gear ratios for AEG's

[Pointman PUG]

Hi folks...quick question!

so I was thinking of speeding up the rate of fire for my gun and I was looking at some gear sets on eBay....problem is im clueless as to what gear ratios to get! Do you go for small (13/1 I think is the smallest ive seen) or do you go large (18/1 is about the largest ive seen) for rate of fire!? Also what problems might I encounter doing this and will my standard piston take it!?

Any recomendations of brands will be appreciated.

just for info its going in a g and g gr 15 raider short

thanks all



ohh also its the pneumatic blow back version of gearbox...incase that makes a difference!!

 

[sp00n]

18:1 is the normal ratio for most guns. As a rule if thumb the lower the numbers the higher the rof but the motor will not produce much torque (so no big springs)

 

[Airsoft-Ed]

Sp00n nailed it.

High speed gears are anything between 13 and 18:1 high torque goes from 18 to 28:1.

I'd say that generally there's not really much need to swap out the gears, but if you want to, don't alter the ratio by more than 2, unless it's a mentally serious, hardcore build. I can get about 25 rounds per second with a 9.9v battery, M100 spring, high torque motor and standard 18:1 gearing.

I can't begin to imagine how mental my rof would be with 13:1 and a high speed motor, but I'm not sure how the pulling power really factors into it.

I guess you could compare it to gears on a push bike.

Low gear = low ratio. Super easy to pedal and the parts move super fast, but you don't get very far very fast, which is akin to having a weak spring.

High gear = high ratio. Hard to pedal and the parts move slow, but you go a lot further a lot faster, which is akin to having a heavy as hell spring.

 

[joshcowin]

i spoke to a guy last year who fitted these to his gun

http://www.airsoftworld.net/modify-quantum-gear-set.html

spend alot on it like a short stroke piston,piston head,cylinder,cylinder head,spring guide,spring,new wiring etc and that was shooting at 58rps on a 11.1v lipo which is insane,it was only shooting 295fps but i wouldnt like to get in the way of it

 

[sp00n]

Sp00n nailed it.

 

[Pointman PUG]

Thanks guys!

as far as I know I have a standard spring (m 90) but im not sure of the motor...g and g own motor I guess....not checked on the specs of motors yet to see what will match....I have a standard barrel for now and I dont know if a 6.01 barrel will bring up the fps too much(I hit 320 fps on the chrono with standard barrel

 

[Ian_Gere]

You can get +40fps from a 6.01mm TBB, it depends on how good the seals are between the air nozzle & cylinder head, air nozzle & hop rubber, and hop rubber & barrel. If you're getting 320FPS from a M90 spring then your air seals must be really excellent. I'm wondering if you actually have an M100 spring with average seals? Either way you might be better off with a 6.03mm TBB, if you need to come in under 350fps.

 

[Pointman PUG]

You can get +40fps from a 6.01mm TBB, it depends on how good the seals are between the air nozzle & cylinder head, air nozzle & hop rubber, and hop rubber & barrel. If you're getting 320FPS from a M90 spring then your air seals must be really excellent. I'm wondering if you actually have an M100 spring with average seals? Either way you might be better off with a 6.03mm TBB, if you need to come in under 350fps.

nice one dude...but I was thinking of short stroking the piston so a 6.01 might help with the loss of compression from the shorter piston stroke....just some stuff im throwing around to see if it works!
if the wife gives me the nod I'll video the before and after and post it on youtube!

this my plan so far

deans connectors (ordered)

16 awg low res silicone wire (ordered)

ascu or mosfet

13/1 gear ratios

6.01 tightbore barrell (PDI preferred)

8mm bearings ( if they fit or 6mm otherwise)

im sure there are lots more needed to make a RELIABLE gearbox...but ill come accross them as I research the full build....or you good folks inform me of what is possible!!

 

[Ian_Gere]

I can recommend Kanzen steel bearings. I haven't tried the ceramic ones but I wouldn't be surprised if they are about as good as gearbox bearings can get without getting CERN to make them.

 

[Pointman PUG]

Cheers ian...will have a look!!!

:-D

 

[Pointman PUG]

Sp00n nailed it.

High speed gears are anything between 13 and 18:1 high torque goes from 18 to 28:1.

I'd say that generally there's not really much need to swap out the gears, but if you want to, don't alter the ratio by more than 2, unless it's a mentally serious, hardcore build. I can get about 25 rounds per second with a 9.9v battery, M100 spring, high torque motor and standard 18:1 gearing.

I can't begin to imagine how mental my rof would be with 13:1 and a high speed motor, but I'm not sure how the pulling power really factors into it.

I guess you could compare it to gears on a push bike.

Low gear = low ratio. Super easy to pedal and the parts move super fast, but you don't get very far very fast, which is akin to having a weak spring.

High gear = high ratio. Hard to pedal and the parts move slow, but you go a lot further a lot faster, which is akin to having a heavy as hell spring.

thanks guys....so if im running a low ratio gear set (13/1) will I need a high TORQUE motor rather than a high speed motor.....in my head I figured this to be the other way round for some reason!!

 

[sp00n]

thanks guys....so if im running a low ratio gear set (13/1) will I need a high TORQUE motor rather than a high speed motor.....in my head I figured this to be the other way round for some reason!!

You can run a high speed motor with high speed gears, just make sure the motor is a good quality item and is rated for it.

That said I am running standard guarder gears, a guarder m100 spring, guarder bearings/shims/spring guide, and a g&p high speed m120 motor in my mp5k, I don't know what the rof is, but I need a tappet delay plate as its just not feeding bbs in fast enough (I am told that I "should" get around 22 bbs per sec from this setup though)

 

[Ian_Gere]

If you have a read of Ed's recent adventures in gearbox-land you'll see that it's not quite as simple as 'good motor will work with any gears'. I totally forget the thread title but it wasn't long ago...

 

[sp00n]

If you have a read of Ed's recent adventures in gearbox-land you'll see that it's not quite as simple as 'good motor will work with any gears'. I totally forget the thread title but it wasn't long ago...

ed was using hi torque gears with a high torque motor, and iirc he was displeased at the trigger response

also i did say " is rated for it" with regards to the motor

 

[Ian_Gere]

Yeah Sp00n, I wasn't meaning to suggest you are a pillock or anything; just pointing PUG to a thread in which these issues have been discussed recently. I think you're right about Ed's problem, but I'm sure we went into some detail about the whole subject.

I spotted Burst Wizard King Kong Mosfets on sale somewhere recently PUG. Probably Airsoft World (my memory is so sh!t) - down £5 to £25 with your choice of connectors.

 

[Pointman PUG]

Nice one Ian....just stripped and rewired my gearbox and cable for 16 awg....but like a twat I bought the wrong size heatshrink!!! And also put deans on rather than tamiya...will let everyone know tomorrow if it worked or im a dreamer that just cant solder!!!

 

[sp00n]

Yeah Sp00n, I wasn't meaning to suggest you are a pillock or anything; just pointing PUG to a thread in which these issues have been discussed recently. I think you're right about Ed's problem, but I'm sure we went into some detail about the whole subject.

I spotted Burst Wizard King Kong Mosfets on sale somewhere recently PUG. Probably Airsoft World (my memory is so sh!t) - down £5 to £25 with your choice of connectors.

sorry if i came across as aggressive, it was not intended, and if you though i did, i can only apologize. The problem with the internet, you can say one thing and it can be taken in 2 completely different ways.

 

[Ian_Gere]

Nice one Ian....just stripped and rewired my gearbox and cable for 16 awg....but like a twat I bought the wrong size heatshrink!!! And also put deans on rather than tamiya...will let everyone know tomorrow if it worked or im a dreamer that just cant solder!!!

Deans are supposed to be better. I have a pile ready to go in Jetta, my G36KV; prima facie they have less surface area of contact, but the contacts are much more solid. A major bonus is that they take up less room than either small or large Tamiya connectors. Just do your batteries too...

 

[Pointman PUG]

Right....a quick update!

rewired my g and g. Gr 15 m4...not too much of a headace too do,I replaced factory wiring for 16 AWG silicone wire all the way throughout the gun as well as strip the gearbox (thats a given if your rewiring) cleaned out all the factory grease an replaced with silicone grease..I didnt re shim as I felt the shim job done at the factory was superb.

I then replaced the tamiya for deans connector and re built everything again.although the g and g I have is blowback its just a few more steps than a normal v2 gearbox...I am in no way an engineer or techy (im a storeman by trade...so thick as fuck!!....although I do get to drive big ass forklifts!) I would say anyone with patience (those gears can be a pain to line up when closing the outer gearbox casing...eehhhh boys!) can do this job...just take plenty of refrence pics and have an organised workspace!

right,end result.....well I cant really tell about the rate of fire...it may be feeding 1 possibly 2 bb's more a second.

The single shot has improved a lot but I can still pull the trigger faster than the gun can cycle.

th sound of my gun has changed....it has a more pronounced "thud" too the sound of the shot....like the piston has more force to it.....it....is....awesome!!!

next up,13/1 gears and a tightbore barrell

will let ya know how it goes!

 

[sp00n]

You used silicone grease on the gears? I don't want to worry you but every guide I have seen has said to use white lithium grease, I use guarder Teflon gear grease.

If silicone grease is ok, I stand corrected though.