My Pm727.

tweinke

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Well time to post a picture (if I can figure it out) and some first impressions. Went the rout of building my own stand which turned out ok although two more inches taller would be ok.
 
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Looks pretty good. Do your casters have locks on them? Is the mill bolted to the stand?
 
Got so excited that I got the picture posted I never finished my comments.o_O I built my stand from 2x2 tubing and shot for about 41 inch table height.I do have a set of hockey puck levelers to install as soon as I have them finished. A nice set of drawers will go under the mill also. After a good cleaning and spindle break-in I changed the oil in the head. Some silver particles but no real huge amount of them. I already have a Shoptask 3 in 1 so I decided to machine the excess tee nuts from my hold down kit to fit the 727. One thing I did find was that the center t slot is narrower then the outer two. Boy what a difference from the Shoptask,I really like the 727 smooth and capable of decent cuts.The money spent was well worth it. just knowing I do not have to switch from lathe to mill and back sure makes projects more fun. I think I will built another Touch DRO set up for this machine because it seems to fit my purposes well. So all in all I am very satisfied with my PM727.
 
Dieselshadow yes the mill is bolted down to the stand, the casters do not have locks which is not realy an issue once the leveling feet are down. I do not have a lot of extra space in my garage so i did keep the stand mobile to be able to clean or rearrange the shop area.
 
I totally understand that need my friend.

With the leveling feet, it should stabilize the machine and make it smoother.
 
Nothing like having 10lbs of shoot in a 5lb box.:rolleyes:
 
Made up a spindle square similar to the one sold by Edge . Was off .005 in x, adjusted that out easy peasy. checked for nod .0065 . hmmm what to do? didn't have much time left to spend but thought about it a minute decided to check column bolts of course no allen wrench at home to fit. will bring one home from work tomorrow and a torque wrench. Decided to try one more thing, loosened the back base bolts holding it to the stand now at .003. I did not crank the bolts for the stand very tight to start with so as an experiment I tightened them till the lock washers just reached full crush then the nod started to increase after that. Those back two bolts through the base are far enough forward that there is no base casting touching the chip tray and I think you can flex the base pretty easy. Will play with that a bit more tomorrow. Tried the front bolts and no noticeable indicator movement. anyone else noticed this?
 
I will check this later today and confirm but I dont believe I had that issue. I did have to adjust the nod (y-axis) by putting in a few layers of aluminum foil under the front of the column.
 
You have to figure out if the nod is due to the column being out of squareness of simply due to the head/spindle being out. What I did was to get a 6" machinist square and clamp it to the table. Then put a dial test indicator in the spindle. The you zero our the indicator with the head all the way down and everything locked down snug. Then raise the head until you get to the top of the square, snug everything down again, and check the dial test indicator. Do this for both the x and y axis. Do it several time to get an average reading in each axis, the more times the better for the average. The reason you need an average is that there may be minor differences in readings due to inconsistencies in how snug you make the lock down knobs on the head each time you move it.

Once you have measurements for both axis, then you can start the shimming process. I used layers of aluminum foil. Then when you have the column properly shimmed, you can move to squaring up the spindle / head by means of using the spindle square you made. Like you stated, getting the x axis in tram is easy, and it is made easier if you made some tramming aids that attach to the head. Here is a link to the type of tramming aids that I made and installed. This is from the Hoss Machine website: http://www.migration.g0704.com/Projects2.html#way This definitely makes it easy to tram the x-axis. If there is still nod present, you will need to shim the head at either the top or bottom, between the spindle head and the carriage base, depending on which way the nod is off. You just need to loosen up the three lock down bolts where the head rotates, so that there is enough room to get some shim material in there. Then tighten things back up.

I hope this makes sense. Let me know if it doesn't.

Thanks,
 
3d, all makes sense, I have watched Hoss's vids on tramming several times. I am waiting till the weekend to borrow a good machinists square and then will check the column. basically I would say the mill is as good as it gets without going further. I did re run my experiment with tightening the rear two bolts and it does effect the amount of nod that I measure. I think I need to be sure it is not caused by the stand. will asses that this weekend also. I used the flattest part of my garage floor to weld the stand components so not overly accurate but did lay a straight edge across all directions and was pretty good. Tonight after I checked the column bolts with a torque wrench my nod as measured with the spindle square was at .001 in 6 inches that is the span of the tool I made. also if I push backwards on the column I can measure about .0015 deflection. at this point checking column square then starting over with the rest seems to be the best idea. I do not know how tight a spec I should shoot for so comments on that would be good.
 
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