Shopsmith Forums

I too wonder about the tach readings. It would be interesting to have a another known rpm motor or something to take a reading from to see if it too is reading high/low/or right on.

When I first got my tach I was experiencing some instability which turned out to be my fault as I was too close to the shaft, the instruction called for at least 2" and I was trying to use it almost touching. So sometimes a quick check of the instructions helps as it did for me.

Ed

In response to one idea-I’ve put in a new quadrant and worm gear. So I have good meshing there.

I, too, questioned my tach so I tested it. It’s a Harbor Freight photo style. I compared it’s readings with readings from a tach that’s a magnetic style. With 6 data points they where + or - 25 rpm apart.

These readings with the photo style where taken at the left end of the quill (next to the poly belt).

At “B” 1190 rpm
“G” 1491
“J” 1993
“M” 2525
“Fast” 4711
“B” again 1176

Now at “B” the idler shaft read 1867 rpm and the shaft was very very hot. Never checked this heat component before. But it was hot. And I have a new noise that’s cyclical.

The motor shaft read 3565 rpm.

I think(changed my mind from earlier opinion) you need to cut 1/4" or so from the floating sheave 'snout'.

The idler shaft is notorious for getting hot. Belt tension aggravates it.

Thank you for your insight and suggestions but I’m stopping here. The speeds I have available are good enough to run my sanding station. I have other Mark Vs to do the other functions.
Thanks again.