So my 1965 F Truck has the original MPH Gauges that don't work great, and frankly, they're not much chop as Australia has gone Metric in the interim.
So I bought myself a set of ELING 85mm 2in1 GPS Speedometer with Tachometer with 4in1 Multifunction Fuel Level 0-10Bar Oil Pressure 12V with Alarm Red Backlight for SUV Vans off Amazon to fit to it after checking with the Australian National Heavy Vehicle Regulator that they were cool with a GPS Speedo, and because it was Pre-1969, and therefore pre-Australian Design Rules I'm actually cool to run whatever form of GPS I want, as long as I have something to say how fast I am going.
Rather than adapt it into the dashboard, I decided that I am going to leave the factory gauges as they are in the dash, and mount these to the new roof panel that I am making anyway, so that way I can also glance up at my speed rather than looking down and around the steering wheel, seeing a speed in MPH and trying to do the mental maths to change it to KMH
It is designed to be modular, print 2 end caps and 1 mount, print 2 end caps and 10 mounts, doesn't matter, it's all gravy.
Minimum amount of gauges you can have is 1.
I just glance up, there it is in KMH, and I'm good.
Free to use, go nuts, make your own, add them to your projects, etc.
Best printing orientation I have found on my Flash Forge Creator Pro 2 is that you need supports, but to print it from the top (Where all the holes are) down orientation, so the top is on the build plate.
The other advantage to this is that if you have any artifacts on the print bed that come through, doesn't matter, because that part bolts up against the roof of the car.
Best print settings I found was:
Every wall is 5mm, so by maxxing out the top and bottom layers, everything is solid, it's a hollow shell, no need to make it any more hollow than it needs to be.
All the bolt holes are 5mm for commonly located self tapping screws and the main harness hole is 25mm which should be more than enough to get wires in for the type of gauges I have used.
The author marked this model as their own original creation.