved to Africa.

The NEH bike uses a two stage drive, using two clusters. The intermediate cluster is circled. The Travel Bike uses an 8-speed internal brake hub.

The following chart shows the existing gearing on both bikes, and a proposed gearing for the Electric Handcycle:

The key figure to look at is the right hand column. The Full High Gear Inches. The NEH bike high gear is 82 gear inches. For each turn of the pedals, the bike will move 82 inches times pi (to get the wheel circumference). This about 21 feet per pedal revolution, and about 21 MPH at a cadence of 90. This is fast enough for gentle downhills, but on a big downhill, you begin to wind out.

The Electric bike is proposed to have the following gearing:

Upper Chainring: 25t

Intermediate derailleur small cog: 9t

Intermediate derailleur large cog: 44t

Intermediate drive: 24t

Front derailleur small: 13t

Front derailleur large: 36t

This yields a full high gear of 106, and a low gear of 7.8 gear inches. This low gear is lower than both existing bikes, and the high gear is higher. But this is done in large part by using a pretty extreme 9-44 cassette at the intermediate drive. We’ll see if that really works out.

This photo shows the chain draping over four gears in the intermediate cluster on the NEH bike. Also shown is the chain driving down to the other cluster at the wheel.

On the NEH bike, we used an old freewheel and rearranged the cogs so we have four drive cogs (13 to 38t). A fifth cog with proper spacing is used to drive the next stage gearing at the hub.

Pardon the viewer image below. It does a bad job showing the Excel spreadsheet. Better if you click the download link after the viewer and view the spreadsheet directly in Excel.

Download Handcycle_Gearing_V1.xlsx

2015-12-20 Kickoff Meeting and Video - Measuring the Past to Build the Future Electric Handcycle

2015-12-28T04:08:05Z

This video shows Ted and Cody riding my two main handcycles. The first one is called the Travel Bike. It is a lightweight, narrow handcycle that comes apart and is perfect for travel. The second handcycle is my everyday bike that I keep at home. I’m mainly seen running my two border collies with this bike. That is my bio-assist version.

The kickoff meeting was held at Wojcik Cycles on December 20, 2015. Our main goal was to make detailed measurements of both existing handcycles and be able to design a new bike using the best features of both.

The Travel Bike getting measured. Notice the silver coupler in the black tube. This is a stainless steel S&S Coupler http://www.sandsmachine.com/spec_ssc.htm that allows the bike to break down in minutes and fit just about anywhere, including the back of a Fiat taxi in Italy.

We measured the head tube angles and the steering trail. This illustration shows that the travel bike has just a little bit of trail. We’ll probably use a similar head tube angle (55 degrees) and trail on the Electric Handcycle, but we’ll use a 20” wheel.

Measuring the trail on the New England Handcycle. Again, the trail is small…a few centimeters.

Ted Wojcik (left) and Cody Wojcik (right) with the tools of the day. We got all the key measurements made, and Cody started a Solidworks model of the geometry of both existing bikes.

2015-12-27 The Electric Handcycle Design and Build Vendor - Ted Wojcik Cycles

2015-12-28T03:50:57Z

The Electric Handcycle project formally got kicked off when I visited Ted Wojcik cycles and worked with Ted and his son Cody. Ted is a long time framebuilder and Cody is a mechanical engineer. Between the two, they have plenty of talent and experience to build a great machine. Ted has made all sorts of bikes, and has worked with electric bikes for years. Cody has worked on drones, so he know electric motors and mechanical design.

Ted’s website: http://www.tedwojcikcustombicycles.com/

TED WOJCIK CUSTOM BICYCLES
4 Wilder Dr.
Unit 10D
Plaistow, NH 03865

phone: 603-479-3799 - Monday-Friday - 9am-5pm EST.
email: tedwojcik1@comcast.net - anytime!

Ted’s shop is in a modern industrial park off of Route 125 in Plaistow, NH. Its a big shop, with easy wheelchair access, and plenty of room in the shop and offices.

Ted has a full shop, lots of machine tools, and full welding ability. I asked if he could weld titanium. Ted said (and I’m sure he’s said this before) “The only thing we can’t weld here is a broken heart or the crack of dawn.” Good line. I do think we’ll be using some titanium on this project.

Ted and Cody at the front door.

I look forward to working with both of them. I believe that an electric assist handcycle will let me keep up with able bodied riders, even when climbing hills. This will mean I can go out with able bodied cyclists and spend more time riding and having fun. I’ll get more exercise, even as the motor provides an assist.

2015-12-26 How To Choose the Angles on a Handcycle

2015-12-27T03:38:46Z

Download Design_a_Handcycle.pdf

Download Design_a_Handcycle.pptx

Detailed Video: The Morph From All Angles, and Close-ups on Everything

2012-02-21T03:31:17Z

https://vimeo.com/37042854

This video gives a very detailed look at the Morph 4. It is 30 minutes, and it's unedited. But if you were to watch it, you'd have seen every single detail I could think of that makes the Morph what it is. You'll see how every part operates, and how it all works together.

Here's a few screen shots from the video.

Video: Morph Tests and Punch List

2012-02-12T02:03:00Z

This video shows a detailed test of the Morph 4's morphing ability, along with videos showing six items that need to be updated on this bike and on the subsequent 5 units that we are building.

Overall, it works very well, and the most difficult item -- morphing -- works really well. But some of the issues are significant and make riding difficult. The main issue is the seat tilts forward in high mode. This is due to an interference in the automatic seat adjuster, and it will be fixed on the next unit, and hopefully retrofitted on this one.

Here's the punch list:

1. Seat tilted down in high mode.

2. Pedal post clamp too weak - pedaling forces let the chain tension get too low.

3.Cable fraying on the centering spring support (minor issue)

4. Front end holder - how to keep the front end stable when released when getting on the machine. (turns out when the footrests are far enough forward, it will stay put)

5. Parking brake too weak - You need to put a lot of forward force on the front wheel when you morph up. The current parking brake actuator isn't strong enough.

6. Crutch holder - needs to to be much easier to load and secure the crutches.

Overall, not a bad list. I hope to take the Morph for some real rides soon.

A couple other items not shown:

7. Footrest clamps not strong enough - the footrests droop after a while. But they are super convenient - easy to adjust the footrests and to fold them when storing the bike.

8. Hand pedals - need something more to grab onto - they are just an aluminum stub right now.

1. Seat tilted down in high mode.

2. Pedal post clamp too weak - pedaling forces let the chain tension get too low.

3.Cable fraying on the centering spring support (minor issue)

4. Front end holder - how to keep the front end stable when released

5. Parking brake too weak - You need to put a lot of forward force on the front wheel when you morph up.

6. Crutch holder - needs to to be much easier to load and secure the crutches.

7. Footrest clamps not strong enough - the footrests droop after a while.

Hand pedals - need something more to grab onto

Could the Travel Bike Front End and Footrests Work on the Morph?

2012-01-26T17:26:55Z

I just got the new Morphing Handcycle, and I'm of course comparing it to the main handcycle that I ride today, which is what I call the "Travel Bike." That bike was built to come apart, so you'll see a steel coupler that lets the frame break apart. The Morph uses the same coupler. But the Morph puts your feet way over the front wheel to reduce overall length. This post uses some cheap photoshop-like techniques to compare the Morph with a theoretical coupling of the Morph rear end with the travel bike front end. After all, they use the identical coupler. So click through the images to take a look.

Download Morph_Using_Travel_Bike_Front_.pdf

Five Days to Go: A Look At the Morph under Construction

2011-10-24T03:49:00Z

Today is October 23. We have five days to go before the Oct 28 unConference, and construction of the Morph is hot and heavy in San Diego.

Earlier, on September 17, I visited Graham Butler and the Morph Team to review the final design of the Morph, and to plan how the first production prototype of the Morph could be shown at the upcoming MassTLC Innovation unConference. (bit.ly/masstlc2011) Above, Graham holds the front end of the Morph. The upper part is aluminum, while the lower fork is made of steel.

Intrepid Cycles is located in San Diego. Graham also builds frames in his home country of Brazil.

A screen shot from Graham's computer. We tested different rider sizes. It looks like Bill and Rory both fit easily on the same bike. The footrests mainly take up the difference, along with the adjustable pedal post.

Seth Arseneau drove from Albuquerque to work with us. Seth is handling the rear, morphing part of the bike, even though here he's holding the front end which was made by Graham and company in San Diego. Seth is focused on some of the highly machined parts that make the Morph do its magic.

These are the "upper morphing arms." They allow for an adjustable lift system so a variety of rider weights can be accommodated with a single version of the Morph.

This is the assembled upper morphing arm. The silver parts have been machined out for weight reduction and cool looks. The tool did not cut all the way through so we maintain maximum strength in the arms. Note the metal table. This is Seth's very cool fast welding table that makes holding weldments easy.

The upper morphing arm, upside down. You can see the lead screw and the "carriage" which allows the mechanical advantage of the gas springs to be changed by turning the bolt on the end of the lead screw.

It may seem like a minor thing, but I need a crutch holder so I can stow my crutches when I ride. We used a couple of pens taped to together on the scale model to see how that might work.

As the Morph moves down, the crutches will tilt back.

When all the way down, the crutches will tilt back nicely. Maybe we should have a little flag on them for visibility.

Here Graham is checking out the Morph with a proposed storage system that hangs under the seat. (shown as a rubber band.)

Bill's idea is to have something that hangs below the seat and can hold lots of groceries, for example. Especially in high rider mode.

This is the Schlumpf Speed Drive. It gives a 2.5x increase in gearing when you hit the button in the crank center. This 2.5x is important, because we have a very small front wheel...only 18" in diameter. This is 1.5x smaller than a 27" (700c) normal bike wheel. So, when you morph down, you'll engage the Speed Drive and you'll have plenty of gearing to get all the speed that the low, fast, highly maneuverable Low Rider mode offers.

Bill used his Travel Bike on the trip to San Diego. The front end of the Travel Bike has many similarities to the Morph. Same 18" wheel. Same 8-speed internal hub with brake (from Shimano). Also, a couple bungee cords are holding my wheelchair on the back, and that also acts as a luggage cart. Nice setup!

Morph Design is Done! Ready to Roll at Oct 28 MassTLC unConference

2011-09-30T02:21:14Z

The Morphing Handcycle design is done, and we're building six units. This post uses a CAD model that is close, but not exact to what is being built. The first of the Morphs will be unveiled at the MassTCL unConference http://bit.ly/masstlc2011 on October 28. At the end of this post is a CAD model that you can view in 3d using Solidworks free eDrawings viewer.

The Morph in High Rider mode. This is a screenshot from an earlier design. The red tubular member on the top has been replaced by the milled aluminum part on the new design in the first picture.

(Wheels and seat back hidden) The adjustable lift system lets us handle almost any weight of rider and make them "weightless" so the Morph goes up and down in seconds with no effort. The dual gas shocks give us plenty of lifting power.

Loosen the four bolts that cinch the carriage (in light blue), and then turn lead screw (dark blue) to adjust the mechanical advantage of the gas shocks. Then re-tighten the carriage, and you're ready to ride.

The bolt with the blue dot turns the lead screw that moves the carriage to adjust the lift. We're confident it will work well and look great! (we tested the mechanism but not this specific design)

The Morph in Low Rider mode with a rider. This is the view that comes up from the CAD model below.

Here is the e-Drawings file for the SolidWorks model: You'll need the free e-Drawings Viewer (for Mac or PC)

Download Morph_4.easm

Some tricks: you can click on a part of the bike and right-mouse click, the choose Hide, and it will be hidden for easier viewing of other parts.

The hide feature is handy.

Click the blue circular arrows to rotate. Click the green arrows to move from one view to the next.

Morph Parts Taking Shape: Seth Arseneau Making the Chips Fly

2011-08-20T16:41:47Z

Seth Arseneau in his machine shop. Seth is playing multiple roles on the Morphing Handcycle project. First, he is helping with important decisions about exactly how to build the machine. Right now, Intrepid Equipment is building enough parts for seven Morphing Handcycles of the Morph 4 design. Seth has already contributed to the design that is being cut from metal right now. Seth suggested that the main morphing joint be made from an external bottom bracket so it is strong, light, and easy to construct. That change is in the design. He also suggested that the upper morphing arms be made from a single plate of aluminum, rather than the welded tubular design we initially had. This has also been included in the design, Seth has cut the first pass of the arms on a friend's CNC mill.

Seth's experience with cycles and handcycle racing has been paying dividends on this project. You'll hear more about some new designs in a future blog post.

This is the upper morphing linkage arm. So nice to see it in metal, instead of CAD! Nice job, Seth.

Drawing for the upper linkage arm. We are planning to remove much of the metal for lightness and look. The outline will not be a hole, though, to keep the arm rigid. We are planning to anodize the part, and then take out the material, so it will be a two-color part.

A 7000-series aluminum oval part for the lower linkage arm.

Seth likes an exact fit. Here, all the cross supports are lined up to make sure they are all identical and accurate.

Here you can see where the cross support fits in the lower linkage arm.

Historical Review of Morphing Handcycle Blog Posts (May 2005 to June 2009)/ Welcome Seth Arseneau

2011-07-28T13:20:00Z

Seth Arseneau is a handcycle racer, a machinist, and a handcycle builder. Seth is joining with Graham Butler and Intrepid Cycles to work on the morphing handcycles. We welcome Seth to the team!

While I was putting together information for Seth to review, I figured I'd put it all in a blog post for posterity.

So here, Seth, and anyone else, is an overview of the Morphing Handcycle Project, with links to key blog posts, and a screen image from each one.

Our Website: www.movewithfreedom.org

Need to update that 2009 on the upper right!

http://www.movewithfreedom.org/MWF/Morph_HC/Archive.html

For posts dating from May 11, 2005 to February 28, 2008, we used the Apple Blog tool for our blog posts.

What follows are key postings from that first archive:

http://www.movewithfreedom.org/MWF/Morph_HC/Entries/2005/5/11_Very_Early_Email_about_%E2%80%9CTransforming_Wheelchair%E2%80%9D.html

First post 2005 Email from Rory

Original Morph - combination of Morphing Handcycle and Morphing Wheelchair:

http://www.movewithfreedom.org/MWF/Morph_HC/Entries/2005/7/5_Early_Design_Work_-_Powerpoint_Animation_of_Wheelchair_Handcycle_Design.html

This Intention document served as the design input for Morph II

http://www.movewithfreedom.org/MWF/Morph_HC/Entries/2006/10/24_Template_2.html

Rory's original side view of the Morph that started the whole design sequence.

See the original post here.

Bill riding the first Morph II prototype in April, 2007

See the original post here.

Morph can go from low rider to high rider instantly....

...for very important reasons!

See the original post here.

Figuring out how to do seat correction was a long standing issue. The above link is a Powerpoint that explains the issues. We eventually made it all automatic (Thanks Alan Ball)

See the original post here.

The goal of Morph III was to get much lower in low rider mode -- to more closely match the Bobby Hall handcycle upon which the low rider mode is modeled. See the original post here.

Morph III high rider mode. See the original post here.

Note that the original Morph II had 5.1 inches of trail. Ouch, that was bad, and had to be fixed. .

We struggled with how to make the seat tilt work. Doing a manual adjuster wasn't even easy to do, and you would have had to fix it on each morph up/down. See the original post here

A look at the Morph III frame. Click the link above and then play the animation. See the original post here

We had major issues with Morph III regarding steering and seat tilt. We did radical surgery in the shop. Don't try this at home. It partially worked. View the original post here.

View the original post here.

As we struggled to get the Morph to ride lower, Alan came up with the idea of having the main tube nestle between the rear frame. He called it "Twin Flanking Members." It worked, and we are using this approach in the final design. http://morphhc.posterous.com/twin-flanking-members

View the original post here.

This was a breakthrough from Alan Ball - a way to make the seat adjustment automatic. We're using this on the finished design. View the original post here.

View the original post here.

Detailed discussion about trail in high and low modes.

http://morphhc.posterous.com/morph-iii-trail-and-head-tube-angles-online-d

View the original post here: http://morphhc.posterous.com/april-2-2009-morph-iii-first-road-test-in-der

View the original post here: http://morphhc.posterous.com/april-3-2009-morph-iii-meeting-at-baron-engin

View the original post here: http://morphhc.posterous.com/april-14-2009-morph-ii-and-morph-iii-measurem

View the original post here: http://morphhc.posterous.com/morph-ii-vs-morph-iii-side-view-orthographic

View the original post here: http://morphhc.posterous.com/the-morphing-handcycle-in-action-rory-morphs

View the original post here: http://morphhc.posterous.com/comparing-the-morph-ii-to-the-bobby-hall-hand

View the original post here: http://morphhc.posterous.com/solidworks-as-built-models-of-morph-ii-you-ca-0

The Morph II did not turn well in low rider mode.

By dropping the front fork, we were able to get the steering geometry we wanted.

It had almost 8" of trail. Very bad. See the post for the whole story:

http://morphhc.posterous.com/what-a-difference-a-tab-makes-repairing-our-m-0

This post provides dowloadable as-built models of Morph II. These are .EASM files from Solidworks. The post also has a link to download a free viewer to see these files. View the original post here: (and download the files from here also) http://morphhc.posterous.com/solidworks-as-built-models-of-morph-ii-you-ca-0

We decided that a knee joint wasn't a good idea. But it's still interesting because this joint tracks what your knee wants to do in morphing from low to high. See the full post here: http://morphhc.posterous.com/powerpoint-animations-exploring-a-morphing-jo

Throughout the project, we struggled to make the new design match the geometries that we already knew worked. This post provides documentation of those geometries: http://morphhc.posterous.com/a-tale-of-four-handcycles-1982-to-2008-with-s

The post also includes three nice photos of Bill Warner riding his Bobby Hall bike, with his dog, Jake: http://posterous.com/getfile/files.posterous.com/morphhc/SvyXzHLkRyNI0UbQAd7b...

This post provides scale drawings for Bobby Hall, Morph II, and the "Morph Out" which became Morph 4. http://morphhc.posterous.com/bobby-hall-handcycle-compared-to-morph-2-and

After the fixes to Morph II, its geomtry seemed ideal. This presentation seeks to nail down exactly what that geomtry is. View the original post here: http://morphhc.posterous.com/just-like-your-teacher-told-you-geometry-is-i

Comparing the Morph and the Travel Bike - Side View Photos/CAD

2011-07-10T23:50:00Z

The previous posts review the Travel Bike, because it shares many design elements with the Morph. Having just spent the weekend in Newport on the Travel Bike (as I wait for the Morph 4 to be completed!), I wondered if we could use the very cool hinged footrests from the Travel Bike. The short answer: No. The Travel Bike, as compact as it is, is way longer than the Morph in high rider mode. And your legs sit well ahead of the steerer tube, as opposed to behind the steerer tube in the Travel Bike. Too bad. The Travel Bike's footrests are light and functional. Here's some more details.

Side view of the Travel Bike.

I used Keynote's instant alpha feature to grab the CAD Man from the Morph pictures. I scaled both drawing so the front wheel was the same size.

Using the same scaling techniques to see the Morph in Low Rider next to the travel bike. Note that you sit about one full head height lower. The overall length is about the same.

Adding the Morph in high rider, we see how much shorter and higher the bike is, even compared with the (mostly grayed out) Travel bike.

It's interesting to note how much more your leg bends from low rider to high rider. This is because the seat moves up and forward, but the footrest stays in a similar place (it does rotate about the front contact point, I think.)

Like I said, no but you'll see.

The instant alpha took away some of the foot of our CAD Man.

These footrests are hinged at the top of the vertical orange line, and also where the two lines meet. Go off a big curb? The footrest just bends forward, no problem.

Red lines show center line of your shin in both bikes.

I hadn't realized that the seating position relative to the steering axis was that much different. It's a good 16" (size of the front wheel). This keeps the Morph short, which is really crucial for indoor maneuverability.

And there you have it.

How a Handcycle Can Break Apart For Travel: Photo Survey of the Travel Bike

2011-05-16T14:30:00Z

Since the Morph will use some of the design concepts of my Travel Bike, here is a photo survey showing how the bike comes apart. It gets very small, and will fit in most trunks, and can go on small airplanes as well. The Morph will use the same coupler on the main frame, and it will have a similar fold-down seat. The Morph will put the centering spring entirely on the front, so the step of unhooking the centering spring will not be required.

Click on the small right arrow to view successive images below. This will give you a photo animation of how the Travel Bike comes apart:

Click on the small right arrow to view successive images above. This will give you a photo animation of how the Travel Bike comes apart.

Below is a photo survey showing more detail about the Travel Bike. It has a coaster brake in the hub, so the cam-based reversing brake isn't needed. The internal-gear hub has 8 speeds, which is okay for basic needs. The Morph has a full derailleur system, which will give it much more gear range.

Travel Bike photo survey.

Here's a picture of me on the Travel Bike. These photos were taken on a trip to Atlantis in the Bahamas. Thanks to Miles D. for demonstrating the disassembly of the handcycle.

Analyzing A Deceptively Simple Centering Spring for the Morph

2011-05-16T02:15:00Z

This post will go over the centering spring design we'll be using on the Morph. This design has been used on the New England Handcycle for over 30 years with great success, and it was carried over to the Travel Bike (shown below) that was built for me by One-Off Titanium (Mike Augspurger). The Travel bike and the Morph share many design elements, including the 16" front wheel, the coupler to allow breaking the main frame into

Here is the centering spring as installed on my Travel Bike. Note the silver coupler in the main tube. Because the bike comes apart here, there two carabeners below allow the centering spring to be dismantled when the bike is taken apart.

Closeup of the centering spring. I can't say it's pretty, but it works perfectly, as the explanations below will outline. This same mechanism will be incorporated on the Morph, but on the front end, rather than under the main tube. And, we'll make it look much nicer.

This series of three photos shows how one chain becomes slack and the other stays tight when the rider starts turning the wheel.

This is a bottom view (well, the bike is flipped vertically) showing the size of the wings.

When the wheel is turned, the wings pull on one chain, thereby stretching the elastic.

As the wheel is turned, the moment starts decreasing, while the stretch on the elastic, (I call it the "gap"), increases. The lines in red on the left side show the relative sizes of the moment and the gap.

As you start to turn more sharply, moment starts to fall quickly, even though the elastic is still being stretched more. This creates exactly the characteristic you want: Good centering near center, and up to about 45 degrees, and then a reduction in centering as you turn even more. Because the handcycle can make extremely tight turns, even more than 90 degrees, its important the the centering spring not fight you when you're doing these tight maneuvers.

At 100 degrees, we see that that gap is big, but the moment has dropped to almost zero. Just perfect. You can steer as extremely as you want, but lets say you need to grab the rear wheels and push like a wheelchair -- the centering spring will make sure the wheel stays straight.

Below are the five slides in a picture viewer, so you can click through them without the explanations above.

Here is the Powerpoint in case you'd like to play with it.

Download Handcycle_Morph_Centering_Spri.ppt

The Morph will implement the same mechanism, but the wings will be fixed to the main tube, and the elastic will be on the front end.

Morph 4 Design Review - Screen Images

2011-05-13T19:44:40Z

Bill, Seth and Graham had an extensive design review online today. The screen images are presented here. Later I will make posts that provide annotation. But for now, here's how things look. There are some little elements on the main tube that are not supposed to be there. (they were for an elastomer-based adjustable lift system that we didn't end up using.) Otherwise, things are getting very close. More later.

Some of the images show a yellow triangular upper morph arm. We decided not to use this. It creates a confusing look. Later images go back to the original design.

Morph Seat Angle - Upper to 95; Lower to 110 Discussion and CAD Models

2011-05-03T16:00:00Z

One of the design issues we've been working is how to get the seat back in high rider mode to tilt back enough.

Date: May 3, 2011 1:50:10 PM EDT

From: Graham Butler

Upper linkage design. This is based on the rear triangle of a suspension mountain bike. It integrates the weight limit adjuster and the will be stiffer than the original design because it is a true triangle. It is also much easier to build.

Seat position: I have tweaked the position and length of the upper seat tilt corrector arm to accommodate 95 degrees in high rider and 110 in low rider. This was actually really easy to do.

I have Seth working on the release system in ABQ. He is making good progress linking the shocks to a dual pull brake lever.

I was wondering whether we could nail down a date for you to come to San Diego for a meeting/progress session?

I am free for the rest of the month, although I will have a show to go to in the first week of June. Ideally it would be good to doing mid to late month.

One think that I have not had a change to work on is the centering spring design, but I have been thinking about it.

What do you think of the new upper linkage? Is it what you had in mind in terms of look/ appeal?

Let's talk soon.

Best

Graham

An Improved Backpedal Brake and Release for the Morph

2011-04-08T03:29:00Z

[From Graham Butler April 4, 2011, with photo captions by Bill]

I have reworked the reverse pedal brake. I have found a spring that will offer enough torque to offer 1lb of correcting force at the end of the lever. This should be enough to get it back over center. I have reconfigured it to be a pull action not a push action. Added a mounting hole at the front for a light or other accessory. I think that this could be a really neat feature. This will be a nice place to include some machined aluminum light fittings or some chrome. I also through it might be nice to have a logo emblazoned on the front of the brake release.

I am also going to settle on 95 degrees for high rider, and 110 for low rider seating position.

Backpedal braking mechanism. Inside the red cam is a roller clutch. The cam does nothing when pedaling forward. But when you backpedal, the roller clutch engages, and then the cam rotates backwards. This image shows that the brake is "on". The cam follower (in black) is being displaced by the red cam, and is putting tension on the brake cable.

As the cam rotates counter-clockwise during backpedalling, the follower will approach the peak, and braking will increase. When the black follower goes over the "top" of the cam, it will fall to the rest position (the cradle part of the cam), and will remain there until you backpedal again. (Remember, when the crankshaft is rotating forward, the roller clutch does nothing. But when you reverse the direction of the shaft, the oblong needles in the roller cluctch jam instantly and grab the shaft with gusto)

While we've had a cam-based brake on the New England Handcycle for 30 years, we've never cracked the issue of what happens when you want to make the cycle go backwards. For example, rolling back out of an elevator. We did add a little release for cable tension, but this was very dangerous, as it was easy to forget to turn it back on, only to find that your main brake is gone when you need it most.

So, for this project the goal was a "failsafe" brake release. It was harder to figure out than you would think. At first, we were trying to force the brake back on after a release by having the pedals reactivate the brake. But one day, while walking around at Dogpatch Labs in Cambridge, I saw lots of Solidworks models on the screens of one company, and I got to talking. I asked them to review the brake release problems and one of the engineers said quickly "you need a deadman mechanism." If you hold it, the brake is released. If you let go, then the brakes will work.

Voila. We created a big handle (in black) that serves as a grab-bar for steering when you go backwards. And by pulling backwards on this handle, you rotate a silver cam, which moves out of the way of the brake cable, reducing brake tension, and allowing the bike to back up. (The pedals go backwards when you back up, and without the release, the brake would come on immediately.

Design Items to Think About (From Bill)

1. The red cam could be in any position when you attempt a release. The way that the release is "unreleased" when you let go is from the coil spring. That spring has to generate enough force to allow the silver "slacker cam " to re-energize the brake, essentially by going from "off" or slack cable, to full on, or fully taught cable.

2. The black cam follower moves in the machined slot, and its pulling the brake cable on the other side. The brake cable force acts in one direction on once side of the follower, and the cam force acts in the opposite direction on the other side. This might torque the cam follower and make it jam in the slot.

3. The working brake is now moving over two friction points: the redirecting "pully" the top, and the "slacker cam" below it.

4. Nice clean mechanism, looks like it will be simple and reliable.