MPCNC in Switzerland

Progress on my colorfull MPCNC:

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So far I printed all the parts and everything except the drag chains and the 6/32 screws has arrived.

The pipe cutter broke after about 20 cuts, even though it claimed to be made for stainless steel…

The working area is ~60cm x 50cm x 7cm (23.5’ x 19.5’ x 2.5’).

 

Some build progress pictures of the base plate:

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Ryan, if you ever do another revision of the MPCNC, please please please use M4 screws instead of 6/32, they were almost impossible to find, even Amazon and Aliexpress proved difficult, and metric screws should be easy to source no matter where you live…

But thank you for this great design, so far it was a fun building experience :slight_smile:

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The 6-32 screws and the drag chain finaly arrived last week, so here are some more pictures of my build progress:

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The legs stick through the main plate so that I could lift the entire machine by about 20mm if I ever need some more Z space.

 

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The bottom_corner and lock_corner parts are solvent welded together witch acetone.

 

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XY gantry, this was a bit difficult to get square, it’s still 1mm off at 300mm distance…

 

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Z axis.

 

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The drag chain for the Z axis and spindle/laser cables.

 

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Drag chain for the Y axis. I use 10mm steel reinforced GT2 belt, I know it’s not necessary but it’s what I had lying around…

 

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Since the spindle tended to get very hot on my old cnc I decided to print a replacement fan that should keep it cooler. It holds up to 10’000 RPM and moves a lot of air.

I hope to finish the build this week, the only things left are the electronics and the calibration.

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Finish is a strong word…“Use it this week” is more like it. There is always fun stuff to try out.

Cool build!

Holy crap! The spindle should support itself now! :lol:

I didn’t even think about that, the additional lift should make it a bit lighter ?

And yeah, finished is the wrong word, I hope to get it running so that I can cut the parts for the electronics enclosure.

After that there are some small things I would like to make, and since I live in an apartment I should build an enclosure for the entire MPCNC to reduce the noise a bit…

You know, if you bumped the RPMs up a little more you could do away with the Z stepper, just fly up or down as needed. :slight_smile:

Well, why not take it a step further and just mount the spindle to a quadcopter?

No more gantries that take up all the space in your garage and infinite build volume! ;D

Shit, now I’m actually thinking if something like that would be remotely possible :smiley:

And it would blow chips out of the way as well.

Have you seen the videos of quadcopters painting fences? I think there’s still a lot physics that aren’t going to be modeled well enough to measured fast enough to make that work… But it would be fun to try! It might be more possible with something that gives you less force back, like extruding paint, and in an environment with accurate measurements, like fixed IR cameras and fiducials on the quad. Maybe lasers?

Since the quadcopter moves by tilting, the spindle would have to be mounted on a gyro. As an added bonus this makes it into a six axis machine :smiley:

And I don’t remember the name of that router that is a mix between cnc and handheld… It uses a camera, markers on the workpiece and a display to guide the user in moving it, and it has an inch or so in the x and y axis that it can correct if the user pushes it of the path. The quad would need a system like that to correct for turbulences…

Everything is working :slight_smile:

I did a quick square calibration and it was only off by less than 0.5mm on a 500mm diagonal.

I have different stepper drivers for the X axis than the rest of the axis, and even though they are all A4988 drivers, the current sensing resistor seems to be different. On the X axis I have set the potentiometer to 0.75V and the drivers get a bit hot, on the Y and Z axis I have it set to 1.2V and they barely get warm. All motors stay cold to the touch.

And here’s the crown test:

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I didn’t have any paper at home, so the whiteboard and marker had to do :slight_smile:

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So it turns out that the steel reinforced PU 10mm GT2 belt is too strong, or rather not flexible/bendable enough.

To get it tight enough for it to run nice over the pulley I have to tighten the cable ties so much that the force on the motors is too much and they start to lose steps when going too fast or when encountering a small obstacle.

I ordered some normal glas fiber reinforced rubber 6mm GT2 belt which should fix this problem…

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I’m working on the calibration again, the spindle is perpendicular to the board now.

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Tomorrow I will face the spoilboard, drill a bunch of holes into it and add some threaded inserts.

Still waiting on the GT2 belt…

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2 steps forward, 1 step back…

The spoilboard is faced and has a bunch of holes drilled for indexing pins, some of them have threaded inserts for the clamps:

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And I built an enclosure:

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But for some reason I thought my table was 900x800, when it was actually 1000x900, so I can redo all of that work :confused:

1 Like

What? No!

You need to learn to build things too big to start instead of too small… Much better in the long run to cut it down instead of trying to cut up. :slight_smile:

What you need is a board stretcher.

I’ve been heard to say, “dang it, I cut it twice and it’s still too short.”

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Just to clarify, I have to redo the enclosure, not the entire MPCNC :wink:

I got all the boards and I’m headed to the local makerspace to cut and drill everything :slight_smile:

This time I triple checked everything, but I still have the bad feeling that I will mess it up again…

what’s the specs of your spindle? it looks like a generic Chinese unit which i am looking at getting. I’m just not sure how many watts and what controller.