The Hell Ya Beller Fun with hot, pointy, sharp, and caustic stuff.


Keeping Good Company – Part 2


A couple years ago I was flattered to learn that one of my projects was referenced in a TED talk by the guy that invented the Arduino.  Today I learned that one of my designs has been incorporated into spray painting drone by the artist/vandal KATSU.  The project is fully detailed on the Icarus One website in case you want to build one and make your own social commentary.  KATSU is controversial and I'm not sure how I feel about his work but I think it's cool (and surreal) to see my designs remixed and extended like this.


Maker Redux

For the last eighteen months I've been working with a group building a way for people with ideas to get things made by people with tools.  Here's the big idea:

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Vendor provided CAD data.

I'm going to build an enclosure for my CNC mill to keep coolant and chips from going all over the floor. It took about ten minutes to model the mill table in FreeCAD but modeling all the aluminum extrusions was looking like a lot of work.  Fortunately it isn't necessary


More and more vendors are providing CAD data in their online catalog.  As long as they provide data in one of the non-proprietary formats, it should import very nicely into FreeCAD.

McMaster-Carr's catalog is legendary and many of their products have CAD data associated.  You can download in a bunch of different formats that are compatible with FreeCAD, HeeksCAD, or probably any other CAD system on the planet.

Just click on the part number . In the item detail pop-up there's a CAD link that will take you to a page where you can get 2D and 3D CAD models and also see some dimension data online.



Misumi's site is maybe even better.  Misumi will custom cut aluminum extrusions without a setup fee.  The nice thing is they also provide custom CAD data for the parts you specify.  For example, if you want a 330 mm extrusion, they'll cut it, but you can also download a 330mm model to use in your design.

In the design at the top of the page, I used three different length pieces and played with them in FreeCAD to verify that things would line up on the table the way I wanted.



I wish all vendors provided this, along with detailed specs, schematics, and illustrated parts lists.  If you know other noteworthy vendors, drop a comment.

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Electronics Chassis Modeled.

I have all the little bits for the electronics chassis modeled now.  I think all these parts will be cuttable for me.  I still have to model the endcaps for the tube and some minor cleanup.  Then it should be ready to cut.

In the full assembly picture below, I don't know why the edge of the tube is showing through the wall of the shell.  It isn't penetrating and the shell isn't set to transparent but FreeCAD's rendering is goofy.




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FreeCAD design of OpenROV

A while ago I started thinking about building an OpenROV.  They've got a very successful kickstarter campaign underway but I plan to self-source it.

The project is open but the design files are all done in Autocad Inventor.  I wanted to see if FreeCAD could model everything, so I started redesigning the files as fully constrained sketches.

This means the the critical dimensions of the various parts can be changed and everything else will adjust correctly.  If you want to change the thickness of the acrylic used, it's relative straightforward to adjust the dimensions.

So far, I've done the major frame pieces.


One other change I'm making with my design is the shell.  The stock OpenROV has a large shell that is made from a single piece of acrylic.  It has two 90 degree bends to wrap around the sides.  This is a problem for me for a couple reasons.  First, FreeCAD can't model the bends yet.

More importantly, the piece is too large to cut on my laser cutter and requires a hot wire bender which I'd have to build or buy.

My variation cuts the shell into three parts that are glued together.  It's not quite as attractive as the stock design, but easier to build and will fit in the build envelope of a smaller laser.   I'm publishing my files on github. My next bit of work will be to model the parts inside the tube.


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Scout: A printable tribot


Here's the first iteration of 'Scout'.  A simple printable frame for a robot based on two continuous rotation servos and an Arduino.

The idea was to limit the number of printable parts and 'vitamins' to the bare minimum and keep the total cost for the bot below $50.  I'll use this to teach the robotics merit badge in December.  Here's how the costs breaks down:



  • 2 Futaba S3003 servos or equivalent (modified for continuous rotation).   $4.50 each.  I found deals on ebay to buy sets of 4 for $16 with no shipping.
  • 1 arduino diecimila.  $20 - 25.  Also an ebay deal.  A nano may work better.  I'm still looking into this.
  • 3 o-rings for tires.  $3.00. Might be possible to replace these with rubber bands.
  • 9V battery
  • adapter
I still have to add some form of input.  This can be as simple as a bump switch (couple bucks)  or I may have enough budget for an ultrasound sensor.  Stay tuned.




Fun with a $1.00 pumpkin

I actually made this pumpkin two years ago and had a blast with it.  Most fun I've had trick-or-treating since I was twelve!

I wrote it up as an Instructable this year.


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FreeCAD is becoming my favorite modeling tool

It's taken a while to get used to the interface and there's still plenty of bugs to work around but the FreeCAD project is really moving along nicely.  The sketcher makes designing parts like the ones below really simple.   I learn things better with an actual project rather than just trying to copy tutorials so I launched into this silly thing:


No Secrets: Open-source CAM Application Bares All

Note: The following article appeared in Digital Machinist Volume 5 No. 3 Fall 2010. HeeksCAD has continued to mature since then. The current user interface may vary significantly from the images below.

No Secrets: Open-source CAM application bares all.

In the opening scene of the 1981 movie Raiders of the Lost Ark, explorers come upon an idol hidden in the jungle. Weaker men flee, but the hero, undaunted, continues on to discover a treasure.

The first words on the HeeksCAD website are a little like that: “HeeksCAD is not finished, yet. “ Those who make it past this warning, will face challenges but are ultimately rewarded with a prize: HeeksCAD and it's CAM plug-in HeeksCNC are quite usable – and powerful- even in their unfinished condition.


Custom Grippers – Model simulation in HeeksCAD!

I really love HeeksCAD as a design tool.  There's a lot of features that are hidden like easter eggs and a new one got added today.  This isn't an obvious feature so I made a little youtube video to show how it can be used.