WillChair Page 6
I don't know how to put into words just how difficult it is to build a powerchair capable of being this smooth at low speed while being able to wheelie this effortlessly and controllably. A LOT of factors have to be just right - weight distribution, center of gravity, programming, motor compensation, gearing, etc. It's easy to make one wheelie. Not so easy to make one do it while still performing well in other areas. This is quite an achievement.
Click to play all videos. Click the box in the bottom right corner to make full screen.
Wheelies are not just for fun. They are necessary to navigate most places. This video is quite a bit of an extreme example, but wheelies are very useful in normal day to day activities. What if you are in town and some jerk is parked in front of the curb cutout? If there is not another cutout you are stuck in the street. Many places have a step to get into them. Can't wheelie? Then you can't enter without lots of ASSistance.
So, what do you do when it's 100+ degrees F outside and the yard needs mowing? You sit inside by the ac and mow of course! This is my 60 inch 14.5 horse power mower meant to be towed behind an ATV or tractor. The chair doesn't even know it's there. According to the manual it weighs 350 pounds dry. FYI - This is a finishing mower not meant for stuff this tall.
13.5 mph does not sound fast.... That is until you're doing it on motorized recliner across a bumpy cow field! The hill in this video is entirely too steep and sandy for safety in a powerchair, or even an ATV for that matter. The center of gravity being far enough rearward to keep the front casters from digging in is the only thing stopping her from getting stuck in the sand at the bottom. Common sense is used to keep from ending up in turtle mode on my back going up.
The polished aluminum thing in the bottom left corner is the bearing cap. The camera is fixed to the seat pan. This shows just how well the suspension works in use. Definitely not a gimmick just to add $$$$ like on a manufactured powerchair.
Only the big black mouth curr in the beginning is mine. That's WyleE. Every dog in the neighborhood follows me.
How I'm recording these videos. One day I'll break down and buy a suitable camera for this, something such as a GoPro Hero or Sony Action Cam. Yes, that is my rather expensive Canon 70D hanging upside down on a homemade bracket. Use what you've got! I'm sure the warranty would cover it.
I have not been able to access this area in years. This chair has no problems getting around. Much of this area is often under water.
Those poor front casters take a beating! You can see why I used the massive bearings and axle!
The beach? Yes, it can even go on the beach! Feel free to try in a typical powerchair.
A little offroading fun. And no, the caster fork is not bent. That's the distortion from the lens.
At least I'm not hard on it......
I'm usually in it doing this. A creek runs right along that tree line. There's some soft spots near the edge. I didn't want to get stuck or go swimming! I cleared off several acres of this that day and still didn't need to charge the battery.
More to come soon as I get time to build on this page!
william clarkon October 24, 2016
Hi Brian. Thanks for the comments. I think the Invacare motors would do good. Unfortunately, they use a sin/cos signal for feedback to the controller. The high power Roboteq I use does not recognize this. It uses Trapezoidal commutation from the motor's hall sensors for position and feedback. They do make lesser powered controllers now that would work with them, but I can't say if they would have the power needed for a wheelchair. Roboteq should be updating the model type that I use to recognize sinusoidal signals. If so, that could possibly work. Either way, sinusoidal is better suited for a chair. It's quieter. Trapezoidal gives a low rpm growl.
I am no engineer and delving off into building your own control system like I have is going to require some serious studying just to make it work, much less be SAFE and reliable. Adding brushless to the mix thoroughly complicates it even more. The more you learn the more you'll realize why almost no manufacturers have even tried..
I'm currently building another, as you apparently saw since you mentioned the belt drive, that is a progression of this one's basic design. I'll shoot you an email.
Brian Eppon October 23, 2016
William, I have had ALS for 6 years now and have been in a power chair for the last 5 years. If you look me up on YouTube, you'll see that I remain very active for a guy who can't do much of anything. I saw John's BM2 a while back when I first started using my chair. At that time there was so much going on with doctors and all and I didn't know how long I'd even live. But it turns out I'm one of the lucky ones (some might say"unlucky ones") that is living longer with ALS. I keep slowly loosing more body function, but that's not taking away my desire for adventurer. I saw John's BM3 and started planning on building my own. I've been slowly planning and researching for the last year. Been a little discouraged at trying to find comparable parts in the US like motors and the F55 frame but I figured I'd just build from the ground up and use the biggest eBay wheelchair motors I could find. But now that I'm starting to raise funds for the build and I have a friend that builds experimental airplanes and is excited to help me build, I decided I wanted to go brushless. This as you know adds a lot more complexities to the build. Then after days off reading though John's forum, I found you had put together a brushless powerchair. I was thrilled and impressed with your machining skills and your design! I was thinking about using the INVACARE 3G STORM brushless motors which would be easy but I didn't know if they would hold up or even preform properly. The motors you use look bullet proof! I really like the idea and looks of your belt drive setup. can you please email me at firstname.lastname@example.org for some further questions?
thank you, Brian Epp
Gerald Jacobsenon June 1, 2016
Hey Will; how are you man... Are you building these bad boy chairs for others yet??
Carl Wingeron December 21, 2015
Hi William could you contact me at email@example.com I would like to talk to you about your build. Thanks
william clarkon February 14, 2015
Gerald, that's the exact same issues I ran into. I couldn't believe just how expensive chairs were, especially considering how (not so) capable they were. I bought that same Invacare GB chair. It got me by, but stayed broken and couldn't go where I wanted either. Burgerman has the best site and forum online to help us out building something better. I post on his forum a good bit. Him, myself, and Lenny Robbins (he did the majority of the actual code writing) have spent a good bit of time developing the computer code that controls the chair.
I'm currently working on making more available. It's a long and complicated process though. Hopefully it will work out though. I hope you have joined his forum and post some. It's a great resource!
Gerald Jacobsenon February 12, 2015
Wow. Nice work.. C 5/6 complete quad for 27 years now. Also belong to the few of us that hate ASSistance as a general rule... Coming from a motorcycle riding/racing background.. I just broke my 14 year old rwd gb motored invacare arrow for the last time... Went to look for a new chair that was faster and no bigger than what I had with bigger tires with smoother ride on rough terrain and most importantly RWD!!!.. To my dismay.. I could barely find a RWD chair period. So with no choice.. I overpaid for the same thing as before a new/old version of the Invacare Arrow GB all black short frame about 33" inches long.. But now stuck with small ass tires again.. Sad at this stage the year 2015 the electric wheelchairs have gotten less mobility independence than 15+ years ago.. I have read all of Burgerman's wheelchairs. com and just now for a link to your this page.. Bravo on doing something about this the right way and direction.. I would buy your invention in a minute if only it was available to the masses.. Same situation as BM chair being a one off. Anyhoo GREAT JOB. Gerald From Canada
william clarkon February 4, 2015
Gregg, I work in Columbia now. I left you a voicemail. I will try to call you again soon. Building more is slowly in the works now. I currently have some of the electronics pulled out of it for testing and prototyping some interesting features I'm experimenting with adding to her, but SHOULD have it back together as soon as I can get a day or two off. I would be happy to talk to you or even let you try it.
Gregg Vowellon February 3, 2015
Hey William my name is Gregg Vowell. I'm a T12 paraplegic for 25yrs. I would love to talk to you about this chair and options on building one. I live in Columbia, Ms call me when u can. 601-466-3090
william clarkon December 26, 2014
James and Sheila, thank you both for the comments. I'm hoping to make them available to those that need it. It's a long, slow, expensive process. I'm just a typical working class guy with not much extra time. Keep your eyes open here in the coming year. Maybe there will be good news for others!
James Ricky Brelandon December 25, 2014
Would love to have one, this is one of the best wheelchairs I,ve ever seen