Building a 76rps gun

[Skywalker]

Alright guys. I cant find much info on this, I need input.

The issue #1:  High speed set up, drop a lipo on it, anti reversal spring breaks within 20 seconds. Easy to fix, but whats to say that the lipo won't break it again? Gears and pistons I understand breaking from use with a lipo, and those things will happen. But when the anti reversal disengages its just such a PITA because its SOOooo close to working. If I have to take my gearbox apart I want it to be reeeeaaalllyyy broken. (Fun fact: this gearbox (and anti reversal latch/spring) is closing in on 3 years old. It might have been about to break with or without the Lipo)

The goal #1: Replace anti reversal latch by using... ? Computer controlled mosfet? Active braking mosfet? The force?

The issue #2: Whatever can replace anti reversal latch, will it still work correctly with dual sector gear. (found here: http://forums.airsoftmechanics.com/http://www.southcarolinaairsoft.com/newforums/viewtopic.php?t=9  )

The goal #2: High speed motor + Dual sector gear + 11.1 20c Lipo = 50+ RPS (I hope)

If nothing else, I can do that with a regular mosfet and keep the anti reversal latch in...  But I don't wanna

[Stomper87]

Have you thought about using a battery like this?
http://www.airsoftgi.com/product_info.php?products_id=5807

It was pulling 27 bb's a second on a stock KWA m4.

[Skywalker]

eh I know there are bigger and bigger and bigger batteries out there. The thing is, if the actual gearing produces the high ROF without higher voltages, they'll last alot longer.... or under higher voltages, shoot WAY faster.

Sure that battery would make it shoot faster...  But that doesn't really solve any of the challenges I'm trying to overcome

[SteevoLS]

It's a spring, and at 3 years old it was bound to die of old age. I can't count how many I've seen break just from being bent too far outside of the gearbox.

Get a new AR latch spring, install it, swiss cheese and short stroke your piston, perfectly shim your gears, make sure you have a polycarb piston head, correct your angle of engagement, and you'll still be left with a very failure-prone gearbox. What version gearbox are you using?

[Star_folder]

Yeah, you should replace the spring, there is no replacement for an anti reversal latch. AB Mosfets just stop the motor, the spring can still make the gears turn the wrong direction after the motor has stopped moving.

And what motor did you have in mind? High speed motors usually don't do well with the DSG because it requires alot of torque to get the gear moving because of the required spring to make sure pre engagement doesn't happen. Speaking of which, what spring are you planning to use?

[Skywalker]

its a good ol v2.

yeah with the dual sector gear, i could basically just cut the piston in half to reduce weight. I haven't picked a piston yet, I'm thinking to go deepfire titanium.

Right now i've got one of those guarder high speeds, only about 40 bucks. I have no issue grabbing a systema A to Z if thats what I need. I've got a m110, and I was going to just grab one of those spring guide spacers that RiotSC has for sale.

[Skywalker]

i think the m110 was non linear though. so in that setup it'll be a little weaker

[Star_folder]

Yeah, you'll need one of those spring spacers, else you will go through pistons faster than you can replace them.

There is a very large thread on ASM about good pistons to use with the DSG. I suggest trying to find it, has alot of good info, the winner is the SHS 7 metal tooth piston. I know it can be found on EhobbyAsia, but I think it is out of stock atm, I don't know where else you could get the piston, but there are other options. If I remember correctly, the deepfire piston doesn't do so well with DSG set ups because it's too ridged, and the titanium is weak or something like that.

Anyway, Don't waste your money on they systema motor, much better can be had for much cheaper. JG stock motors are very strong and are a favorite for this kind of set up. An older world record of rps was set with a JG motor, the super torque version, 70+ rps believe it or not. Anyway, I would suggest either that or the G&P Devil Jet M170 motor. In my tests, the G&P M170 seems to be stronger than the JG motor, and much, much faster.


http://forums.airsoftmechanics.com/http://www.southcarolinaairsoft.com/newforums/viewtopic.php?t=5
Here is the thread, quite lengthy, but a good read nonetheless.

[Skywalker]

yeah i've seen that thread... I was kind of thinking to drop the gears in there and keep with the re-enforced CA piston I have until it breaks... etc etc. It would make sense that the titanium was too brittle.

I've got a couple motors to try out, and yeah i love the m170 devil jet that i have. ... But what makes you say that the systema is no good?

[Star_folder]

But what makes you say that the systema is no good?

It's not that they are no good, but that it's nothing really special, for $100. You can get motors that are as nice or nicer for much cheaper, the G&P M170 is a good example. You can get the G&P M170 for a little more than $50, while the Systema motor is $100.

[SteevoLS]

Systema in general no longer deserves the pedestal people put it on. The G&P M170 is a prime example, but there is almost always a cheaper part that will function just as well if not better than the Systema version.

[Skywalker]

Alright, so basically I need a devil jet in every one of my scars.. lol


I pretty much know the answer to this but, does everyone agree that a devil jet will pull a M130 spring with high speed gears? These ones to be more specific... http://www.airsoftatlanta.com/Bravo_Airsoft_High_Speed_Steel_Gear_Set_p/27450.htm

[Dominum]

Systema in general no longer deserves the pedestal people put it on. The G&P M170 is a prime example, but there is almost always a cheaper part that will function just as well if not better than the Systema version.

Yep, which is why I have been favoring the less expensive Taiwanese companies of late.

If you want that kind of speed, be prepared to do a lot of custom work, and even more reading beforehand. Don't fret about the AR latch, they break, replace it. Keep us updated with a parts list and details of the build please. I have never really tried to make a crazy ROF (40+) setup, though when I had my DSG in my P90 it clocked at 33RPS.

[Skywalker]

what motor were you running with in the p90 dom?

and where did the v6/7 DSG go? you sell it?

right now its

classic army re-enforced piston
M110 non linear spring
idk what piston head (stock ?)
bravo steel high speed gears
guarder high speed revolution motor
somewhere around 25rps with a 9.6 1600mah

goal is

(use CA piston til it dies...) then whatever piston works best
some spring experimenting because of half stroke
some piston head that doesn't suck
dual sector gear set (high speed 14:1 gear ratio)
G&P m170 devil jet motor
non braking mosfet
11.1v stick type lipo battery

i think thats all i'd need to get to 40 - 45 rps

throw all that in the cut down SCAR pdw, along with a 5000 round box mag...... (maybe mod the mag to try and get it to feed fast enough lol)

[Dominum]

Either an EG1000 or a Magnum, maybe both at different times. I still have my DSG, I will do an epic high speed build with something when I have some time and am not working on other people's guns or working on games, the AOSC, setting up the web store, doing inventory, or going to my day job, etc. Just too busy.