Centroid Community CNC Support Forum

I've been running my homebuilt router with Centroid Acorn for awhile now and really am loving it...I decided to add a 4th axis to be able to do rotary machining, but I can't figure how to home the "A" axis...I have home and limit switches for X,Y,and Z axes but not the A, so when I press cycle start to home all, X,Y,and Z run to the home switches and A just spins...I've read, searched, and changed settings to find a solution, but haven't been successful...any help would be greatly appreciated.

start by posting a fresh report.zip so we can see your configuration setup.
and a photo of rotary would be nice to so we can see if you have a home switch installed or not.

Thanks cnckeith...I will send a report as soon as I actually get my 4th axis (end of this week) installed...I've been trying to get everything ready by using a spare stepper motor I have to simulate the 4th axis so I would not be wasting a lot of time...there was no mention of limit switches when I ordered it.

most of my 4th axis installs do not use a physical home switch. (typically there is no such thing as a limit switch on a rotary axis) i set it up to just simply "home out" right where it is sitting. (M26/A) see this doc for more info on custom home programs. https://www.centroidcnc.com/centroid_di ... amming.pdf

there are about 10 different ways to home a rotary axis but the most common is to home it right where it is sitting. no switch needed.

others prefer to line it up with a visual mark and home at that location
others will send it home before powering off so when they turn it back on it homes at the same spot.

what method you end up doing all depends on the application and what you are trying to accomplish.

For when I use my 4th axis, I have disabled the 4th axis homing in the .HOM file, otherwise it will sit spinning forever. As Keith says, you can set home manually.

Thanks cnckeith and Muzzer...I'll look into this over the weekend

As an alternative position, and since the rotary axes I have built are often used for furniture parts that have rectangular faces, often with mortices, I almost always use a homing sensor. This is accomplished (usually) by replacing one of the set screws with a square head bolt that has a bit off length and then making a bracket for a prox sensor.

Heres a screen grab from my "Acorn Rotary" videos showing one mounted:

Gary Campbell wrote: ↑Thu Jul 13, 2023 8:59 am As an alternative position, and since the rotary axes I have built are often used for furniture parts that have rectangular faces, often with mortices, I almost always use a homing sensor. This is accomplished (usually) by replacing one of the set screws with a square head bolt that has a bit off length and then making a bracket for a prox sensor.

"i may not always use a homing sensor but when i do........"

Hey... I use that sometimes....

Thanks Gary, I'll keep that one in mind