Monday, June 25, 2007

Finished product

It's taken me a while to write this, so bear that in mind.

Next comes steering. With the skilled help of Gilmore & Sons Welding and Fabricating Inc., Dan Gilmore, a friend of my father's, welded the steering arm in place. It looks downright professional! The only problem is attaching it to the frame. I got two control arms with the steering shaft, so what better way to hold it in place? I ground down a tiny bit of the inside of the arm so the shaft could spin relatively freely and drilled a hole in the front pipe to mount it on. I quickly realized the problem... It wouldn't stay in place. Friction alone isn't going to keep it there, so while the steering wheel is mounted, it doesn't quite do a whole lot. However, I did get to clumsily drive around my yard in a circle about once and a half. Then the chain broke. Well, that custom screw I made broke. I have to find a different way to mount that sprocket.

The motors in R/C cars have one side flattened so you tighten the setscrew down there. I'm going to try that with this motor and my trusty Dremel. The chain is fairly loose, so when you let up on the throttle, it goes from the motor pulling the wheel (tension on top) to the wheel pulling the motor (tension on bottom) with this unsettling "chunk" noise. I think the gap between pulling and being pulled is what keeps messing up the sprocket. I need to either really tighten up the chain or fashion some kind of tensioner.
As for brakes, we've decided on a refined version of the stick of wood. We've got these motorcycle chocks that go on a trailer to hold the front wheel of some motorcycles in place. Thus, it is shaped somewhat wheel-like. I figure if I hack off the sides to make it fit around the wheel and mount it to that back bar, i can just use the springiness of the metal itself as a brake. I'd say it's a much more solid plan than the stick of wood, even if it's the same basic principle.

If you're having trouble visualizing the brakes, think of a razor scooter.

In the time it took me to post this message, I've gone and gotten that thing welded, by the same guys in fact! So now, it's drivable. It takes some effort to steer, but it works. I added a bar on the back for a passenger to hold on, which tweaks the frame a lot on turns.

I've also fashioned a new ignition switch that's much more stable than the previous one. Looks better too.

My parents threw a graduation party for me and my friends Ryan and Henry where the GoFast was the talk of the town. Many a demonstration was granted and my sister drove it into a tree while I wasn't there (and hadn't given permission). It pulled the wire out of one of the battery clamps, broke the steering column support, mangled my new ignition switch, and popped half the front axle off. Once I had listed all the damage, I fixed it and the steering seems to be working better, which at this point, sounds better than it really is.

I aim to provide a video of the GoFast in action soon.

Wednesday, June 6, 2007


Yes, it moves. I finished the whole drivetrain thing, so now the marvelous GoFast goes fast. Unfortunately, it really does need brakes, or steering. My dad thought that the motor's friction would be enough to slow the thing down, but it isn't. So here's the deal. Please leave any and all braking suggestions in the comments! I need them.

Check the pics for more detail.


I got the sprockets and chain via UPS today. I no longer am waiting for any parts. I've cut the keys and installed them, so the rear wheel no longer freewheels. I also stuck the little sprocket on the motor, with a bit of spacing. Not much, but enough. I have to drill holes in the rear sprocket to mount it to the hub, but after that, I break the chain to the right length, and stick it together. Then we move!

Friday, June 1, 2007

Tinkering Time

Work continues on the GoFast. Today I got the rear wheel centered and spaced appropriately. I also mounted the throttle on the steering wheel, and made a little control panel consisting of one switch and a voltmeter that will be used like a fuel gauge. I'm probably going to get a bigger switch and throw in a lil status light. Saturday and Sunday I will be away getting scuba certified, so no GoFasting there, but Monday I will get that steering shafty thing welded, and then I can mount the thing and have some control! No power yet though.

Thursday, May 31, 2007

You see me rollin'

I finally got this monster assembled enough to roll it on its own. I mounted the rear axle on, slid the tire in, and with the help of one Nick Krywolpusk, we got it on the ground. It was really an exhilarating and uplifting feeling to finally be able to sit in the thing. I couldn't steer it, nor could I drive it, but it was such a great thing, to see something that I put together finally look like a vehicle. More to come.

On a side note, my PC's power supply decided to die, so it's "better know your Mac" time for me.

Wednesday, May 30, 2007

Done... ish

Done... ish
Originally uploaded by zzm634
Now that looks like it can go somewhere. I could have probably shown this at my presentation and said, "So yeah, I finished!" Bonus points if you can pick out the things that still need to be done.

It sure doesn't look like a traditional go-kart.

Things to notice:
  • The back wheel is sitting above the frame when it will be mounted below when it's finished
  • The steering wheel isn't actually connected to or supported by anything
  • No chain or sprockets


I gave my presentation for this project today. It didn't seem to go too well. I can assure you all that this thing is more finished than it looks. Stuff left to do:

  • Rear axle
    • Drill holes in pipe
    • Line up and mount bearings
    • Make spacers for rear wheel
    • Assemble
  • Mount seat
    • Mark holes to be drilled
    • Bolt it on
  • Steering
    • Wheel
      • Cut out sheet metal and mount custom shaft housing
      • Sand down more off wheel for throttle
    • Shaft
      • Get control arm welded
      • Mount to front axle
    • Wheels
      • Stick 'em on
  • Add pimpin' stereo system
  • Brakes?
It's mostly sliding stuff on and bolting stuff in. The hardest part will be finding somebody to weld that thing on the steering shaft. I expect to finish up everything either today or tomorrow. When my chain and sprockets arrive, I can finally get this thing moving.

Tuesday, May 29, 2007

Tenth Hour

FINALLY, my parts arrived. The crucial rear axle and steering column came via UPS today, and I couldn't be more excited. Unless I realize that I don't yet have any sprockets or chain. But besides that, I can finally make this thing at least look like it can move. I got some replacement E-clips from a (very) nearby landscaping place that happens to sell and repair lawnmowers. I had to saw off a bit more of the front pipe to give the wheels some clearance. I made some spacers out of copper pipe to fill in the gap. For the steering column to fit in, I'm either going to drill another large hole in the front pipe, or I might use one of the steering arms to keep it in place. I only need one anyway, and they gave me two, which I will need to weld onto the column.

Speaking of steering, the steering wheel I had carefully selected doesn't fit on my steering column. It seems like they should, same number of splines and all, but despite my best efforts, I couldn't get it on. So, I hacked it off. In the little bag o' tricks that came with the steering column, there is a mounting plate. So I'm going to cut apart a little sheet metal to the right shape and custom fit it on there. Shouldn't be too much trouble.

Also, the throttle I have is designed to be mounted on a scooter handlebar, so I've ground a bit of rubber off the wheel to affix it within thumb's reach.

After getting the motor hooked up properly, I'm starting to wonder if I should have included brakes on this monstrosity. I was planning on throwing the motor into reverse for brakes, but since I discovered the motor has no reverse...

Here's my idea for the simplest brake. There's a bar on the back of the kart, a rear bumper if you will. If I attach a piece of wood to it on a pivot, and rest the other end on the tire, I can slow down or stop the tire by pressing the wood against it. I'll draw up a picture.

Ninth Hour

I can't believe how much I got done today (yesterday). It all started when I realized I had other stuff to do besides wait for parts to come in. Then I kinda winged it from there.

I cleaned off that piece of wood I had been using as a table and went to it with my trusty circular saw. I cut it to size, and then realized the wheels would need more clearance in the front. I also had to leave room for one (two?) batteries on each side. The result is the most awesome octagon ever seen. I bolted that to the frame with some U brackets, leaving some spacing for the clamps. After mounting the controller to the back, I screwed some blocks and eye hooks to keep the batteries in place.

Tomorrow (today) I expect to get the seat mounted.

Really picking up momentum.

Saturday, May 26, 2007

Back in business

The motor is back in action. In fact, it's better than ever. Nothing was wrong with the motor as it turns out. The two batteries I was using were marine batteries, meaning they have short circuit protection. For those who don't know, a short circuit would be just directly connecting the two terminals. This makes sense for a marine battery that could be say, dropped in salty water. However, high-amperage applications like an electric vehicle for example could be misconstrued as a short circuit, which is why the batteries weren't delivering. I stopped down by Wal-mart and picked up two automotive batteries (2 * 12v = 24v) and lo and behold, the thing moves. And it MOVES. Much faster than I've ever seen it go.

I'm back on track. I FINALLY found some gears and sprockets that will fit my purposes. After six weeks of searching and the help of my surprisingly internet-adept father, we've got the right drivetrain on its way here, and I'm going to cut and mount that hunk of plywood onto the frame to hold my stuff down. The motor might be a problem... considering the shaft is 15/32" and the sprocket is 1/2", but I think it will be "good enough." I will most likely end up making my own little collar from copper pipe which just happens to be a little under 1/16" thick.

While I couldn't find the E-clips I needed to get the front wheels mounted and ready to roll, I did notice a nice, keyed, 3/4" shafted gasoline engine at pep boys today. Not only was it tempting, since it would fit perfectly with a wide variety of sprockets, it made the "hybrid" aspect of this project that much more attainable.

No I will not finish this project by the time I have to give a presentation on it, but I will finish it in the following weeks shortly after.

It's thundering like a BEAST outside. No rain, just thunder. I'm surprised we still have power. Peco's been good about no power outages recently. Time to play F.E.A.R. with the lights off :D