Hello folks, As I have mentioned in another post, I recently finished my first set of parts on the mill. Although I was happy in getting them done, I just didn't think the finish was up to snuff. By that I mean, the parts had a somewhat dished look (concave) about them. I checked this using a precision straight edge and a flash light. Sure enough you can see light come through in spots.
Anyway, I never really checked the tram on the mill, so I decide now was the time. Before I jumped into anything, I researched all I can about tramming. I found Hoss's videos very informative...Here's part #1
[ame=http://www.youtube.com/watch?v=40Q61UAnOTA]G0704 Tramming Part 1.wmv - YouTube[/ame]
I started by checking the spindle to the column, using the RDM method used in the above video. My drill rod measured 8". I started at the top...centered my "0" and moved down to about a half inch from the end of the rod
The spindle was out by .002 fore and aft. I needed to shim the front of the spindle.
The Mikini really doesn't have any place to place a shim, other than under the spindle. As the head is bolted directly to the linear bearings. So I loosened the 6 Allen bolts that hold the spindle in place and gave the spindle a light tap downwards. This gave me enough room to place a .001" shim between the spindle collar and casting. Also, the shim is only .250" wide x
.750" long....only about .250" is inserted into place..the rest is used as a handle
I rechecked the runout and all was good, as I had even readings on my dial test .
Now it was time to check the left and right runout. Here I was out close to .0045" out of true The shims were installed on the left side of the spindle. The best I could get was about .00003" runout at the bottom of the rod. Which isn't to bad for what I do.
Now it was time to tram the head to the table. Btw, I'm using the same setup as Hoss has in his videos.
I started out checking the front to rear. Here I was out by .004" , the odd part here is that it was leaning backward. Normally, you would think the mill would nod forward. Anyway, I loosened the six large Allen head bolts at the base of the mill ( I used a ratchet with an Allen wrench socket )....just enough to be able to rock the mill and place shims on both sides of the rear....about .0025" in this case.
After getting even readings front to back....I checked my left to right position...again I was out by .0045". I needed shims placed on the left side of the column. After all was said and done, the only spot with no shims was the front right corner ....
Being that I'm a rank beginner at this milling stuff, the above took me about 6 hrs to accomplish But, it was worth it..... I made the Mikini a bit better and exercised this old man's brain cells a bit