Gear ratios ??

[IntelligentCelestialBeing]

Im getting into airsofting and building my own weapon systems and i would like as much knowledge about teching as possible. 

 

Can anyone explain to me in detail what effect different gear ratios have on the weapon and what gears would be best for me ? 

 

Im building a relatively low rate of fire weapon as i only use semi automatic. Im maxing the fps at 350 and getting a high torque motor (for better trigger response without adding higher rate of fire) with a M100 or M110 spring. Im also planning on getting a spectre fet to reduce risk of overspin and for general durability and performance. 

 

Also if you havw any important info i need to know about teching that would be great 😊

[Iceni]

The ratio is the number of turns of the motor, to the number of turns of the sector gear.

18:1 is 18 motor tuns to 1 sector turn, 1 sector turn is 1 shot.

Therefore you can divide the motor RPM into the gear ratio.

30K motor  on 18:1 gears is 30,000/18 shots per minute. 1666 RPM. Divide again by 60 and it's the Rounds per second. 27 RPS.

However, this doesn't account for the losses in the system. A motor is under load so it spins slower, You also have different batteries that affect motor speed. 

So that 30k is actually the no load speed.

I recently asked about motor losses in another thread. There's a fair bit of information in there from a few of the forum users.

The outcome was that a lower ratio gearset 13:1 with a HT motor has the best balance of trigger response and speed when used with a 7.4v lipo. 
 

 

 

Be very careful with the information you read online. Lots of it is from the USA airsoft market, They have a higher FPS limit. So they have different gearbox requirements.

[Sitting Duck]

a 25k to 30k motor on 7.4v "as is" would be a good starting point

(probably say 14~17rps, bit of snap but nothing too crazy & no real overspin)

 

I'd be tempted to run with that for a while that go much further with limited experience

wait until gun plays up or needs a service or something

[IntelligentCelestialBeing]

On 08/06/2019 at 13:18, Iceni said:

The ratio is the number of turns of the motor, to the number of turns of the sector gear.

18:1 is 18 motor tuns to 1 sector turn, 1 sector turn is 1 shot.

Therefore you can divide the motor RPM into the gear ratio.

30K motor  on 18:1 gears is 30,000/18 shots per minute. 1666 RPM. Divide again by 60 and it's the Rounds per second. 27 RPS.

However, this doesn't account for the losses in the system. A motor is under load so it spins slower, You also have different batteries that affect motor speed. 

So that 30k is actually the no load speed.

I recently asked about motor losses in another thread. There's a fair bit of information in there from a few of the forum users.

The outcome was that a lower ratio gearset 13:1 with a HT motor has the best balance of trigger response and speed when used with a 7.4v lipo. 
 

 

 

Be very careful with the information you read online. Lots of it is from the USA airsoft market, They have a higher FPS limit. So they have different gearbox requirements.

 

 

You my friend is a god send. Thank you so much the information you have provided has helped me out a lot. Ive always wanted mathmatics that i could use for my builds so i can build them more efficiently and ensure i dont cause too much stress. 

 

If you have anymore mathematical equations i can use please do let me know 

[Iceni]

The math is pointless. It only serves to compare a built gearbox to another built gearbox.

You have to be able to match the build standard or better it to get the same results.

As such I could hand you all of the components, Cherry picked, polished and primed. If you can't build the gearbox to the same standards as mine your numbers will always vary. 

It does give you a starting point. And with that you can start digging about and build a picture about a component.

Math in airsoft is almost as wooly as a lot of the hard facts. The industry is based on smoke and mirrors, Offering product X at a premium even tho there might be no basis for that been an improvement.  The more gearboxes you deal with the more you see this, Upgrades for the sake of upgrading are pointless. You have to know what it is you want, And ask about getting exactly that.

You will make mistakes, And ask stupid questions. There is nothing wrong with been wrong when people correct or laugh at a stupid question press them into the thinking that makes it stupid. 

Oh and there are people on here that know far more than me. SittingDuck is a good reference for any information. His posts might be long but he always takes the time to explain what he is seeing or doing.