TAIG "head" makes alot of noise

[Smertrios]

When the head on my TAIG is moved up (-Z direction) at 30IPM it sounds fine but when its moved down (+Z direction) at anything over 12IPM there is alot of vibration and the stepper can even stall.

[cartertool]

Originally Posted by Smertrios When the head on my TAIG is moved up (-Z direction) at 30IPM it sounds fine but when its moved down (+Z direction) at anything over 12IPM there is alot of vibration and the stepper can even stall.

Up is +Z and down is -Z

Anyway usually there are problems when moving up because the gib can shift and make the slide tighter, so I haven't heard of any problems when moving the head down...

I assume you are using lube on the ways?
Could be that the gibs are just generally too tight, or too loose, so that there is a binding movement...

I'm running a new z-axis at 30 ipm rapids...

You may want to reduce acceleration or velocity, and maybe play with pulse width (what control software are you using?)

[Smertrios]

I typed the Z directions down wrong for some reason sorry about that as for the TAIG its brand new and dripping with oil running with a Xylotex 4-Axis "box" and mach2 demo. The steppers ate 269oz holding torque and can power the x,y,z no problem well at least no problem except when lowering the head.

[cartertool]

I'm pretty much at a loss - have you taken the z-axis apart at any point?
The reason being that given the mechanics of the mill, down feed should always be easy.

If you swap the leads on the motors (so the z-axis is now powered by the x-axis drive) does the problem still occur

If you swap motors (take the motor off of z and replace with one of the other axis motors) do you still have the problem?

All I can think of is that it's related to the acceleration and velocity and pulsewidth settings in Mach2, try cutting them down and see if it helps (especially acceleration)

Did you buy the mill from me or another dealer, or Taig directly?

With the control off, does the axis feel like it feeds smoothly when fed by hand turning the screw?

Originally Posted by Smertrios I typed the Z directions down wrong for some reason sorry about that as for the TAIG its brand new and dripping with oil running with a Xylotex 4-Axis "box" and mach2 demo. The steppers ate 269oz holding torque and can power the x,y,z no problem well at least no problem except when lowering the head.

[Smertrios]

I think the gibs need to be adjusted or rather tightened up I believe the whole head assembly is tilted so that when its going up the bottom part is being dragged up but when the direction changes the bottom part is pushed and kind of skids when the speed goes above 12.

[cartertool]

Originally Posted by Smertrios I think the gibs need to be adjusted or rather tightened up I believe the whole head assembly is tilted so that when its going up the bottom part is being dragged up but when the direction changes the bottom part is pushed and kind of skids when the speed goes above 12.

It's pretty easy to adjust them. Adjust the clamping shoes first with the motor off the mill, then mount the motor and adjust the tapered gib on the slide.
Here are the two pages that detail most of that:
Some Notes On Setting Up the Taig Milling Machine
and
Some Notes On Setting Up the Taig Milling Machine V2

[Smertrios]

The factory head assembly was loose I could actually make it tilt slightly just by lifting up on the motor and I did't have to lift very hard. Now after adjusting the head 5 times it feels solid but the GIB is soo loose it not applying any pressure at all in fact what I did was tighten the top screw until I felt pressure on my wrench then I backed off 3/4 turn and tightened up the bottom screw. TY Much I never would have been able to fix this without help.

[Smertrios]

Whats is a good lubricant to use with a TAIG mill? I know the machine shop I worked at used regular motor oil for everything from manual bridgeports to the $100,000 VMCs but I can't remember the oil weight.

[cartertool]

Glad you have worked out the gib problem - working smoothly now?

For oil Taig says ATF, but any 20-30 wt oil will be fine. I use a light way oil which is "stickier" that I get from MSC.

Originally Posted by Smertrios Whats is a good lubricant to use with a TAIG mill? I know the machine shop I worked at used regular motor oil for everything from manual bridgeports to the $100,000 VMCs but I can't remember the oil weight.

[Smertrios]

I thought I did because the head was moving without the stepper stalling. Another problem is with the stepper motor mount. I can leave the screws loose and hold the motor with my hand and the z axis will move up and down with no problem at all but as soon as I tighten the screws the stepper will start stalling again when the IPM is above 12.

[cartertool]

When mounted correctly the motor will but up against the end of the tube. If it is not in contact with the end of the tube then screwing it to the plate will cause it to cock to one side and cause stress. Readjust everything and make sure the stepper is square to the leadscrew.
The articles I posted show how...

Originally Posted by Smertrios I thought I did because the head was moving without the stepper stalling. Another problem is with the stepper motor mount. I can leave the screws loose and hold the motor with my hand and the z axis will move up and down with no problem at all but as soon as I tighten the screws the stepper will start stalling again when the IPM is above 12.

[Smertrios]

I know its an alignment problem but its not caused by the stepper being "cocked". When the mouting screws for the stepper are barely tightened I can see the cable shake a little and I can feel it wobble a little in my hand (I have to hold it to keep it from moving that is how loose it is). What happens when I tighten the screws in that it can't "wobble" as easily so the screw is much harder to turn because the nylon tubing has to flex more than it should. Believe me when I say its "a little" and not from a serious tilt caused by not being seated properly. Maybe the motor mount is messed up?

My 2 cents worth says the threads in the tube might not have been cut straight or the holes in the flex collars are not straight (either the bore or 4 nylons tubing holes).