TnT CNC: March 2014

This is going to look like a lot of effort but please take the time and read my suggestions so that you are able to start milling with minimal issues. There are probably several approaches to squaring but this is what worked for me. Like GrandPa Elwartowski used to tell me when I worked for him at his shop... You can't re-drill the hole after you drilled it, so make sure you get everything lined up correctly to start out, then the next 10,000 holes will be a cinch to drill. The thought of drilling of 10,000 holes didn't make me happy but he was right about how well everything worked after getting everything squared up.

Here are some of the things that I needed to do:

1) Start out with everything loose. Only the top Vwheels should be tight.

2) I haven't used any locktight and don't plan on doing so until I get to a point where I feel the machine is usable whithout further modifications. I am very close to that point now.

3) the bottom Vwheels should be adjusted so that a small piece of paper fits between the rail and the wheel. This will probably leave a gap when the paper is removed. This is ok because you need everything loose to square things up.

4) also make sure that all 4 of the Y rail end plates are loose. Snug is Ok.

5) the y rail end plates should not be tightend to the bottom 1 inch square rail that holds the platen (i.e. Waste board). Ideally both of the waste board rails and waste boards should be removed for the next step, but if you can ensure the Y rail end plates will not haing up on the 1inch rails then proceed.

6) you should position your assembly ( without 1inch rails and waste bords) on a flat surface. This truly means flat, so if your flat surface is out by let's say 10 thousands then your setup will also be out. Note you can compensate later but it's much tougher after the fact. Think, table top, counter surface or anything that you can put a straight edge on and not see any gaps under the straight edge. Remember to check the straight edge in two different directions.

7) ok, with the assembly on a certified flat surface you are ready onto start the squaring process. You need to measure down from the top of the rail to the surface in 4 separate locations close to the end plates. Those measurements need to be as close as possiable to each other ( 1 to 2 thousands is great). Once you are convinced that all 4 measurements are equal then tighten all 4 Y rail end plates. After you tighten then check your measurements again. Keep doing this until you get it right as you will be very thankfull in the end.

8) Now that the 4 end plates are square to your flat surface, you can put the 1 inch rails and waste board back on the CNC.

9) after putting the waste board back on the CNC re check the height of the Y rails to the surface of the waist board. If your 4 separate measurements are the same of within a couple of thousands then proceed. If not try adjusting the waste board rails. DO NOT TRY TO READJUST THE END PLATES AT THE Y RAILS, OTHERWISE YOU WILL NEED TO START ALL OVER.

10) NOTE for this step only the Top Vwheels of the gantry are tightened and the bottom Vwheels can be turned easily by hand without moving the gantry. With the gantry placed somewhere near the center of the X rails, measure the distance between the two X rails front and back (you should measure as close to the Vwheels as possiable). Write your measurement down. Move the gantry toward one end and take another set of measurements then do the same at the other end. You should now have two measurements for all three locations on the X rails center, left and right. Take all three sets of measurements and determine if they are close to each other, if they are then that is your measurement that you should end up with after tightening the end plates for the X rails. Re-measure after tightening and repeat until measurement is equal as you move the gantry from left to right.

11) there really isn't any adjustment for the height of the X rails from the milling surface, however measure down from the X rails at both ends and determine any difference. A couple of thousands out is great, anything more and you need to hunt where your are out.

12) now that you have the Y rail end plates squared along with the spacing between the X rails, you need to adjust the bottom V wheels on the Y and X rails. I adjusted the non concentric nuts until I could no longer turn V wheel by hand then I backed off the adjustment very very very slightly ( about 1 degree of rotation). Do this for all 8 of the bottom Vwheels on the Y and X axis.

Now try moving the gantry around (left to right front to back) everything should move smoothly. If not start looking for problems with Vwheels or rails or something else.....

13) Now for the Z axis. This time you start by adjusting the Vwheels first. After doing so take a machinist or carpenters square and place it on the wast board 90 degrees up to the side of the black mounting plate holding the grinder. You need to adjust the Z rail from the back until the black plate is square. If you skip this step your end mills will only cut on one side and not the complete end. This will make your finish flat milling not so flat. At this point you should be able to easily turn the Z screw. By hand and move the z axis up and down.

14) using the machinist square check everything you an reach from the waste board. This includes the side Y rails, the X rails and everything you can get to on the Z axis.

BTW sending you some stuff (tools and jigs) by UPS to help you with your set up.

Before moving on to step 15 you can always call me and Bi#{[].

15) install the belts ( I will add more info on this step later).

16) Next is the wiring!!!