I received my AltMill the first week in November 2025. After setting it up and and adjusting the sensors according to the sensor troubleshoot video, I realized that the Y1 sensor will not set. I can run it all the way in and all the way out and the light stays on. I made sure the soft alerts are turned off before attempting the adjustment but when I touch the sensor wires behind the housing, the light goes on and off. I also notice that after homing it, the Y1 motor continues to run for about 30 seconds and the light on the sensor is on then the Alert 14 appear.
I still have not gotten to where I am able t use the GSender Spoilboard program to surface my spoilboard, yet. I also notice that when every time I home the gantry, I get different reading for my Y Home position, even if I Zero it out before jogging the spindle around. There are other issues but that will be for another top. I even tried $RST=$ several times but still keep getting erroneous home values.
@johna58 If the light on the sensor comes on and off simply by touching the wire, I’d assume you have faulty wiring or sensor. You may want to double check everything. Also try swapping Y1 and Y2. If all looks good, a call to Sienci may be in order. They are closed between Christmas and New Years so don’t delay calling them.
I am going to assume that you have the integrated sensors bump stops. I just had this problem with my ALTMILL. The problem turned out to be that the Left and Right sensors were not in alignment. Jog your machine all the way to the back until it faults out. then compare the distance from the sensors on both the right and left side. in my case there was a larger gap on the right side. The solution was to remove the lock washer on the left side. As soon as I did this all three axis’ homed perfectly.
I do notice a small gap on the left side. I measured it and it is about 1 to 2 mm. With the controller power off, I am able to push the gantry back against the bump stop. When I jog the gantry forward (does not have to move far) then back the gap on the left side returns.
I will take your recommendation to see if it makes a difference.
I was able to push the gantry back as well and even removed the bolts from the gantry to make sure that they were both aligned. But as soon as I jogged it back it would hit the left axis and not the right. both the sensors have to be exactly aligned so that both sensors trigger at the same time. What I did was jog it all the ways back until it hit the hard stop. Then I found that the right side had a gap and the left was against the gantry. As soon as I removed the washer on the left it homed correctly.
I’m not 100% certain but I don’t think that’s the case. From what I understand, Y2 is only used for squaring, not homing. I think the gantry was hitting the Y2 bumper stop before Y1 could be triggered. By removing the washer on Y1, you moved it forward and it could now be triggered.
But I could be wrong. I’m just basing that from what I’ve been reading on this forum.
I want to thank all for contributing your insites to my dillema. I realized that I relied on the video only when I built my Altmill. After going back and reviewing the documents and listening to all of you, I realized that I installed the Y-sensors outside of the bump stops. Once I corrected that (reading the instructions), I was able to home properly. I now have a few more challenges that I will post in the other groups approriate for the issue.