Spindle Loose In Rf31

CannonFodder

CannonFodder

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Hello Friends,
I need help in the proper procedure for tightening up the spindle inside the quill on my RF31.
If I put a half-inch bar in a collet, I can grab it and when moving it, hear and feel the looseness of the spindle. The wobble measures about 3 tenths when I put a dial on the surface of the spindle where it exits the quill.
I have not disassembled a machine before. Any advice is appreciated.

CannonFodder (Robert)
 
Their might be a little grub screw near the lock lever that is a little side adjustor. Or do you meen it moves up and down?

3 10th's wobble dosn't sound too bad, others may chip in with how much better than that they get.

Stuart
 
I agree with Stuart, because of the way the quill is supported in the main head housing, 3 tenths is fantastic! Remember, we are dealing with a machine that was built to price and not a high quality toolroom machine designed to hold tenths all day long day in and day out.
Another thing to check is the axial play of the spindle in the quill itself. This will determine the play in your bearings. Be sure to lock the quill before you make this check as there is considerable backlash in the rack movement system as it is usually assembled.
 
Are you absolutely sure it is 3 tenths? Please write that as a decimal for me please. 3 tenths is absolutely nothing to worry about.

"Billy G"
 
Thanks for your responses! Yes, I used a Mitutoyo dial gauge that shows .0001 between marks. I can push .0003, let go which returns to zero, and pull .0003. That occurs in any direction of the X - Y plane. I don't feel any play vertically (Z).
The reason I am concerned is first, it wasn't there before; and secondly I have a super-cheap all-in-one mill/lathe unit that has absolutely no play at all. You can shake the spindle and it feels like your shaking a single casting with no moving parts.

Are you also telling me that on your mills, you can feel and hear movement from side-to-side in your spindle?

Thanks again for all your help.

Robert
 
My PM25 has .003 sideways movement in the quill when it is free. When locked I don't know, never thought to measure it. When it's locked, I'm milling and quill movement is not a factor. I drill holes with the lock dragging and hope it's .001 or better. ,
 
Also, I should have clarified. This shaking is identical with the quill locked or not. The quill in the body of the mill is rock solid.
 
Try that test again with the spindle warmed up. Run it at a higher speed for a bit, then take the measurement. Once things expand a bit, the play may go away.
 
Okay, I got some more (amateur/questionable) data.
The twenty minute warm-up at 3,000 rpm, didn't change the spindle-in-quill shaking and clanking at all.
But I did notice the vertical movement of the quill within the casting, that you guys mentioned, when the locking lever is not tightened. It goes away completely with the locking lever on, and moves .020 vertically if you really lift it forcefully up.

But that brought in a new observation. If I run the machine, turn it off, and shake the spindle, I get the reported looseness and clanking. But if I forcefully bang the quill up and down through that .020 movement and then try to shake the spindle - rock solid. Then, turn the machine on again, turn it off, and shake the spindle again - clanking. I can repeat this back and forth and it works this way every time.

In my untrained mind, I'm picturing the vertical banging is pushing the taper bearings temporarily together and tighter, and the running of the machine returns the bearings to their less-than-tight configuration. Okay, I've embarrassed myself enough, what do you guys think?

Robert
 
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