My Adventures with the MPCNC

Finally, all things are squared and ready to roll! Now I just need to get the settings figured out for Estlcam on the MEGA/Ramps (is there a definitive recommended setup yet?)

The uploaded pic is how it looked a month ago and for the life of me, I could not get the Z assembly to square up. PETG and ABS make up the parts and they just seem to have too much give. I reprinted the 525 middle assembly in PLA and slapped it in place and everything is sitting damn near perfect now! (pics of that soon)

I’m stoked to get this beast running now! Primarily it’ll be for engraving/cutting but I’ve also put together a laser kit that will need some attention soon.

Ohhh, you’re brave! You have an endmill installed and it’s sitting on the kitchen table! SHMBO will not be pleased!

Haha, it didn’t last long in this position/state. I was given orders to remove it before Thanksgiving even though I told her the laser could cook the turkey then the Dewalt could carve it perfectly! It’s now in the garage on a proper table.

Here’s the current state of affairs; still need to do up an electronics enclosure and figure out my workpiece clamping. Thinking about the drag chains to keep wires clean and need to 3d print a Frickin Shark to hold the Frickin laser beam!

Let us know how that laser driver works. I have been contemplating upgrading from the cheap Chinese driver I have to one like that or a slightly different one from eBay.

Okay, a shark shaped laser enclosure would be epic!!

I wanted to do that so bad! I figured I could get a nice shark stl from grab cad and just cram my current laser holder in it in solidworks. I think it would be hilarious!

No shark yet, but some progress. I snagged a Ramps Enclosure from Thingiverse and modded it, needed to cut out near the printer port and power input after the fact as the kit was slightly different. I’d likely split the black pieces into 2 if I was going to print it again.

Today’s mission is to try to get the MPCNC to draw a picture. I mounted the ‘Spring Loaded Pencil Holder’ and just need to figure out how to make the code. Hopefully back soon with some results!

Video uploading…

Results attached. I used some scrap cardboard and my designer material clamping system (patent pending).

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I rushed into trying my first cuts today and messed up the settings in Estlcam somehow…need to go through the basics again. Some cuts went well and deep enough but others were above the wood and some only scratched the surface. I also need to get some proper bits to do this for real so order has been made.

I built up a dual outlet power box with a remote dimmer switch for spindle control until the relay gets here as well, but of course I wired the dimmer backwards and it’s full power when I turn it on then fades to low as I increase the rotation. Derp!

No pics until I clean up these little things and try again. Maybe tomorrow with any luck.

What size did you make your work area

Is ABS too soft a material for the printed parts?

Very cool build…going to start working on mine ASAP!

P.S. OSHPark board in this image http://d1wtzfwblm06ov.cloudfront.net/wp-content/uploads/2016/10/03-128x72.jpg
Got a link?

ABS is okay but it has some flex and these are long prints so warping is an issue (for me anyway). I used PETG for the flexing parts like corner pieces and clamps and initially used it on the center assembly. I couldn’t get it to square up at all though so redid the center in the new 525 design with PLA for ultimate rigidity. Perfect square right on installation! I made a few parts in ABS but some cracked with fastening.

Originally mine was 38 x 38 but I shrunk it down a couple inches each side so I can put handles on the board to make moving it easier.

To answer your question (that I missed), the laser and small board are from here; https://sites.google.com/site/dtrlpf/home/diodes/6w-nubm44-445nm-laser-diode
and the larger Optlaser board is from Optlaser.com

I also tried a second time to cut with the CNC and found it wasn’t a code issue but my Z-Axis was binding which caused it to raise but not fully lower. Loosened the coupler from the bearing up top and greased the leadscrew and away she went.

Burning wood on this one as I’m using a drill bit, but I put in an order for some real end mills so more to come. Now to focus on the Laser.

Looking good! i’m curious about how strong that laser is going to be! Try cutting some plexiglass :slight_smile:

Dang more than 6W! That is a big kid toy for sure.

Yeah, that’s why i’m curious how it compares to the popular 2.8watt laser here. And it only costs 120 dollars, so i’m a bit skeptical/don’t know how much power it will actually have…But to be honest, I barely know anything about lasers. :stuck_out_tongue: So it’s always nice to see somebody else try it first.

Jay from Jtech put the specs up on a different thread the higher the power the larger the focused spot size (https://www.v1engineering.com/forum/topic/mpcnc-laser-engraver-checklist/#post-19662). I know it doesn’t go all the way up to 6W but I’m sure it follows a similar trend. Other than that who doesn’t want more power!

I’m a laser noob myself… won’t the intensity of the laser determine the focal dot size? I honestly don’t know yet but will report the results.

The Optlaser driver will accept PWM or TTL and is rated to 5A so should do the trick. Now to figure out what software will create G-Code with PWM and will that run off the RAMPS D9 terminals? It also allows for a ‘TEC’ module but I have no idea what that is. Admittedly, I’ve been more focused on the initial build and getting the rotary cutting, Laser is secondary so has largely been ignored until now.

I still have a lot of research before hooking things up but those are some of the questions I’m going to be answering along the way. The cost of the 6W VS the 2.8W JTech…I’d chalk that up to the 6W being a simple laser and casing and the JTech coming with that kickass control board, support and QA.

I went for the big dog to try cutting other materials but will be getting a more reasonable laser as well if this one doesn’t allow decent engraving/etching. The MPCNC is going to be my ‘Do anything’ machine with heavy focus on modularity with tool choices.

Lens generally will control dot size.

If you are going to be using D9 you do not need to remap your pins in the firmware. Image2GCode for example, you tell it the code that it should use for controlling the laser. I believe it still would be M106 S for fan control (for marlin). Default setup will use D9 as the fan.

A TEC is a thermoelectic cooler. You would use a tec module to cool your laser. They are little blocks essentially that have a hot and cold side. Would attach the cold side to your laser heatsink and a fan to the a heatsink then to the hot side.

The Nubm44 diode is definitely more powerful but will have a larger spot size than the NICHIA ndb7875 with the same lens type. Should still be able to do decent engravings though.

I’d double check before using the D9 PWM directly. It’s modulated but it’s a 12 volt PWM SIGNAL and most drivers run off 5volt PWM. I took a quick look on opt laser site and found this…

Looks like D9 is out, looking at the docs and this driver wants 5V for analogue but I saw something on remapping the pins so not an issue. I’m intrigued by the data on the post about the focal dot size;

1W 405nm : 4 MIL = 0.004″ = 0.1 mm = 100 micron
2W 445nm : 8 MIL = 0.008″ = 0.2 mm = 200 micron
2.8W 445nm : 9 MIL = 0.009″ = 0.23 mm = 230 micron
3.8W 445nm : 15 MIL = 0.015″ = 0.38 mm = 380 micron

The huge jump from 2.8 to 3.8 would seem to indicate my 6W is going to be quite unsuitable for fine detailed images but should still be fine for cutting. Is there any data on sub 1W lasers? Do they put out enough to burn wood? More research needed :slight_smile:

Thanks for the TEC info, my Google-fu was weak yesterday and the few links I followed told me nothing. I’ve bookmarked a few Laser specific forums so will check around in those as to when/why I’d care about a TEC setup.

On order and holding me back;

  • Proper end mills for the DeWalt
  • Laser heatsinks x2
  • Shop Vac (should be here Tuesday!)

I fired up the Image2GCode program and it seem really simple, also appears to give the proper PWM in the Gcode on quick perusal so it should do the trick. I’m also playing with S3D which I use exclusively for printing but can’t seem to import the .NC files from Estlcam. More play needed.

Edit: just saw your post Leo and you’re right :slight_smile: