How to TRAM a CNC Machine: The generic model/vendor-agnostic method to describe the basic principles Introduction: A CNC machine, can only be as accurate - as it is Built. Therefore, during initial assembly (or subsequent adjustments) it is in your best interest to build the machine as square as possible. The following generic concepts apply to any machine type - we won't go into the specifics of how to achieve it on a per-machine basis - but rather want you to understand the concepts so you are aware of what may need careful measurement or adjustment to ensure your machine is as tram as possible 1) Square frame/base Make sure to square up the base assembly as exact as possible. 2) Perfectly flat XY plane: On most of our machines you have two Y rails sitting on some sort of base assembly. As the base of the machine, from which all other movable components attach - its important that this sub assembly creates a perfectly flat plane from which all the other axis can reference: This mean - that no corner is raised or lowered causing the frame to twist. Ensure the two Y rails (or whatever other substructure defines the base plane) are perfectly flat and true. 3) Perfectly Square Z / Uprights: Make sure that the Z axis / Uprights are perfectly square to the XY plane established in (2). If your Z axis leans forward or backward - your Z axis motion axis will also never be square to the XY plane 4) Gantry not rolled forward/back Make sure the Gantry beam is not "rolled" forward or backwards. It must also be perfectly square to the XY Plane. As on most of our machines the Z axis is solidly referenced off the Gantry (no forward or back lean adjustment in the Z axis itself) - you correct any lean in the Z axis by correcting the roll of the gantry itself, or the lean of the Uprights as in section (3). 5) Gantry parallel to the XY Plane Make sure that both sides of the Gantry are the same height above the XY plane - if one side or the other is lower than the other - your cuts will be deeper toward on side and cut edges will not be square either. 6) Router mount square in all directions With the knowledge that every axis is moving perfectly square in its X, Y or Z direction because you built/adjusted the entire frame to be square, the last thing to make sure of is that the Router mount itself is attached squarely to the Z axis. If its leaning left or right adjust it until the imaginary line through the endmill is perfectly square to the XY plane. Note only side to side adjustment is possible here. If its leaning forward/back - see sections (3) and (4) above
Well done Peter! A simple tramming guide for making sure the machines are square and true. This will be a great help to many building their first machines. Thank you
Just did all these measurements and my Lead 1010 works perfectly after moving it from my house to the new Shop. Just some minor adjustments to the router mount, along the X axis. Great article, thank you.
I finally had some time to spend getting the LEAD 1010 re set up after the failure, when I finished a made a few cuts of shapes and check the actual cut with the design, everything worked out spot on! with no end mill in stock, I did have a 0 flute and that is what I used! it did an amazing job in soft pine. Thanks
