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3D Printed External FC Switch Box / Expression Box


FC-External-Switch-Box-3D-Print-Build-with-Tags.jpgI mentioned this idea in another thread... was inspired by @lqdsnddist build of an external switch box. I modeled a 3D switch box in Tinkercad, to match the profile and switch spacing of the FC-12. Designed it to accommodate four momentary foot switches and two expression potentiometers, to max out the ext switch/pedal usage for my FC (I have two expression pedals)

I had three failed prints before finally getting a successful print the fourth time around, using black PLA. The final print took ~40hours. It turned out really solid / strong with the internal supports. I tried a few drop tests, standing on it, and stomping on it. Just drilled out holes for switches and pots, wired it / soldered it up.

Seems like its gonna work great! I'm gonna do a bit more finishing work - sanding / smoothing - and will come up with some way to add some kick tags. Probably will use the foot switches for Volume +, Volume -, and either some patch navigation, reveal, or layout switching. And the two "expression potentiometers" will be mostly assigned to delay time / feedback, or maybe some other effects or levels on certain patches.

If anyone wants to try and print one out, attached is the 3D model... there was definitely a bit of a learning process in getting everything set in 3d print settings, and it required some minor adjustments during the print... but if you have patience and a 3D printer, give it a go.

Below is a photo montage documenting the progress so far.


Gotta get some better potentiometer knobs and figure out the kick tags.


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Fractal Fanatic
Nice work!
What slicing parameters did you use? Ie infill and outside/top/bottom layers.
Also, how thick is the top plate?


Wow... that turned out pretty incredible.... makes me wish my local Harbor Freight sold a 3D printer, and more so, I had the know how to do something so cool with it.

Did you look into taking off the right end cap and attaching it to the side of the box ? Then maybe add a little tab where you could bolt it onto the FC using the existing threads on the unit ?

Chad Beattie

Anyone ever tried those online sites where you send them the files and they ship you the finish printed result? This looks really cool. I don’t have a printer either.


Anyone ever tried those online sites where you send them the files and they ship you the finish printed result? This looks really cool. I don’t have a printer either.
I have, but depending on which you choose and the method they charge by, this would cost a fortune.


Thanks all! For those wondering about specifics of 3D printing, this is what I learned:

1. Material:
ABS shrinks (up to 8% apparently) and it's almost impossible to print something large like this, at least on a printer like mine. I have an older (2016?) Flashforge Dreamer. The three failed attempts were all using ABS, and all had significant warping, leading to catastrophic print failure. Part of the problem might be due to the fact that the print size was at the max limit of the printer's capabilities... I suspect that the heated plate does not stay hot enough toward the edges and that's why they always warp up off the print surface. I tried several tricks that I saw online, but all three prints with ABS failed. PLA is much more forgiving.. it only experiences minor shrinkage/warping. I suspect that if I wasn't maxing out the print capabilities, there would have been no warping at all with the PLA.

2. Print Settings:
In the FlashPrint app, these are the settings I used:
Layer Height: 0.18mm
Perimeter Shells: 2
Fill Density: 15%
Fill Pattern: Hexagon
Print Speed: 60mm/s
Travel Speed: 80mm/s
Extruder Temp (PLA): 200 Celsius
Platform Temp (PLA): 50 Celsius
Bottom Solid Layers: 30 Layers
Top Solid Layers: 30 Layers

Most of the above settings are defaults for my printer, but I set the bottom and top solid layers to 30 layers so there would be a solid bottom area to screw a bottom plate into, and a solid top for drilling and attaching the switches/pots. 30 layers * 0.18mm = 5.4 mm. In hindsight, I could have increased this even a bit more on the bottom (just for screwing a plate on), but should have enough meat as is.

3. Print Process:
For the most part, after leveling the print surface, I was able to leave the print unattended... at about 10 hours in, I did notice two of the bottom corners started to warp up just a tiny bit. I watched over it every few hours, and didn't notice any further warping... it printed perfect from hour 10 through hour 35. At about 35 hours in (~85%), it was printing the top surface, and I noticed that the whole print bed was starting to shake a good amount when layers were filled. I panicked a bit becaused that's what happened before catastrophic failures on ABS prints. As I watched it, I was able to determine the cause: The print bed is leveled using three set screws with springs -- it seems a small amount of motion/jittering started to loosen the set screws causing the bed level to go out of whack, resulting in even more vibrations. I waited until a layer was finished, then temporarily paused the print. I manually re-tightened the the screws to visually reset them just a bit, and added a piece of Gorilla tape on them so vibrations wouldn't cause them to loosen any further. Then, I un-paused the print. This stopped the vibration issue with the build plate, and I think saved the build.

Total cost for the PLA plastic used is probably about $10... and probably a few bucks in electricity. But the real cost was time and patience.

Re other questions:
a. The top thickness is about 1/4in. It's very sturdy.. probably could have gone with 3/16in, but seems pretty good as-is. I drilled out the holes in several passes, each time getting larger, until they were a snug fit with the switches/pots.
b. I didn't try removing the end cap of the FC... I didn't necessarily make it CAD accurate to the millimeter.. I used a side photo of the FC and tape measure dimensions to get it very close though. My intention all along was to have it just sit beside the FC.


More progress on the build of 3D printed FC Extension Box:

1. Got some better potentiometers
2. Added a bottom plate (PLA print), and added non-slip rubberized tape
3. Printed out some vinyl sticker style "kick tags".

The TAP functions are the ones in the main text area that aligns with the FC, and the HOLD functions are beneath in white. This is what I decided for functions:

1a. Tap: TUNER toggle
1b. Hold: UTILITY > Amp Levels -2db and Save

2a. Tap: LAYOUT MASTER MENU (Easy access to all layouts)
2b. Hold: UTILITY > Amp Levels +2db and Save

3a. Tap: REVEAL HOLDS (This feature is great... glad they brought it back, like it was with MFC.. makes every layout extra useful)
3b. Hold: PRESET > Select Main Preset (/Panic Mode)

4a. Tap: LAYOUT INC +1 (With Wrap on to switch between my main three layouts)
4b. Hold: LAYOUT > LOOPER (quick access to Looper Layout, outside my main three)

By moving all the Layout Navigation and Misc Utility stuff to the external box, I now have all twelve switches dedicated to functions that require LED indicators for ON/OFF status. The flexibility of the FC ecosystem is truly mind-blowing... a bit of a learning curve to get going, but once you wrap your head around the layout options, per-preset overrides, stand-ins, control switches and reveal/holds, it's amazing! So happy with my setup now. Thank you Fractal for building such thoughtful products!

Make sure to download the latest firmware (7.01) if using external momentary switches - vital update.

PS: You guys (Fractal) should mass produce these EXT Switch Boxes Extensions like I've made. Total materials cost is less than $30.. and probably far less in bulk.... I bet people would be happy to shell $100 for something like this.

Here's some more photos:




@lqdsnddist -- Attached is a Photoshop PSD with the kick tags template that I designed. The faux led lights can have colors changed in layer blending effects, and all text / shapes on separate layers.... If you want to do something similar, or use this as a starting point. I ordered some vinyl sticker paper to print from inkjet... its a bit shiny, but looks pretty good.


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