Electrobite an Electric Wheelchair Conversion
by jonsarriugarte in Circuits > Robots
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Electrobite an Electric Wheelchair Conversion
My Wife Kyrsten and I built the Electrobite in my shop "Form & Reform" in West Oakland.
Kyrsten and I started on this project Aug 2009 and finished it just in time for Burning Man . We took an old electric wheel chair and made it into a prehistoric creature known as a trilobite. I enjoyed working on another great project with my wife (these projects keep us on our toes, I hear building a house together works too). This is the 3rd car of 5 we have made the 1st being the SS Alpha Fox and the 2nd was the giant iron snail car The Golden Mean. The scale of this one is great and I’m really liking working with hand hammered sheet metal mixed with forged steel parts.
Following is the basic process by which we built this amazing vehicle. This is meant as a process guide for building any kind of wheelchair based vehicle and as a loose guide for building this one. There are far too many details in this project and each step could be broken into many different standalone Instructables. I hope by posting this you gather your own team and make your own dream car together. The sum of the parts makes wonderful things!
For more info see: Electrobite
Other builds
The Golden Mean a Giant Iron Snail Car
Zeppelini
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My blog:
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Wheelchair
This is the 1st of 3 wheelchairs I have done and I love how much time I spend on the art part and how little time I need to work on motors, steering linkages, drive trains and general mechanics of a full car build.
After building the Electrobite I was contacted by a few people that wanted to give us wheelchairs for future projects. Larry was nice enough to give me a Quickie wheelchair and help me out with some spare parts and programmers.
I checked out Craigslist and found quite a few late models for under $500.
Make sure the batteries are good and everything works before purchasing.
Make sure to get the heavy duty ones. Most of these will hold 300-400 lbs. total including your chair. Keep this weight in mind as you design and build your vehicle. Dressed I'm 200 lb., plus the traction/batteries at 75 lb. meant I had to keep my shell weight under 125 lb.
Once you get it back to the work shop use it, play on it, take it to a party and drive it around the neighborhood. You will have a much better idea of what needs to be fixed, its range, how to drive and a very small appreciation for what it’s like to need one of these every day! It's quite an eye opener for how differently people treated me in one, even close friends.
After test driving on loose surfaces I made a few upgrades to the tires by adding lawn tractor tires to the rear and bigger foam filled ones to the front.
After building the Electrobite I was contacted by a few people that wanted to give us wheelchairs for future projects. Larry was nice enough to give me a Quickie wheelchair and help me out with some spare parts and programmers.
I checked out Craigslist and found quite a few late models for under $500.
Make sure the batteries are good and everything works before purchasing.
Make sure to get the heavy duty ones. Most of these will hold 300-400 lbs. total including your chair. Keep this weight in mind as you design and build your vehicle. Dressed I'm 200 lb., plus the traction/batteries at 75 lb. meant I had to keep my shell weight under 125 lb.
Once you get it back to the work shop use it, play on it, take it to a party and drive it around the neighborhood. You will have a much better idea of what needs to be fixed, its range, how to drive and a very small appreciation for what it’s like to need one of these every day! It's quite an eye opener for how differently people treated me in one, even close friends.
After test driving on loose surfaces I made a few upgrades to the tires by adding lawn tractor tires to the rear and bigger foam filled ones to the front.
Frame
After stripping the chair frame down, it was time to integrate a new frame to hold the new shell, seat, electrical system, and controller.
Starting with a steel rail that was bolted to the aluminum frame of the chair we welded a tube frame for the seat to mount to. Our design had to take into consideration the clearance of the front swivel casters so we marked the full radius of each wheel out in chalk on the floor. We then drew the outline of the whole creature on the floor.
We played around with ideas for the ribs and settled on a mix of forged tube and sheet metal layers that would let light come though. Kyrsten added a rivet detail to the bottom of each rib after I ran each piece of tubing though the furnace, roller and fullering by hand with hammer and anvil. These pieces were now welded to the seat rail. Now using the caulk drawing on the floor I bent tube to make the outline of the head and tail. Using string, tape and wire I played with the head/frame elements, settled on what we liked and bent more tube to complete the basic frame. It was now starting to look like a trilobite!
Starting with a steel rail that was bolted to the aluminum frame of the chair we welded a tube frame for the seat to mount to. Our design had to take into consideration the clearance of the front swivel casters so we marked the full radius of each wheel out in chalk on the floor. We then drew the outline of the whole creature on the floor.
We played around with ideas for the ribs and settled on a mix of forged tube and sheet metal layers that would let light come though. Kyrsten added a rivet detail to the bottom of each rib after I ran each piece of tubing though the furnace, roller and fullering by hand with hammer and anvil. These pieces were now welded to the seat rail. Now using the caulk drawing on the floor I bent tube to make the outline of the head and tail. Using string, tape and wire I played with the head/frame elements, settled on what we liked and bent more tube to complete the basic frame. It was now starting to look like a trilobite!
Sheet Metal Body
Kyrsten took over the sheet metal work and patterned each piece 1st in paper, then cut them out in 22ga cold rolled sheet. Each piece was cleaned with alcohol and DA sanded to remove scratches. This would provide a good surface for later adding the patina. Care was taken from this point forward not to scratch.
I set to work on the eyelids and horns. The horns were forged from tube using a power hammer and the eyelids were cut from 1/4 plate, then upset on the edge to make them look thicker and organic. Another plate was hand fullered for the base of each horn.
Now it was time to fit the flat sheet metal to the compound curves of the frame. Each piece was hammered using various hammers (rawhide, ball peen, and others) and a stump with a concave bowl in it. after getting the general shape I trimmed the extra off, clamped it in place and welded it solid. Before I welded the bottom sections, Kyrsten had an idea to add rivets to those pieces. It's a great detail that we saw on many of the fossils we looked at while researching for this build.
I set to work on the eyelids and horns. The horns were forged from tube using a power hammer and the eyelids were cut from 1/4 plate, then upset on the edge to make them look thicker and organic. Another plate was hand fullered for the base of each horn.
Now it was time to fit the flat sheet metal to the compound curves of the frame. Each piece was hammered using various hammers (rawhide, ball peen, and others) and a stump with a concave bowl in it. after getting the general shape I trimmed the extra off, clamped it in place and welded it solid. Before I welded the bottom sections, Kyrsten had an idea to add rivets to those pieces. It's a great detail that we saw on many of the fossils we looked at while researching for this build.
Controller Mount & Seat
To keep things simple we decide to use the original controller that came with the wheel chair. However it didn't look very...natural. We settled on burying it in the seat and covering it in the same leather as the seat.
Kyrsten and I wanted a comfortable ride, so we came up with a 3 part foam seat attached to a plywood base. Great for rough terrain.
Our great Friend Amy Jenkins of cozyrampage agreed to upholster the seat. Her and Kyrsten played around with ideas and settled on making the seat resemble the spine with sections that matched the ribs. The leather they found matched the color so well, that most people walking up to it don't notice the controller, or that there is even a seat there! Well done girls!
Kyrsten and I wanted a comfortable ride, so we came up with a 3 part foam seat attached to a plywood base. Great for rough terrain.
Our great Friend Amy Jenkins of cozyrampage agreed to upholster the seat. Her and Kyrsten played around with ideas and settled on making the seat resemble the spine with sections that matched the ribs. The leather they found matched the color so well, that most people walking up to it don't notice the controller, or that there is even a seat there! Well done girls!
Patina & Finish
Before we did any patina work, we removed the shell from the wheelchair base.
The shell was moved outside and the patina chemicals prepared. We wanted a warm brown feel to the shell so I chose a patina using water and cupric nitrate 32-1, ferric nitrate 32-1 and gun bluing16-1. We used bug sprayers for each chemical. Before applying the chemicals, we washed down the whole shell with plain water. Keeping the section we were about to treat whetted, we started spraying the gun blue, then cupric, then ferric. Gun blue was used in combination with the cupric to fill in bright spots. The completed sections were kept wet to keep air from changing the earlier sections we had finished. Once the entire shell was patinaed, we used a weak solution of baking powder to stop the reaction, rinsed one more time with water and finally dried it off with air nozzles and the warmth of the sun.
Krylon K07006 Polyurethane-Satin spray cans were used to seal the patina. This brings out the warmth of the finished metal. It took 3 coats to seal.
Now it was time to assemble all the parts again and add the wiring for the lights
The shell was moved outside and the patina chemicals prepared. We wanted a warm brown feel to the shell so I chose a patina using water and cupric nitrate 32-1, ferric nitrate 32-1 and gun bluing16-1. We used bug sprayers for each chemical. Before applying the chemicals, we washed down the whole shell with plain water. Keeping the section we were about to treat whetted, we started spraying the gun blue, then cupric, then ferric. Gun blue was used in combination with the cupric to fill in bright spots. The completed sections were kept wet to keep air from changing the earlier sections we had finished. Once the entire shell was patinaed, we used a weak solution of baking powder to stop the reaction, rinsed one more time with water and finally dried it off with air nozzles and the warmth of the sun.
Krylon K07006 Polyurethane-Satin spray cans were used to seal the patina. This brings out the warmth of the finished metal. It took 3 coats to seal.
Now it was time to assemble all the parts again and add the wiring for the lights
Eyes and Lighting
The eyes were made by our good friend Tansy Brooks. She 1st sculpted the eyes in clay and marbles; once done she coated it in place with molding rubber and hard plaster so it would hold its shape. Plastic wrap was used to protect the shell. Now she removed it from the eye socket and removed the clay and marbles. She then built the inside of the lens creating a 3/8" thick void for the cast resin to pour into. After casting, the molds were removed and the fresh casting adjusted to fit the lids on the shell. Rubber bump-ons were used to shock mount the lens in the steel. A bottom lid was now forged to snugly hold the lens in place with bolts attached to the sheet metal below.
A hole behind the lens was made to mount the LED to.
Two more LED light mounts were added to the bottom front of the shell to work as ground effects under the shell.
Two red LED lights were added to the rear for safety.
Next, Kyrsten got busy fabricating a battery mount for the 12v system that would run the lights. The electrical system for the chair is 24v so we had to have a separate electrical system for the lights. I mounted 2 switches next to the controller for the lights, wired all the lights and mounted the battery box on the frame. Wheel chairs are great for this as they have multiple threaded attachment points all over the frame. I wired in a charge plug so we could easily charge the batteries later.
The blue lights really make it look like it floats in the air!
A hole behind the lens was made to mount the LED to.
Two more LED light mounts were added to the bottom front of the shell to work as ground effects under the shell.
Two red LED lights were added to the rear for safety.
Next, Kyrsten got busy fabricating a battery mount for the 12v system that would run the lights. The electrical system for the chair is 24v so we had to have a separate electrical system for the lights. I mounted 2 switches next to the controller for the lights, wired all the lights and mounted the battery box on the frame. Wheel chairs are great for this as they have multiple threaded attachment points all over the frame. I wired in a charge plug so we could easily charge the batteries later.
The blue lights really make it look like it floats in the air!
Done