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LMS high torque mini mill tramming issue

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  • LMS high torque mini mill tramming issue

    I just got my high torque mill from LMS friday. I finally got it set up and bolted to the table. I am ready to start runming it so today I started trying to tram the head...well, I've run into a problem. I cant adjust the nod on the mill, only the side to side. I'm afraid it is way out, and I'm not really sure what I can do. There is no adjustment that I know of.

    I'm talking about at least 1/16" out.

    What should I do?

  • #2
    Originally posted by J S Machine
    What should I do?

    Contact the machine supplier Monday for tech support. If they can't fix it crate it up and send it back.

    Seems odd that there is no adjustment for nod...
    "The Administration does not support blowing up planets." --- Finally some SENSIBLE policy from the Gov!

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    • #3
      Completely tear down the machine and clean and be burr everything. I found paint, chips and crap everywhere. I added a rear brace to my mill while it was apart. I got .004 in a 6" circle on my mini mill front to back and .000 side to side.
      I duplicated this brace:
      http://www.hossmachine.info/images/c...01_800x600.jpg
      Last edited by Bmyers; 08-28-2011, 10:01 PM.

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      • #4
        Originally posted by Grind Bastard
        Contact the machine supplier Monday for tech support. If they can't fix it crate it up and send it back.

        Seems odd that there is no adjustment for nod...
        It's just the nature of the beast with these particular benchtop mills I guess. they are designed to move side to side, but the nod is fixed amd should be pretty close. I'd be happy if it were within a few thousanths, but it is way further out than that.

        Somebody else suggested shimming it, but I'm not sure. I could deal with that, but I'm not sure shimming will fix this issue with the amount it is out.

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        • #5
          You place shim material under the base of the post. I use Mylar sheets.

          Here's a short vid of how I test tram on mine:
          http://www.youtube.com/watch?v=ZfioLDhBNBQ

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          • #6
            Originally posted by Bmyers
            Completely tear down the machine and clean and de burr everything. I found paint, chips and crap everywhere. I added a rear brace to my mill while it was apart. I got .004 in a 6" circle on my mini mill front to back and .000 side to side.
            I did take the column apart from the base, and stoned the circular mating surface, as well as the piece that is bolted to the base with the bolt through it. I found exactly what you said you found..not a deburring tool in that factory, and overspray like crazy. However, my efforts didn't help much.

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            • #7
              From what pictures I could find of that mill, the circular part that the column bolts to is mounted to the base with one bolt each side. Sounds like you've had that off and cleaned those mating surfaces-

              That's the start, but now the shimming would be done, either in front of those bolts, or behind them. Which way is the nod- if the column is leaning towards the front, the shims would also go in front of those bolts, and vise versa. There's not much length to the contact area there, so whatever shim material you use is going to have a decidedly measurable effect. Can't hurt to experiment. Don't crank the bolts down like a gorilla- once you place some shims, the circular piece won't be in full metal contact with the base, and you don't want to crack those feet.

              In any event, first know the direction of the nod, then place an equal thickness shim on both sides in the same location (front or rear of the bolts). You will see a change in the nod. Once you determine what thickness eliminates the error, you can use some filler to fill the gap that will be left, keep the shims in place, then bolt it down snugly but not overly tight. When the filler has cured, you can put a bit more torque on the bolts. As I said before, there's not much length to the contact area there, so even a 1 thou thick shim is going to make a very measurable change in the nod. Do some experimenting- it certainly can't hurt anything, and you'll have some experience in aligning your mill. At the worst, you just put the bolts back in without any shims and take the thing back-
              I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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              • #8
                How did you measure the 1/16". The column may be angled on the base, or the head/spindle may be angled in the column. You need to know which before you attempt any correction.

                Correct procedure is:

                1. check the column ways are square with the table surface. Adjust as necessary.
                2. check the spindle rotatational axis is square with the table surface. Adjust as necessary.

                You can't do 2. before you have done 1.

                Phil

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                • #9
                  Originally posted by philbur
                  How did you measure the 1/16". The column may be angled on the base, or the head/spindle may be angled in the column. You need to know which before you attempt any correction.

                  Correct procedure is:

                  1. check the column ways are square with the table surface. Adjust as necessary.
                  2. check the spindle rotatational axis is square with the table surface. Adjust as necessary.

                  You can't do 2. before you have done 1.

                  Phil
                  Very good point, You need to figure out where to shim before you shim.
                  You could even end up having to shim both.. maybe even in diffrent directions.
                  Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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                  • #10
                    This procedure applies for both the x and y axis. You need a cylinder square or at least an angle plate (for checking 1. or you could use a precision level) and an indicator. You can't disturb the 1. adjustment when adjusting for 2. You have to shim the head on it's carriage, if it has one. If it hasn't then you are kinda stuffed and need to work out a plan B compromise.

                    Phil

                    Originally posted by philbur
                    Correct procedure is:

                    1. check the column ways are square with the table surface. Adjust as necessary.
                    2. check the spindle rotatational axis is square with the table surface. Adjust as necessary.

                    You can't do 2. before you have done 1.

                    Phil

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                    • #11
                      I think I found a good starting point.

                      http://homemodelenginemachinist.com/...p?topic=6007.0

                      This details what has to be looked at.

                      Looks like I'll have some rebuilding to do

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                      • #12
                        That is an excellent article and reveals the real weakness of this design - it is not easy to align the head to the post. I had not seen this one prior, so thanks for dredging it up.

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                        • #13
                          Thanks for the all the info in this thread - it is really timely for me as I just recently acquired a mill and need to figure out how to tram it.

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