This is my first forum post, I did use the search function but could not find an answer to my question.
So I have flattened my wasteboard with a 2" surfacing bit (4 carbide insert cutter), which went well but I made the following observation that I cannot understand:
On the left side of the wasteboard I feel no ridges after surfacing but the ridges start to appear after the middle of the wasteboard and get bigger the further away the cutter got from the middle.
I almost seems like the maching is more out of tram on the right side than on the left side.
As an fyi, I did not attempt to tram the machine yet, as I wanted the wasteboard flattened first.
the Onefinity CNC machines are gantry-style machines. The first step must always be 1. ensure your machine is accurately rectangular (“square”) and coplanar (“not twisted”). Step 2 is flattening the wasteboard and adjusting perpendicularity of motor axis to machine bed (“tramming”) is only step 3+4.
Yes, spindle axis is less perpendicular to machine bed on one side (more “out of tram”). Front-to-Back Tramming can be adjusted separately at each X axis end. See “Tramming” above, but conserve order of proceeding. First step, prior to tramming and surfacing, should always be ensuring a machine with coplanarity adjusted (“not twisted”).
Coplanarity (“not being twisted”) means that all four machine’s feet are in one geometrical plane. You adjust it by altering the height of one machine foot (three feet are always in one plane (table with three legs can not wobble) e.g. with Any Surface Leveling System Feet of QCW frame or with height-adjustable Casters under the table’s feet. Crossing fishing lines method to adjust it works well).
I will only add that after tramming your x axis gantry on both sides there will still be a minimal tramming error in the center due deformation caused by the weight of the spindle on the tubes. A stiffy will help but not completely eliminate this issue.
I just wanted to say Thanks! I had no idea about the coplanarity setup - although it does make perfect sense.
Did the fisherline test and had to shim one of the feet (I chose back right) up by 2 mm. Now I don’t get those marks anymore.
The machine seems to be in good tram front to back as well, as I cannot really see any ridges after surfacing of the wasteboard with a 2 inch cutter head.