Chopper Shop

Hi all. I posted an intro post in the general discussion here:
http://www.rcuniverse.com/forum/m_10...m.htm#10824122


The Cliffs Notes version is I'm creating an RC build curriculum for a non-profit after school program, where we also build chopper style bicycles. It seems what I want the project to be is a giant scale, Iguess like a 1/5 scale.

My questions are related to parts and expense. Being non-profit means budget is tight. We collect some random stuff people donate though, so I'm hoping to be able to build in a sort of frankenstein style. I see a chainsaw motor is a common build for ex. What other parts can be sourced? We have plenty of bicycle parts - gears, sprockets, etc. We have a pocket bike someone donated, some motorized scooters, stuff like that. What else can be borrowed? And what cannot, requiring me to either find an in kind donation or buy? TIA

racer365r

DVP im sure will be on here to chime in,the guy i think lives in his shed i think he has many projects started and not many finished
you should look at vasilisg here he is a proper homebuilder,it's cool

Dirty_Vinylpusher

Hello DC2Man I see you found your way back here again



Chopper Shop
What you're thinking of doing is not impossible at all.
If you wanna keep it simple - ie a car with 4 wheels, a motor and no suspension, you should be able to do it rather cheap.
The only thing that will cost a few $$$ is the controls.

A pocketbike motor, chain and sprockets is a good start as you have a motor that's strong enough to pull any size car you end up building.
Using a chainsaw motor requires a bit more engineering as you'll need to fit a drive sprocket to the clutch, which can be tricky and take up valuable chassis building time.
The motor also has built in mounting points, another thing that will have to be manufactured for any kind of "agricultural" motor.

Scrap steel is usually easy to come by, square or round tubing is ideal for a large car like this.
You'll also need some 90degree angle steel and some steel and aluminium plate for mounting various bits and pieces.

For wheels you can use anything that's the right size.
Trolleys, mobility scooters, mini quad bikes etc all have good wheels for a project like this.
If you find a rear axle from a mini/pocket quad it'll have the sprocket and brake disc already mounted on it which could be a bonus.
Most pocket bikes/quads run one of 2 sizes of chain and sprocket but the sprockets are interchangeable with matching mounting holes.


The steering will be the biggest challenge but as you've built gokarts before that shouldn't be a problem - just downsize it.


As for aquiring cheap/free parts, go around to a few scrapyards, metal recycling places and mechanics shops.
Stuff like balljoints and linkages you'll need for the steering are usually available for a fraction of the new price.
Ball bearings can be pulled from old fans, powertools, chainsaws and other engines.
Straight shaft brushcutters have a nice long stainless steel rod inside the shaft connecting the clutch to the head.
Old outboard motors usually have rodends in the linkage to the carbs.



I hope you go ahead with the project and look forward to seeing pictures of it.

racer365r

hi

a little paranoid to think every irish man is dc
i am surely not this person thanks but i know this person i didn't say anything about your build either as they are class in
fairness,i just said it seems you don't get around to finishing them much

Chopper Shop

Thanks.  This will be an addition to the curriculum so any kid who wants to and sticks around can build one.

My main concerns are the servo, bearings, ball joints, engine/motor, trans/chain drive, and suspension if we choose to do suspended cars.

Foxy

Hi again Chopper Shop, I think you've done the right thing starting again in this forum, there are a lot of more diy inclined folks in here. You're right, home building suspension is neither easy nor cheap, but that's ok, there are a multitude of large scale shocks available, some relatively cheap, some expensive, but that will require you to go around the 1/5th to 1/6th scale mark. Quarterscale (as it's known, literally 1/4 scale) stuff is a bit bigger, but from what I've seen, a fair bit more expensive.

Dirty_Vinylpusher

The servo you will have to buy but they're not that expensive.

Like I mentioned earlier, all the other stuff can be scavenged from scrapyards.

For shocks you could look at moutainbike shocks but you'll have to replace the springs with softer ones, or set up a cantilever system if you're using stock springs.