I’m still (slowly) working through using the Little CNC Milling Machine. I (mostly) successfully milled a PCB, but before I did that I managed to grab a piece of HDPE and mill something.


I started with a vector file of one of the Milwaukee Makerspace logos, taking just the (“new style”) helmet and I brought that into MakerCAM to create the cutting paths. I created a pocket for the inside part, and used a profile for the cut to remove the part from the material. Since I was just using one bit I exported both jobs into one file so it could run it all at once, since I didn’t need to change tools.


I then used GrblController to connect to the machine and send the G-code needed to cut the part. I’m still not convinced everything is working as it should be, because either I keep doing the math wrong (possible) or the machine seems to step down farther than I expect it to. More experimentation is needed.


I secure the HDPE piece down to a piece of MDF that is attached to the bed of the machine. The bed is a piece of Aluminum and I’d rather dig into the MDF if I go to deep than carve into the Aluminum. I’m still not totally happy with what I’ve got going on with the bed, but I’ll work on that another time.


Let the milling begin! Again, it seems like the machine was going a bit deeper than I estimated. I’ll have to work on getting the speeds & feeds more dialed in, but that’s pretty much a true statement with every CNC machine & material combo, right?


Here’s our final piece. I made the pocket deep enough that you can actually see some light coming through. Nice! There’s one little bad spot around the outside cut. I should have added tabs to hold the piece down, since it shifted a little when it was finally cut all the way through and the bit took a bite out of the material.


In a way, this is an update to my original HDPE milling experiment, which is fitting, because I used a Shapeoko the first time. Now, when the Shapeoko was first presented on Kickstarter it was presented as a CNC mill that would cost around $300. Well, it ended up casting quite a bit more, but six years later we’ve got the (under) $300 CNC milling machine you can have at home. Yes, the work area is a little small, but we’re going to rectify that in the future.

Pencil Sharpener

It seems like most of the houses I’ve lived in had this feature… you could go into the basement with a pencil and there would be a pencil sharpener attached to the wall (or a wooden post) and you could sharpen a pencil.

This “feature” was something I just expected, and when I went downstairs into my basement (where I already spend a lot of time because my workshop is down there) I realized there was no pencil sharpener! Then I thought about it, and remember that (even though we’ve lived here for over three years) there was no pencil sharpener in the basement! Well, there was, but it was a crappy electric one that fell apart and then I fixed a few years ago. Oddly enough my mind just filled in the spot that says “there is a pencil sharpener on the wall in the basement” even though there wasn’t.

So I asked people… Have you lived in a house where there’s a pencil sharpener mounted to a wall in the basement? And over 100 people on Facebook replied.

I distinctly remember the previous house we lived in had one. I didn’t take it with us because we didn’t own the house, and I just figured it was a “feature” of the house, like a stationary tub or whatever. You wouldn’t take the stationary tub when you moved, would you?

Doctor Prodoehl has a pencil case with many pencils (she prefers the Mirado Black Warrior) and she has tiny pencil sharpeners that are portable. I wanted a classic wall mounted pencil sharpener in the basement, dammit! So I ordered one…

I found the X-ACTO KS Manual Pencil Sharpener, Metal Finish for $9.99 on Amazon Prime. I had it in two days. It’s glorious.

Pencil Sharpener

Now, when I decided to mount the pencil sharpener to the wall (or a wooden post) I had some problems. I mean, where should it go? I didn’t want it in the way, but wanted it accessible. I opted for a wall near our “storage” part of the basement. Here’s where it gets tricky/weird/problematic.

First of all, the sharpener came with two screws but the base has three holes. Weird. I then drilled two holes, screwed in one screws, then the second screw, and the head snapped off the second screw. Argh! This was okay though, because I then realized the spot I had chosen didn’t even allow for a brand new pencil to be sharpened because it was too close to a shelf to get a pencil into the sharpener!

I then drilled more holes, and moved the pencil sharpener to the right a bit. Plenty of room for pencils! I also used some larger drywall screws. It’s in there good, and should remain in place… until we move, when I remove it to take it with us. Just in case.

As for that photo above, yes… you can see the word “BiBle.” on the wall. Which is pretty weird. I mean, I’ve never noticed it before, but it is in a darker corner of the basement, and I’ve never really shined a bright light on that wall, or used a camera flash on that wall. What does it mean!? Hell if I know!

When it comes to 3D modeling for the majority of the 3D printing I do, I tend to turn to OpenSCAD. OpenSCAD is known as “The Programmers Solid 3D CAD Modeller”, and it’s free software available for Linux/UNIX, Windows and Mac OS X. Yeah, you create objects by writing code. It’s weird, but so am I.

If you’re one of those cloud-loving weirdos (who also uses Chrome) you can also opt to use, which is a (blah) “browser-based” version of OpenSCAD. Sort of. It definitely has it’s usefulness (Chromebooks!) but anytime I can download and install an open source application, I’ll opt for that route.

Now, once you get used to OpenSCAD (assuming you want to) you can refer to the cheat sheet or read the entire OpenSCAD manual. But suppose you don’t exactly want to write code, or you aren’t good at it yet… Perhaps BlocksCAD can help.


BlocksCAD puts a “blocks” interface on top of OpenSCAD. You may have seen this block-thing in use with Scratch. It’s a good way to teach kids how programming works. (There’s an Arduino-ish block application call mBlock that works with the Makeblock robots. And yes, there’s lots more scratch blocks stuff out there.)


I took a model I made in OpenSCAD last week and recreated it in BlocksCAD. It took quite a bit longer (probably because I can write code fairly quickly) but the results were good. The blocks really help show the structure of things. For anyone whose had to remember bracket placement, semicolons (and tabs & indents if you care about readable code) the blocks interface hides all of those things. Again, possibly a good thing for beginner coders.


In BlocksCAD you can toggle between the blocks interface and seeing the code. This is great, as you can see the code that gets created by the blocks. Note that you cannot edit the code in the code view. This is (slightly) annoying, but I can understand why this decision was made.

There are things that BlocksCAD doesn’t support, but the basics are there. (I’d love to see comments added.) The basics are enough to get a beginner (child or adult) started with building blocks into a program that generates a 3D model. Sweet!


You can also easily share the models you create. (Okay, that’s probably the one nice feature about a browser/cloud-based thingy.) You might notice from the image above that the holes are weird looking, as in, not very round. What’s going on?

Rod Holder

Here’s the original model that I created in OpenSCAD running on my computer. Note that the round holes are super-round! I get them round by adding the line:

$fn = 100;

to the top of my code. The $fn thing controls the number of facets used to generate an arc. It’s the difference between a round circle and a low-resolution circle consisting of x number of flat sides. (You can also use the $fn to allow you to quickly render models by setting the number low, and then raising the number before you do your final render.)

Rod Holder

Here’s what I got when I copied the code from the “code view” of BlocksCAD and pasted it into OpenSCAD and rendered it. Blah! Low-resolution holes. If I added my $fn = 100; line it rendered what I really wanted.


Okay, so I also downloaded an STL file from BlocksCAD and it looked like this. Hmmm, much better quality than the low-resolution version I got from the code I copied. So what’s up? Well…

When you render objects in BlocksCAD there’s a “smooth” option with Low, Medium, and High settings. So, if you choose the High setting, you get a much better model. The code view doesn’t show whatever the $fn/facet setting is for the model, but it must be adding it when it does the render. Makes sense.

BlocksCAD has a few quirks, but I think it’s a great concept. While I’d love to see a downloadable version, I hope Einsteins Workshop continues to provide the web-based offering for those who want to use it.


Here’s an old project I never wrote about… Every now and then I just experiment with things, and this piece started with using Inkscape for an illustration of a rocket. Here it is. Pretty boring!

Rocket digital

I ended up creating a scene for the rocket. Look, it’s going to Mars! Someday I’d like to go to Mars…

Since I tend to think of any illustration as cutting paths I tend to avoid strokes and just use solid objects, which comes in handy, especially if you decide to use digital fabrication techniques to create things.


I next took my illustration, which was essentially a two-color design on a black background) and created color separations. One for the silver, and one for the red.

Cut lines

I then created DXF files I could load into Silhouette Studio so I could cut stencils and paint the scene onto an 8″ x 8″ canvas. (Yes, sometimes I mess around with paint.) You might also notice I added registration marks, these are things you learn from years of working in the print industry and printmaking.

Rocket on canvas

Here’s the result of cutting two stencils and spray painting them onto a black canvas. It turned out okay, but I didn’t love it. (Probably because I don’t love painting.) What I do love is the fact that with vector artwork it’s easy to scale things, so I did.

Rocket on wood

Here’s a 12″ x 12″ version of the artwork, but this time I used a piece of painted wood and just applied cut vinyl to it. I really like how this one turned out. In fact, it’s hanging in the shop right now.

Sometimes I get so caught up in creating 3D (or 2.5D) work that I forget how much I like doing 2D stuff. I should probably do more in the future.

PCB Milling

One of my goals with the Little CNC Milling Machine was to make my own PCBs. I’ve typically made my own printed circuit boards at home by etching them with chemicals, but the mill opens new opportunities to etch and drill the boards, so I gave it a shot.

I knew the basics, but did a a quick search for posts that might explain things a bit more. (I should note I planned to use Fritzing, Inkscape, MakerCam, and GrblController, all free/open source software available on multiple platforms.)

The two useful posts I found were: PCB designing and isolation milling using only free Software and Hello World, How to Mill Printed Circuit Boards (PCB).


I wasn’t really planning on documenting this in-depth, but I got a few photos and screenshots, so I’ll share what I can. I had some bits I grabbed from eBay, 0.1mm Carbide PCB Board 60 Degree V-shape Engraving Bits and 0.8mm Carbide PCB Endmill Engraving Bits (a total of 20 bits for under $10) to work with, so that’s what I used. (I may want to try some 45 degree bits and 0.6mm bits next time.)

Milling Traces

Here’s the “isolation milling” I did with the 60 degree engraving bit. Not bad! You can also see a little mark on the copper board where I homed the machine.

Yeah, I did not have double-sided tape, so I just tapped the board down to my spoil board. The board wasn’t completely flat, and bowed slightly in the middle. I’ll use double-sided tape next time, which will also help with cutting the final profile of the board.

Set Home

I swapped the bit from engraving to drilling and drilled all the holes. It seemed to work well, so… yeah. (Sorry, no photos of drilling!) I then switched back to the engraving bit to (attempt) to cut out the board…

PCB Milled

It worked, but I miscalculated how deep it would need to cut, and ended up lowering the z home and re-running the job again. I might want to use a different bit next time. When I thought the board was cut out enough I pulled it off the machine.

Light Test

The board held up to the light. Oops! Well, the holes didn’t all work. They were close, but not quite all the way through. I ended up using my Tiny Drill Press to finish the holes, and it didn’t work very well as it was difficult to hit the center. Not great.

I also didn’t cut all the way through with the outside profile. Not a big deal for this board, as it would be easy to cut out on the band saw, but more complex boards may not have this luxury. No matter, the amount of board left was paper thin and it came right out. I’ll definitely use a different bit for the final cut next time.

Final PCB

Here’s the final board. It totally worked, but there’s plenty of room for improvement. This probably won’t be the method I use for all my boards. OSH Park does a great job and prototyping PCBs, and Seeed Studio is great for production runs, but I’ll probably mill any new boards I want to test out before sending out to a fab house. Milling also allows me to have a PCB in an hour or so, versus waiting a few weeks.

Of course I’m (sort of) limited to single sided boards, but most of my PCBs are pretty simple, so I’m not concerned yet. Also, once I master the single sided board, I’ll certainly try a two-sided board, I mean… how hard could it be!?

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