If your machine's coin door has two buttons already built in, why not use them to control the machine volume?
This mod will work with or without a coin mechanism in place. I've tested it on a SMVE and MET Pro. There's no reason it wouldn't work on any machine with two coin reject buttons (volume up and down assigned to unique reject buttons).
There are other solutions to external volume control like Pin-Vol or headphone/volume control like ones from Pinnovators. Each have there positives and negatives. I was looking for a simple, inconspicuous home-use solution.
This is a proof of concept at this point.
This is a fairly easy mod using a couple of switches, wiring and clips, a handful of screws & nuts and a mocked-up bracket made of cardboard.
It does require relocating the key hangers from the coin mechanism brackets. I simply moved them to the newly created mounting bracket.
The next version will include a proper bracket (most likely bent aluminum bar stock drilled out for mounts and switches) and wiring harness connector that uses the existing door harness. [EDIT: see later post for wiring harness upgrade and photos]
Enjoy the proof of concept video [EDIT: Revised video, less shake and reject buttons fine-tuned]
MATERIALS NEEDED for mock-up:
A. 2 x sub-microswitch with 1.9" straight flat actuator (5647-12693-31)
2x sub-microswitch with 3" straight flat actuator (5647-12693-08)
B. 4 x #2-56 machine screws with nuts
C. Corrugated cardboard for creating "L" brackets
D. Zip-ties OR wire ties to fix the "L" bend of cardboard brackets
E. Misc. wiring of your choosing to connect it all and maybe some alligator clips
F. Optional 1-3 beers
Need for future revision:
A. 1 male + 1 female pinned .100 connector for wiring harness [Edit: completed, see below]
B. Bar stock, sheet metal, thermo-formed polymer, etc. to create bracket [Edit: created a version with plexiglass and corner braces. Not the best but better than cardboard. See below]
The instructions below are in the pictures. This is not a complicated mod. First machine took a while to get going, but the second one was done in 30-45 minutes. This is by no means a final revision but rather a proof-of-concept hack.
Good luck modding your machine. Any improvements or suggestions are greatly appreciated.
To address the of the Pinnovators' concerns (below in the thread):
A. "squeaky as hell" I now have the microswitches dialed in to the point the slightest pressure on the coin reject button triggers the switch.
B. "sometimes the happ buttons would get stuck if not pressed straight". I have not experienced this. Also see "A", immediately above
C. "you have to push it every time to move the volume you can't just hold the button". This is no different than opening the door to adjust the volume. Agreed, repeatedly pushing buttons to change the volume isn't ideal but I've got to get some exercise somehow.
--No shame in plugging. I like your products (saw them in Allentown) and might pick one up at TPF.