New Relay Board Open Source Design, 3D CAD Models and Parts Source Options

[Steve_R]

Hi everyone,
About 4 years ago I designed and built a solid state relay board for my 914. I built a few extra ones and you can read all about that
HERE.


After building those I realized that not everybody wants solid state relays. So, I designed a version that uses the stock electromechanical relays. I started building a batch of 10 and I got distracted with another project. Recently, I had some more time and I completed those. This relay board uses the stock relays for power, heater and fuel pump. There are no provisions for the rear window heater. The relay socket used for the window heater is used to store an extra relay.
This board uses an ATC style fuse and has an LED that illuminates when the relay board is supplying power to the fuel pump. This is useful in diagnosing fuel pump issues. The LED illuminates for about 2 seconds when the key is turned on and remains illuminated when the engine is running.
I am selling this last batch for $325.00 each. This board does not come with any relays or the voltage regulator. I’ll cover the shipping and sorry, I can’t ship international. Message me if you want one. No need to reply to this post. I will edit this post and remove this section when they are all gone.

Okay, with that said, I will not be making any more of these. I will be making this design available to the 914 World Community. I have attached the 3D solid models (in STEP format) to the next post. Also, I attached a PowerPoint (PDF format) that outlines the construction process as well as the sources for all of the parts. There are 3D models for the solid state relay version as well as the stock electromechanical relay version.

This design and associated files is completely open source and can be used by anyone for any reason.

These boards are designed to be CNC machined from plastic. I used a CNC VMC. However, I think a CNC router would also work. I don’t think a 3D printer would work with the current design. However, I it could easily be modified to work.

[JeffBowlsby]

As admirable as this design and effort is, I see an issue on the wiring list.

The wire re: connection 1 is the circuit for the starter solenoid from the ignition switch. It needs to be a 10 ga wire not 14 gage.

Also, with the discrete wires as circuits why not just affix a gasketed, removable bottom plate instead of the potting compound?

[johnorm]

As admirable as this design and effort is, I see an issue on the wiring list.

The wire re: connection 1 is the circuit for the starter solenoid from the ignition switch. It needs to be a 10 ga wire not 14 gage.

Also, with the discrete wires as circuits why not just affix a gasketed, removable bottom plate instead of the potting compound?

Jeff I agree with the 10ga for connection #1 but I have a question on some of the other connections. Based on a current flow diagram I downloaded the majority of the original wire size, for regulatory board, was 0.5mm (18ga) and 1.0mm (16ga.). I'm I wrong to assume a 1.0mm wire converts to a 16ga vs 14ga on Steve's table?