Dear Dan,
using CNCJS with GRBL 1.1. on a Protoneer CNC shield
I believe I was too optimistic with my answer.
The homing moves in the proper direction with $23=3. (it’s clear)
Here the description of the homing issue.
When I hit “homing” the CNC runs properly the Z command (fast up movement until the microswitch then a small forward movement then moves to the final position ~1 mm away), thats seems ok.
Then the XY motors run, reach the Y endstop (for example) WITHOUT the little forward movement then the X endstop WITH a little forward action, then the motors stops.
Here the command
client> H
ALARM:8 (Homing fail)
ok
Grbl 1.1h ['’ for help]
[MSG:Check Limits]
[MSG:’$H’|’$X’ to unlock]
To be able to use the motors I need to remove the alarm then I can move X motor, +X.
For Y axis as soon as I click +Y I can ear the switch then everything is blocked.
Why the Y microswich contact does not offer the little forward movement like the X axis.
Homing direction is controlled with the $23 parameter. Grbl defaults expect all switches at the max for each axis. Based on the grbl documentation, I think $23=3 will get you the behavior you’re looking for - inverting the homing direction for X and Y, but leaving Z homing to max.
Yes, the CNC Shield (I’m using v3.00) can control spindle speed. There’s a VARIABLESPINDLE defined in the firmware, which appears to be enabled by default. The same pin turns the spindle on and sends the speed information, so M3 S1000 turns on the spindle at 1000 RPM, where the S parameter sets the speed. To change spindle speed to 500 RPM, you’d issue M3 S500. M5 turns the spindle off. You set the max allowed RPM with $30.
The CNC Shield doesn’t have a SpindleDirection pin defined on the Arduino, so spindle rotation is assumed to be clockwise. If you have a reversible spindle, you’ll want to define a direction pin so you can use M4 for counter-clockwise rotation.
Of course, you need a spindle that’s got RPM control too that will respond to a 0-5v dc Pulse-Width Modulation (PWM) signal. Options include the Chinese spindles that come with a DC PWM controller, or a Variable Frequency Drive, or an after-market add-on like the SuperPID. I’m using the PWM controller that was sold as a “development kit” from the V1 store for a while. I think the components may still be available in the store, but this is definitely not a turn-key solution - it requires an Arduino nano, flashing that firmware, and some additional circuitry to get it all up and running.
Just thought of another option - some people make spindles out of the brushless motors often used in radio control aircraft. The electronic speed controls (ESC) these use are designed for 5v dc PWM control.
Dear Tom,
I wish if you could help me setting up an LCD display on a CNC Shield with GRBL.
I would appreciate if you could let me know which LCD display model to purchase.
I have found an Arceli 12864, is it compatible ?
Unfortunately, the Arduino Uno that does the actual computational work for the CNC shield doesn’t have enough memory to support any sort of a display. This is a limitation of the Arduino hardware, not anything “wrong” with grbl. If you absolutely have to have an LCD screen, you’ll need to use a different controller. If you’re going that route, it’s hard to beat the boards that @vicious1 offers through the V1 Shop, but they mostly run Marlin rather than grbl.
Alternatively, you can find different controllers to run grbl. If I were going that upgrade route, I’d look for one that supports 5 stepper drivers.
I run v1pi on a Raspberry Pi 3B to get a gui interface for managing jobs. This allows any web browser to control your machine. You have the choice between cncjs or octopi as the user interface.
Salut a tous, je suis entrain d’imprimer les pieces vous avez des conseils que l’achat des tubes et possible d’avoir des moteurs qui se connectent direct a la carte sans soudure .
