"The HULK" - Mean Green (and Purple) Primo - 600x440mm - Orlando, FL

I have to say, I am in love with this machine. Don’t get me wrong, I still love my LowRider build too, but there’s something immensely satisfying in watching this dual-endstop beast zero itself out. And with the Z-touch plate, there’s no more back breaking or standing on my head trying to get the machine ready for a job. Just simple and easy. And I’ll admit I spent a lot more time getting every last thing perfectly square on this machine than I did with my first build.

Footprint: 37" x 29"
Usable: 600x440mm (23.6" x 17.3")

I’m not going to tease you with pages of printed parts. Let’s get straight to the money shot!

Please note: Not an official MPCNC Primo logo. I was just messing around.

Now for some details:

The foundation is a plywood torsion box (3/4" faces, 1/2" slats), plus another 3/4" MDF for the top face. The individual slats were cut on my LowRider build.

I added 40mm fans to the steppers to keep everything nice and cool. They are wired to distribution blocks on the side of the machine. They run on their own 12V power supply, but turn on automatically with the main unit by way of a 12V automotive relay.

Raspberry Pi with V1Pi and CNC.js.

Power and spindle switches. The spindle itself is activated by relay strip from the fan header, but can be defeated at the switch in an emergency.

Remixed midway risers for X-axis support. The original design came from Thingiverse but they did not have the proper clearance for the bolt heads, so I had to cut out some notches with my limited Fusion 360 skills. All good now; nice design, otherwise. I may add a link to the updated STL at some point, but it got resized by a factor of 10 somewhere along the way and needs to be corrected.

The feet are elevated 3/4" over the table surface. This allows for the spoilboard to be set below the feet. These images are of initial test results and verifying of machine operation — performed after tramming the spindle. The final spoilboard will be a solid piece instead of scraps and won’t have brad nails in it, though the machine didn’t seem to care about the nails. I used a 1/2" Freud dovetail bit to surface the current boards, as I couldn’t locate my clearance bit at the time. The spoilboard itself is recessed 1/4" into the table top.

Equipment drawer and spot for LCD panel (if ever needed) and Z-touch plate.

I’m working on some ideas for dust collection. Rapid prototyping was done on the laser cutter using poster board to determine precise fitment before firing the acrylic part. Initial concepts fit well, but the hope of using the Z-axis tubes for vacuum (per Thingiverse) did not yield enough suction. This is a work in progress and more will come. The neodymium magnets are plenty strong, but I think it needs some sort of pin/slot engagement between the attachment and the base to ensure it doesn’t slide horizontally.

I would say that figuring out the dust collection is high on my list of things to do…oof.

As a final note, I’m thinking about downsizing my LowRider to handle 24"x48" sheets and gaining back some space. It seems like it may be the best combination of form and function.

Thanks for looking! If you have any questions, let me know. I look forward to seeing more of your builds too.


Thanks for posting. I’m pretty interested in what you come up with for a spoil board.

Also, I had a barney dinosaur flashback…



That may be for the best. I would worry about all that extra torque being added to the top of the z. It’s a cool idea though.

Have you juiced up the current to the steppers or been having heat issues?

Most excellent build, dude!

1 Like

I love this build. You really care about it and you have patience to solve all the issues on your list. It really shows. Thanks for sharing.

I also really like that primo logo.


I definitely wasn’t going for Barney, but I see where you’re coming from. Maybe I could do a little device orchestra and get the steppers to play the tune…lol.

I’d love to see a CNC plan for something like: https://www.ronsusser.com/inventory/listing/1950-chicago-coins-band-box-jukebox-orchestra-speaker-beautiful-condition/

1 Like

That’s a fair point of concern, but I should note that the vacuum hose is coming from above and, if anything, pulls upward. But it is definitely on my mind to ensure the core remains level.

I haven’t juiced anything up regarding the steppers at this time. I just know the steppers tend to run a bit hot, and my Florida garage is already a sauna. I also know that I have a tendency to leave the machine powered on for long periods of time, including overnight, when I pause multiple times during a long project. The fans just add some peace of mind, and happen to look pretty cool too.

Thank you for the kind words!

That’s pretty cool. I would imagine those people are hand carved though? I’ve tried looking for CNC plans a few places and not had a ton of luck, although I have bought a few 3D models and DXF files from Etsy. Most of the stuff I want to do I can usually design in Illustrator — I’m good with 2D, pretty rough with 3D.

I was really thinking something more like this: Country Roads on Electric Toothbrushes

I really appreciate the kind words! Thanks!

When I was a small boy vacationing at the NJ shore with my family we used to go to a burger/dog place in Neptune NJ that had one one these on the wall, I was mesmerized! :grinning: I could probably figure out the mechanics to get the band members to move as one, getting the horns to move differently from the strings and the drummer differently again would be more difficult. And I’d be completely lost in the electronics required to make things work in time to the music. But these days I’d think 3D printed ‘musicians’ would be acceptable. Some things just stick in your head for many years and for me, the BandBox is one of them.

1 Like

Wow, excellent build!
Not a big fan of the color choice to be honest, it makes it look cheap despite this being actually one of the highest quality build I’ve seen so far (but that’s just my opinion )
But it doesn’t really matter, it’s a tool after all, the colors need to disappear under a nice crust of dust anyway!

I suggest you to protect your wooden table using some kind of wood sealant (epoxy, clear cot, oil, whaterver). That will make it look even better and also prevent it absorbing humidity which might warp it.

Again, really well done, great work! Impatient to see some stuff you made with it!

1 Like

My second attempt with dust collection. So far, the results have exceeded my expectations! The video below shows a short clip of 0.07" clearance with a 1/4" end mill. There were only a very minimal number of chips remaining when finished. For the total volume of wood cleared, I was very happy.

Note: It wan’t particularly loud in my shop, but the recording seems to have amplified the sound.

New base plate and shapely vacuum tube attachment.
One of the things I wanted to accomplish was to retain the usable space of my initial design. This specially-shaped vacuum attachment allowed me to keep all dimensions intact by squeezing everything into the available corner area.

In a MacGyver move, I’m using a shower curtain loop with rollers and a spare bungee to redirect upward tension from the vacuum hose to the X-axis in an effort to avoid placing any torque on the core. So far, this seems to be working just fine, and frankly it could look worse.

New dust shoe attachment.
I reworked this attachment for the new configuration and added 5 “pins” that slot into the underside of the base plate. It is completely removable. The strong magnets hold it on, and the pins keep it from sliding around. The open notch helps to take it on and off more easily by allowing it to slip around troublesome parts.

If anyone is interested in the plans, I’m happy to share. One thing I will point out about this design is that the base plate fastens directly to the core, so it does NOT move up and down with the spindle. I actually prefer this, so it’s not continually jamming the brush farther into the work-piece as it reduces Z-height, but it’s unlike most of the designs I’ve seen, so I thought I would point out this distinction.

Thanks for looking!


That is some serious dust collection engineering. Nice work.

1 Like

Thanks! I still have a lot to learn when it comes to 3D modeling, but this turned out to be a good project to work on the basics. YouTube has been an invaluable resource. It has definitely given me some more confidence that I can create additional parts if needed. And that’s really my only goal with all of this, to learn and grow my skills, so I’d call it a resounding success.

1 Like

That is a great attitude. I stopped trying to make furniture that my wife would appreciate and just focus on learning and shop projects. I have the skills to make her some things she does appreciate, but I don’t hang my whole hobby on those projects.

1 Like

This looks great. I’d love to get a copy of the models and see how this would work on my setup.

@jchaager Here is a link to a Dropbox folder with the items.

Please note, this is designed for use with the V1 Makita RT70x mount (included).

What’s included?

The vacuum attachment and dust shoe attachment are each 3D models in STL format. There are also a couple of renders of each item.

The core base plate is a flat vector file included as both DXF and SVG. Please note, the BASE PLATE IS INVERTED since all of the pockets are to be made in the bottom of the plate. I cut mine on laser, but it could just as easily be cut on CNC. I have not turned this one into a 3D model, though it would be pretty straightforward to do so if someone needs help with that. I chose 1/2" acrylic for the strength and rigidity, and ease of cutting on the laser.

The Makita RT70x mount is also included with both the original STEP file and a print ready (rotated) STL — in case you have trouble finding it elsewhere, as I did. Please note, these print upside down.

Please read this first!

My main concern is that the pin slots may need to be enlarged slightly. I relied on the kerf of my laser cutter to produce the small amount room for the pins to slot in comfortably. You may need to adjust the pin hole size, or set your CAM to over-cut by a small amount, depending on your methods.

The same may be true for the vacuum slot, and you may need to dog-bone those internal corners or file them out since the vacuum attachment is rectangular. This is probably something I should update in a future configuration to work with a 1/8" end mill.

The following image is also included in the Dropbox, which contains a legend for machining the base plate, but this will also be important later for installing the magnets. It would be easy to accidentally glue a magnet in a pin slot.

Other notes

  • I affixed the base plate to the core with M4 screws using the existing holes in the bottom of the core. These screws must be countersunk or they will interfere with the shoe attachment.
  • I used these 8mm x 3mm magnets and affixed them with 2P-10 CA glue. Make sure your polarities are correct on both parts!
  • I used this 80mm brush because I already had it available, however, there may be better options with a less obtrusive hem. It was attached to the shoe with simple hot glue. I’m considering creating several attachments with varying brush lengths for different types of jobs since they can be interchanged so easily.
  • The vacuum attachment is designed for a flexible 2.5" hose which should be attached with a hose clamp. Though I only run a couple feet of 2.5" hose before bumping up to a 4" line.
  • The shower curtain ring I used for preventing torque on the core.

If you have any questions or run into trouble, let me know. I can always update the Dropbox if new and better ideas come about. Thanks and good luck!


I’m thinking that vehicle is occupying too much space… maybe downsize the vehicle, not the lowrider!

Looks like the suicide squad. Maybe add a pic of Harley on there somewhere.

1 Like

@jchaager It occurred to me that the internal corners of the vacuum slot are not conducive to CNC cutting, so I made an additional note above.

Also, I have added a new STL to the Dropbox for the vacuum attachment with filleted corners that should accommodate cutting the vacuum hole with a 1/8" bit.

Seriously, the car needs to go! :stuck_out_tongue:

Funny you should mention including a pic somewhere. I actually picked up a sock to go with the Hulk theme to use as a filter, I just hadn’t gotten around to installing it. But you have motivated me. I’ll have to check out the Harley socks, maybe I can find one that’s a more accurate color match!

My lowrider has an Operation sock, but it could use a wash…

1 Like