Sacramento, CA - Crown Test Done - Now the Hard Part

Finished initial assembly on my 630x330 (25x13) MPCNC. Passed the crown test.

Thanks Ryan

This is my first CNC tool. Printed the parts with an Ender 5.

Pretty much a stock build. I used unpolished stainless steel, 0.065 wall, tubing. Got it for $5/foot on ebay.

Next…

  • Move the machine to my garage and mount it to my bench
  • True up the frame and gantry
  • Cut a plane with my Makita 701 router to verify the spindle is perpendicular
  • Install and plane the spoiler board
  • Cut the milled parts for a low rider
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Welcome Bryan! That is a slick looking build. Very neat.

Have you checked out the perpendicularity tester? It works great.

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Thanks Marion.

It is getting there. Cable management is a challenge. I expect cable chain to arrive today.

I wasn’t aware of the perpendicularity tester. I’ll check to see if it fits the Makita 701 collet.

Welcome!

Great choice for a build size, you should have no problems with that one!

So, if you look closely at my crown test pic above you’ll see it is very sloppy.

I’m a programmer by trade. As my engineering friends are fond of saying…

“Beware of programmers carrying screw drivers.”

Today I noticed how much slop there was in the tool when the steppers were on so I started looking for the cause.

Long story short, I didn’t have the correct allen wrench for the set screws on the motor shafts and I never got back around to tightening them. They are tight now.

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Hahahahah!!!

Dang pulleys. I think we need to make that the question on the contact page, “please before you email me, check your pulleys one more time!”

Install the pulleys permanently onto the motors with epoxy when you sell them. :laughing:

It is making me wonder how many gave up on the machine or thought is sucked and it was just a loose pulley or two!?! I might need to factor in lock tight into the cost of each kit like lube.

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That thought crossed my mind. I wonder if that is what happened to Thomas S.? Like him, I started with cranking up the tension in the belts.

I scanned the trouble shooting forum. Did find some fixes for issues I had but not the pulley set screw problem.

Shoot we almost did not have a lowrider because of it. After two days of trouble shooting and making new parts I figured it just didn’t work. Started taking it apart and the pulley fell off!!! It is by far, not even remotely close to anything else the biggest issue.

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Loctite is available in little 0.5ml tubes… it only takes a drop per set screw. I think purple is the type recommended for small fasteners like those.

Only sold one so far ever!

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Yeah, I’m not loving those set screws. First time they come loose I’m thread locking them.

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You could add it as an option on the bundle :slight_smile:

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Fixed that for you

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Test cut worked well, see below. Thanks for the test gcode Ryan.

I don’t see any ripples in the bottom of the cut out. I guess my tramming jig works well enough for a 1/8" dia bit.

I’m going to surface some 2x4 pine with a 0.75" dia plunging router bit, i.e. use my CNC mill as the worlds slowest most accurate planer.

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Sweet test file confirmed, I will have to add it to the basics page somewhere, or make a new page. Cool! Thanks everyone.

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As the owner of my favorite hole in the wall gyro/sandwich shop says…

No, no no! Thank you!

It seems like your invention is bringing a a lot of non-machinists into the the CNC world.

I think it would be a good idea to create a CNC Newbie subforum. The “About this forum” thread can have FAQ tips like…

  • Check the pulley gear set screws.
  • If your crown test is sloppy, see video for a known good example, then something is wrong.
  • If you can wiggle the tool while the steppers are on something is wrong.

Speaking of the crown test…

Some of the design looks wrong, i.e. the flourishes around the clubs, even when it is right. It might be a good idea to have a simpler print test, e.g. a circle nested in a square with known dimensions.

If it isn’t a copy right issue I suggest a deathly hallows with 25.4 cm wand length.

This does come up once and a while. The reason I have grown to love it is the fact that is not perfect. As soon as you put in “perfect” shapes people will start measuring them and chasing decimal points of perfection. The simple case for nearly every single new build is “don;t worry about it, just use it for a little bit, get it dirty”.

For me it is a huge bummer to try and help someone for weeks try to dial in the machine to ultra precision, then have them ask what router they should buy or how to mill wood. Make some drawings, do a few simple cutouts, do some carves…then worry if you need to even bother with more precision than how it is built.

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That was me! Lol I figured for $2 I couldn’t go wrong.

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