RichAuto B11E PulseEquiv default value outside of limits.

[g]

I was doing some testing and made some 2" squares with conventional milling.  I noticed the X axis was off slightly (-0.04"), but the Y axis was accurate. I repeated the cuts with various cut depths and speeds, but the results were the same, roughly -0.04" on the X axis on each piece.  My bit was measured with calipers and those values were used for the tool in Aspire. If I do the same 2" square with climb milling I get the exact opposite and the dimension is off by +0.04" on the X axis, but still accurate on the Y axis.  Speeds/Feeds I tried were between 10k-14k at 15ipm-30ipm.  Depth of cut tested was anything between 1/16" to 1/2" on a compression 1/8" bit with the same results/variations.  

The I2R Manual suggests checking the PulseEquiv setting, but when I attempted to adjust the value it errored and said the new value was outside the upper limits.  The default value on the RichAuto B11E controller for PulseEquiv is 12,560.000 and I attempted to change it to 12,500.000, but the error said it was outside the limits and would set it to the limit which was 10,000.000.  After the value changed it forced a reboot.  I rebooted everything.  Upon booting up, I homed all and the X axis zipped across the gantry blowing past the limit switch due to the speed and smacked into the side plate on the gantry.  Clearly 10,000 is not an appropriate value.  I reset the config back to default through the menus, rebooted, and things were back to normal.  Am I just misunderstanding something with the PulseEquiv values?  Is there something else besides PulseEquiv settings that may lead to a consistently off measurements in the final product on only one axis?

[Chad]

I believe that you are misreading that pulse equivalent....the screen displays the word equivalent, stopping with the L...which is often confused for a number 1. The correct setting will be 2560.00 for that generation of machine.

However, there are numerous other factors like bit wobble and the actual bit diameter.


Measuring the bit with calipers is a good step but not extremely accurate. A better option would be to use the bit to cut a shallow slot and then measure the slot...which will account for both bit diameter and any wobble.

One additonal note is that compression bits often encounter more deflection than a standard 2-flute spiral...especially if its a 4-flute compression bit, which will also may have trouble with increased noise.

[g]

Thank you very much. I’ll try the other methods of checking you listed and if all else fails, then I know what values to use for adjustment. Greatly appreciated!