So I’ve been getting this random homing issue where the Z homing sensor would seemingly stop working for no apparent reason. It would work when I manually checked the sensor using a steel straight ruler, I could see the red light go out on the sensor and the light would go from green to red on the F1 screen. But whenever I tried to jog or home it would not detect the little arm on the z slider.
After several hours of troubleshooting and research, and testing different positions of the little metal tab manually by unscrewing it and manipulating it by hand, I couldn’t figure it out. After a bit of time, it would always start working again for no apparent reason.
Then by accident today, I happened to have the z axis all the way up in the home position and the tab was in the sensor with red light on, and I reached across for something with my arm and I noticed the light went off. I pulled back and the light came back on. I did it again and once again the light went off. I figured out the shade from my arm was helping the tab on the z axis to trigger the sensor. I always assumed the sensor was some sort of metal inductive thing that detected the metal arm. Apparently it’s a light sensor though. In the afternoon, when the sun hits the front of my house, the sun must hit that sensor at just the right angle that the arm isn’t blocking the light or something. I closed the garage door and problem solved.
I’m going to design some sort of shade to 3d print that I can attach to that homing sensor bracket. Just wanted to share though in case it helps someone else.
Yep, after a couple of years with my Elite I ran into the same thing yesterday morning. The now lower sunlight at dawn hits my machine at just the wrong place and I get “Z motor alarm”. I noticed the sun on the sensor, so I rebooted holding my hand to shade the sensor and it worked.
I too 3D printed a little blind, which works great.
This is awesome idea for a fix. I have a 3d printer. Didn’t even think about doing a simple fix like this. Just been shutting the garage door that time of day. Thanks for the file.
thank you Jim. I will let you know I had the same problem yesterday even with covering up the sensors and turning off the overhead fluorescent light. I kept getting closed stepper errors, over and over again. then suddenly I got it to work, and I still don’t know why, because the shading clothes were completely off. There is some sequence of events you need to follow to successfully home that I have not figured out yet. right now i am fully immersed in getting my 4th axis lifting to work and register properly.
Hi, Jimmy, sorry for the long delay. The light shade you sent works great for the z axis, but not for the x and y they need to be completely different. I think you have the gen two now and I hope you are making some for it. please let me know what I owe you for the z shade and if you send me your address, I can send you back the other ones. I will keep two just in case I do something horrible lol
Hi, I made 20 of them…I thought they might fit all the sensor, but like you said…only good for the Z axis. Don’t worry about $$$, they took about 20 min to print 20 of them and I kept 10. No need to send anything back . Once I get my spoil board on and get the wiring tidy I might try and design a cover for X and Y. I will let you know for sure. I was able to do a short test run of the Jtech 34 watt…I’m looking forward to being able to cut and engrave some cool stuff with it. Here is my corny video
LOL that is exactly how my machine looks too stuff all over the place. I will be making my own video soon with the bells and whistles that I have installed so far. no laser yet. and i am not switching over the ATC till the next iteration of the software.
I recently upgraded my machine with the Redline Uprade. I was having the random Z axis sensor error during homing. I thoght it was a loose connector as I wiggled it and I saw the tiny, and I mean tiny, red led light up and then go off when I wiggle the wire. Turns out my hand was blocking the light, but I didn’t catch that at the time. Same problem off and on for a few days. I switched the sensor with one of the Y axis ones and got the same problem. Bright late afternoon sun was coming in through my shop window and I thought I saw that the tiny led was on. Got closer to check and again used my hand to shield and I saw that it was off. Moved away, cleared the error, moved the Z down 20mm, rehomed, and same blasted error. Anyway, took me awhile to figure it out, and I couldn’t test my black tape fix as the sun had set more. Today I fired up the machine and it homed as normal. Tried it with the carriage at several positions on the table and the bright sun glaring through. All worked well.
I do have an outdorr roll down shade for this window, but we have been having strong winds here, in the East Bay, Ca., and I dont want it flopping around.
I’ll download and print your part as it looks way nicer than black electrical tape.
I also ran into the same problem a few weeks ago and after discovering it was a light issue, Onefinity sent me a file to print an IR cover. It’s very similar to the one Ian posted. This one does not screw in, just snaps on over the IR sensor.
. Once I get my spoil board on and get the wiring tidy I might try and design a cover for X and Y. I will let you know for sure. I was able to do a short test run of the Jtech 34 watt…I’m looking forward to being able to cut and engrave some cool stuff with it. Here is my corny video 
