New to CNC

Mostly Printed CNC - MPCNC Advice
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Hello, I’m looking to build an MPCNC as I have a Rambo1.4 sitting around without a home. I’m a hobbyist, did some machine operating by trade before establishing a career in electronics repair. I’m experienced with 3d printing, but I haven’t done much milling. Recently at work I’ve been working on our Stepcraft 840, but I’m learning as I go.

So, how would a newbie like me go about learning the ins and outs of milling? Things like rotational speed of the spindle, feed rates, flutes to use for each material type and job. I understand a lot of this is hands on experience, but there must be some good resources one can delve into before I start breaking flutes.

My interest in building a MPCNC would be to mill aluminum, at least 3-5mm to make brackets and mounting plates. I’d like to eventually get to milling an entire object out of bar stock when I get more experience. Also wood/mdf/acrylic for the wife’s projects.

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The general advice is to start easy and go faster until something makes you mad. Some conservative instructions are on the milling basics page.

Aluminum is a bit trickier.

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Other things to think about, if you haven’t already picked up on them in other threads (or your own personal experience):

  • Keep your Z axis as short as you can
  • Get Loctite for your grub screws
  • If you’re set on milling aluminum with endmills, keep it as small as you feasibly can
  • You will likely have better success with some sort of speed control and air assist than any sort of lubrication
  • Loctite + Grub Screws
  • You’re dealing with an unfeeling robot that has a potentially lethal spinning chunk of metal, assume it wants to kill you
  • It’s also got a computer for a brain, assume it knows how to start a fire and will do so as soon as you look away
  • Unless you like chasing oddly stepped shapes, put Loctite on your grub screws
  • If the goat arrives before the initiation instructions, acceptable alternatives and/or inspiration can be found in this thread :candle: :goat: :candle:
  • Did I mention that you might want to consider Loctite on your grub screws? Those buggers have a nasty habit of getting loose and throwing things off
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All good advice. Thank you. I’m an experienced machine operator and I know better to trust the robots. Respect them, never trust them. I always wire external e-stops outside the enclosure as well.

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For the record, I assume there are at least three or four people who have the same questions or concerns when I post on the forums, so I hope you didn’t feel patronized. :slight_smile:

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Your best friend is trochoidal milling. I cut through 1cm in two passes without lubricant, think I could have done it in one.

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Not at all! We all need to keep the basics in mind, cockiness gets you hurt

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I will research that, thank you