All I can say is that when I connected the Z axis endstop signal wire to ground on the controller, it rebooted. I tried it a second time to ensure I didn’t connect the wrong pins, and it rebooted again, so I didn’t do that again.
For those of us not versed in this (including me!), how about providing a schematic rather than reciting theory and experiences? Also post controller settings that need to be set and the corresponding values. Thanks!
These are my controller settings…
$0=10
$1=25
$2=0
$3=5
$4=0
$5=1
$6=0
$10=0
$11=0.010
$12=0.002
$13=0
$20=0
$21=1
$22=1
$23=0
$24=300.000
$25=1500.000
$26=250.000
$27=1.000
$28=1000.000
$30=1000.000
$31=0.000
$32=1
$38=0
$40=1
$100=79.980
$101=80.074
$102=80.000
$103=100.000
$104=100.000
$105=100.000
$110=12000.000
$111=12000.000
$112=6000.000
$113=1000.000
$114=1000.000
$115=1000.000
$120=500.000
$121=500.000
$122=500.000
$123=200.000
$124=200.000
$125=200.000
$130=715.000
$131=572.000
$132=50.000
$133=300.000
$134=300.000
$135=300.000
Note that the Makerbot-style PCBs have a different pinout than you’re using.
The diagram I showed earlier orders the pins V-G-S:
You seem to be using different-but-similar Makerbot-style switch PCBs, but your sketch shows S-V-G:
Miswiring them like that would cause all the trouble you’re having, by shorting the power supply directly to ground.
The pins in my Paint diagram aren’t in the same order as the actual board. They were arranged that way to keep the diagram clean. The pins are connected properly.
When I did my “ground to signal” pin test, the limit switch board wasn’t connected. I merely connected the ground pin on the connector to the signal pin to test the outcome.
I guess the others will have to help you, all I have is schematics, theory and personal experience with this specific controller, can’t do any more. If makerbot has changed the hardware or firmware, I’m clueless.
I guess you’re on your own. Good luck.
What I installed last night consisting of two micro switches & two resistors is working perfectly. The controller is expecting 5 volts or 0 volts, and my new circuit is providing exactly that. It may be a unique and unconventional setup, but it works perfectly and protects the equipment, which was the objective from the beginning. I’ve always been a “think outside the box” type of person. Just because I do things differently doesn’t make me wrong. There are more than one way to accomplish most things on this planet!
After installing the dual microswitches utilizing the voltage dividers at X2 and Y2 to the Z axis endstop controller input, I noticed that when the unit was first powered on, the diode laser would flash once. I swapped out the new setup with a single Makerbot endstop limit switch to the Z endstop controller input, and the flash still occurred. Puzzling…
I contacted Lasertree because I had checked with them about the compatibility between their K60 diode laser and the Makerbase DLC32 v2.1 controller prior to purchasing the K60, and they said they had tested that combination and that everything worked properly. I sent them everything possible about the configuration of the laser setup, and I’m awaiting a response.
While waiting, I investigated further. I plugged the new voltage divider switch setup back into the controller, and unplugged the Y axis Makerbot endstop switch, and the flash didn’t occur when the unit was powered on. I then plugged the Y axis Makerbot endstop switch back in and disconnected the X axis, and again, the flash did not happen. So there’s something peculiar happening when all three endstop controller inputs have switches attached.
Since the flash was only happening with three endstop switches attached, I decided to revamp the setup, installing a dual microswitch/voltage divider setups on both the X and Y axis. I also decided to add covers to dress them up a bit!
Now, when any of the 4 switches is pressed, a “Hard Limit” error appears on the controller display, and the unit instantly stops. The diode laser also does not flash when powered on. This project is officially complete!
I’ll post back when Lasertree responds when their findings…
It simply prevents a short to ground. You could have added it in series with the switch and skipped all the extra hardware.
You should not parallel X and Y switches. If your controller is running 1.1 GRBL or later, it can report which switch has been activated. Surely they did not defeat that possibility.
As @jkwilborn tried to tell you, the configuration on that controller board is not clearly understood. No matter who made it, it is still an electronics circuit based on TTL rules. I am sure other users of that board did not have to go to the means you show here to make it work.
Thanks for the info.
Don’t get me wrong, I am glad you got it working. One of my favorite sayings is, “I will take blind dumb luck over skill any day.” 
Well, I have to heavily apologize!!! I just finished cleaning up my workshop and came across the cord & connector I put together when I did my initial testing. I somehow managed to switch the VCC and S wires, so when I performed my tests, it was connecting VCC to G, not S to G, and that would explain why the controller rebooted. I did the same test on the Z and Y axis endstop controller inputs and it rebooted both times, so I decided that the controller wasn’t expecting to sense a fault when S to G where connected.
At that point, I examined the behavior of a Makerbot endstop switch circuit board on the bench using a variable DC power supply and a good quality digital multimeter. When the microswitch was not pressed, there was 5 volts on the S pin. When I pressed the microswitch, it showed .4 millivolts. This confirmed in my head that S should not be connected to ground, but should be registering a low voltage that it would be interpreted as “LOW” and create a fault condition. I performed the same test on another generic endstop limit switch compatible with the Creality 3D printers, and it showed .2 millivolts. This again reinforced my beliefs in how it should work.
I’ve incorporated Arduino Uno, Nano, and Mega microcontrollers into several projects, including two on my laser setup. I added a motorized platform to make it really easy to adjust the height when needed. I used the Two Trees CNC controller kit.
The two buttons in the center move the entire platform up and down. The other sets are used for the occasional calibration. The “Top” and “Bottom” buttons move the platform all the way up or down, using two limit switch circuit boards. I have a rotary tool for engraving the coated stainless steel cups, and also engrave a variety of objects of varying thickness, so being able to quickly adjust the platform height was been extremely nice. The laser head in the photo is my old 5.5 watt Two Trees head I started with. The new K60 has been sooooooo nice!
I also incorporated an Arduino Nano inside the enclosure I made that houses the DLC32 controller and the driver board for the K60 diode laser. The Nano monitors the signal to the K60, and automatically turns on the exhaust fan as soon as the laser fires. The Nano code module I wrote continuously motors the K60 signal, and waits 60 seconds after the K60 stops to turn off the exhaust fan, which is enough time to evacuate the cabinet of smoke and fumes.
For the platform circuit, I used two of the endstop switch circuit boards that came with the CNC kit. I never had the need to read the voltage on the S pins of these boards. I plugged them in, and they worked. Based on my experience with my Arduino projects, “LOW” was interpreted as a voltage below a certain point. From Arduino’s documentation:
So based on my experience, I had no reason to believe that “S” should be connected to “G”.
Again, I sincerely apologize for any confusion created no my part. I wanted to post this to explain why I followed the path that I did. I love designing and building things. I’ve gotten as much enjoyment out of building the new laser and cabinet as I have making things with the laser. I was a software developer for 42 of my 48 years working. I loved starting with nothing, asking appropriate questions, and then designing a solution that helped others. I started with an Atari 400, then progressed upward through PC’s, a Unisys mainframe in the Air Force, a PC based Unix system for 8 years, then Open VMS and SQL server for the last 25 years in the educational arena, support 40+ school districts. So, even with many years in the technical realm, it’s still sometimes easy to go down a rabbit hole!
Thank you to all who worked to set me straight!
Trust me, a lot of us have been there. Thanks for sharing the pictures. That is an impressive setup you have there!
Thanks Mike… Much appreciated…
