Lead screw making noise

[clembrant]

I just built a router using 5/8-8 lead screw. When I jog it the lead screw makes a thumping noise. I replaced the lead screw, but it still does it. I just wanted to know if anybody had run into this and what they did to resolve it.

[svenakela]

Clembrant,
I don't get it, is it a one-sound-per-revolution-think or a constant noise?
Did you check your alignment and that the nut is ok?

Regards,
Sven

[2muchstuff]

How much shaft endplay is there or is the nut on the shaft have play in it. If the shaft has endplay then I would suggest 2 angular contact bearings set opposite of each other with some tension between them.

[clembrant]

I took motor off today and found noise was coming from motor. Didn't notice it before because it wasn't very noticeable until hooked to machine. It is one thump per rev. I'm using xylotex at 1/8 step.

[svenakela]

Ok, great you found it. Do you manage to repair it or do you replace?

Regards,
Sven

[clembrant]

I contacted xylotec and they said my computer is probably too slow to run mach 2 software. I'm going to try turbo cnc and see what happens

[Fixittt]

Its probably resonence in the motor. Alot of Xylotex users have had this problem.
Here is my thread on my machine and how Im going about solving the issue.
http://www.cnczone.com/forums/showthread.php?t=30988

[clembrant]

I hooked my faster computer and it fixed my thumping problem, but now I have a new problem. I'm getting vibration at higher speeds. Right now I'm maxed out at around 32 ipm.

[jeffs555]

How long is your screw? What kind of bearings do you have on it, and how are they arranged?

[svenakela]

Make sure everything is aligned and that the screws are "tensioned" properly. Screws tend to flex a lot when they are loose.

--S

[clembrant]

I've got double angular contact bearings on both sides, tension is pulled to one side. Other side floats(slip fit) in bearing and connects to stepper motor.

[svenakela]

Originally Posted by clembrant I've got double angular contact bearings on both sides, tension is pulled to one side. Other side floats(slip fit) in bearing and connects to stepper motor.

But then the screw itself isn't "stretched". If the screw is only fixed in one end it will tend to vibrate as it can move in the other. By tension I mean that it should be tensioned as you do with a rubber band.
Hope that helps.

Regards,
Sven