Mark VanHorne

Retired Boeing Technical Fellow. 41 years in commercial airplanes production engineering.

Environment Sensor

I live in an area in eastern Washington state that gets wildfires during the summer.  There have been a few small ones recently, and this week the temperatures are going to be in the high 90s and low 100s which will greatly increase the fire danger.

I built an environment sensor to measure temperature, barometric pressure, humidity, airborne particle concentrations, and light intensity.  From those data, I calculate dew point and heat index.  I write all the data to a small TFT display and drive everything with an Arduino Uno microcontroller.  This way, I can measure atmospheric conditions to get my own data about the potential for fires and their impact on air quality.

I built a prototype system on a solderless breadboard to get everything working correctly, and then hardened it by mounting the components on a base that I designed and printed on my Prusa MK3S and soldering the electrical connections using a "perma-proto" board.

To design the base, I imported models of the arduino and the perma-proto board to use as reference geometry.  I created construction geometry of the axes through all the mounting holes and projected those axes onto a base plane.  I didn't have a 3D model of the TFT display, but I did have a 2D drawing provided by the manufacturer.  I took the dimensions of the display and created more construction geometry to get the locations of the centerpoints of the mounting holes.  Once I had the mounting hole locations, I created bosses at each point and extruded them vertically along the Z axis until they contacted the lower surface of each component.  I added 3mm internal threads to the bosses.  I then drew a sketch of the shape I wanted for the base and extruded it.  Added some fillets around the base of the bosses and the base was done.  I printed it on my Prusa MK3S and it came out great.

Attached file shows what I built and what the Fusion model looks like. Last slide is photo of the "view" off my deck in September 2020 when the Cold Springs Canyon Fire drove the Air Quality Index to ~400 for about 2 weeks.

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Prusa Bed Flattening

OctoPrint has a plug-in for visualizing bed flatness, and has a link to a procedure where you replace the build plate standoffs with nylock screws, and then adjust the screws to make the bed more flat.  My bed was out of flat by 1.249mm and I got it down to 0.153mm which is well within the ability of the printer firmware to correct when it takes the bed measurements.

Here's a video from "Chris's Basement" that shows the whole process:

Attached file shows my flatness measurements before and after doing the flattening procedure.

OctoPrint Bed Visualizer.pptx
1.93 MB

Prusa MK3S Upgrades

I recently did some upgrades on my Prusa MK3S adding side drawers, a camera mount, an LED lightbar, an extruder visualizer, and a textured build sheet.  Attached file has photos and links.
Mk3S Upgrades.pptx
13.2 MB

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How to use Thangs

I'm experimenting with the Thangs search function using a .STL file as the "search string".  I'm not having very good luck.  As shown below, I took a known part in Thangs and created a similar (but not identical) model of it in Fusion 360.  When I used the part I designed as the search criteria, Thangs was unable to find a match.

When I worked for a large commercial airplane company in the Seattle area, we had some Ph.D mathematicians and a team of highly skilled software developers in the 3D geometry field working on a project to develop a capability similar to what Thangs is trying to do.  It is an extremely difficult problem to solve.

Is there a better way to do geometry based searches than the way I am doing it?

Sundial Design and Printing

Because I recently moved to an area that is mostly sunny (Eastern Washington State USA), I got interested in sundials.  I bought a book about sundials from Amazon that was first written in 1938 and republished in 2020 for Kindle.  ~350 pages about the history of sundials and detailed geometric construction instructions for many different types.
Using the instructions in the book, I designed two sundials in Fusion 360 and printed them on my Prusa MK3S machine.  I used Google maps to get my exact latitude to use as a design parameter.  Both sundials came out great.
Interesting to apply the latest digital tools to make a very old analog instrument.
Attached file has photos and description of what I did.   I may make a few more just to see if I can do it.
Great projects for a retired engineer.

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Tutorial Suggestion

Kevin - If you're looking for ideas for a Fusion 360 tutorial, designing a phone amplifier like the one below would be interesting.  With direct modeling, it could be done with sweeps and splines, but it might be fun to use the the Sculpt (Form) workbench. 

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Modeling Logos

My guitar instructor wants me to make a pickguard for one of his guitars that has his band's name and logo on it.  The logo was designed by an artist friend of his.

Is there an easy way to import a logo (or any other "artistic" shape) into F360 as a sketch and extrude the sketch to make a solid?

I imported a .jpeg of the logo as a canvas and used the spline function to kinda sorta sketch the profile using the canvas as a guide, but it didn't come out very well.  I could probably do a better job with the spline control points, but no matter how you do it, it's a lot of work.


Hi Everyone - Kevin, Thanks for setting this up.  Here's a great book that I used at work about how to setup and cultivate Communities of Practice:  The last CoP I setup grew to about 185 members and was focused on additive manufacturing.

I worked at Boeing for 41 years in commercial airplanes production engineering as a member of the Technical Fellowship and retired in October 2020.

I do CAD modeling, 3D printing, and Raspberry Pi/Arduino electronics.  For 3D printing, I have a Prusa MK3S and a Monoprice Mini Delta.  My workshop also includes a music studio where I create original compositions and covers.  

I've been using Fusion 360 for a couple of years and before that used CATIA V5 in my work.  I occasionally use OnShape too.

Looking forward to interacting with people here to get better at Fusion 360.