Airsoft P90 BTC Chimera/HPA trigger and selector microswitch conversion by malcolmnz

Last crawled date: 3 years, 12 months ago

This is the 3D printed hardware you could use to convert a Tokyo Marui P90 from the standard trigger and selector mechanism, to micro switches for both jobs. This is intended to be used with either a BTC Chimera, a HPA system such as a Polarstar, or your own home brew setup.
In some of the supplied pictures I used a switch I had lying around as an example. The first photo and the photo of the small tactile switch, show the correct switch, which is a SP0603 6mm SPST Micro Tactile switch from Jaycar Electronics. You should be able to find something similar nearly anywhere. https://www.jaycar.co.nz/6mm-spst-micro-tactile-switch/p/SP0603
The microswitch for the selector is also from Jaycar, and is an SM1036, also a very common design. One of the STL files models the body of this switch so you can compare. You do not have to print that part. https://www.jaycar.co.nz/spdt-sub-miniature-microswitch/p/SM1036
Trickiest part of the install is gluing the two selector mounts up inside the body. It is actually quite easy with a pair of angled tweezers and some super glue. Just hold each mount as far back and up as it will go. I haven't tried acetone to see if that will work, as I wanted to be able to remove it during development.
Cut some rectangles out of 1.2mm thick prototyping board to suit. The selector one has a rectangle cut into that to allow the bottom of the switch to sit flush with the bottom of the board. It cannot sit lower, as correctly installed the selector board mounts sit the board as low as possible.
The selector switch requires a small lump to be added to push on the micro switch, as per the photo. You can use whatever, I used some epoxy putty.
The trigger stop and trigger button depressor have a little extra meat on them. Sand these to suit. There should be no excess travel on the trigger microswitch, or during a game under stress you will definitely over squeeze it and break the glue on your mount or damage the switch itself.
I figure if you are actually undertaking such a conversion, a little gluing/soldering/sanding the trigger tolerance is probably no challenge to you.
This was all done in Sketchup, and printed on a completely stock DaVinci.