My New MPCNC

Hi All

Just finished the basic build on my CNC, have to admit its been a fun build although having a crappy 3D printer excruciating at times.

Altogether its taken me 2 weeks to get to this point and done my first plot with the unit.

Completed Unit

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Plotting Test

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Temp Home Made Motor Splitter

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Basic Electronics

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So far the build has went pretty well, I do have issues with alignment and my Z Axis is out by quite a bit so I will have to see what I can do with this.

Learning the CAM software will be fun but that’s for another day.

Still To Do

Create Housing for Electronics
Create a better wiring system
Fix alignment and Z Axis

All in all I am pleased with this build, for a CNC machine I have to say its been quite an easy system to build, some time, lots of plastic and a few steel bars, motors and electronics. For anyone that is interested in building one of these and is not sure, its beginner friendly and all the instructions on the this site and help from the forum members will easily get you through the process.

My reason for this build will to be to use it for building Scale Models, currently building a 1:100 Scale Build of the Bismarck (2.5m long gah, all 3D printed so far, if interested I will put some photos on here)

Cheers

Druid

 

Are your motors wired in series? It reduces the heat of the driver considerably. I can’t tell from your fancy-shmancy perf boards.

Hi Jeffeb3

Its basically a copy of the Vicious wiring loom just using a little PCB to plug the motors into, so I think the wiring room is series so my little PCBs are aswell, the only reason I did this was I didn’t have the vicious wiring looms and didn’t want to cut up my stepper motor connections.

Hi All

Slowly getting there, fixed my issues with my Z axis hopefully.

Working on the X and Y square, its not too bad, getting there, tolerances quite good aswell even if the squares are offset.

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The 20mm square is sitting at 19.98, the other squares were pretty much the same +/- 0.02 - 0.04mm. The thin rectangles not so good, but more to do with the squareness and the thickness of the pen point.

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Cheers

Druid

Hey All

Before I go out and buy a more expensive spindle I am planning on using my Dremmel until I get used to the machine, anyone got any advice on bits, looking to cut plastics and thin wood up to 3mm at the moment, also some surface engraving but this has to be fine in the 0.1mm, 0.2mm range.

Cheers

Druid

The dremel has enough power to handle deeper cuts, as for bits I am not sure the collet size but 1/8" or 1/16" would be a good place to start, single flute. For your fine details get a nice v-bit.

The problem with the dremel is the runnout, so fine details are harder to get. On most dremels you can physically wiggle the collet, not usually a problem on how most people use them, but different when being used as we do in the CNC.

Hi Ryan

Thanks for the reply, I will have a look for single flutes 1/8 or 1/16 will work as I can get away with 3.2mm bits.

I am hoping the runnout will be fine as I replaced the collet and collar with a proper chuck and there seems to be no wiggle or play, its seems solid at the moment.

Cheers

Druid

 

Hi Ryan

While I am waiting for my Dremel Bits and some more PLA filament to print a Dremel Mount for my CNC I decided to quickly add Endstops and 2 new wires for the steppers to try your auto squaring firmware.

I am only using the LCD at this point, looked into the menu and I take it you haven’t added the possibility to control each stepper motor just to test they are working and no checks for the endstops?

Cheers

Druid

That is not possible as far as I know, it only happens during homing. When you move an axis they commands are linked like Siamese twins. so to test they are moving in the right direction I just move an axis in small steps if they both move in the right direction, home that axis and you will see the magic happen if your axis is not square. from there you can either move the endstops into perfect position or adjust the offset in the firmware. The M666 X1.2 will let you test for a value to put in the firmware (X is either X or Y, 1.2 is mm and can be any number).

You are in some uncharted waters here, be careful. You are the only one to try this as far as I know other than me.

Also, before you home, you should check M119 from the console to verify the endstops are triggering right.

/Unsolicited advice

Hi Jeffeb3

When I load up the serial monitor in Arduino what I get is unreadable (e⸮⸮⸮⸮N⸮P,⸮⸮⸮n⸮⸮) and when I send M119 it does nothing.

Any Ideas?

Cheers Druid

Ignore last question, forgot to set the baudrate!!!

Arduino serial monitor works fine, but you should try pronterface or repetier host too (in your copious free time). They have the console builtin, but also have buttons for common things like movement and hoping.

You still have to set the baud rate though. :slight_smile:

Hi Jeffeb3

Moved to Pronterface, its quite good, thanks.

Setup up all my axis and Endstops, modified the configuration file to set my Endstops to normally closed as I prefer them that way for safety reasons, hopefully the Mega has enough protection against Endstop jittering.

Have to say good work Ryan and Jeffeb3, it works really well, going to leave it on autosquaring and do some plot tests and cut tests with it, initial tests though I created a 50mm x 50mm square, 100mm x 100mm off Zero and the pen hit the exact start point of the square each time, the only thing I cant figure out is when I home my Y the Z homes aswell, not a big deal as long as I remember to adjust my Z up before powering on, before I rip up my wiring is this a software default?

Cheers

Druid

Great. A new guinea pig, if we make changes.

That’s not how it’s supposed to work. How are you commanding the home?

Hi Jeffeb3

I am just using the Home X and Home Y commands in the LCD menu to test the homing functions.

Hmmm. OK. I’ll have to look closer at that. That shouldn’t be happening. I don’t know what that choice in the menu does, but it’s probably just trying to home Y, and there’s something in the code that’s making it also do Z.

If you get a minute, can you try it with G28 Y from the console and see if it also does the Z?

Hi Jeffeb3

Sorry I made a mistake its when I am homing on the X not the Y, from what I can see it only moves the Z down when homing for the first time after machine has been switched on, after that everything seems ok.

Ryan not sure how but my forum post seems to have split into two, I now have this post and a post with just my very first post in it.

Hi Guys

How tight should my belts be? I seem to have issues with stuttering and skipping and since I can play a tune on my belts I am wondering if I have them to tight?

Yea, that’s probably too tight.