Hi!

I’ve just trammed my Sieg X2 cnc converted mill.

I’ve first removed the collumn and trammed the head to the collumn the best I could, by using the rollie’s dad method.

I then did the stiffener plate on the back of the collumn so I could correct the forward tilt the collumn had the best I could.

When using an indicator with it’s magnetic base attached to the spindle, and with the X length centered in the middle of the table (on 0 marking) , I turned it around the 4 corners and got 0 and 0 in front and back borders of right most side and 0 and 0.01mm in the front and back of the left most side.

There are two things I don’t understand:

First is: when instead of rotating the indicator (attached to the spindle with its magnetic base) around the table, where I get all four corners mostly right, if I adjust the indicator below the spindle and close to it’s center (as if it was an endmill) and I don’t move the indicator, but move the y forward and back to the edges of the table (12mm I think) I still see 0.03mm of forward tilt . Why this happens?

Second is:

When doint a test cut with a flycutter on a 55x55 mm aluminum block, on a vise in the center of the X, I noticed that the cut is clean, from left to right the needle of a test indicator remains still, but from front to back there’s a continuous inclination of 0.02mm in this 55mm block. i didn’t notice any concavities, it’s a smooth inclination.

I set the flycutter diameter (70mm) to pass over the complete length of the part, close to 140mm.

I got a ((((((( pattern untill the “back” of the flycutter, when the front had already left the part, started doing a ))) pattern, but as if it was another pass, removing that previous ((( pattern. So the “front” removed a little bit of material, than the “back” started removing again. Why did this happen? Shouldn’t the front and back pass of the flycutter be on the same level? Do I still have some left/right tilt? But if I have some LR tilt, why the indicator on the piece from left to right keeps at the same level?

Thanks for reading!