Some newbie questions

Hello everyone, I plan to build the MPCNC, I had a couple of questions first though:

  1. How powerful do the steppers have to be? Can I use 44Ncm (62.3Oz/In) steppers?
  2. What drill bits will I need for the build process? What sizes?
  3. Can I run the CNC with a MKS Gen L? Should I use a Ramps 1.4 instead? I don't have the budget for a Rambo...
  4. What drivers should I use? DRV? TMCs? A4988?
  5. Will a 500W spindle be able to do Aluminum? My machine will use Stainless tubing, cut area about 530x530mm (21"x21")
Thanks for answering!

Based purely on what I’ve read (still putting my first one together):

  1. That should be fine.
  2. Let’s see, you’ll need to drill out the holes for the tool mount, and to mount the feet to your table, both of which are the #6-32 or M4 screws, so whatever you need to drill pilot holes in your table, and through holes in your tubing.
  3. I’m 99.9995% sure that will be fine.
  4. What your budget/needs can handle. My first build is going to be with A4988’s, but I will likely upgrade at some point.
  5. Given the right bit, speed and feed, yes. Also depends on the overall quality of the spindle and bits.
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500W spindle.

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RAMPS is fine in theory, but lots of the import boards are of poor quality and have a high failure rate. Evidently nowadays they cut too many corners to squeeze the last penny out, so RAMPS is discouraged. MKS Gen L is fine, that’s what I’m using in my second build. I don’t know of any quality problems, but I also don’t know that there are not quality problems like RAMPS.

DRV8825 you can use without touching the firmware at all (RAMPS firmware will work on MKS Gen L without any changes). With A4988 you will have to change steps/mm to half the value but it’s easy to do and it will work fine. I have A4988 on both my builds. I think they are equally good. Trinamic drivers work too, I think the max current is a bit lower and the price is a bit higher but there is no problem with using them.

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Thanks everyone! I have another question: Can the MPCNC do tiny parts? I’m talking 5x3mm (About 3/8" I think?). What’s the smallest I can go?

That might be a tad small, not sure though. I don’t remember anyone doing anything that small. I’ve seen some routered circuit boards, that’s close, but they’re not really cutting anything deep.

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Not routered, not PCB… but starting to get pretty small. MPCNC with 3.5 watt Banggood laser. Haven’t pushed it to see how small I can go but I think “sub-millimeter” is certainly possible. This is a 14 x 14 grid of 1.2mm holes IIRC… and not only holes, but “holes”

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– David

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I’m not making a complex part at all. It’s not detail work. Will it still be impossible? Should I test it out once I build mine?