So, I've just been given a running chain saw and I'm planning on building a gas class puller. I have a basic idea on how they are normally laid out, but there are some things that I have questions about. First off, what final drive ratio should I be shooting for? Are the chassis usually made of aluminum or steel? A picture or 2 of a puller with no body would be great....Thanks!
Gas class puller
- Thread starter riordanii
- Start date
nrctpaXpres
Well-Known Member
the motor has to be under 39cc or run it in the unlimited class.....
my chassis are aluminum
under 20 to `1 depends on motor
we use the centrifugal clutch and machine off the chain (star teeth) for lack of a better word and attach a 25 roller chain sprocket on it...then you go off of that with 25 roller chain ......
use a 2.4 radio you will have less problems...
my chassis are aluminum
under 20 to `1 depends on motor
we use the centrifugal clutch and machine off the chain (star teeth) for lack of a better word and attach a 25 roller chain sprocket on it...then you go off of that with 25 roller chain ......
use a 2.4 radio you will have less problems...
nrctpaXpres
Well-Known Member
I would put either usa1 tire or clod tires on that....the rule says 6.5 tires....
So I just figured out that the free chainsaw has a 2.3 cubic inch motor, which translates to about 38cc's, so I'm good on that end of things. The only thing I'm still trying to figure out is the sprocket on the clutch bell. I know you said you grind off the star teeth and put a #25 sprocket, but do you weld it in place or use some sort of hub?
There are two common ways.
Personally I would machine the sprocket off in a lathe so you have a stub shaft left.
You can then bore your hole in a #25 chain sprocket (normally 15 tooth to 18 tooth) with about a 3 to 5 thousands interference fit. Freeze the clutch bell in your freezer and heat your sprocket with a propane torch then press them together.
or
Just machine with a slip fit and tack weld.
Have done both and each work well.
Mark Damewood
Personally I would machine the sprocket off in a lathe so you have a stub shaft left.
You can then bore your hole in a #25 chain sprocket (normally 15 tooth to 18 tooth) with about a 3 to 5 thousands interference fit. Freeze the clutch bell in your freezer and heat your sprocket with a propane torch then press them together.
or
Just machine with a slip fit and tack weld.
Have done both and each work well.
Mark Damewood
nrctpaXpres
Well-Known Member
Larry Jaques silver soldered them on after a press fit i guess I have even seen them pinned on somehow...welding cast parts is hard...or get a steel one maybe that will work better....Damewood has good suggestions.