ich habe die Suche bereits benutzt, konnte zu meinem Problem jedoch keinen passenden Thread finden.
Ich habe meine MPCNC mittlerweile vollständig aufgebaut und sie funktioniert soweit auch. Der Arbeitsbereich beträgt 600mm x 400mm x 95mm. Es wurden NEMA 17 Motoren mit 59ncm verbaut. Angesteuert wird die Fräse über einen Arduino UNO mit CNC-Shield V3.00 und DRV8825 Treibern. Als Kabel zu den Schrittmotoren nutze ich Standard 1,2m Schrittmotorkabel,
Nun zum Problem:
Sobald ich Endschalter am Shield anschließen, passiert es, das sie ohne Kontakt ausgelöst werden und die MPCNC steht. Selbst wenn ich nur Kabel an den Pins anstecke (ohne angelöteten Endschalter), wird anscheinend ausreichend Spannung induziert, um den Endstop-Pin auf 0Volt zu ziehen.
Daraufhin habe ich einen Pullup-Widerstand eingebaut, der leider auch kein Verbesserung bringt. Pulldown, das gleiche Ergebnis.
Hat mit jemand einen Rat?
Danke im Voraus
Florian
Hello Forum,
I have already used the search, but could not find a suitable thread to my problem.
In the meantime I have built up my MPCNC completely and it works so far. The working area is 600mm x 400mm x 95mm. NEMA 17 motors with 59ncm were used. The milling machine is controlled by an Arduino UNO with CNC-Shield V3.00 and DRV8825 drivers. As cable to the stepper motors I use standard 1,2m stepper motor cable,
Now to the problem:
As soon as I connect limit switches to the shield, it happens that they are triggered without contact and the MPCNC stops. Even if I only connect cables to the pins (without soldered limit switch), it seems that enough voltage is induced to pull the limit stop pin to 0Volt.
I then added a pullup resistor, which unfortunately doesn’t improve things either. Pulldown, the same result.
Use normally closed switching. You can also use shielded cables. Try it without the router running to see if that is the source of the electrical noise. Separate your signal wiring from any power lines.
Hi Mike,
thank you for your quick answer.
I’ll try normally closed. hopefully it will work with GRBL 1.1.
But i am wondering about the electrical noise. I allready tried without the router running. I’m sure that the steppers are the source.
I just plugged in two jumper cables (10cm long), without a switch attached. The pins are located next to the Y-Axis cables an can not be seperated more. When the steppers move the core arround then there is this sudden stop an UGS tells me, that a hard limit was triggered.
now i tried:
normally closed
normally open
with or without endstop
shielded cable (without endstop)
shielded cable - shield connected to ground
shielded cable - shield connected to 5V
nothing worked… (except from normally closed and the pins just connected via jumpers…)
I dunno… I have always had success using normally closed end limit switches and separating out the mains carrying cables from the signal wires. Could your power supply be noisy?
You can set $10=19 to turn on endstop reporting, then you will see the endstop state in the report (the ?). That should make it easier to separate the variables. There should not be any emi able to trigger a normally closed endstop. The pin is connected straight to ground all the time. Can you make a jumper on a cable?
I also think the idea to check your PSU is a good one. Something is fishy.
TBH if you are relying on a suppression cap to get by with you are heading for trouble… IMHO you will be much better off pursuing the cause of the noise and fixing that - especially if you are employing N/C switching
