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Worthy project or piece of scrap?

So after input from @RobinHood I decided to do some more tests. Measured digitally rpm and temp during 15 min run cycle with and without belt. The motor is rated as 15500 rpm with no load and - surprise - my tachometer showed rpm very close to the 15500 mark even after a 15 min run time. The temp during this time only rose to about 38C from a starting point of about 25C. After another 15 min with the belt the temp rose to about 41.5C. Warm but not hot to the touch. Temp was taken near the bearing end of the motor body where the temp was the highest. The spindle did not get as warm as the motor body.

My conclusion is that the machine still runs reasonably well and is worthwhile fixing/restoring.

rpmtach.png
temp.png
 
Question for people with a similar old Dumore 5-021 toolpost grinder. I have over tightened the nut on the spindle pulley and am afraid I may be trying to turn it the wrong way. The similar looking nut on the motor pulley has a left hand thread (ie it loosens when turned clockwise). I assumed the over tightened nut on the spindle would have the same left hand thread but am not sure. So I would like to know how it is on your Dumore grinder. Does the spindle pulley nut on yours have a left hand thread?
 

combustable herbage

Ultra Member
Premium Member
On my themac the spindle is right hand and the motor is left hand if you know the motor thread the spindle should be opposite?
If you have the parts breakdown it might say left hand thread in the part description.
 

PeterT

Ultra Member
Premium Member
Hmmm... that probably explains why TPG motors are fixed direction, not fwd/rev. I always thought that was rather limiting from grinding standpoint. But upon further consideration, maybe not from a spindle or wheel nut unthreads at high speed & shoots yer eye out perspective.
 
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