I always have in mind make some homemade HATs for the Raspberry Pi, a HAT (Hardware At Top) is a hardware specification for addons for the Raspberry Pi, the idea of this boards is be a hardware plug "at top" of the Raspberry Pi, this specs was released when the model B+ was out.
HAT have some specs about the support hardware from the main board called spacers, this spacers needs to be 10mm or 12mm to keep the HAT far away from the main board.
Unfortunately this spacers are very hard to find in my state (nobody in the several hardware stores knows them!), so I decied to try with 3D printing with good results.
Step 1: Design With OpenSCAD
My inspiration comes from this thing in thingerverse. I need another lengths apart from this standar lengths and I don't have Google Sketch Up installed.
What to do?, I decided to use OpenSCAD, a parametric modeller and super lightweight, this code is for a M3 Spacer of 12 mm of height, change the dimensions for you needs, let's do it!
- Install and open OpenSCAD
- Copy and paste this code
- Set height to your needs (or dimensions)
- Press Render (F6)
- File->Export->Export as STL
As you can see the code is simple, very short and very useful.
Step 2: Time to Print
This is a very crucial step, I use a Makerbot Replicator 2, for this machine I need the Makerbot Desktop Application.
- Open the Makerbot Desktop App
- Drag and drop the STL generated in the step before
- Create the number of spacers of your preference (ctrl+c and ctrl+v)
- I highly recommend high resolution (see image for more information), you can play with this parameters in your printer software. (Note: Check the temperature and speed, Makerbot Rep. 2 use PLA)
- Enable rafts (to avoid curling)
- Click save settings
- Go to Export Print File
- Check the time and total of material of the model
- Clic "Print preview" if you have doubt of your model
- Click in "Export Now"
- Copy the .x3g generated file to the SD of the Makerbot and start the printing process.
Remember, always exist a millon of different ways to print something, experiment with the parameters, don't stuck with one configuration.
Step 3: Making the Thread
If you see closely, you can note there's no thread in the spacer!.
Don't worry, we can make a thread in a easy way, for this we will need a M3 screw of enough lenght (10 mm for the spacer of the photo), an allen for the screw and a tweezers to hold the spacer.
- Try to rotate the screw in the spacer with careful and a little force by hand
- Now take the allen key and continue rotating the screw, if you need help you can use the tweezers
- Continue until you pass the spacer or the screw head touch the spacer
Sometimes you will need a little of extra force, if the screw have a part in the spacer, don't worry, you can apply a lot of force from this point.
Step 4: Testing
Yes I know, you are thinking, "Ohh dude, this will not work, it's too weak for my heavy needs", I know I need to experiment a lot to check the reliability of this spacers.
For now I leave you this little test, the tool weight 500 grams aprox, as you can see, this spacers can handle the job of hold a PCB, but I don't know if this spacers can hold something more heavy. I need test more :)
This is all for the moment, if you have some doubt, something is wrong, unclear or missed, let me know please.
You need help with your Raspberry Pi project? let me know:
Have a nice day!!!!