[xaruum]

If the back of the Z column is already deformed from having the Nut torqued down too much, then a even a heavy duty washer will just deform until it meets the surface of the column.

You would need a belville or dock washer, they are much much thicker and designed for distributing very high loads all the way out to the edge of the washer, giving you more surface area between the nut and the column.

[Taflin]

If the back of the Z column is already deformed from having the Nut torqued down too much, then a even a heavy duty washer will just deform until it meets the surface of the column.

You would need a belville or dock washer, they are much much thicker and designed for distributing very high loads all the way out to the edge of the washer, giving you more surface area between the nut and the column.

Not the back the front. It wasn't deformed too much and sprung back. Belleville washers are designed to supply spring tension, they might suit the task though. The washers (2) I used are very heavy, 3/16" thick. Smaller one in the front larger fender washer in the back.

[Vicanic]

Ok, quick question. Is there some method or technique to attaching the headstock to the dovetail mount? because I trammed the machine up, then attached the headstock, swept the table, recorded the measurements. Then I took the headstock off, checked all my bases again to ensure they hadn't moved, then reattached the headstock and swept the table again. Totally different measurements.

So either I am attaching the headstock wrong, or my headstock isn't lining up with the dovetail plate, and if that is the case, either something is broken, or what is the point of running the indicator up and down the side of the dovetail mount in order to make it perpendicular to X? wouldn't it be better to adjust the dovetail WHILE the headstock was attached and use the data from the sweep?

[xaruum]

The headstock is not automatically aligned by the dovetail when mounted.

You will need to align the headstock by hand every time you mount it.

If you think through your last question, there is not a way to adjust the dovetail once the headstock is mounted.

As long as you have aligned the left edge ( when you are facing it ) of the dovetail so that it runs in parallel with the Z throughout the range of motion, then aligning the headstock should be a straightforward process. This is because usually the clamping side of the headstock will be on the right.

After mounting the column to the base, y should be around .0005. If not then shim appropriately. Then adjust the x tilt of the column. Now that you know that your z is running perpendicular to x/y, mount the headstock and run a sweep. For any adjustment in y you can shim behind the dove tail. For any adjustment in x, you use your deadblow (gently - you could knock the whole column out of tram) to tap the upper or lower end of the headstock on the right side.

This method generally works because of the fact that we machine to a given tolerance for error. So even though the left edge of the dovetail is running perpendicular to x/y, the headstock still has roughly .001~2 of play. That small amount of play will easily account for sweeps that are .005 off.

[Vicanic]

ok, well I just finished cleaning and reassembling the machine. I was unable to find what the torque was previously, however I am reasonably certain that it was around 15-20 ft lbs. So when I reassembled it this time, I aligned the column until I had no visible movement on the indicator, then I torqued it to 25, which was about 1 and a touch revolutions past nick carters 'choke up on the wrench' tightness recommendation. trammed in the headstock, then made a couple light cuts again. When I measured it afterwards, it was about .002 out of alignment on the column, and .00075 on the Y sweep, and .004 on the X. Still dunno whats wrong.

[awerby]

Did you change out the stud? It sounds like it's still not tightening correctly.

Andrew Werby
www.computersculpture.com

[BAMCNC.COM]

Is your acorn nut tight?