Centroid Community CNC Support Forum

I am working on upgrading my Sienci Labs altmill cnc router (MK2) to use a Centroid Acorn and I'm having issues getting the homing sequence to work on the Y axis (X and Z work fine). The Y axis controls the gantry and has master (Y1) and slave (T2) stepper motors.

I am tying to get the Y axis to auto home with hardware pairing and relay auto squaring, but I've yet to figure out what is the problem. It starts to go through the process, but things go awry at the point where the slave axis home switch is activated. It's hard to tell what exactly is going on, but it's like the slave axis (Y2) is trying to move after the the home switch is activated, but the message on the screen from the Acorn says it is moving the master (Y1) stepper (it's not).

I have four proximity switches on the machine and they did not like being wired together (X, Y1 and Z) so I have them wired individually on inputs:

5 = X home
6 = Y home
7 = Y slave home
8 = Z home

I have the auto squaring relay for hard-pairing on output 1 and everything is wired as in diagram 15200. The relay does change state in the homing process.

The router has 57-76 integrated Nema 23 closed loop stepper motors that can handle 24 VDC signals, so I have them wired to the Acorn terminals (not the 25 pin Dsub).

The only kind of odd thing is the altmill is designed so that X and Z are "normal" and their home position is at typical around 0 (X can go approximately +49.000" from there and Z can go approximately -5.000") whereas Y home is set at approximately +49.000" and can travel back to somewhere around -0.200".

I am wondering if the macro "homing_relay_square.cnc" can not deal with this setup?

Attached is a report. Please disregard the spindle, probe, etc setup as I have not gotten that far yet. I'm guessing it's something simple that I'm missing, but I'm kinda stumped.

Any help is appreciated.

hello.

what make model axis drive/motors are being used?

typically " integrated Nema 23 closed loop stepper motors" would be wired to the DB25 using a BOB, we've seen plenty of them that say they are good with 24 vdc but are not.. so sure thing to get things running well is to use the DB25 connection as seen in the schematic you mention.

"The only kind of odd thing is the altmill is designed so that X and Z are "normal" and their home position is at typical around 0 (X can go approximately +49.000" from there and Z can go approximately -5.000") whereas Y home is set at approximately +49.000" and can travel back to somewhere around -0.200"." you can home out in any direction you want as long as the home switch is at the end of that direction! set the direction to home in the Wizard homing menu.

can you post some photos of the machine, picture goes a long way in helping us give you good advice.

also, if you can i'd recommend wiring all XYZ home switches into one input Defined as "HomeAll"
the slave is of course on "SlaveHomeInput"
as seen in the axis pairing and squaring manual. page 14 (starting on page 12)

I basically have the same configuration on my SB Desktop Max, and I also had what sounds like the same situation upon the first homing. Make sure that your auto square relay is breaking the step signal to the right driver. It should be disconnecting the slave. Sounds like it is disconnecting the master.

Like Scott says, you may have crossed up the slave and master switches or motors. Here is how I locate the motors and sensors for a Y gantry:

Yep, Sword & Gary...I had the master & slave home switches mixed up. It works now, but I still need to make fine adjustments to bring it into square. Thank you for the assist!

cnckeith, do you have any proximity sensors you recommend? I did try wiring them in series as is depicted on page 29 of the "paired_axes_user_guide", but as the red text on that page states: NOT ALL PROX SWITCHES LIKE TO BE WIRED THIS WAY, your results may vary. This is an input saving technique that works with some types of Prox switches but not all.

It would be nice to free up some of the inputs.

I'll post photos of the machine and motors later today or this weekend.

Thank you all!

Most will say that you should always use NC proximity sensors, and I get it, but in the "HomeAll" situation and to save on outputs, NO sensors are the answer. And really, if one or more fail for any reason, how hard is it to trouble shoot them?

The other option is to use a 4 channel relay to change NC/NO...https://www.amazon.com/dp/B00LW2G7V6?re ... in_title_1