Source for sprockets?

I used both bicycle and motorcycle sprockets and chain on my home-made sawmill. Since both had to transmit substantial power I left the sprockets hard and splined the shafts slightly oversized so the sprockets broached a tight-fitting seat when pressed onto the softer shaft.

I used a 52-tooth lathe change gear to index the transmission shaft to machine it for the 13-spline motorcycle sprocket.

Annealing isn't difficult because you have the visual indication of color change to dark blue, or the red glow, and can check for machineability with a file.

-jsw

cheapest source I know of is weldon units at Mills Fleet Farm

I haven't used them because every time I weld together parts machined to final size I have to correct for some heat distortion, for example a built-up fork joint that closed tighter. Do they generally run true after welding?

-jsw

My favorite source is the local scrap yard. I have not picked up any sprockets, but there is always a bike or two there. A bike shop might be worth checking.

Dan

This is too easy.

Old bicycle freewheels/casettes. 99% are are steel, and hard. Older ones would be better for you as newer ones are thinner and have specialised tooth forms that vary and are intended to make it easier for the chain to derail, which you would not want. Look for five-speed or six-speed; they came in common combinations of teeth, won't be too hard to get matching teeth.

They get tossed as junk when the teeth are a bit worn but you don't care, you want registration and a few percent power-loss or remaining wear (decades, likely) is no matter.

A 30-tooth rear has a diameter of just under 5 inches. The central bore is usually around 1.5 inches, and frequently they have cutouts; so you can hit them on the "spider" with a blowlamp and soften them there for cutting/drilling.

Any good bike shop will have loads, and chain. Tell them what you're doing & smile and they could be free.

Hmm, good question. It probably depends on the intended use. I don't know.

SPACELY, of course. Ask George Jetson. (Sorry, had to do it.)

There's a guy in Canuckistan (Canada, for those of you in Rio Linda) who does wooden sprockets/gears, if you want a DIY project. He has tons of vids on YouTube. Matthias Wandel is a wonder.

Otherwise, see these:

Love it.

Interesting request. Go by a vitamins or health food store. And if you can find the time, gradually start taking 20 grams and then more of dietary supplements twice a day. But don't miss a day !!

Only if you clamp the piss out of them first, then weld a bit on one side, then a bit on the other. SOP for not warping when welding.

Golf carts and people buggies have sprockets and drive motors... They are tough and sizable.

Martin

MyMaster-Carr has sintered toothed-belt sprockets (I'm guessing that is what you are looking for, not metal chain sprockets). They are VERY machineable. Not REAL cheap, but a lot cheaper than Stock Drive Products or W. M. Berg.

Jon

Hey Carla,

Buy up a couple of old bicycles at garage sales. The sprockets they use are "good stuff".

Take care. Good luck with the project.

Brian Laws>Hi all,

I needed two identical sprockets to drive the two lift screws at the same rate so I went to a bicycle shop. Two new-old-stock 3-speed rear hub sprockets plus a short chain remnant cost me $13, IIRC.

I do a lot of engineering design while poking through piles of used stuff. The necessary preparation is knowing the minimum size that's strong enough and the maximum that will fit, plus the limits of my machining ability to make adapters for other than standard-sized keyed shaft hubs.

-jsw

Thanks George, that was the winning solution!

From your links I got the tradename of what we needed and then found 'Weldasprockets' at my local farm / implement store for about $13 each (40 chain, 26 teeth) and was easily able to bore out the center to my spec... Threading the material for setscrews near the perimeter was a bit dicey as that area seems to be hardened... but everything worked out fine.

Thanks again!

Carla