Sorry for the delay. Here’s my controller box:
Thanks David!
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Nothing too fancy to report here. I haven’t been using the MPCNC too much lately. I went to use it the other day and the raspberry pi I use to run cnc.js was acting up. I was in a crunch, so did that project manually using the scroll saw.
This weekend I played around and got it up and running again. I re-ran one of the cuts from the last project and it cut quite well.
I’m not doing anything too fancy with it today, but I am making some decent chips in Purple heart. I’m making a magnetic knife block to hold some custom kitchen knives I bought. Final project is a solid block of purple heart with an Ikea magnetic knife holder embedded in the back.
I took a short video of the chips being cut.
It’s raw video, so turn your volume down first
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Well. The cut went well, but the knife holder won’t work. Even with as thin as I made the wood, the magnets aren’t strong enough to hold knives.
I’m thinking I’ll start over with the design. Maybe I’ll use larger, round magnets that are evenly spaced instead of the smaller strip magnets that the Ikea holder uses. I have more testing/playing to do.
Maybe I should be testing with pine instead of the purple heart 
I ordered some of the 1.26" super-strong magnets off Amazon. Let’s see if these hold better. If they do, then all will not be lost.
https://www.magnet4less.com/home, that place has it all and SUPER strong ones are available.
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I’ve used K&J on work projects for years. They have a great calculator you can use to get estimated holding force for different separation distances, magnet materials, magnet sizes…
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I’m still having issues with the core wobbling on the x and y axis. I’ve come to conclusion that it’s something wrong with the pipes. Either the thickness is off or the ever so slight bend in the pipe when I first got them is causing issues.
Today I ordered some 1" stainless steel from metalsdepot. I’m going to replace the X-Y cross bars, all 4 of the side bars and I went ahead and ordered new Z pipes… cause why not.
When they come in I’ll replace them and see if my wobble issue goes away.
Min wiggled but the parts holding the pipes to the core broke under the bolt head and didn’t show till disassembled I sure caused by over tightening on my part
I had some time in the shop while waiting for paint to dry, so I replaced the one easy pipe to get to with the stainless steel one. Just replacing the one pipe has reduced the amount of wobble I can do using my hand. One of my pipe camps is broken, so I need to print a new one.
My wife has a project I need to cut for her, so I need to get this pipes replaced soon.
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My wife needed me to cut some stuff on the CNC, so I took this morning (had the day off) to replace all the tubes on my MPCNC with 1" stainless steel ones that are straight.
Unfortunately, I went from one issue to another.
The good news is, the new tubes got rid of my wobble.
The bad news is, one of the axis is now too tight and just sits there and grinds. At first, both axis were grinding, but after messing with the Y axes (loosening and tightening various bolts) I was able to get the Y axis to run the full length of the machine without issues.
The x axis, on the other hand, is still grinding. I messed around with it for a little while, but finally gave up for now. I switched over to the big CNC that my friend hasn’t picked up yet and used it to cut the wife’s parts.
Here’s a video update of the Z axis wobble showing it ‘fixed’: https://youtu.be/dSVj6QzhGzE
I’m wondering if my 3d printed parts are too tight at this point. For the other tubes (which I think were under-sized as well as slightly bent), I think the smaller parts managed to do okay, but they’re not working well now.
I might try to get out there this weekend and work on the machine some more, but I have other projects that currently have priority.
I would say make sure things are loose enough, and hopefully by tomorrow it will relax enough to work. Other than that, you can turn up the current a bit.
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I know one thing for certain… My issue is not related to the hole spacing on the Z tubes.
Had a little fun with the mill when drilling the holes in the new tubes yesterday 
Anyone that’s worked on a mill long enough will see the small goof I made in my setup. Well… there may be multiple goofs, but one in particular.
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Heh, yeah. Amateur hour! /s
Seriously though now it’s killing me… Should have used v blocks? indexed off the wrong end of the tube? What is it?!
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V-blocks would have been nice, but I don’t own any.
The ‘goof’ I made is that my referencing block that the tube is pushed up to is on the opposite side of the tube I referenced my 0 off of. So if my two tubes are off in length from each other, then the holes will be slightly off from one tube to the other.
In this case, my tubes are about 1/32-1/16" off, so if I put both of them on a table on the bottom, you can see the holes don’t line up.
In usage, it doesn’t matter, it just means the one tube is offset of the other by a touch. You can’t even see it once all the plastic pieces are bolted on.
After drilling the first tube, I should have bolted the reference block to the right of the tube. I would have needed to offset the tube in the vise enough to the right to get the block to it.
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How about if you put them upside down?
Probably better anyway if they’re the same length as referenced from the top of the Z axis anyway, since that’s the side that you can see, and the side that I line up when I’m assembling the axis. (I make sure the tubes are flush to the top of the motor mount.)
I didn’t think about that, but yes… The holes would be identical if measured from the top.
Lol. Doing it right … accidentally.
Sounds like you just need to also take a minute and cut the right side to length with the same jig.
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I didn’t leave enough stick out on the side of the vise to get an end mill in there.
I could have moved the whole setup over an inch and then reset my x axis, but didn’t.