I have been using the Wrapped Job Setup in V-Carve Pro to establish the diameter of the cylinder and size of my jobs (engraving a cylindrical object), but when it comes to cutting the pockets the width and length of my jobs are inaccurate.
Let's say the job is .040" wide and .5" long. When the cut is finished, it will be .150 wide, and .575 long. Keep in mind that this cut is being made across a cylinder being turned on an A axis.
I have a Chinese USB CNC 6040 with an A axis that is using Planet CNC Software, this A axis is mounted on a leveled piece of iron with a dead tailstock that rolls about the objects center axis. The A axis is also calibrated according to inches moved across each 90* rotation ( if I tell the A axis to move 1", it rotates 1"). The X,Y,Z axis calibrated according to inches moved over 4 inches. At first I thought maybe it was my calibration that was messing with the cut, but after running calibration tests over and over again it seems to be something else in my configuration.
I use Mach 3/2-WrapY2A ATC(inch)(*.txt) post processor. This wraps the Y axis cut path across the A axis. I do not understand much more about it than that. I have it installed on my machine, but V Carve seems to handle it's integration well enough for me to use it through their GUI.
Anyways, when I save the toolpath, I am prompted with a window titled "Wrapped Output", I am asked to establish the diameter of the cylinder again. This diameter has text underneath it that tells you that the Model is wrapped X degrees around the cylinder, according to the diameter entered / diameter previously entered.
If I feed in the exact diameter of the space I am trying to engrave, the model is wrapped 360 degrees. When this file is run on my machine, the A axis spins dozens of times about its axis. If I feed in a diameter that is 4x bigger, it will say that the model is wrapped 90 degrees around the cylinder. This often comes close to where I intended, but fails to be precise enough to be considered functional.
I have tried to make accurate cuts for weeks, but cannot seem to figure out the issues.
If you are privy to this problem please let me know what factors could be at play here. I know a piece of software like V-Carve Pro has precise and dependable functions, and I have calibrated my machine the best I know how.
I apologize if this topic has already been covered on here and would appreciate being pointed in the right direction if there is already a discussion on this topic.
I'll just go back to breaking cutters.