Introduction: 3D Printable Modular Electrical Connector
In this instructable I will be showing you how I used Tinkercad to design the connector for a prototype device I was building at the time.
Computer with access to the internet.
Step 1: What's the Goal
My goal for this project was to design an electrical connector that did multiple things. I wanted it to be as low profile as possible but it also need to be robust enough to hold the weight of battery modules together. It also needed to be able to house multiple data pins and an XT90 connector for high power applications. The whole connector needed to be easily dis-connectable and re-connectable with a latching system. I did a lot of research ahead of time on different latch systems and decided on a dovetail style latching system, therefore, that is the style that I will be covering but you can use the techniques that I used in your own designs to fit your needs.
Step 2: Where to Start
Since I didn't know how I was going to incorporate any sort of electrical connectors at first I simple just started with the dovetail design. I didn't design a latch for it yet either, this is just to see how secure the design would be and what sorts of tolerances I would need when 3D printing the piece. I started by setting up a back plate that I could affix everything to. Then using the boxes and wedges I created a dove tail groove that couldn't be reverse. I left just a small gap between the triangles of the dovetails so that the mechanism could slide freely once printed.
Step 3: Start Adding Features
It can be overwhelming trying to design everything perfect the first time, that is why I slowly added in the various features I wanted so that I could test everything out. I'm going to be skipping over a lot of the various versions of the dovetail designs since I have so many and just focus on how I made the features to keep the length of this instructable down. The next mechanism I added was a latch. In the picture you can see the wedge mechanism that uses a spring. I needed to create a mechanism that could be assembled after it was printed rather than being printed within the connector. Again I used boxes and wedges to create the parts and then I just grouped them together. I then chose a spot on the dovetail that had a block of material that I could cut out of using the "hole" shapes to fit the latch pieces into. The other dovetail connector simply has a rectangle cut out for the latch to catch on. The little bumps on the side of the button are so I can push it into a 3d printed grove and not have it fall out if you tip the device upside down.
Step 4: Little Details
It can be difficult to design smooth items in Tinkercad since there isn't a fillet or chamfer tool built into it. Instead what I do for a fillet is take a cylinder with the dimensions of the fillet I want and make it a "hole" rather than a "solid" and combine it with a box that is 1/4 the size (make sure for a clean round you increase the number of sizes on the cylinder to 64). Then you can group the shapes to create your own fillet tool. You can now make your new shape a "hole" and group it with the shape that you want the fillet on. For a chamfer, you can just use a wedge, make it a "hole", and group it to your shape to get the geometry your looking for.
Step 5: Adding the Connectors
So I wanted to use XT90 connectors for my power plug and I used 3 pin Molex connectors as my data pin connects since that is what I had laying around. I mocked up the connectors in Tinkercad by measuring the connectors and by using wedges and boxes, I had a virtual plug that I could move around and cut out a space for it in the dovetail. Again I made multiple versions of this, what I find extremely helpful is the ability to adjust your models by ungrouping them and moving the shapes slightly. I essentially just cut a connector sized hole in the model and then used boxes to connect the cavity to the back of the dovetail plate so that the connector could be inserted.
Step 6: Results!
I am very pleased with the results I was able to achieve. After tweaking a few parts of the design, the connectors were as good as they were going to get for being 3d printed and utilizing the current design. This was a Senior Design project I did in high school. My group and I are slowly planning out another version so maybe I will post another instructable on the next version. This was my first instructables so I hope you enjoyed it or were able to learn something from it.
Participated in the
Tinkercad Student Design Contest