Hot Idler Shaft

nothungry3 · Post by **nothungry3** » Mon Sep 02, 2013 9:01 pm

After spending the summer disassembling and re-assembling my new 60's vintage shop smith, I am finally getting to see if I like it.
The idler shaft gets very hot. I noticed the top of the headstock was running hot, so I backed off on the gilmer belt tension a bit. The headstock is cooler now but today I noticed that the idler shaft is very hot (150 F) after about 15 minutes of running.
The hardware is in very good shape, the bearings are tight, and the it runs quietly (compared to before). I am not very confident in the gilmer sheaves alignment however. The belt is original, a little frayed on the edges but intact.
Does this sound normal?

charlese · Post by **charlese** » Mon Sep 02, 2013 9:10 pm

Don't know about the Gilmer, but the idler shaft (hub) on the poly-V machine I had got pretty hot pretty fast.

Shopsmith told me during phone call the hub is on that shaft helps with cooling - it acts like a heat sink.

billmayo · Post by **billmayo** » Mon Sep 02, 2013 10:00 pm

Sounds normal to me. I run the Gilmer belt with about the same deflection as the Poly-V belt. The factory method of tighten the Gilmer belt is too tight for me and will make the idler and drive sleeve bearings run a little hotter than I like. I try to keep the Gilmer belt slightly off the back hub of the drive sleeve so the belt does not fray. There are other recent posts by me on the way I do that.