I set a feed rate of 16 ipm in Vcarve and then discovered (after it broke a 1/16 bit cutting brass) that the Onefinity controller had reset the speed to 35 ipm.
The same thing happened with a toolpath set at 32 ipm – it got changed to 35 ipm.
Why is this happening? Is 35 ipm the minimum speed of the machine? How do I fix it?
Thanks!
What controller? Masso or Buildbotics?
With BB I went 5 ipm yesterday. Also never seen it increase federate.
Masso has feedrate override doesn’t it? have you got it set above 100%?
On the original invoice from 2021 it is called a Onefinity Controller. It is a black box with absolutely no identifying information on it.
The touchscreen says it is a CNC Controller v1.0.8 which I assume refers to the software version.
Ok, it is the original Buildbotics controller running 1.0.8 version software.
I had the same thing purchased in 2021. So I can say for sure there is no lower limit on the feedrate.
I would first check that the gcode that Vcarve is making actually has the feedrate you intended it to have. For that you are going to have to open the file in a text editor and search for “F” and see what numbers you get.
I would search for F35 as well,. If you find that then the problem is with Vcarve.
Really helpful Chris, thanks. Examples from the search apparently defining X and Z speeds (oddly, no equivalent syntax for “Y”):
Line 12: G2X-0.0312Y0.0549I0.0086J0.0300F35.0
Line 256: G1Z-0.0417F8.0
The problem was VCarve. After I ran a test in hardwood I reduced the feed rate in the tool database for the “Brass” definition for the bit in question. I checked that it was right in the project toolpath by looking up the feed rate found under the “select” button, not realizing that under the “edit” button the old rate was unchanged and that that was the one that the machine would follow (Grrrr!).
Glad you figured it out.
Just so you know the F value( as in F35 ) is modal and applies to all feed moves. That is moves that happen after a G01, G02, G03 and a bunch of lesser used others.
So X Y and Z will all travel at that federate whether they appear on that line or not and any line after that - until another F value is encountered.
When a G00 is encountered ( rapid modal ) it basically sets the feed value to maximum until a feed move is encountered again. Then feedrate goes back to the last used F value again.