Dual sector gear setup

[Mohawk]

I have an extra kwa sr7 waiting for a good idea so I thought I might try one of these:
http://www.airsoftgi.com/mobile/product ... ts_id=8117

Or

http://www.airsoftgi.com/mobile/product ... ts_id=8119

Which ratio would be best and who should I talk to about partnering up because I do not want to go something this complicated alone. Y'all go ahead and discuss I'd love to hear some opinions.

[Star_folder]

To my knowledge, both Dom and Skywalker have built guns with these in them, I'm working on one right now.

Simply put, the first set has a higher ratio, and won't need as much power to turn. It won't be as fast, but would be a little easier in the long run.

The 14:1 ratios will be faster, but will also require a bit more power to turn. Granted, using either set isn't exactly the easiest thing in the world.

Now, what are you planning to do with these? Are you looking for a rate of fire higher than 50? It's not uncommon for those 14:1 gears to reach 70+rps, and those 20:1 can get up to 60 or higher. You'll need an extremely high torque motor, a very good battery, and a good mosfet to keep the trigger contacts in one piece. Beyond that, you'll need lots and lots of time to make the gearbox as efficient as possible. Next to a DMR, this is probably the most difficult thing you can do with an AEG.

Not trying to scare you away, just want to let you know the kind build this will be. It will take a good bit of time and effort.

[Skywalker]

Too much to say from my phone. Will edit when I am at computer

[Mohawk]

Yeah I figured as much, what about using them with one of those aws raptor setups or is that to "smart" for the gearset? Along with one of g&p's high torque motors? Why a ht motor instead of high speed?

[Star_folder]

Actually, I'd be more worried that the gear set could burn out the mosfet. I wouldn't use a raptor with the system until everything else works fine. In my experience, raptors are finicky and burn too easily. I'd get one of steevo's mosfets, or someone else's cheap mosfets to make sure the system works well first, and then put the raptor in.

Skywalker used a G&P M170, However, I'd suggest an SHS High Torque or Lonex High Torque. They are faster, and more capable than the M170, and are actually comparable to a G&P M180 motor, but they're a fraction of the cost. The reason I suggest a torque motor instead of a speed motor is because speed motors don't have the torque to pull the system.

Let me try to explain. You've got your gear sets, the torque gearsets are like 32:1 ratio, and speed sets are like 13:1. That means that the bevel gear spins 32 times for every 1 sector gear rotation, or 13 times for 1 sector gear rotation. Have you ever been on a bike with gears, having the different ratios. You know how the lower ratios require more power from you to get them turning, while the higher ratios, it's really easy to get the wheels turning? Same basic thing. Because the ratio is lower, you'll need more torque to get the job done, not more speed.

Something else to consider with the DSG is that you'll need a spring twice as powerful as normal to get usable fps and not have any Pre engagement. I'm talking M170 for 300fps with .2s, you'll have to go even higher for more fps. The piston is pulled back half way and then released. Effectively, that makes the gear ratio half of what it would be normally. So while the 20:1 bevel and spur gears are indeed 20:1 ratio, the DSG means that is halved, making it a 10:1 ratio, and that 14:1 with the DSG is actually 7:1 ratio. Pulling an M170 spring on that low of a ratio requires crazy amounts of torque.

[Mohawk]

Ok so I'll need a good piston too, would a 14.8 (I think that's right) lipo be good or something else? I think I understand the concept and a kwa 2gx shell seems good for it with the beefed up front. Please by all means correct me if I'm wrong I really want this done right. Just to recap the parts (ignoring the work specs for now) I would need a m170~ spring, the gears, piston, motor, mosfet, high voltage battery. What about compression? Type 0 or 1 etc what would work for the load?

[Star_folder]

the cylinder doesn't really matter, you'll only be using half of it anyway. Compression would be the same as any other build, just make sure it's good to go.

With a piston, the SHS 15 tooth piston is the best for the job. The steel teeth are the strongest on the market, the only thing that needs to be done is removal of the extra teeth, and epoxing the piston rack in place. Full tooth pistons have a tendency to collapse in the middle of the rack due to the lack of support from the piston body itself, epoxing them in place helps remedy that issue.

Yes, a 14.8v would be ideal, but a large 11.1v could cut it. You should also be able to use a strong 7.4v battery, but at those speeds, you might as well use a standard sector gear set up and not worry about the DSG.

2gx shells aren't indestructable, you'll still need the normal shell reinforcement mods to make sure it stays in one piece. You'll also need to find some 9mm steel bushings. I think SHS makes some, but I'm not 100% sure.

[Mohawk]

I know it's not perfect but the shell does seem a bit stronger. I really wanted to give this a shot, but if it's going to be so unreliable to the point of I can only show off for a few thousand rounds and then it breaks I may not. Can this honestly be done somewhat reliably to be useable or is it just a gimmic?

[Star_folder]

It can be done reliably. There are people all across the nation that run these kind of set ups for hundreds of thousands of rounds before something breaks. Though, given the rps they are at, that's considerably quicker than hundreds of thousands of rounds in normal guns. Still, it should last you long enough to be used for several games before it needs maintenance.

Unlike "normal" builds, however, this is something you'll want to take apart every so often, before something breaks, to make sure nothing will break. You don't want something to snap, and then wreck the insides of your gearbox because you didn't open it up for dozens of thousands of rounds.

[Mohawk]

Alright sounds worth it, will y'all be at soco? We might just need to have a "campfire discussion" before I get into this and blow a ton of money.

[Star_folder]

I'm planning on being there, yeah.

[Mohawk]

I really don't want to just "buy" one of these guns or even pay someone to build it for me, I really want to do the majority of the work but after my m14 dmr build I'd like supervision... Don't get me wrong I can build a cool AR but these extreme specialties scare me.

[Star_folder]

Perhaps you should try just a normal high speed build first. Grab yourself a good motor and a set of 13:1 SHS gears and go from there. Once you feel you've got a good handle on it, then just get the new gear set and install those. That'll give you a good middle ground test, and won't add much to the over all price of the system. Considering you can use all the same stuff from a 13:1 build as you can for your DSG build. You just modify a few things and i'll be good to go.

[Skywalker]

Can somebody link him my thread, It was on page 4 or 5.... I typed my whole thing out, then the thunderstorm took out my internet

Honestly, I disagree with kory on the practicality of the build.

[Mohawk]

Ive done 2 hs guns but no special gear ratios, I had a g&p build shooting 34rps and my current sr7 can do 35 at 340fps. I get the minor details but 70rps was just too tempting