Homebuilt "Primary" Belt-Drive

[gone_fishin]

gonna start this with nothing but...

i want to build the manual belt/pulley system MotorbikeMike mentioned elsewhere & we thought it would be a good idea to do a project style thread about it...

it looks like there will be some serious interest in this, so let's keep the OT to a minimum please, and try to not get too mad-scientist on us...the goal is to develop a primary drive that can be bought off-the-shelf and built at home using standard hardware, as much as possible anyway.

i'm gonna start searching for pics of existing systems...

 

[SlicerDicer]

http://www.heeters.com/PulleyClutches.shtml

Maybe that would be good for the clutch? then you can run a single belt to the back? Not saying you have to get it from there just the ball rolling idea

Edited: It was while you replied here is the chain/belt great minds think alike

http://www.webcom.com/sknkwrks/powrfrk2.jpg

Combo chain/belt drive?

http://www.webcom.com/sknkwrks/powrfork.htm

I know your not using a fork to do it but can give some good ideas from off the shelf stuff

 

[gone_fishin]

neat! i could see that in there on some systems, maybe even mine...never having had a need before i'm just now learning about these components.

my personal plan, right now: belt primary (manual) / jackshaft to adjust ratio & offset in /chain secondary to rear wheel.

 

[SlicerDicer]

The bearings may be good to look into some of these. For the jackshaft.

http://www.machinedesign.com/BDE/mechanical/bdemech6/bdemech6_30.html

 

[MotorbikeMike]

First system to study: Whizzer

HI All! I'm getting ready to go to Antique Motorcycle Club of America
event this weekend and am rushing to do errands now so I'll write more later.
Look at how, in my 08 prototype that the belt-pulley clutch assembly effectively
offsets the drive system, yet is still inline, Mike

 

[gone_fishin]

still too new for me to decipher what i'm looking at...i'm sure you'll 'splain when you have time

this rough mock-up shows how far i need to offset back in to line up with the rear sprocket, the zip-tie is the balance point of the engine/centerline of bicycle, the end of the chain is roughly at the centerline of the jackshaft, which should fit directly behind the seattube:

 

[SlicerDicer]

Augi, I am curious what you are planning on putting over the motor shaft/pulley. I am only curious as if your leg gets in the way get ready for some grinding. So what kinda shield are you going to do? Custom fabricated?

I did not realize that motor was so wide...

 

[gone_fishin]

i'm imagining a mesh/perforated cover over the primary & i'll be installing a pull-start.

 

[MotorbikeMike]

Engine/Drive offset

Hi well I got to tell you Augi, that I think that the most important starting point is to have the engine centered in the frame (plumb) BUT, the centerline would best be determined by it's "balance" or Weight distrubition". This may not be as hard to figure as one might think. Get a friend (ok if he is likkered up, but only a little) and put the engine on a piviot.
If yer friend is too likkered up, use a piece of pipe lying lenghtwise under the engine, and play till you have the balance. NOW..........
Now you can figure out how to do the frame mount, as balance is critical unless you rever in Razzberrys, or roadrash.
More to come Mike

 

[srdavo]

I volunteer to be the 'likkered" up friend
okay...that''s my mini OT.

sorry