[james_III]

I recently purchased currently my best home CNC machine, actually this is only one that moves right now, so might be only third best. Same Chinese design like most, but all axes are fitted with ball screws, this was the main reason to go with this design. I did order machine with 300W spindle, much cheaper this way. I have used this machine couple of weeks now and I can't really pinpoint any fault of it, it was bargain to start with. There is small issue with spindle, it needs 48V10A PSU to work at full speed. Luckily China also produces plenty of suitable power supplies. Controller is arduino uno based grbl shield with nema23 steppers from dumpster. And now I have forgotten what I was planned to write here, so lets put some video content right about here.

https://youtu.be/zV2pFv8Du3U
Sorry about bad angle but my current working space is really limited, I made tripod extension to get this far. There was not much to tweak and no instructions, but cheap price have to come somewhere.

https://youtu.be/VTLMjcgbDfo
First speaker test, if engraving is no good, so there need to be secondary thing. This was approx 5 hours later from unboxing video.

https://youtu.be/H2WDEiAU5o4
Current state, investment for Vcarve desktop and that's very affordable software with small engraving machine like this. Unfortunately Vcarve did cost slightly more than this machine
Maybe later with more and better videos.

[apt403]

Were the screws for the stepper motors threaded 10-32?

[james_III]

Were the screws for the stepper motors threaded 10-32?

No, everything is millimeters, mounting screws are M5 and these are not included.

[apt403]

No, everything is millimeters, mounting screws are M5 and these are not included.

That makes a lot more sense, considering everything else is metric - I picked up the same machine (frame kit + 300w spindle). Checked the bolt holes with a tap yesterday morning before leaving for work. Thought they were 10-32. After reading your message I checked again, and they are M5 .8.

How's the spindle working out for you? The engraving looks good.

[james_III]

Spindle works ok, I did get yesterday PSU with maximum voltage 48V and now it clearly spins faster. There is small balancing issue with spindle, but it happens only on small RPM section and can be avoided. First time my machine can start spindle without any hassle on its own, without killing underrated power supply. To get 36V I had to connect three 12V powers supplies on series, but not anymore. Still I'm thinking getting spare spindle, just in case, but have to study what should it be.

[james_III]

Lets have some tools organized
Attachment 307916

Second layer, note 12mm wrench what was included, still finding 12mm nut somewhere.
Attachment 307918

One way to keep material in place, there is really no need for tightening more than your fingers.
Attachment 307920

Z probe is nice to have, but you could live without it.
Attachment 307922

What I really like to have is pulse wheel with direction switch, just like running big CNC machine. Not sure will it be possible at all, grbl developers speak something about jogging but when and how it functions is completely different matter. Because UNO+grbl works so good, why not slave another uno for jog, sd card and small display to view current running mode. Whit this setup machine can run without computer and you can set zero, that's basically what you need.

[james_III]

Minor update, this is second motor coupling witch fails at the wrong time I did order more strong spider type couplings to fix this issue for ever.
Attachment 320998

BTW original couplings are wrong size, ID should be 6X8 but actually it is 6.3X8, this might cause slippping.

[RunForrestRun]

Why are they breaking? When I got my 3040 the X-axis was stiffer than the others. It turned out one of the bearings on the upper guide rod was broken (damaged in shipping?)

[james_III]

Maybe it is quality issue, not sure. I try to run machine very gently without any fuzz, so this thing is mystery but will be sorted.

[Jon.N.CNC]

Minor update, this is second motor coupling witch fails at the wrong time I did order more strong spider type couplings to fix this issue for ever.
Attachment 320998

BTW original couplings are wrong size, ID should be 6X8 but actually it is 6.3X8, this might cause slippping.

Lol what the hell. Never seen that before. How did those motor/drivers manage it. I have the same machine here (donated) I can stop the motors by putting hand against gantry.

[jfong]

Any slight motor mis alignment will cause fatigue and will lead to a broken coupler eventually. A similar one of mine broke after a year or so. Rapid was set at 1500rpm. The replacement has been ok for 2 years now.

[apt403]

Lol what the hell. Never seen that before. How did those motor/drivers manage it. I have the same machine here (donated) I can stop the motors by putting hand against gantry.

Just took that photo. X axis stepper, running the machine right now (literally) on a solid coupler I turned out of 6061 until a replacement shows up. I'm running 270oz-in steppers with KL-4030 drivers on a 3040.

[awerby]

The trouble with solid couplers is that a little misalignment will snap the shafts off your motors or screws. That's why people go through the trouble to use spiders and helicals. But the aluminum helicals are pretty useless; mine all broke the same as yours. Steel works better.

[apt403]

The trouble with solid couplers is that a little misalignment will snap the shafts off your motors or screws. That's why people go through the trouble to use spiders and helicals. But the aluminum helicals are pretty useless; mine all broke the same as yours. Steel works better.

Yeah, definitely only a temporary solution - luckily the cutting forces these things can take is low enough that I can get away with using set screws - there's a little bit of play from the screw acting as a pivot.

Hopefully I can get some proper motor couplers on all three axes soon. Haven't quite decided between Oldham or Lovejoy type couplers.

[james_III]

Milling some PCB´s and all is fine, except my camera focus but.....
https://youtu.be/GMlBijRb3sA