Any advice on methods of tramming the Z axis? Mine is custom, but it's very similar to the Z on the minimill and the c-beam machine.
Mine is custom as well, and I need to build in some sort of Tramming adjustment. Maybe slots or stand-off bolts? In all Axis directions of course. I also need to consider building in a good vertical and horizontal straight edge to line up on.
If your build hasn't changed since the photos you posted back in April, you've got a weak spot where the column is attached to the base so tramming may have limited impact as flexure may be in control here. I would suggest cutting some extended side plates with slightly oversize holes. That will allow you the adjustment you seek and once tightened will provide a proper hold. If you need any additional shimming, I suggest aluminum foil tape.
Hi Rick, Thanks for the response. My post wasn't very clear - this is on my router, not the mill. C-beam long axis, big wheels to support custom carriage plates, c-beam lead-screw Z. I'll post some pics later, but it's very similar to the OX design.
I think that tramming the z axis is just as important as tramming the router. A perfectly square router will still not cut properly if the z axis is not square.
Okay: This IS about tramming the Z axis. On my 1000x1250 CNC router. It is NOT related to my minimill. Hopefully this clears up the confusion. My Z carriage plates appear to be a little bit off. I'm going to make another set, but I was looking for ideas for an adjustment mechanism that I can incorporate into the new design.
The most important part is a fixture or method to measure the variance in the tram. For X axis (Left/Right) adjustments, you can just adjust through the use of the mounting corner blocks, they have the ability to shift/tram the spindle left/right.
Sure - I can adjust the spindle easily. But, if the Z axis is at an angle to the gantry, it's going to move more like an escalator (at an angle) than an elevator (vertical). Even if the spindle is square to the bed, plunges will be at an angle. (Hopefully that is clear). I need a way to adjust the entire axis, not just the spindle.
I would need to see more of your machine to advise. In what I am saying you can tram the spindle left/right. You are talking about what I called forward/backward, and that can usually be done by loosening the C Beam that the Z Axis is attached to, and rotating that.
I'm talking about clockwise/counterclockwise rotation when viewing from the front of the machine. (See terrible PhotoShop art attached.) The X axis (horizontal in the picture) is level and square relative to the Y rails, in both the X and Y directions. There may be some pitch (rotation about X axis) on the spindle / Z axis, but what I'm concerned about at the moment is roll (rotation about the Y axis, as indicated in the image.) I can rotate the spindle mount clock/counterclockwise relative the the Z axis c-beam by adjusting the black router mount. What I cannot do is rotate the Z axis relative to the X axis. If I had used eccentric spacers on both sides of the Z, I could probably adjust those to properly align it with the carriage. But, I did not. I think I'm just going to have to make another set of plates for the Z with some slots, but I don't see that being as rigid. I was hoping someone else had already solved this. :/
Just the 90-degree blocks connection the OB router mount to t-nuts in the c-beam. I can adjust the router mount relative to the z-axis c-beam, but I can't adjust the c-beam relative to the X axis.
That is exactly what I was saying above. You can loosen those 90 degree blocks and rotate the spindle in the two directions that you have made with those arrows, the roll as you called it.
Yes. But if the axis is rotated, then it moves down at an angle. Even if the spindle is pointed straight down - mine is - the Z is still rotated.As the stage moves down in Z, it will be offset in X based on the Z distance moved. (Basically, the Z is aligned with the hypotenuse of a triangle who's upper interior angle is determined by how effed up my carriage plate is.) Squaring the spindle isn't sufficient - the axis has to be squared, as well. Mark's suggestion about the eccentric spacers makes sense, BUT that also means I have to make another plate with larger holes for the eccentric spacers. If I'm making another plate or set, I was hoping for a solution with more adjustability, like a jack screw and a pivot plate between the Z and the X carriage. I can certainly build that, but surely there is a better option. ?
Hey Rick, do you have any source to where I might find your "minimill additions"? Every post about the minimill, I see you adding great solutions and more, but unfortunately I can't seem to find any "build" or anything where I could see what worked and what didn't.
The suggestions I offer are generally in response to a specific need which I may or may not have had personally. Sorry, no central repository. And as for which I may have added into my own minimill the world will never know. I was about 90% finished with my supersized, uber-reinforced version when I changed course and parted it out for my current build. I thought I had taken photos prior to the metamorphosis but couldn't find any.
