Willchair 2 Build Page 2
This is what almost all of the parts started out as - Raw blocks or bars of material. There are no off-the-shelf powerchair parts except the seat cushion and arm troughs. Everything was custom designed and built by me. That's about the only way to do it and get it how you want. Click any photo to enlarge it.
If you're ever granted permission to use a waterjet, take it. There's one in the area I'm over at work. I do all of the setup and programming for it every day, but rarely the operating. I picked up the material I needed and whacked out most of the flat parts in my off time. Very finicky machines but they're about the best way to quickly chop out parts like this.
The wheel hubs being whittled out
Short cellphone video of one cut. This is time consuming and tedious work!
Power threading the axles. You know why good taps are so expensive?
Because they're worth it.
Rinse and repeat until you have all of these parts within .0005" - twice. One for each side.
Swingarm mounts. These were a lot of work. Starting with DOM tube or good seamless pipe would have been MUCH easier. None was available locally and ordering was expensive. So, I whittled them out of solid 1018 round bar.
How to build a bird nest in 3... 2.... 1.......
While patience is a virtue, time is money. Carbide don't mind hitting it hard enough to make blue chips, but this was hss. The tool survived nonetheless.
I TIG welded the flat plates for the shocks on then back in the lathe for finish machining them for the bearings to press in.
The caster barrels and goodies inside. No individual pictures. More of the same as done above. They're O-ring sealed to keep the nasties out. Those are 3/4" id tapered roller bearings. Because replacing busted bearings is a pain I made these to outlive most species of tortoise.
Swingarms were bent on a cheap hydraulic pipe bender. This was the most "difficult" to get right portion of the build since I had no way to precisely get the bend required and it has to be correct to get the chair balanced, casters to fit, as well as the overall length/width of the chair. Ye olde calibrated eyeball was used (and lots of wasted pipe. Details farther below)
Front axles. Made from 10mm (ewww metric) chrome rod
Jigging up the caster forks. They came out dead nuts square and to size. Real welders may laugh, but that's A+ for us mere mortals (with crap quad hands that can't wear gloves at that) fighting an overheated TIG torch.
They weren't supposed to fit that close. The cheap hot-out-of-China tires I sized them by were 1/2" shorter than these Kendas. Same size designation on the sidewall. Good ole " nominal" sizing.
I'm reminded of an old quote that's not mine but fits. "Sometimes you just have to piss with the cock you've got"
No proper bending or notching equipment available, so I 3d printed the ends of the pipe from the "perfect fitting" CAD model and used those to make these paper templates to slide over the pipe. Bend and trim the pipe to make the ends match the templates. It took a whole 10' joint of the pipe before I got two to fit right. Not perfect but within 1/8" in every direction from the CAD model. That's within most production tolerances and passed my backyard QC check.
Then these were hit with the flap wheel for beautification purposes.
You won't get a much closer fit than that
The motor mounts. Four jaw chuck for the win. The lip on the gearboxes snap into the recess to keep any side loading off of the bolts.
Now we have a rolling chassis
Lots of rubber back here on the business end. I think Sir Mix-A-Lot wrote a song about ladies shaped like this.
I won't go into much detail on how the belt tensioners work, but they revolve around this little beauty, which in itself was a whole nuther project to make. All of it was done on my 60+ year old South Bend Lathe.
Very Short video of it being trued in the four jaw chuck