Willchair Build

An accident years ago left me needing to use a powerchair full time.  After a few years of using what money could buy I decided nothing available was suitable to give me the freedom I needed. I built the first one in 2012 or so.  It took a few years and a LOT of trial and error over several iterations.  This page is documenting the fourth one I have built.  Most of the difficulty came from my requirements:  A few days worth of battery range, silly powerful for towing, fast charging, compact, durable, reliable, lightweight, and safe.  That meant it was going to have to be lithium powered and brushless, which has not and still is not properly done off-the-shelf.  Adding to the complication is there are no acceptable wheelchair controllers that fit the bill for these goals either. 

I have built everything from 8 second 1/4 mile drag cars to automated conveyor systems to fuel injected street rods to small CNC machines to remote control lawnmowers to 3d printers to computers.  Designing and building a PROPER outdoor capable powerchair with indoor size and manners from scratch has been the most time consuming and complicated project that I have taken on.  

A few quick specs:

Length: 35 inches long from the back of the tires to the front of the casters

Max Height: 42 inches to top of the backrest depending on adjustments.

Minimum Height: Folds down to 24 inches to fit through most airline cargo doors

Seat Height: 18 inches from the ground to seatpan

Width: 28 inches at the widest point from outside to outside of the rear wheels

Voltage: 14S, which is about 46.5v in use

Battery Capacity:  4,650 Watt Hours

Speed: 8.5mph

Ground Clearance: 5.5 to 6 inches

Suspension Travel:  3.5 inches front.  3 inches rear.

Tilt:  46 degrees

Weight: 264 pounds

Follow along on the pages below to see how it came together.  None of this is pulitzer worthy documentation.  It's mostly just cellphone snaps while working.

Build Pages

CAD, Design, and Build Theory

Only click here if you're a nerd too.

Hardware Build

CNC and manual machining of most of the parts required.  Lube up your modem.  Media heavy.

Battery

How and why along with building the LiFePo4 lithium battery.

Wiring

The least enjoyable part.  Extremely important to get right.

Assembling

Cramming ten pounds of crap into a 5 pound bag.

Testing and Videos

Bringing it all together.