This Stargate model by Glitch is absolutely incredible. The first parts I printed were the rear pieces and I was blown away by the detail, so much attention to detail for a part so few people will see. I will be honest, building the Stargate is a bit of a mission, using surface mount LEDs without a surface was interesting to say the least. I would strongly recommend using SodaPopin5ki's LED mounts rather than fumble around in the dark like I did. But Glitch has done a great job of making things fit together well and the build video on YouTube was really helpful.
For the electronics I quickly decided I wanted audio and proper address control. I also didn't fancy manually soldering everything on stripboard given all the components involved. For this reason I've made a custom PCB with connections for power and audio. I initially tried to get everything working on an ESP32, but there were conflicts between the Adafruit Motor Shield and the WiFi. I've switched out control to a Raspberry Pi 3 which conveniently fits the left 2 screws in the ramp base. From there everything can stack up and you get a relatively clean install with full control via web browser. You'll need to use the Adafruit Motor Hat rather than Shield with a Raspberry Pi of course.
I've uploaded a video to YouTube of the Stargate in operation here: https://youtu.be/44F3BeYHxLQ
You can view the source code and more detailed instructions here: https://github.com/danclarke/WorkingStargateMk2Raspi
If you're building the model yourself, here are some tips I have:
- The mechanism for moving the top chevron up and down needs to be trimmed to make it work correctly. I think this is what the video means by trimming the pins. Loosely assemble the entire mechanism, and you'll be able to see where you need to trim. I had to trim only one side by about 6mm. I think it was the left side, but make sure to check in your build.
- The pads on surface mount LEDs are super easy to rip off, at least on the rather cheap ones I was using. I used a tiny dab of hotmelt on the wires to add strain relief. I'd recommend going a step further and adding a bit of hotmelt on top of the solder joints. The solder will hold no problem, but it's really easy to accidentally tug on a wire and the pad comes off. The glue will add a little extra support to protect against accidents.
- I used hotmelt glue to diffuse the LED light in the central chevron segments. However, be careful since it will soften / melt even PETG.
- Spray on PTFE spray is great for all the moving parts to reduce friction as much as possible.
- The standard code from Adafruit for driving the stepper motors isn't brilliant. You'll need to up the I2C bus to 400Khz+ and check on the latest pull requests. The PRs allowed me to use Microstepping for all gate movements, making it much smoother and quieter. If using my code from Github, this is already done.
- Consider using PETG motor mounts and gears if you're going to be using the gate constantly. The motors can get hot enough to slightly soften the PLA if they're active for long periods of time, or using the standard Adafruit Rasperry Pi motor code which never 'releases' the motor.
- To make wiring easier the 4 white LEDs on each side of the ramp can be wired in series from 12V. This negates the need for a resistor and having to wire up all the LEDs in parallel. Make sure your LEDs are bright enough at 3V prior to assembling.
- It takes longer to keep track of the wires for each chevron than just sort out the ordering in code.
- Lightly sand the mating surfaces prior to using CA glue, this will result in a much stronger bond.
Gate and main base printed on Prusa i3 Mk3 in E3D Silver PLA. Ramp and other scaffolding printed in Real Filament Silver on Anycubic i3 Mega.
The clear chevron components are printed in 'Smokey Black' Real Filament PETG. This is to make the chevrons appear to blend in with the gate when not lit like the show. Standard transparent PLA was used for the ramp LEDs.