Hi All,
I decided to build a cnc at christmas, mostly on a whim. My friend sent me a link to the mpcnc and as I’ve been 3d printing for many years it all made sense.
Any how, it’s alive so i just wanted to pop in and say thanks. This form is an invaluable source of info and the machine exceeds my expectation.
Some specs:
520x520 build.
Duet3d wifi control.
Stainless tubes
1.5kw chineese spindle.
Dual endstops, with my own tube mounted stops
All petg.
I’m sure you’ll see me around!
~
Mike
Nice! And already making dust.
Does the duet use dual endstops? Is it running Marlin?
That is a big spindle too. I can’t wait to see what you make. Nice job.
Yes the spindle is a bit bigger than i wanted but they sent me the next size up by mistake. Its only 200g heavier off the top of my head so didn’t return it.
I doubt I’ll ever use 1.5kw but at least i shouldn’t have to worry about heat in the motor.
The duet is running dc42’s originsl firmware. There’s some config hoops you have to jump through but you can do duel endstops with the homing macros. You need to remap the axis you are homing into two independent drives, then home them at the same time, then remap them back together.
Happy to share just don’t have access to the configs at work.
~
Mike
Nice, welcome to the crew!
Nice one and welcome…
I think I ordered the same spindle. It hasn’t arrived yet. Are you happy with it?
Hi Peter,
It’s nice and quiet and seems well ballenced. The vfd did not explode so that exceeded expectations. The fan on the vfd is noisy. I’ve seen mods on youtube to make it thermostaticly controlled and I’d see why you’d want to do it ruins the kalma of my shed while you are setting up a job. Cutter noise drows it out when you get going.
The earth pin on the motor is not connected to the case which is something i have addressed.
The motor is pretty heavy, that said my mpcnc can throw it around at alarming speeds without loosing steps. I also have a pretty heavy 30mm mdf table so the whole thing is stable even though its on wheels.
1.5kw is more power than you’ll ever need but given thats a chinesse rating having some headroom isn’t a bad thing. You won’t be able to run it very hot with printed mounts or things would sofen and get pretty catastrophic pretty quickly I’d imagine. Ive not even got it warm yet but its early days for me.
These air cooled spindles want to run fast and I’m not sure if the lower safe speed is going to be a limitation for me or not. I’m just learning about feeds and speeds.
That said, it’s scary how fast you drive a 6mm single flute through plywood.
Just to be clear to anyone else considering these i don’t have the mpcnc experience to say if this is is a good or terrible idea. It’s off the beaten track i think but I’m going to have fun seeing what it can do.
~
Mike
Thanks Mike, it showed up today. As you said it’s pretty hefty. I noticed your ground wire. Given the spindle is mounted to plastic, does grounding it to the body do anything? I was thinking of running pin 4 back to ground on the vfd.
Still waiting on some parts before I can do any real damage.
cheers
The safety reason you ground the case is, if something goes wrong inside the machine and the hot wire ends up touching the case. If the case isn’t grounded, nothing will happen, until you touch it. If it’s grounded, it will short and destroy itself, or a fuse, or a breaker instead of you. This is especially true for things like refrigerators.
It will also reduce the RF noise.
Just in case anyone is interested, I’ve posed my end stop tabs on thingiverse. https://www.thingiverse.com/thing:3449665
~
Mike
Hi Mike, Bit late to the game but I’m about to build a MPCNC in the UK. Where did you source the stainless steel tube if you don’t mind me asking?
Hi Richard,
I’m no affiliate, maybe you can find cheaper I didn’t hunt hard. The delivery was fast and their website is easy. I’ve used them a couple of times without issue.
I had them cut the tubes to length and to be honest I wouldn’t bother next time. I wasn’t expecting 0.01mm accuracy but I barely got tubes within 5mm in some cases and I’m pretty sure I could give my 5 year old an angle grinder and get a squarer cut. Nothing short, and I used them as-is - just if I did It again I’d get longer lengths and cut myself with a little more love.
FWIW I used [Stainless Steel Tube - 25.4mm od x 1.5mm 304 Bright Polished] and I’m roughly 550mm square.
~
Mike
For comparison, I ordered my steel from SpeedyMetals (USA, not UK, 
) and my parts were cut 2-3mm over target and there was less than 1mm length difference between any of the six identical tubes.
http://www.speedymetals.com/pc-4494-8276-1-od-x-0065-wall-tube-304-stainless-steel-annealed.aspx
Thanks @mclinc and @merrittgene. Yeah I had found metals4u during my search, not a bad price really but interesting about the lack of accurate cuts. I may just order oversized and trim to correct sizes my self.
And to carry on the comparison metals4u ~£60 speedymetals ~£140 for similar sizes. That’s quite a price different over in the US.
I was also wondering about Bright or Satin Polished. How are yours holding up against the bearings?
