CNC Machine Adjust and Fine Tune

As mentioned in the previous post, we recently added a CNC machine to the shop.  After viewing several tutorials and playing around with the software, we were off to make some things happen! For some reason, I expected to take it out of the box and start cutting and carving perfect objects right away.  Did not happen!

I looked around the shop and realized that out of 10 pieces of machinery, there were two that I did not have to tune before using.  They were the lathe and the planer.  All the other tools had to at least be squared.  If the unit has a table top, it had to be squared.  Saws have to be adjusted to cut square to the table.  The bandsaw has all kinds of adjustments.

Well, out of the box the CNC cut deeper on the left side than it did on the right.  I put the square on the table top and found that the top was bowed upwards in the middle, it dropped slightly on the left and right.  The top is made of multi-track t-track.  I took the top off and disassembled it.  I rearranged some of the multi-track pieces several times, but could not get the top level. 

After examining the multi-track pieces, I discovered that the edge where the next piece joined was not square, it had a small angle on it.  So every time I tightened the table top to the bracket on the bottom, it would pull the top in a bowed shape. 

I finally gave up and decided to "redneck" it by inserting shims at each corner and two other low spots.  The result was a perfectly flat table top.  I used plastic pieces cut from small retail packaging, you know, the kind you need tools to get in to. 

I put the top back on the machine and made a couple of cuts.  It was still cutting a little deeper on the left.  I loosened the table top brackets that connect it to the frame on the right side and inserted shims there.  After a few changes, I got it to cut evenly side to side. 

Finally, I used a sheet of plywood to cut a line around the perimeter.  This line came out just right.

The entire process took the better part of the day, but we now have a machine that cuts or carves perfectly flat.  We are looking forward to incorporating it into some of the products we offer.  If you see any items over at Lucy Hardware that you would like personalized, just drop us a line.