Project Frankenmill – Part 17, Tram

Tonight I did some very preliminary measuring for tramming the head and column. Mostly just practice to start wrapping my head around it.

I started with the DTI in an ER20 collet holder in the spindle. First up is checking the Y axis, fore and aft. The back measurement is down .005″ over ~7.25″, which I think means the head is tilted back.

Next, the X axis. I actually trammed this in by loosening the head mount bolts and tapping the head with a soft hammer, so it rotated around the boss on the Z slide. Things moved a bit as I tightened the bolts, but by doing a cross-torquing pattern and going a little at a time, I got it to be within 0.0005″ over ~7.25″. Could do better, but it was just a quick 2 minute job. No sense in going nuts since I’ll have to take it apart to shim the fore and aft to fix the error above.

Next up, an attempt to see how the column tilt is looking. I used my granite square, mounted the indicator on a mag base on the head, and ran the head up and down with the Z stepper. The Y direction is actually pretty good as-is, it’s not even out 0.001″ over ~9″

X axis isn’t so good though. Seems like the whole column is tilted to the left, I’m measuring 0.015″ over about 8″. Guess I’ll need to shim up the left side.

I plan to do the measurements again, then take some other measurements so I can do some trig to get some approximate values for shimming. I picked up a shim assortment from McMaster a few weeks ago, so I should be good to try once I come up with some numbers.

Perhaps that 0.015″ I’m seeing in the left-right direction is not column tilt, but some combination of gib fit and wear in the ways. Maybe I should also expect to also see fore-aft movement if this is the case?

I’ll have to think a bit more to see if there’s a way I can determine the source of it, though there’s really little harm in shimming up the column anyway. Easy to undo if I determine it’s something else.

I do have that new, unfinished gib sitting on the shelf. I should really get that thing fitted before I go crazy with tramming anyway.

Related Posts

Project Frankenmill – Part 33, Claustrophobia

Final positions for the DIN rails and wire management have been nailed down. It’s much more tight than one should really wire a panel like this, but…

Project Frankenmill – Part 32, You’re Gonna Need a Bigger Boat

It seems to be a rule that no matter what size electronics enclosure you have, you will always have at least 10% more stuff that you need…

Project Frankenmill – Part 31, Full Pull

While I still haven’t gotten into the detail of squaring and tramming, I’ve been intensely curious to see if the new Z axis would be happier with…

Project Frankenmill – Alpha and Omega

Since 2009, I’ve been messing around with CNC machines. I started out with a small manual milling machine from Grizzly, and converted it to CNC using a…

Project Frankenmill – Part 30, Do You Even Lift Bro?

Hauled the column back down to the shop and mounted it back on the machine. Sure is a lot heavier than it used to be! Muscling things…

Project Frankenmill – Part 29, More Machining and Motion

Had some productive time in the shop during the holiday. First step was to make the counterbores for the M6 cap screws a bit deeper. Easy to…

Leave a Reply

Your email address will not be published. Required fields are marked *