The Project Pad

dana wrote:you might be better off with less traction, with such a high center of gravity shifter cart tires might make it flip instead of drift. You probably just need several sets of tires depending on the track event you are running

Oh, and very nice work BTW. I love seeing projects that are TERRIBLE ideas executed so well

Hey thanks! The project is really the fun part for me; I like making cool s**t

I'm thinking of the kart tires for a straight high-speed run rather than for drifting- I don't really want to blow up a tire designed for going 5 MPH when I'm doing 80. For drifting I found some at Harbor Freight for $5 each that I think will work.

Quick cost update- scooter parts sold on eBay last night and shipped out today at lunch. Here are the new totals:

Scooter..........................................$100
Engine, bike parts.............................$100
4 new front wheel bearing.......................$8
keyed, weldable drive hub......................$12
expansion pipe, muffler, spark plug..........$90
Cutting & sanding disks........................$20
carburetor........................................$74
new ignition coil.................................$11
12T sprocket.....................................$13
22T sprocket.....................................$15
520 chain.........................................$17
pod air filter.......................................$5
top-end gasket kit...............................$15
Pier 1 wall basket................................$10 (you will see why later...)
ATV throttle........................................$8
SOLD Electric motor and controller..........-$112

Total.............................................$386

So you have already made money on the scooter purchase, awesome.

So much awesomeness with this. Dress up like an old guy and go ripping the shit out of Walmart...

Friday update: Body work, brakes, controls

Started off the day by making the brake caliper carriers and welding them on. Started with this:



And ended up with these:



When I made the mounting hubs for the disks I was shooting for as short as possible without the calipers rubbing on the tires... nailed it!



Bolted them up, did a quick alignment, and tested range of motion. Marked up the body work and trimmed it so the wheels now clear:





With that done, I started in on cable routing and controls. Here is the basic concept I came up with:



Then took apart the steering column and stripped out all the excess wiring and electronics. I trimmed the the console plastic to move the throttle inward on the handle bars and cut a hole behind the headlight to run the brake and clutch cables into, but given the angle it puts the cable at I'm going to end up doing something different.





I measured out the throw of the ATV throttle vs. the carburetor, and it is only about 75% of what I need to get full juice.





I used a die grinder to remove some internal stops to get more, but it's still going to need a secondary mechanism to achieve the correct motion ratio. Here is the max I get currently:



Moving on to hooking up the brakes, I used some roll pins and #6 nuts to make cable stays:





Welded them onto the frame, hooked it all up, and here it is:





I tuned them in so they are balanced, then took it for a test ride down the hill I live on. They do the job, but the motion ratio on the lever is designed for one caliper not two so effort it high. Going to have to change that.

More bits showed up in the mail today, so more to come tomorrow

This came across my news feed today, you may want to think about putting a wheelie bar on if your running kart tires. https://www.facebook.com/photo.php?v=671686129533304

Hahahaha nice find! Don't worry, wheelie bars are already part of the plan

For those who can't see it-

[youtube]https://www.youtube.com/watch?v=19wYCVGJBcM[/youtube]

And a few more:

[youtube]https://www.youtube.com/watch?v=OG8pAAZW6FE[/youtube]

[youtube]https://www.youtube.com/watch?v=XTrlnxslYrY[/youtube]

Short update-

Here is a visual of how the motor fits in the scooter:





With the motor now a confirmed runner, I went ahead and replaced the three top end gaskets yesterday, then took it outside for a bath. That's all for now!

When do you hope to have it done by? Can't wait for vids

No real timeline per say, but I'd like to screw around with it this summer. I don't imagine it will take too much longer, but there are still a number of details to work out and parts to fabricate.

I cant get over the color of that thing. Its so terrible, but so perfect.

how are you going to route the expansion chamber?

dana wrote:how are you going to route the expansion chamber?

It's going to get cut up and made to fit. The plan is to run it along the side of the cylinder, over the gear case, then a transverse muffler. As a friend of mine like to say, it will be "a bit of a science project" to make it all fit.

lorge1989 wrote:I cant get over the color of that thing. Its so terrible, but so perfect.

I was going to sand it down and repaint it, but it does have a certain charm looking so incredibly crap...

the german wrote:

lorge1989 wrote:I cant get over the color of that thing. Its so terrible, but so perfect.

I was going to sand it down and repaint it, but it does have a certain charm looking so incredibly crap...

I would keep it as is for sure. OEM quality too.

Got some more work done tonight. I started with sorting out the brakes, which were lacking when I did the last test. To fix this, a mechanism was needed to give the appropriate mechanical advantage for running two calipers on one lever (rather than just one caliper/lever like in a bike. I welded a tab on the frame for a pivot, and found some appropriate aluminum flat bar in the scrap bin for the lever arm, which I gave a 3:1 ratio. This system yielded much improved feel at the hand lever and easily locked up the front wheels in my driveway test.



Next up, the rear sprocket. Machined a step in the keyed hub to the correct size for the sprocket, and welded it up:



Here is the hub on the axle- it's going to be a VERY short chain.





I'm now just waiting on some more scrap square tube so I can fabricate the motor mounts, then work on exhaust and cooling. More to come soon hopefully!

My plan was to fabricate motor mounts next, but in thinking about it and looking at layout, I realized I didn't know where it actually needed to be to fit the exhaust in there. To solve this, I ended up doing both at the same time. I started by setting the motor as far back as possible, then welding a cross-tube in front of it which the front mount will be welded to. With that in place, I started on fabricating the expansion pipe. Here is what I started with from the junk-yard; it's original application is a 250 KTM, but of course it was no-where near fitting in my application.



Cut it up and make it fit the way I want it to! Doing this in my garage, so all the cutting, mitering, and grinding is being done with an electric angle grinder.











With the pipe done I was able to determine where the motor needed to be laterally and weld in the front motor mount.



Started on the lower mount next, more of that to come tomorrow hopefully

Progress for the night: Engine is mounted, chain is on, floor pan has been roughly trimmed to fit the exhaust. It's starting to look like something!

Great......now I'm hooked on building one of these. This is far by one of the coolest oddballs things someone has done

for some reason i feel the need to re-iterate how absolutely retarded this is going to be. This will defiantly be the scariest thing you have ever driven/ridden.
Great work, it looks so good.

AngryTaco wrote:Great......now I'm hooked on building one of these. This is far by one of the coolest oddballs things someone has done

Hey thanks! You should do it- I'm having a blast building it so far

dana wrote:for some reason i feel the need to re-iterate how absolutely retarded this is going to be. This will defiantly be the scariest thing you have ever driven/ridden.
Great work, it looks so good.

Hahaha you aren't the only one! There are quite a few people, many of whom are accustomed to very fast bikes, karts, and race cars, telling me that I will die on this thing. That said, they all want to drive it when it's done

I seriously spent an hour on CL last night looking for a cheap scooter............

I'm thinking of using a 440cc snowmobile engine

AngryTaco wrote:I seriously spent an hour on CL last night looking for a cheap scooter............

I'm thinking of using a 440cc snowmobile engine

We might as well stop being little girls and go ahead and pick up a 600cc motorcycle engine.

and slap a k24 on there?