This time the FP3 that is already sold....but not shipped yet and noticed that if run at top RPM for ten minutes or more, while it runs quiet enough it becomes progressively more difficult to move the quill in the head. Which is quite curious as it seems so smooth and quiet and doesn't seem overly warm to the touch.
So yesterday I said what the heck, and take it out and apart anyway. It was smooth as silk and with no sound (tuning by hand) but it did seem like it didn't spin freely enough, so figured it either had some preload on the thrust bearings, had too much grease, or the wrong kind of grease.
What I found was sure enough some preload on the trust bearings, the grease amount was about right but black as the ace of spaces and therefore must not be Kluber. So I cleaned it all up with carb spray, both needle and thrust bearings appeared and felt absolutey as new and applied Kluber.. One other surprise is that the lower thrust bearing was upside down ! The spacer/washer with the grooved race, should be the closest to the end of the spindle but this one has the all flat spacer in that position. So I'm thinking, ahah, maybe that's it.
So I get it all back together, this time with thrust bearings oriented correctly, and it moves and sounds beautifully, like a brand new spindle.
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Re install it in the head, turn it on 500 rpm, works great, stop it, turn it 1000 rpm and within 3 seconds it seizes up !!!! (V belt slipping, shut 'er down)
A major WTF ? on that one...I even imagine things like perhaps that thrust bearing was upside down for a reason....but I get the spindle back out and it still turns beautifully. Then I realized the culprit has to be the big bevel gear's thrust bearing must have seized some how....but how, and why now of all times ?
Took the top apart and immediately saw the problem....the split threaded collar that one uses to put the light preload on that gears thrust bearings...it's clamping screw was loose ! That apparently allowed that collar to thread itself too tight against the gear's thrust bearings, thus the seize up. Apparently just the act of removing and reinstalling the spindle was enough to be the "straw that broke the camels back" in that regards and it seized it.
Once the collar was knocked unthreaded a bit, all was well. but while I was to that point I took the bearing apart to see if there was any damage. To my surprise it looked pristine as new.....but there was not one hint of grease or oil in the thing....dry as a bone. So, I Klubered it, put it back together with light preload, made sure the collar screw was tight, reinstalled the spindle....and viola, now it can run at 2500 RPM indefinitely and the quill moves just fine, temp barely above room temp.
Bottom line is the humor is that here I was trying to make something better, that was already ok, just not perfect...but somehow made it infinitely worse with the seize up.
But the reality is I did make things better....only the real problem was not where I thought it was...problem was in the bevel gear bearing preload (and lack of lubricant), not the spindle.....although at least now I know the spindle is better too.
Plus it's a good thing the problem happened on my "watch" as it would be a major WTF ? if it happened soon after the new owner took possession of the machine.
So yesterday I said what the heck, and take it out and apart anyway. It was smooth as silk and with no sound (tuning by hand) but it did seem like it didn't spin freely enough, so figured it either had some preload on the thrust bearings, had too much grease, or the wrong kind of grease.
What I found was sure enough some preload on the trust bearings, the grease amount was about right but black as the ace of spaces and therefore must not be Kluber. So I cleaned it all up with carb spray, both needle and thrust bearings appeared and felt absolutey as new and applied Kluber.. One other surprise is that the lower thrust bearing was upside down ! The spacer/washer with the grooved race, should be the closest to the end of the spindle but this one has the all flat spacer in that position. So I'm thinking, ahah, maybe that's it.
So I get it all back together, this time with thrust bearings oriented correctly, and it moves and sounds beautifully, like a brand new spindle.
=========================================================
Re install it in the head, turn it on 500 rpm, works great, stop it, turn it 1000 rpm and within 3 seconds it seizes up !!!! (V belt slipping, shut 'er down)
A major WTF ? on that one...I even imagine things like perhaps that thrust bearing was upside down for a reason....but I get the spindle back out and it still turns beautifully. Then I realized the culprit has to be the big bevel gear's thrust bearing must have seized some how....but how, and why now of all times ?
Took the top apart and immediately saw the problem....the split threaded collar that one uses to put the light preload on that gears thrust bearings...it's clamping screw was loose ! That apparently allowed that collar to thread itself too tight against the gear's thrust bearings, thus the seize up. Apparently just the act of removing and reinstalling the spindle was enough to be the "straw that broke the camels back" in that regards and it seized it.
Once the collar was knocked unthreaded a bit, all was well. but while I was to that point I took the bearing apart to see if there was any damage. To my surprise it looked pristine as new.....but there was not one hint of grease or oil in the thing....dry as a bone. So, I Klubered it, put it back together with light preload, made sure the collar screw was tight, reinstalled the spindle....and viola, now it can run at 2500 RPM indefinitely and the quill moves just fine, temp barely above room temp.
Bottom line is the humor is that here I was trying to make something better, that was already ok, just not perfect...but somehow made it infinitely worse with the seize up.
But the reality is I did make things better....only the real problem was not where I thought it was...problem was in the bevel gear bearing preload (and lack of lubricant), not the spindle.....although at least now I know the spindle is better too.
Plus it's a good thing the problem happened on my "watch" as it would be a major WTF ? if it happened soon after the new owner took possession of the machine.
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