WheelchairDriver

Please post any picture, product, proposal, or idea, for any kind of mobility solution that is NOT a walker, and NOT used solely in a typical seated position.

These can be standing wheelchairs, wheelchairs with a high degree of anterior tilt, wheelchairs that recline flat, prone carts, forward leaning devices (sport motorcycle riding position), or anything that moves between these positions.

I'm trying to compile a list of odd ducks and see what can be learned from them. The odder, the better. The more detail about how they work, the better.

Here is an example of one such device.
https://www.freedomconcepts.com/product ... s/journey/
I welcome any comments on the usability, ergonomics, or medical usefulness of such a device.

I like this one because it is still upright enough to allow forward visibility and allows some weight to be borne by armpits. Very curious how well the pedaling function works.

My need personally is for something that removes weight bearing on the lower spine. Most standing wheelchairs are not appropriate for me because they rely on knee blocks to bear a great deal of the weight and chest straps are only for stability. For a standing chair, I would need a torso harness attached to a strong chair back, so my lower half could "dangle". So, also looking for any upper body or underarm support harnesses. Maybe variations of climbing or fall arrest harnesses adapted for long term use.

Just out of curiosity - Did you also ask about this on Quora? Looks familiar, and I know you got a pointer to WCD in the answers there... (Guess how I know...)

I hope someone here has some suggestions.

ex-Gooserider

Not sure any here have any experience of anything similar.

ex-Gooserider wrote:Just out of curiosity - Did you also ask about this on Quora? Looks familiar, and I know you got a pointer to WCD in the answers there... (Guess how I know...)

I hope someone here has some suggestions.

ex-Gooserider

That was me. We wrote previously about standing chairs and Guzzis via messages in this forum. My condition is getting worse so I need to figure something out quick while I can still use tools.

Helium weather balloons. And a harness. And a personal fan for directional control.

Not far off from my original inspiration for unique mobility solutions.
https://www.goodreads.com/book/show/144 ... ckey_Stick

The illustrations inside the covers show all of his other iterations.

I've just learned about Frame Runners
https://www.paravidasport.com/2022/01/0 ... -changing/
I am very excited about this.
With a few body support modifications, I'll be able to not just walk, but run. I might even have my 2 dogs pull me around.

This may be an option for some of you depending on the nature of your injury.
It works well for many people with Cereberal Palsy.

https://by-conniehansen.com/ is the inventor and maker in Denmark.
https://www.rad-innovations.com/ is a US maker.

Another device that looks promising for my condition is the Meywalk walker.
https://www.symmetrikit.com/meywalk.html

I don't like the way its set up to require another person to raise a bar for you to enter. They could have put that within reach of the user.
And I need to be a bit more horizontal.
I'm thinking something like this with office chair adjustable gas struts as the vertical members would be the bees knees.

And here is my latest test.

https://youtu.be/NKFM4EHsf84

That looks like it will tip forwards... And put crap loads of pressure on your pelvis/genital area. Go down a slope and face plant. Maybe move the whoe seating (or whatever that is called) back a long way.
Also looks like you would be better with a single rear wheel.

Thers another issue that I never mentioned. A social one. I would be embarrassed in that position. Maybe its just me.

I've moved the rear shock mounts closer to the pivots to soften the rear a lot and changed the front shocks to oil dampers with rebound adjustment. That lets me feel the weight shifts a bit better and handle them more gently. It gets a bit light in the rear going downhil but I havent face planted except when I was completely horizontal and downhill stopping with an air mattress atop a board merely placed on it. It was still a more gentle dumping than my M3 when a front caster hit the grass and tossed me head first with rotation. In order to be thrown in this position there is a lot of sliding static friction to overcome, and not much rotation. I am able to extend my legs to the rear to counter balance if I start to go forward. This seat will undergo plenty of changes before it is a daily driver

There isn't any genital discomfort. In fact, one of the goals is to reduce the pain of pudendal neuralgia by opening up the lumbar facett joints. The large surface area reduces stress an any single point. The best my back and body ever felt was at the end of a 10,000 mile road trip on a 2000 Ducati ST2. I spent a lot of that trip with my feet on the rear pegs. This was an attempt to recreate that. I find it quite comfortable and that is enough for me. As far as social stuff goes, it feels like I am sitting backwards on a chair, something I used to do a lot before. Going head first feels... more deliberate, somehow. I'm much more sociable when it does NOT feel like all my private bits are being struck by lightning.

It isn't for everyone, but it helps me get traction where I need it and puts me in a better position for welding, tinkering, and typing. If someone has a backup chair which they can modify like this, it might help stay mobile while pressure sores heal.

Around 20 years ago on request, I made a narrow single bed with a wheelchair control system, batts, and casters. For a local ward full of ill kids. It allowed them to leave the hospitals double doors and go out into the sunshine. It got used a fair bit I was told.

Burgerman wrote:Helium weather balloons. And a harness. And a personal fan for directional control.

Ha ha thanks for the laugh, BM. Bit difficult to get into the stores/shops with that, but I love the mental imagery.

slomobile, your prototype would've been ideal for me a few years ago. It reminds me of a japanese wheelchair I was very interested in but couldn't get in the uk.. have you seen this one? https://www.youtube.com/watch?v=affS1NmsIwg

Thank you so much for posting that! I have not seen it before, or anything like it except my chair. It might help with a justification letter.

Its good to know I'm not the only one looking for a chair like that.
The changing seat angle is really useful. It lets me pick something off the floor right in front of me, or stay level on hill. At a park recently I started messing with center of gravity by lowering the seat and chest pad as far as it would go, scooting forward as far as I could, and sudden stopping downhill to get it to tip forward. The rear casters came off the ground, but the stock F3 front antitip wheels stopped it safely every time. My glasses flew off once but I felt perfectly comfortable and picked them up without changing my position. I could even do 1 finger push ups to put the rear casters back on the ground. It was a fun day.

Prone chair update.

Spent 10 straight hours in the prone chair Saturday judging a state robotics championship in a busy school athletic complex. Its longest continuous test yet. There were no awkward interactions. People seemed to accept its odd shape.

Was easy getting through doors, except occasionally I would forget that I was dragging my feet and they would bump the door frame. I could simply pick up my feet and put them in the rests, but It might be possible to trap feet between wheels and doorway. I need to work on that. Narrowing overall width by turning batteries 90 degrees is probably the solution. I had only brief pain and felt even better the following day due to the mild exercise of stabilizing and shifting my body position. By contrast, in a regular chair, I do not get any appreciable exercise, I can only last about 2 hours in a regular chair and have significant pain and reduced strength and mobility the following 2-3 days.

There was 1 incident when positioned between 2 folding tables that were set up to accomodate folding chairs on one side only. Judges were sat at the tables, all facing the front of the room. My prone chair was too long to turn and face the correct way, but I could drive the chair into the gap, then turn my body to the side of the chair, facing front of room. I then laid on my side with the chest cushion under my armpit holding me up. It was more comfortable than it sounds. However, when it was time to leave the room, I switched on the joystick and turned toward front of chair. I bumped the swingaway sideways and it went so far that the stick contacted the chest cushion, pushing the stick forward. The chair drove forward pushing the joystick module into the table, which drove the stick forward even harder, knocking the table over, which finally allowed me to release the stick. I think the solution is to limit the swingaway motion to no more than 180 degrees.

So far so good. New PM, wiring, and battery box received for building next prone chair frame from ground up. Someone from the local maker space donated a very used but functional Jet chair and a set of 3 year old batteries still in their original box. We'll use that as an Ardupilot rover development test mule and then redonate to someone local in need.

End of update.

I'm reconfiguring the original prone chair
* to give it a seat from a Can Am 3 wheel motorcycle,
* 4 wheel drive adding hoverboard parts rather than rear casters, moving CG rearward for less forward tip on braking,
* relocating shin trough hangers forward,
* rear suspension arms from a Permobil C300 in order to make more room for my feet to tuck in behind the drive wheels.

Still need:
22mm ID spacers to adapt the narrower C300 suspension trailing arm bores to longer existing frame pins.
14mm OD turned stepped shaft for attaching shin trough hangers in existing forward seat frame bushings.
Fabricate rear upper inboard shock mounts, replacing existing rear tie down plates. C300 arms have cast in tie downs.
Remove single side caster arms from c300 suspension arms, replace w/urethane bushings in caster bearing tubes for mounting rear crossmember.
Fabricate rear crossmember, joining both rear suspension trailing arms flexibly at the caster bearing tubes, hoverboard pivot at center of crossmember.
Fabricate hoverboard pivot. A joint allowing 280 degree rotation of the hoverboard/skate truck, while passing wires through the center, and providing some type of encoder feedback for hoverboard steering angle.
Mount hoverboard motor drivers on skate truck if possible, crossmember otherwise.
Program controller for hoverboard motor drivers. Read joystick commands from Rnet using CAN2Rnet library to update real time kinematic model for target steering angle and rear speed and rear direction(forward/reverse).

A few photos as it sits today will follow when I get their file size shrunk.

280 degree rotation?

When I shuffle or move my chair about my casters go a full 360 degrees frequently as they must. So you are throwing away the full tank steer thing and restricting its movement and making it steer like a car?

Not quite. My goal is to achieve nearly all the same overall chair movements that a regular chair with 360+ casters can do, but do it by slowing the main wheels briefly, spinning the powered rear "caster pair" quickly 180 degrees, then reversing wheel direction under program control when it nears a steering limit, rather than spin a dumb caster 360 slowly.

It will behave differently. I don't know how differently, or if it will even be tolerable. I'll tweak the code to get it the best I can. It might work, might not, this is how I find out. This is to prevent wire wind up. Slip rings are an option that I can go to if I must, but they have cost and reliability issues at high amps.

Also, I could use coiled wires that will allow a couple full rotations then do a quick powered unwind when the chair stops. But I want to find out if the 280 degree limitation is a viable option because it is the most robust mechanically of the options.

Its not viable as if I am doing a general slow or fast manoever say near my PC or at a table, or whatever, then it frequently occurs that the caster roates more than 360 degrees, maybe even rotating 2 or 3 times if I circle the joystick while barely moving.

So its going to feel extremely odd if it keeps ignoring the command while it tries to unwind or cant do certain positions...

Also consider that with tank steer main drive wheels you turn right by holding the stick to the right no matter which way you move the chair (backwards/forwards or even if you are stationary. Your casters are going to be driven right? But you are going to need to know which way and by how much at different angles and positions depending on chair motion too. Best of luck figuring out the code to make that work!

Especially as the amount of COMMAND given at the joystick has little bearing on the amount of actual command (torque) sent to the drive wheels as this is mostly controlled by the mixing in conjunction with the load compensation. Load compensation can increase the voltage/amps so motor current can increase by 7 or 8 times when the load requires it. At other times it can be a minus figure.

Today I saw a drawing of a manual chair in a forward leaning configuration that looks good to me.
Slide wheelchair. No idea if a physical example has ever been made or who designed it. If you know, I'd like to make contact.
https://pin.it/13ehlHPHB
https://www.trendhunter.com/trends/slide-wheelchair