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Airsoft_Mr B

Gear Ratios?

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Hey, I was wondering how the ratio of a gear set will effect a gun?

Is there a specific ratio that is best used with a particular gun? For example I was looking at a 13:1 SHS, CORE or ZCI set but how would a 32:1 / 100:300 / 18:1 / 100:200 perform?

Please excuse my lack of knowledge on this subject, any help is appreciated, thanks.

 

By the way I'm looking to upgrade my Classic Army MP5K which has a V3 gearbox.

http://www.airsoft-forums.co.uk/index.php/topic/19941-a-few-upgrades-to-my-ca-mp5k-custom-build/

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13:1 means everytime the bevel gear (i think) makes 13 rotations, the sector gears turns once.

 

Stock gears are normally 18:1, providing decent torque. With 13:1 gears, you may need a higher torque motor, otherwise it will be harder to pull the spring.

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So 100:200 helicals are faster than 100:300 presumably? How do they measure up ratio wise against normal 18:1 flat gears?

Helical gears are a pain to shim properly. If you get it right they're near silent. If not they sound like a cat eating wasps. In a can. Going over a waterfall in a dishwasher.

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Helical gears are a pain to shim properly. If you get it right they're near silent. If not they sound like a cat eating wasps. In a can. Going over a waterfall in a dishwasher.

Lol! So about the same as the stock set up in my Cyma M16A3 then. . . . . . .

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So 100:200 helicals are faster than 100:300 presumably? How do they measure up ratio wise against normal 18:1 flat gears?

 

Helical gears are usually recommended when you're trying to increase FPS rather than RoF. They have a greater meshing area on the gears which allows them to consistently produce stringer torque. If you're after increased RoF I'd stick with good quality flat gears (SHS Super Shooter, Siegetek, Lonex etc). There'll be plenty of other things to absorb your cash if you're going down the high RoF route!

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You hit the nail on the head Lozart I was mainly wanting a quieter gun but yeah slight rof increase would be nice, usually just slam in a bigger battery to sort that though!

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You hit the nail on the head Lozart I was mainly wanting a quieter gun but yeah slight rof increase would be nice, usually just slam in a bigger battery to sort that though!

 

Quieter gun eh? In that case you'll want to look at shimming it properly and maybe a different piston head. Sorbo pad to lessen the impact noise (which will then pretty much force you to do an AoE adjustment - no bad thing).

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Quieter gun eh? In that case you'll want to look at shimming it properly and maybe a different piston head. Sorbo pad to lessen the impact noise (which will then pretty much force you to do an AoE adjustment - no bad thing).

 

Yes, have reshimmed it and replaced the piston head, and it is improved, don't mind the "bang", but the "whirrrrr" is still there so I'm going to experiment further with a high torque motor, 100:200 helicals, Alu piston head and cylinder head and see how it goes, mainly as I enjoy playing with gearboxes . . . . . . . if it implodes I'll think again! -_-

 

Am I right in thinking the AoE adjustment refers to the relationship between the sector gear and the piston?

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Yes, have reshimmed it and replaced the piston head, and it is improved, don't mind the "bang", but the "whirrrrr" is still there so I'm going to experiment further with a high torque motor, 100:200 helicals, Alu piston head and cylinder head and see how it goes, mainly as I enjoy playing with gearboxes . . . . . . . if it implodes I'll think again! :P

 

Good luck with the shimming! I tried, failed, put the original gears in. They stripped, fitted SHS Super Shooter flat gears and now it's way quieter than it ever was!

 

Thing is that IF you can get the shimming dead on helical gears are pretty much silent. Getting the shimming spot on is the tricky bit!

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Good luck with the shimming! I tried, failed, put the original gears in. They stripped, fitted SHS Super Shooter flat gears and now it's way quieter than it ever was!

 

Thing is that IF you can get the shimming dead on helical gears are pretty much silent. Getting the shimming spot on is the tricky bit!

Yes I'd read that, will also be interested to see if it kills the 8mm bearings with the sideways torque . . . . ! Anyway its not a gun I need up and running this weekend so will enjoy experimenting and refining lol!

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