They are out there and work from what I have heard. Nut Encasement by mbef - Thingiverse
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Well that could not possibly have gone any worse. I have no idea why that is one of the worst cutting machines I have seen to date. So painful to watch.
Yep. I could read how disapointed you were. And since the whle episode went so fast, no way to troubleshoot the wood first, ensure he could go to the next levelā¦
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The only way I could get my machine to chatter that bad is if I plunged into titanium.
What in the world did he do?! I have never seen any CNC cut that poorly, even the $200 ebay 3018 ones that weigh nothing.
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Tom was IMHO far too impatient, impulsive, and heavy-handed to properly show what the MPCNC is capable of. A bit more finesse and a thorough going over, double-checking and adjusting all the belts, bearings, and hardware would/could have helped immensely. Instead he rather hurriedly assembled the machine, all the while interacting with chat and doing fifteen other things, and then jumped into the deep end, into a pretty worst-case scenario for cutting materials. No pen-plotting, air-milling, no forum search for specific MPCNC-recommended feeds/speeds, etcā¦ and IMHO little chance for success. He could have simply made a few lighter cuts, in more forgiving materials, and sneaked up on feed and speed settings that would have been more appropriate for his particular build. I like Tom and admire his knowledge and ability to juggle many tasks simultaneouslyā¦ but he seemed a bit careless and heavy-handed IMHO for a first-time MPCNC builder. We all know how fun, versatile, and well-designed the machine isā¦ and itās a shame the rest of the world wasnāt able to see it as well from his efforts. ā David
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Well no refund requests yetā¦so I guess that is a good thing.
He did build it fast and those power tools freaked me out but when it came out squareā¦it should have been good. Honestly that is all I was worried about. I have the utmost confidence it it cutting. I thought we might lose him on squaring the gantry.
I really canāt think of anything other than that spindle mount? Barry has one and seems to feel similar, and another few comments brought it up as well. I am really not sure but it seems narrow and would be super awesome if it was on the silver part instead of the black or at least spread to the top and bottom of the spindle. His build is pretty big and pretty tall but come on we have all seen giant builds ripping things up. I really do hope he sits down and looks it over, something is majorly wrong. Wiggle it from the bit and pay attention to what is actually moving. Video makes it really hard to tell with high speed oscillations what is going on but it looks like the spindle is all over the place first and foremost. That pine with his first settings should have been a piece of cakeā¦I was about to open the Champagneā¦now I might have to go cry into a pintā¦
In case folks here donāt do the tweets. I tried it myself and found the dc spindle did the same crap it did to Tom, then I swapped in my Dewalt and had no issues at all. Iām pretty sure itās the collet adapter on the bottom of these spindles.
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If you look at 38:50ish, you can see the tool.mount being oretty stationary and the tool going wild. I like the guess that itās the spindle/spindle mount. I wonder if he would just move the brackets to the white part just as a test.
Definitely not normal though.
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Or are the zip tie loops too big?
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I agree on the spindle, mine does similar things. Itās just not as rigid as the routers.
However, I also think he didnāt tighten the tension bolts correctly, I had similar issues at the beginning (as far as how much the z axis moved).
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Yeah. Maybe that too. I bet heās going to take a look at this and heās a smart guy. I think he ended it pretty positive. It just needs a bit more tweaking.
I think the next we hear, it will be all fixed.
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I watched Tomās build this week because I want to build a MPCNC - and I still do. But that was rough today.
Tomās build wasnāt exactly good advertising I guess, but thereās a lot to learn for meā¦ I was hoping that it would turn out perfect despite his choices: build it really big in all dimensions, use a cheap spindle, half-assed measurements, no actual bed levelling, wood goes badly but no trouble shooting, the whole thing wriggles around but no fear letās cut aluminum without cooling, ā¦
Iām confident that heās going to double down and make it work (and show us how). I enjoyed watching the build a lot. Tomās approach is a perfect example of stress-testing and that has its merits. It may show us that most of his choices were actually good! Letās hope itās just his spindle 
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Stress testing =/= ramming the spindle into aluminum when it was chattering like a monkey on wood
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I caught part of yesterdays stream, and then this morning sat down to eat a late breakfast and just as I sat down my phone pinged that the stream was starting and I switched over to watch.
Was all excited to see him dig in with actually testing it today - but then dropped my jaw in the first few minute when he said he was going to go straight to wood and aluminum, uhā¦what?!
I expected better common sense from Tom than to go from one or two quick test moves into full on cutting. Do some air cutting first to make sure itās all working. Then test on some foam as a next step and then when it all seems good dig in on the wood. But to go for aluminum when wood wasnāt even working well yetā¦what?
Iām shocked at how non-rigid his machine is. Mine is bigger, printed in PETG, and predates the revision before the burly and I donāt get chatter like that unless I push it to about twice as fast as I know it should go and twice as deep as I know I can cut.
I have to suspect the spindle. Just looking at how much of it sticks out below the tool holder freaks me out a bit. And how close those mounts are to each other. That thing canāt be held very well. Though it does seem his whole z has more play in it than Iād expect and not just the tool mount. I almost wonder if there could be an issue with the dimensions of his tubing since my machine with longer EMT and two stiffness design improvements out of date seems a lot more stiff overall.
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This is one of those times one of us would typically sayā¦āhave you checked to make sure your pulley are tightā, hahaha
It was so bad we all assumed it was running in reverse but so dam strong it was cutting anywayā¦except Barry, he has better intuition.
I am really hoping he says something like " I forgot to tighten the mount screw" or something. Reality though is Barry and his import spindle have a really beefy mount and it wasnāt doing well either. I really do not want to waste my money on buying one but might have to just so I can definitively warn away or recommend them.
At the same timeā¦I have an aluminum videoā¦on a solid machine. 3.5mm 6061, Single Flute end mill, full RPM 25k, 1.1 mm DOC, 3.5 mm/s feed, full depth 0.2 mm finishing pass (little more next time), 1.2mm/s plunge (little less next time), no air. You can hear my router slowing with the load.
vs toms first al-11k rpm, 1mm doc, 10mm/s - (roughly 1/2 my rpm (2x my load), similar depth, 3x my speed = roughly 6 times the load I consider good with no air flush?)
vs toms last, attempt was .3mm doc 11k rpm, 5mm/s - (1/2 rpm (2x load), 1/3 depth (1/3 load), 1.4x faster feed = roughly 0.9 my loadā¦this could have worked but for first attempt less power at the spindle and a bigger taller buildā¦pushing it.)
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Shoot maybe that first attempt in Al cracked the mount and the second didnāt stand a chance or it is just asking too much.
This is going to bother me, I am ordering that stupid spindle to test it myself.
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Did he eventually change the belts in one of the streams? I remember the first one he said he had steel belts.
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OMGā¦$140, not happy with that purchase. 660ās are $53, Germany has to have something similar.
Kress or something maybe. Similar form factor to the 660.
He has a Makita though, used it in the sienci mill one.
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