HELP! I have a project I'm working on that involves making a hand cranked mini air-raid siren utilizing a 12v generator and a 12v siren. I've done a proof of concept rig where I direct wired the siren to the generator and then used a drill to generate enough RPM on the shaft to get the noise I want. Problem is, I'd like to make this entirely manual and will be adding a crank handle once I get the housing built...which means, I need a way to seriously up my RPM. I've done research into building multiplier gear boxes and compound gear trains and pinions and everything in between, but am going to confess that while I'm obsessed with DIY projects, this one is exceeding my engineering knowledge. I am at a loss for how best to approach this build. What ratio would you suggest? 40:1? 50:1? Does anyone have experience building gear boxes that would be ok emailing me with their advice? The input for my generator is a 20 tooth gear (please don't laugh if I'm totally messing up all the nomenclature...most of my life experience comes from writing and baking and a very short (failed) stint as an EE...this is a totally new world for me.) and I got this information from another sub: it’s a 3600 rpm motor so 60/sec. I think the fastest I would want to crank is 2/sec, so, 30:1 gear box sounds about right. With a nice long crank handle a 50:1 should also work nicely. 10:1 is too slow. Ideally (and this might be where it gets really tricky) I'd like it to all fit into a space that's about 5"X3"X3, not including the siren (I can run that further out, using the leads).I'm attaching a photo of the original proof of concept wire up that I did...and don't worry, I know there are exposed wires, I fully plan on isolating the wires, insulating the whole thing and installing the proper resistors. https://imgur.com/a/MaAR2PQ Here is a link to the generator: https://ebay.us/zgAoDQHere is a link to the siren: https://ebay.us/fEgahDThank you in advance!