Rambling and rubling in Mill/drill spindle

Slop in the drive spline?
Tweinke,I have thought about your proposal last knight and this morning I checked the spline slop. When I hold the pulley and move the spline spindle form side to side,there is definite movement,about 0.35mm or 0.013" . But how much is too much,my head says there must be some clearance. How much is just enough?
20181029_081919.jpg
20181029_083128.jpg
20181029_083249.jpg
 
I'm going to guess it is an Asian import. The design suggests that and the round plaque that says, "The place for spindle's adjustment" just sort of sounds like Chinglish to me. If that is the case then it probably has two tapered roller bearings supporting the spindle inside the quill and two radial bearings supporting a drive sleeve at the top of the spindle. The drive sleeve transfers radial motion from the belt to the spindle.

I suggest you check the run out of the spindle. If it is greater than a few tenths then you might consider changing the bearings. Also grab the pulley and see what happens to the run out when you move it back and forth. If the run out increases significantly, the drive sleeve bearings are shot.

If this is an Asian mill then there isn't a whole lot inside the quill - just bearings and spindle in the quill and two bearings supporting the drive sleeve above the quill. Changing them is simple and I cannot think of anything else that would cause the machine to rumble unless something is rubbing on sheet metal on top.
 
What Mikey said but also take a look at the draw bar to spindle bore clearance. My RF-30 Enco mill draw bar had so much slop that the spindle vibrated in the highest RPM setting. I figured out that when tightening the draw bar it would move to one side of the spindle bore thus being significantly off center causing vibration. I made a bushing that was a snug fit in the top of the spindle with just enough clearance for the draw bar. Problem solved.
 
The spline slop was just a thought, some guys with Shoptask 3 in 1 machines have had that problem. I had a knock in my Shoptask spindle and was able to pull the drive pulley and move it on the splines and get a better fit. Temporary repair I know but I don't use the mill part much anymore after getting a stand alone mill.
 
I
What Mikey said but also take a look at the draw bar to spindle bore clearance. My RF-30 Enco mill draw bar had so much slop that the spindle vibrated in the highest RPM setting. I figured out that when tightening the draw bar it would move to one side of the spindle bore thus being significantly off center causing vibration. I made a bushing that was a snug fit in the top of the spindle with just enough clearance for the draw bar. Problem solved.
I had a RF-30 and it had that problem. I will check and maybe implement your idea on this machin if necessary. Thanks
 
Back
Top