minibike

[r_chez_08]

What size tuning should I use? Would 3/4" be ok?

 

[sideways]

Make everything larger than it needs to be so you can machine it down later. Do you have access to a metal lathe?

Just wandering, what section belt are you going to make it for? A section?

Thanks

Hayden

 

[r_chez_08]

Yeah, A section belt.
What size tubing should I use for the frame?

 

[devino246]

http://www.youtube.com/watch?v=gdyWS0-ebow

Hm, interesting. i gotta try that. I wonder if mixing some play sand with plaster of paris would work better for a mold. Guess ill be going to the store to get some bricks and charcoal...

 

[r_chez_08]

I wouldn't try plaster of Paris, as I have heard after drying for ages, still contains some mositure which can ruin the casting. I think I will go for 3/4" round tube

 

[r_chez_08]

Make everything larger than it needs to be so you can machine it down later. Do you have access to a metal lathe?

Hayden

I do have access at school.

 

[r_chez_08]

Will 11" ride on lawnmower wheels with bushings not bearings work ok, as I can get some for £18

 

[r_chez_08]

just bought these
also today i have bought 6 meters of tubing. it is something like 22mm external diameter.
i have also got some vinyl and foam for the seat.
i have given up on casting pulleys, and have decided to buy, or machine some.

 

[KieranM]

i think you should just buy the pulleys, they will be more exact in the longrun, you will also feel more confident with them. sure alot of your money will be spent, but you will be glad in two weeks of buying them.

A for the wheels, i have never worked with bushings so i couldnt give you any advice on them.

 

[r_chez_08]

Thanks for your input I will first try and machine them as my brother may be getting me a piece of 5" aluminium bar x 4" for free if that fails, I will probably use chain.

 

[r_chez_08]

here is some progress i got the aluminium. it is 6" by about 3".
spot the welding error
the exhaust is the end section from a suzuki vitara.
i also have now got the wheels

 

[r_chez_08]

I have now got some steel for the forks

 

[porsche930dude]

i gotta say those wheels look like they have bearings to me. You should be fine using the bushings just keep them lubed. Or you can get bearing for them just get an acurate measurement of the wheel hole and the axle you want to use. Shouldnt be too hard to come by

 

[r_chez_08]

They are bushings, and made of a hard plastic. I may machine some brass bushings on a lathe at school if the plastic ones wear too easily, as the hole wouldn't fit a bearing over 10mm

 

[r_chez_08]

ok, one pulley down. it looks amazing!!! i will post some pictures of it on monday, and the bike frame, with 1 wheel mounted this weekend

 

[KieranM]

took a while

 

[r_chez_08]

Yeah, I have only been back at school a few weeks to make it and there are too many steps! So it takes ages. And in the holidays, I didn't have time to do much as I was really busy :/ but the pulley is looking great and I am halfway through the next one.

 

[redsox985]

Could you do a wax casting so that the mold isn't as picky to get a good cast? I really have no clue. We cast at school but we have a little kettle looking thing, I forget its name. It's fed by a 1" natural gas line. And then we have all the casting sand and molds and a machine for mixing and grinding the sand before casting. I don't know about wax casting aluminum, but I know my mom did it in college with gold.

 

[r_chez_08]

Maybe, but I have gone off the casting idea now, and are machining them from the aluminium billet above.
Casting is too hard

 

[devino246]

Could you do a wax casting so that the mold isn't as picky to get a good cast? I really have no clue. We cast at school but we have a little kettle looking thing, I forget its name. It's fed by a 1" natural gas line. And then we have all the casting sand and molds and a machine for mixing and grinding the sand before casting. I don't know about wax casting aluminum, but I know my mom did it in college with gold.

Your school sounds like the best school on earth.