quill slop/rocking

[banctecbobn]

What is the best/proper way to take the slop out of the quill?

The quill assy is moving around inside the casting bore. Locking down the quill helps but the quill (CNC) needs to move.

Have the older Gold series.

[smallblock]

The Gold series machines were sold from about 1996 to 2001, so its probably in the 10 year old range- There are some tricks I found on my older 17-20 machine, depending on how you are driving the CNC. Is it through the original worm and rack system or by a direct drive ball screw?

[banctecbobn]

Thru the original worm and rack system.

I don't see how that matters, need to know how to get rid of the slop between the spindle and the quill bore.

Not looking for a work around.

[smallblock]

Thru the original worm and rack system.

I don't see how that matters, need to know how to get rid of the slop between the spindle and the quill bore.

Not looking for a work around.

It matters because there are things you can do with the ball screw setup that are more difficult to do with the worm and rack system.
With the worm and rack system you have several direction changes from your CNC drive to the quill- each change has to have some amount of clearance for free movement, so you have a multiplier of the backlash. The clearance between the gear and the rack can only be compensated for by the tension of the return spring maintaining constant contact between the teeth. Under heavy plunge cuts, the spring can be forced back causing some loss of position and requiring a pause to allow the quill to catch up.
If all of these things are no issue, then let's concentrate on the quill and casting bore.
You refer to "slop", but give no measurements or at what point the " slop" occurs. The quill is like a piston in a motor- it must have a certain amount of clearance or it won't move at all, so getting zero "slop" is impossible. The old machines have a split in the casting and 2 tabs for a locking handle. When tightened, the handle will pull the lower part of the bore together and reduce the clearance and eventually lock it completely. A simple way to reduce the "slop" is to slowly tighten the lock until the cnc motor begins to stall- that would reduce any side to side "slop" in the quill and still allow the cnc to function.

[Ira]

I think what you are saying is that when you grab ahold of the quill you can rock it back and forth a little? I'm no expert, and there has been advice on this forum to chrome coat the quill to add some extra meat to it and then have the mill head precision milled...

But, what I did was use two screw holes in the millhead to press the quill up against the back of the millhead (two silver screws in picture). The holes I used maintain contact with the quill through the full range of motion. I used some small pieces of brass rod in the screw holes to protect the quill from the adjustment screws and didn't use much pressure, just finger tightened. They kind of act like gib set screws.

Also, if you're drilling new holes, mine are not in the ideal location, because the quill lock pushes the quill to the right while the adjustment screws push the quill back, so the quill may move or reorient when the quill lock is engaged. It would be better to put the adjustment screws closer to the quill lock.

I havn't set my tram yet, and I don't know the effects of the quill slightly rocking, but it's probably negligible.

I don't really do before and after testing, I just look for things to tinker with and play away. I only notice when I make things worse. Then I rethink things. Let me know if you want measurements, but like I said I just used the extra holes, so you could probably do better thinking about it a little.