Normal for the Drawbar to spin off center?

Mine spins off centre but it’s because I need to machine a bushing for it to centre in the spindle bore.


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That is normal. Mine does it too. There is slop between the bolt and washer and between the washer and spindle bore.

Roy
 
Mine spins off centre but it’s because I need to machine a bushing for it to centre in the spindle bore.

My PM727 did the same. made a bushing and problem solved.
 
I don't know what I'm doing, but will share my experience. :)

The R8 drawbar on my Alliant had the same problem: you could see it spin off center and it would occasionally cause a wobble that I could feel in the quill handle when feeding the quill down. Its an extended height drawbar; I was told to allow tool changes while quill was at full extension and/or for a a right-angle head. Anyway: the bushings were not snug at all with the spindle bore. I made a new set and it helped...kind of.

But then a new issue popped up (or maybe: learned more about the problem): the spindle internal bore was not consistent. About 3 inches into the downfeed, the new bushings would hang up and prevent quill from easily feeding further. It also caused a horrible bounce in the quill feed handle at this point which coincided with the spindle RPM. I think this is the occasional bounce/wobble I would notice earlier, but now that the bushings were tighter: it helped me identify the problem. I think with the original looser bushings: i'd occasionally have the bar a bit more off center than usual and I'd see the vibe.

I have since put the original bushings back on the drawbar. My procedure for now is to snug the drawbar at near full quill extension. I assume original bushings are snugger at the bottom vs top which is why the bar ends up nicely centered at full quill extension. There are near zero wobbles in the drawbar, no vibes, and no quill handle wobble. At some point I'd love to find out why the ID is not consistent, but for now it works.

Hope something there is useful!
 
The top end of the drawbar on my LMS 5500 does wobble some, similar to yours, when tightened into a tool holder or collet, but with no appreciable vibration. I didn’t see anything sticking out of the business end of the spindle in your video. Was the drawbar free to flop off center inside the spindle or was it securely screwed into something? Also, have you tried running the machine with the drawbar removed to see if it makes a difference?

Tom
 
The top end of the drawbar on my LMS 5500 does wobble some, similar to yours, when tightened into a tool holder or collet, but with no appreciable vibration. I didn’t see anything sticking out of the business end of the spindle in your video. Was the drawbar free to flop off center inside the spindle or was it securely screwed into something? Also, have you tried running the machine with the drawbar removed to see if it makes a difference?

Tom

I will conduct the suggestions you provided. The video didn't have the drawbar screwed into any holder, but I have done that before with the drawbar still spinning off center. Makes sense it would since there is a considerable amount of space between the bolt, washer and spindle bore. Doesn't seem to affect my cutting and considering others have the same issue leaves me to assume this space was left for a purpose. Thanks all for the replies.
 
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