Well... I finally did it. PM-833TV (now in my shop!)

Skowinski said:
I suppose that would work the same as shimming the column.
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As long as you always use the vice! It is common to clamp work, fixtures, rotary tables, spin indexer etc. directly to the table. I don't think you would want to shim those each time you use them.
Both your X & Y seem way too far off. Time for some serious adjusting. No such thing as perfect but .001 in 6" seems like as far off as you'd want to be. Less is doable & desirable with a few more tries.
 
You buy this precision mill and don't want to get precision alignment? Seriously? Take the time to tram the mill including shimming the column. A good tram is 0.0005 (that's 5/10ths) around a six inch circle.
 
When tramming the head make sure your head gibs are adjusted properly and the head is locked solidly, otherwise you can also see some nod in the head. As time goes on the gibs will wear faster on the bottom due to the the weight of the head and the nod becomes more noticeable. On CNC machines they often will use a counter weight system for the head, this should also decrease the wear on the lower portion of the gib, Certainly in the X dimension I would be withing 0.0005" at 6". There can be minor variations in the table and also the vise when mounted. You can also try doing a skim cut on a block and measure the corners for height/block uniformity. I was just surface milling a block 7075 and dimensions stayed uniform in the X and Y. In this case the X is 14" plus the length of the 4" surface mill and the block dimensions stayed within 0.0005", on a knee mill you have a bit more flexibility in the adjustments as well as rigidity.
20201124_103214.jpg
 
I probably do need to look at the gibs on the column. But, did have it locked when I checked this first time.

edit: @davidpbest just watched that video, thanks, man for a beginner that looks scary, I'd for sure screw up somehow, then what? lol...
 
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ArmyDoc said:
Looks nice! Did you do it yourself, or hire someone?
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It was done when the retirement house was built. Worked in too many worn out bare concrete floor garages with oil stains everywhere over the years. It's nice.
 
davidpbest said:
You buy this precision mill and don't want to get precision alignment? Seriously? Take the time to tram the mill including shimming the column. A good tram is 0.0005 (that's 5/10ths) around a six inch circle.
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David, thanks for the link. I saw it before but did not feel like watching a long video... Stephan always does amazing work. Actually using the epoxy the way he demonstrates it, is relatively easy. My PM833 is pretty much on the mark on the Y axis and tramming the the X axis was easy.

I used a similar device to the SST gizmo shown here and it really makes traming a very fast and easy process as long as you don't have to fix the column alignment.

Ariel
 
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