Electronics Enclosure Designed in MoI - Ed Ferguson

Here's an electronic enclosure I designed in MoI and 3D printed in PLA plastic. MoI exports the model in STL format to feed a Slicer program, which in turn generates the G-Code to run the 3D printer.

The four-sided box was printed as a single piece. An aluminum bottom plate screws to the four tabs designed into the box. MoI was really helpful in that I could easily re-arrange the individual components to get everything to fit. The build plate on the 3D printer limited the maximum size of the box, and so I had to pack everything carefully.




In addition to the box, I printed a box lid and "nests" to hold the relays (red circuit boards) and the Wago AC power junction connector:




Only a few millimeters to spare on the Robo 3D printer build plate. The box is 7.6" (193mm) square. You can see the temporary support structures on the rear panel. Those are weak bridges so the printer can continue printing the solid wall over the top of openings. The temporary support structures are automatically created by the Slicer program and get knocked out when the print is finished, leaving holes for the cables and square power receptacle. :




You can see the clean square and round holes after the support structures were knocked out. Threaded brass inserts set into the plastic are used to attach the sheet aluminum box bottom. The aluminum sheet drops in from the top and is held by one screw in each corner. All holes and openings are part of the 3D model - no drilling required. MoI was also used to create the hole pattern template for drilling the aluminum plate. I just printed an actual size template from MoI onto paper, taped the paper to the aluminum, and took it to the drill press. The box is surprisingly ridged.:




Bottom view: Cables interface the fixture to additional outside electronic and electro-mechanical components:




The Arduino microcontroller provides the brains to run the whole process via a nested menu UI. I never programmed an Arduino before, but using some code snippets found on the Internet, it went pretty smoothly. The small holes in the lid access the button pads on the Arduino. For the moment I use a toothpick to access the menu buttons via the holes. Soon I'll 3D print some plastic shafts (buttons) to fit between the Arduino and the box lid.

Hi Ed, it turned out great!

How has the Robo printer been working for you, looks like you're getting good results with it.

Also what does the device that you've made do?

- Michael

The Robo 3D printer works great and the Simplify3D Slicer program plays well with MoI.

What I have to learn to do better is add gap tolerances where pieces join together. For example, if a power receptacle is 1" x 2" and I model it as such and Boolean Diff it with the box to make an opening, the receptacle won't fit. I have to temporarily enlarge the receptacle model so the resulting hole will be slightly larger. Maybe there is an opportunity for a specialized Boolean Diff script: Temporarily enlarge cutting object by x%, or enlarge cutting object by x thousandths of an inch in all dimensions, just while doing the Boolean Diff. After the Boolean, the object automatically reverts back to original size.

The fixture is for powder coating very small metal parts in a precisely controlled, even & repeatable way without using a clumsy, messy, hard to control, hand-held powder coating gun. I can't share the entire process and related custom hardware for competitive reasons, but it works very well :)

Ed Ferguson

I also wanted to share how I made the basic solid object for the box lid all in one go. Draw the profile curve and the lid perimeter curve with beveled corners.

Then Rail Revolve. Easy!

Ed Ferguson

+1 to Ed's idea for a Boolean command that shrinks or expands .

MOI does drawings with practically zero tolerance , things fit in its (almost :)) perfect world , but when going to 3D printing there are all kinds of tolerances that stack making parts that fit or interlock together tricky , inside holes need to fit to outside diameters . So some kind of Boolean tolerance tool would be a real help.

PS MOI rocks for 3D printing

Hi Ed & DigiD - a shrink or expand thing like that is unfortunately very difficult. You can't form it by scaling, it would need to be done by offset.

- Michael

Excellent work - nice job!

Awesome!

Always great to see a digital design come to life. Everything looks very neat inside the box, congrats man.

That is really cool thanks for sharing and showing other opportunities with MOI