source for 80T+ 25# sprockets?

[emaayan]

hi..

i was wondering does anyone know about source for sprockets such as these http://www.electricscooterparts.com/SPR-2580.htm (other then electricscooterparts)

currently i'm using cnc driven 85T driven sprockets, however these last about 6 weeks, so i was thinking either to have one created and forged (but it will still wear out) or have an adapter plate that will stick on 110 5 bolt bcd spider on one end, and hold such sprockets as well. at least i'll have off the shelf parts.

 

[Drunkskunk]

No idea where to get one But if they wear out that quickly, there has to be other reasons. A dirty, misaligned, or stretched chain can eat a sprocket pretty fast, but under normal conditions, the sprocket should last for a long time.


Part of the issue might just be a soft, easy to cut steel used to make those gears cheaply. If you have a BBQ grill or a fire pit, you can heat treat it to hopefully last longer. This was written for knives, but the principle is the same. Heat-Treating-for-the-little-pyro-in-all-of-us/

 

[emaayan]

No idea where to get one But if they wear out that quickly, there has to be other reasons. A dirty, misaligned, or stretched chain can eat a sprocket pretty fast, but under normal conditions, the sprocket should last for a long time.


Part of the issue might just be a soft, easy to cut steel used to make those gears cheaply. If you have a BBQ grill or a fire pit, you can heat treat it to hopefully last longer. This was written for knives, but the principle is the same. Heat-Treating-for-the-little-pyro-in-all-of-us/

i have neither , i'm considering to make one from steel 1040 , and heat treat. i have a chainring from 7075T from thorn, which outlasted all of them.
it does seem the material to be the culprit, i once had a nirosta sprocket made and it too lasted longer.

 

[emaayan]

on the left you can see a brand new chain ring, on the right , after 6 weeks usage, the material is aluminum.

 

[agniusm]

I had a recommendation on the DIYELECTRICCAR from member quietcar:

If you make the sprockets out of 1010 or 1020 carbon steel, you can simply case harden them after cutting (or any time there after).

If you are using a decent machine shop, they will be familiar with the steels and even have a shop favorite they usually work with. Ask their advice.

If you supply the material, get what is known as "D2" Tool steel. D2 has high wear resistance, good toughness, and low distortion. It is often chosen when long tool life is required. Perfect for sprockets.

You might even reverse engineer it and find a heat treater, call and ask them what they would use. Have it cut out, then send to them for finish heat treating. (which is what I always did.)