Centroid Community CNC Support Forum

I have a Bridgeport Boss5 running Linux CNC and have not been able to get rigid tapping to work with my machine in both high and low range, is this a configuration that the acorn supports? Mainly the controller needs an input to know if it is in high or low range and then change the direction and scaling of the spindle encoder for the tapping to work.

Yes, the Centroid software with the ACORN board can handle Rigid Tapping. Please check this link out viewtopic.php?f=60&t=1129&hilit=rigid+tapping.

Can it be configured to work in both high and low ranges with the direction change I mentioned?

yes you can rigid tap in either range..just as long as the spindle encoder is directly connected to the spindle at a 1:1 ratio.

and yes you can use an input to let CNC12 know that you have switched into low range.

there is no such thing as encoder scaling.. the encoder is connected to the spindle at 1:1 ratio so it doesn't matter what gear range the machine is in, the encoder always reads actual spindle rotation.

fyi.. rigid tapping in low range is not a common way to go. if you are tapping a 2" hole that requires such torque, i'd recommend going with threadmilling which is included with the Acorn CNC control kit software.
rigid tapping in low range introduces alot of mechanical momentum and inertia to the process, one of the secrets of rigid tapping is to use high range for quick turn a rounds and minimal spindle overshoot.

The 1:1 is the issue for a Bridgeport install, it is easy to mount the encoder for 1:1 in high gear but very difficult to get the encoder mounted so it is 1:1 in both low and high gears. It looks like I may have to settle on tapping in high only, maybe not such a bad thing after all. As for the high gear/low gear input can it be configured so forward and reverse functions properly in both ranges, the Bridgeport needs forward and reverses switched when in low range? Thank you for answering my questions quickly ,I think I will be ordering an acorn to tryout.

Yep!))