High torque with >350 fps build???

[IntelligentCelestialBeing]

Im new to airsofting and im building my own M4. 

I mainly use semi automatic and high rate of fire isn’t important to me. In fact i dont want high rate of fire. However, airsoft fields in the uk have a site limit of 350 fps and i would like to use a high torque motor as i dont want a high rate of fire, but im worried about overspin. 

The kind of build im looking to do is:

Fast trigger response 

low rate of fire as i only use semi auto (not crazy low tho) 

tops off at 350fps with 0.2g bbs (no more than that) 

reliable and durable 

Do you have any advice for what i could do to achieve my goal and whether a high torque motor will be ok to use or will it over spin?

also im not sure what spring i will use but it will probably be m100 or m110

any advice will be much appreciated 

 

[Samurai]

Wrong forum.

High torque motor gives the best trigger response. You can use faster gears, but that combined with a 11.1V lipo might overspin. You already thought of that.

Either you can use 9.9V life battery in that case or go for a smart fet that lets you set ROF without compromising the trigger response. I'd suggest the latter because single shots with high voltage battery and high torque motor eats up the trigger contacts without fet very fast.

M90 will be enough if your airseal is good.

 

[Iceni]

Fast trigger response 

low rate of fire as i only use semi auto (not crazy low tho) 

tops off at 350fps with 0.2g bbs (no more than that) 

reliable and durable 

 

I recently rebuilt an M4 with the help of @Sitting Duck with exactly this in mind.

Fast trigger response
Moderate ROF
350fps
Long service period.


The build I ended up with runs a slightly different gearing, on a decent motor.

13:1 gears, 30K ASG motor ( high torque), cut M110 spring, Mosfet, Bushings.
It's getting close to 25 Rps on a 7.4v lipo, Trigger response is very good.

Most of the parts came from AK2M4, And it wasn't a budget breaking build other than the motor. There are cheaper motor alternatives.

13:1 gears £14
https://www.ak2m4.co.uk/internal-parts/gears/zci-gear-set-13-1-reinforced

An acceptable motor RA HT £29
https://www.ak2m4.co.uk/internal-parts/motors-parts/ra-high-torque-motor-long

M110 spring £5 I had to cut 1.5 coils off for my setup to hit 350fps. If you don't want that hassle grab an M100 spring instead.
https://www.ak2m4.co.uk/internal-parts/springs/shs-ra-m110-aeg-black-spring

Bushings will depend on your gearbox shells. And mosfet is your own call, AK2M4 has no stock of these ATM but he gets stock in very regularly.

Your gears will need shimming and I have no idea about your level of technical knowledge so it might be worth adding in some information about what gearboxes you have worked on. 

If you run that with 7.4v lipo's then overspin should not be an issue. 11.1v may cause you some problems.

Since you say you are new to airsoft it might be worth watching a few video's and tutorials on gearbox rebuilding. It's not always straightforward. And is rarely easy. Tolerances in airsoft are poor and you have to eyeball and feel everything as you work. 

There are loads of threads about this on here.


One thing to note however is it is very easy to make a new gun into a non-shooter with just a few slips of a screwdriver. It is normally advised that your first gun be of a decent enough quality that you don't need to go making any technical changes to it. Something you can buy and have confidence in shooting without modification even if it costs slightly more is normally far cheaper than the upgrade route. 

For example, a decent beginner gun is a G&G raider. Budget £160. It shouldn't need any modification.

A cheaper gun might be a JG M4 at £100. You add the upgrades above and that adds £50. So you have cheaper externals and it's cost you the same. By the time you have added the Mosfet, bushings, shims and any other bits you could happily add another £30-40 to the total cost, Putting it into the £200 bracket.


The second gun when you have a spare is normally when you start to learn to do the tech work. Picking up a poor shooter and getting it running right.

 

[Jedi_Master]

Moved to Advice and Technical Help sub-forum

 

[IntelligentCelestialBeing]

Wrong forum.

High torque motor gives the best trigger response. You can use faster gears, but that combined with a 11.1V lipo might overspin. You already thought of that.

Either you can use 9.9V life battery in that case or go for a smart fet that lets you set ROF without compromising the trigger response. I'd suggest the latter because single shots with high voltage battery and high torque motor eats up the trigger contacts without fet very fast.

M90 will be enough if your airseal is good.

Thanks for the help and i dont usually use forums so i dont have a clue how to use this thing ?? 

 

I recently rebuilt an M4 with the help of @Sitting Duck with exactly this in mind.

Fast trigger response
Moderate ROF
350fps
Long service period.


The build I ended up with runs a slightly different gearing, on a decent motor.

13:1 gears, 30K ASG motor ( high torque), cut M110 spring, Mosfet, Bushings.
It's getting close to 25 Rps on a 7.4v lipo, Trigger response is very good.

Most of the parts came from AK2M4, And it wasn't a budget breaking build other than the motor. There are cheaper motor alternatives.

13:1 gears £14
https://www.ak2m4.co.uk/internal-parts/gears/zci-gear-set-13-1-reinforced

An acceptable motor RA HT £29
https://www.ak2m4.co.uk/internal-parts/motors-parts/ra-high-torque-motor-long

M110 spring £5 I had to cut 1.5 coils off for my setup to hit 350fps. If you don't want that hassle grab an M100 spring instead.
https://www.ak2m4.co.uk/internal-parts/springs/shs-ra-m110-aeg-black-spring

Bushings will depend on your gearbox shells. And mosfet is your own call, AK2M4 has no stock of these ATM but he gets stock in very regularly.

Your gears will need shimming and I have no idea about your level of technical knowledge so it might be worth adding in some information about what gearboxes you have worked on. 

If you run that with 7.4v lipo's then overspin should not be an issue. 11.1v may cause you some problems.

Since you say you are new to airsoft it might be worth watching a few video's and tutorials on gearbox rebuilding. It's not always straightforward. And is rarely easy. Tolerances in airsoft are poor and you have to eyeball and feel everything as you work. 

There are loads of threads about this on here.


One thing to note however is it is very easy to make a new gun into a non-shooter with just a few slips of a screwdriver. It is normally advised that your first gun be of a decent enough quality that you don't need to go making any technical changes to it. Something you can buy and have confidence in shooting without modification even if it costs slightly more is normally far cheaper than the upgrade route. 

For example, a decent beginner gun is a G&G raider. Budget £160. It shouldn't need any modification.

A cheaper gun might be a JG M4 at £100. You add the upgrades above and that adds £50. So you have cheaper externals and it's cost you the same. By the time you have added the Mosfet, bushings, shims and any other bits you could happily add another £30-40 to the total cost, Putting it into the £200 bracket.


The second gun when you have a spare is normally when you start to learn to do the tech work. Picking up a poor shooter and getting it running right.

Thanks for the advice its been a big help ??