My first post is pretty straightforward: what do I need for a spindle? I’m currently printing all the parts for the MPCNC and I’ve been looking at ebay and AliExpress for budget ~500W spindles. Some come with just the spindle and others come with a power supply. If I was already going to use an ATX PSU for the rest of the build, are there spindles that run off 12v? all of them seem to say 110-220v which I assume are the mains for the PS supplied with these kits. If not, and I do buy the spindle with the PSU will that work with PWM? I’m guessing there isn’t any sort of speed controller built in so how would you guys recommend going about adding that feature?
Ideally i’d like a 500w spindle, pwm so I can control speed in the gcode. preferably without needing to use two power supplies.
Yeah I saw that! For my roommates sake though I’d like to use a spindle because from what I understand they are significantly quieter. So I’m looking for advice from anyone who has setup the MPCNC in that fashion.
I made a video on youtube, running a 611 (quieter), and a shop vac. It illustrates the sound level of cutting wood. It is much loader than both the spindle and shop vac.
There are few of threads about this, a few guys are running those spindles.
I recommend you to go for a brushless spindle, for several reasons:
-You get almost constant torque, no matter what the speed
-You get almost constant speed too
-They are quite a bit quieter
-They are generally more powerful (more efficient, for the same power rating you actually get more usable power)
For this, you need to purchase a bundle, including the spindle itself, a motor controller and a power supply. Don't even think of using a computer PSU, they only deliver 12 or maximum 24V, which is not enough.
Then, you can hook up the motor controller to the ramps and use PWM to control the speed if you need to. Or just a simple potentiometer.
Dewalt or Makita style routers are in my opinion the best choice since they are able to run at around 30 000 rpm, while brushless spindles will maybe reach around 12000 rpm, but they are very loud and don’t have constant torque. They are also probably quite a bit cheaper.
Be very careful when connecting the Aliexpress 500W spindle power supply to your electronics!
This is probably not applicable to all those power supplies (as I have read about people making a direct connection), but my power supply had one of those potentiometers where you could adjust the speed. It had a red, black and yellow wire. And as it should be red and black where + and - with a 5V difference. Perfect for connecting to the Arduino… or so I thought.
Luckily I measured the the voltage difference between the potentiometer and Arduino ground and it was 80V! Connecting this directly would have definitely fried my Arduino and maybe even the connected computer. So be careful!
(I thought that the ground level might be just floating a bit and connected a resistor with a couple of kOhms to ground, but this did nothing except that the resistor got really hot.)
If you haven’t bought the spindle yet: There are some sold with a power supply that have a “Mach 3” connection where the speed can be controlled via 0-10V. I would guess (but still measure to be sure) that they have a ground that is close to earth potential and so could be easily connected to the Arduino. Although there is the additional risk that the connected potentiometer also runs with 10V. That would be more difficult to connect an Arduino (but still possible with a cheap optocoupler).