The Cons of my new G0755

My G0755 has always needed 20 or 30 minutes to warm up before I can use H2 or H3. Worse in cold weather. If that isn't it maybe the start capacitor? Bearings aren't too tight are they?
Dave
 
Well, I'll scrutinize the bearings a bit. I have held the spanner nut on the top while trying to loosen the draw bar. Perhaps I've over tightened it. Sound possible? I need to go out to the shop and stare at it for a bit and see if that makes sense.
When your is 'cold' does it run super slow?
I did suspect the start capacitor, only be cause I dunno exactly what a start capacitor does and my problem seems to be on start up!
Hows that for troubleshooting technique?

Thx for the tips
Scotty
 
Well, I'll scrutinize the bearings a bit. I have held the spanner nut on the top while trying to loosen the draw bar. Perhaps I've over tightened it. Sound possible?
No. The drawbar doesn't apply tension to the spindle bearings. It just applies tension to the top and bottom of the spindle tube, and the bearings run outside of that tube.

Problem should not be the starting capacitor, or the centrifugal switch, as it runs fine in the other gears. If the start capacitor were blown, it would not start at all (just sit there and hum at you like an angry bee). If the centrifugal switch were not opening, the motor would never run at full speed (and get very hot).

This sounds like a mechanical issue, maybe an idler gear set for the higher has a bad bearing. Did it used to work correct?
 
Well, I'll scrutinize the bearings a bit. I have held the spanner nut on the top while trying to loosen the draw bar. Perhaps I've over tightened it. Sound possible? I need to go out to the shop and stare at it for a bit and see if that makes sense.
When your is 'cold' does it run super slow?
I did suspect the start capacitor, only be cause I dunno exactly what a start capacitor does and my problem seems to be on start up!
Hows that for troubleshooting technique?

Thx for the tips
Scotty

When cold, 70* for instance my mill will not start in H2 or H3. It spins very slowly and will never get off the start mode. It runs fine in the lower gears as well as H1. Once it gets 10 minutes runtime H2 works great but it needs 20-30 minutes for H3 then all is well. I've read many posts across the internet that talk about mills needing a warm up before going to work. Have you tried a warm up period?
Dave
 
tmarks11
I had the quill cranked down and locked, in a hurry and not thinking, I put my wrench on the top of the drawbar and of course it just free wheeled back and forth. I grabbed a spanner and tugged on the spanner jamb nut while holding the draw bar, when it turned I suddenly realized what I had done. I believe that I returned the spanner nut back to where it was. Never showed any symptoms... until now, so thinking perhaps I tightened it and failed to put it back proper. Since my last post I played with it a bit and it is not too tight after all.

Dave.
I have some out of town errands to run, but I will run it for awhile, then try it in H/3 when I get back . If that is the problem... well what is the problem? Chin-wa motor? Either way I'll respond with what I have found.
Thx guys
Scotty
 
I grabbed a spanner and tugged on the spanner jamb nut while holding the draw bar, when it turned I suddenly realized what I had done. I believe that I returned the spanner nut back to where it was.
Still not going to damage the spindle bearings doing that.
 
Not sure where you're going with this, There is only one spanner nut in this drawing #68, and we've already surmised that isn't likely the problem.
Or have you got a theory that might help solve the problem?

Scotty
 
Asked because I was wondering if we were talking about the same nut once I looked at the diagram. We were not.

That nut sets the bearing preload for the spindle, and if it is too tight would cause excessive heat at high speeds (and if too loose would give too much run-out of the spindle).

If you could run it in H3 before you tightened that jam nut, and now you can't, I would consider adjusting it. Usually, manufacturers specify a torque setting to set the pre-load very precisely, but a quick google of "RF45 spindle preload" (of which your mill is a variant) shows that there is no real torque spec. I would try loosening it maybe 1/16-1/32 of a turn, seeing if it helps, then maybe loosen it again incrementally. There should be a lock washer under it that bends up to prevent it from being messed with.

some good pictures here:
http://www.metalworkingfun.com/showthread.php?tid=405
 
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