Hey there, i’m about to order the MPCNC Bundle but i have a few questions left to clear.
I mainly want to use the MPCNC with a 500w chinaspindle and sometimes diode laser.
Can i hotswap these on the fly or have i change something in the firmware?
And the second question is: Are there still problems with controlling the RPM of the spindle?
The last one i read was in 2021 an it seems that the spindle control caused some problems.
The last question: Could i control my spindle with the MPCNC? Its controllable with an potentiometer and got a mach 3 output.
Can i hotswap these on the fly or have i change something in the firmware?
As long as the laser feature is enabled in the Marlin firmware, and as long as you manually adjust the spindle RPM, no firmware changes are required. V1 has the laser features enabled in the Marlin firmware they maintain for the Rambo board, the SKR Pro board, and I believe the Ramps board. If you are selecting a board other than these three, you may have to make some one-time adjustments in the firmware to enable laser support.
If you want to control the spindle RPM through g-code/Marlin, then there are issues. The spindle RPM and the laser PWM use the same g-code mechanism. I cannot think of a way to set up Marlin to do both at the same time. If you are using the Rambo Board or the SKR Pro Board, it is pretty easy to swap firmware. The Rambo firmware can be updated using XLoader, and the SKR Pro is updated directly from an SD card.
Are there still problems with controlling the RPM of the spindle?
Could i control my spindle with the MPCNC?
I’m not sure of the specific issues you are referencing. The only issues I’m aware of are driving the RPM through Marlin. I don’t know of any issues with manually controlling the RPM. For controlling through Marlin, there are two things that must be done. First you must set up Marlin for your spindle. This is matching the PWM output of the Marlin board to specific RPM values. The second issue is the hardware support to generate the 0V to 10V analog signal to drive the spindle controller. There are a couple of circuits and at least one third-party module to do the voltage mapping. Searching the forum should yield both, but if you have trouble finding them, post back and I’ll thrash around.
As for a 500W spindle, people who have done head-to-head comparisons between the spindle and the Makita router find the router noticeably more powerful. They find the spindle substantially quieter.
For hot swapping, one hurdle will be mounting the laser quickly. One solution is to have a second Z axis. Pull one Z axis out, insert the other, and you are done.
Thanks for the great answer. So i think it’s the best to manually control the spindle RPM aside the laser.
On my CNC3018 all is a little easier to handle. As i read on the v1e laser documentation page i need to have an extra PSU for the laser?! But it seems that i can let the laser and the spindle be connectet to the Mainboard simultaneously.
A separate power supply is not required (assuming the voltages match), but you can have a separate power supply. If you purchase a V1 kit, the power supply is not rated to support the machine and any substantial laser module. In addition, V1 has started shipping 24V power supplies rather than 12V supplies, and your laser module lists12V as input power.
Your choices are to replace the power supply that comes with your V1 kit with a larger (10A probably), 12V power supply, or to use a separate 12V power supply for the laser. With a separate power supply, the ground pin of your laser (in the red connector) must be connected to both the power supply and your control board (any ground pin).
The spindle control issue is not one I’ve followed, but it should only be a problem if you try to automatically control your spindle speed.
I run my Laser off a separate power supply, and I don’t plan on any changes. If you are planning on the kit, then stay the course. If, at some future date, you decide to use only a single power supply, making the change to a 12V 10A power supply is only $20 USD on Amazon.
Note there is a potential benefit of running your MPCNC off 24V instead of 12V. If making rapid movements (such as engraving with a powerful LED laser or plotting with a pen), you have more torque at 24V. That is, you can move faster without losing steps at 24V. Usually, CNC routing tasks are slower and don’t benefit from being run 24V.
