[philbur]

Here is another video on gib adjustment, its for different machine but its different approach:


I have tried this and adjusting gibs this way results in out of spec lost motion i.e. 0.00311" when manual recommended way to adjust gibs yield less than 0.0018"

I have also experimented with getting Y gib tight so it stops this wobble. Its possible (still shades of wobble visible), but results in lost motion greater than 0.0031"

I have new Y ball screw on the way from Tormach. I will replace that, adjust gibs per manual and see what happens.

You can get away with this simpler procedure on a manual mill but it is not suitable for a CNC mill. A manual machine with a lead screw rather than a ball screw will always have some lost motion so having the gibs a bit to tight makes little difference. The machinist will allow (or should) for this lost motion in the way that he uses the machine. Operator allowance is not always possible with a CNC machine, for example interpolating a round hole.

Phil

[MichaelHenry]

Getting to the X-axis ball nut to check that the fasteners are tight isn't too bad. This picture should give you an idea of what's involved:

Attachment 382842

Shout if you need more info.

[coffeetek]

So Y lead screw has been exchanged, behavior of machine has changed, but there is still same problem. This time it shows up as table comes back and closer to the Y stepper, here is video. Anyone with any clues what to look at next, stepper motor or...?

[philbur]

Did you not solve the problem in post 32 or have I missed something?

Phil

[coffeetek]

Did you not solve the problem in post 32 or have I missed something?

Phil

Nope... As you can see still there...

[philbur]

Nope... As you can see still there...

So what's the story behind the before and after photos in post 32. If you want help with the diagnosis you need to explain what you did to cause things to go backwards after post 32?

Phil

[Jim Dawson]

Is it possible that the Y motor shaft is bent? Coupling out of round?

[coffeetek]

So what's the story behind the before and after photos in post 32. If you want help with the diagnosis you need to explain what you did to cause things to go backwards after post 32?

Phil

The only thing that was done there is gibs were played with and adjusted. It is possible to tighten gibs so much to minimize this but then you have trouble with way too much lost motion and steppers losing steps.

[mountaindew]

So what's the story behind the before and after photos in post 32. If you want help with the diagnosis you need to explain what you did to cause things to go backwards after post 32?

Phil

That was what I was thinking. It sounds like the entire history of the machine needs to be reviewed. How long have you owned it? How long did you use it before this problem come up. What changed...........?
What has tormach advised to inspect, adjust and test? In my opinion if you can explain or demonstrate the problem well a couple people around here like turbo step or tmarks and others can quickly point you in the right direction. Myself when I run into problems like this I set down and start asking myself questions. Does the cutter sound right? Does the machine sound right? Does this happen with a different cutter? Different tool holder? Different Speeds? Different feeds? Different DOC,WOC? Different code? Different material? Does the machine have good dedicated clean power? All the connections look good and clean? When you run that code on a 2x4 wood block, what does it do? Silly right, I spent 3 hours chasing a tight fit single point thread setup in cam using my cutters with "wood test blocks " imho the only way to zero in on complex cam cnc operations, if you don't do this every day. Anyway good luck and I hope you zero in on the issue soon. My 1100 has only improved with age