13:1 gears on semi

Anyone had any experience running 13:1 gears on semi. Looking to reduce cycle time on AEG. Probably wont make much of a difference and would need a more responsive trigger to be effective

The gear ratio is a bit of a “controversial” thing, simply because any Gelblaster function basically comes down to the battery, wiring, switching and the motor.

Gear ratios are pretty much the last thing that needs to be considered, and must be properly researched as a whole planned overall package of whatever is being built or designed to achieve a certain goal.

Unfortunately I’m the last person to ask about high RPS blasters, because I’m more about realistic kerchunk fire rates and higher FPS combined with distance and accuracy over brrrrrrtttt speedy bois!

Each component between motors, electronics and gear ratios have endless levels of possibilities in combining separate components in sequence to achieve the desired end results.

You can chuck in 13:1’s with a stupidly high RPM motor and insanely high FPS spring, and yet at the same time could also achieve much better results with 16:1 gears, a lighter spring and a higher torque motor :thinking:

Like anything Gelblaster related, everything is all about trial and error, because there’s absolutely zero guarantees that something that works on one blaster will ever produce the same results on another exact same model :roll_eyes:

Late edit……. I’d rather have a higher torque motor and quality FCU MOSFET than changing to different gear ratios to try and achieve the same results.

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Most of my upgrades in the last few years are higher (not high) rps builds with 13:1 and a more torque based motor. Motors around 28-25k are my personal favourites. I prefer to land around 25rps or a little higher, so not massively high rps by any means, but long term reliability and almost the same maintenance schedule as a normal aeg.

Anything over 30rps and things are moving very quick and you will want to service it every couple of games.

In your case going for cycle time, 13:1 and a high torque motor will do it. Will give a nice snappy semi auto, and a few extra rps in full.

Trigger response/sensitivity is NOT directly related to cycle time, that is one that is solved with a ETU Electronic Trigger Unit. More commonly know as a mosfet. (though a mostfet is only an electric component used in the circuit)

Basically, ETU for less trigger travel and more sensitive trigger, low ratio gears and high torque motor for cycle time.

A high torque high speed motor with 18:1 that has 30rps, compared to a high torque motor with low ratio gears like 13:1 that has 30rps; the 13:1 will have less motor heat, less amp draw on the battery and be more efficient.

I use loads of 13:1 gears, and generally speaking, building the gearbox is the same, just spend time getting bevel to pinion spot on. And anything approaching 25rps use an m100 minimum. You can get away with an m100 upto 30rps, just dont get a jammed ultra in your barrel.

For the lazy easier build, using a shorter barrel (220mm) and a ported cylinder to match it you can easily get away with an m100 and full stroke. Barrels over 275-290mm, I would prefer a 80% cylinder, remove two teeth, and go to an m110. This is to safety net in the event of a jammed ultra, to avoid PME and give you time to get off the trigger.

Another general tip, along with using a stronger return spring, take a couple of loops of it to tighten it further. Then, trim the tail of the tappet plate by about 3mm if 25rps, and if approaching 30rps, you can trim a little more. Over that, trim the tappet plate so it just clears the sector gear shaft, this will ensure it should still feed and seal. At this point you mags are more likely to need attention to keep up with the rps.

What gearbox do you have?
What barrel length?
What motor?
Desired fps and rps?

Happy to help with tips :slight_smile:

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