Name of the gear design in a PTW?
 

Hey guys,

I've been looking at pictures of the insides of a PTW, and one particular gear or gear arrangement made me say "what the?!".

Can anyone tell me what kind of gear design this is?

https://img.skitch.com/20111117-bk1q...w5h1878d6i.jpg

Is this a PTW's sector gear? What are the advantages of this arrangement...? Seems like it would be fragile. It looks pretty impressive..

It is called a planetary gear.

I wonder... Could this by why the ptw's trigger response is so much better (in addition to other things...) The mass of the sector would be much smaller in comparison to the normal aeg one.

With planetary gear set, there are several contact points to transfer the power rather than just one like standard aegs. This will handle more torque, and with higher torque comes faster trigger response.

nice....

And to add to that in the picture you see up top, the upper right planetary gear is a dark colour compared to remaining three. This is a hardened gear, and for $55 USD you can replace the other three gears with this one. There have been reports of guys in Denmark running these things at 600-700fps with an M170 spring arrangement (custom).

There have also been reports of Gen 3 gearboxes running an M110 cylinder for hundreds of thousands of rounds with no issue.

I used to run the M130 for 80% of play and the other 20% divided up between the M150 and M110. I sold my CQBR 2 years ago with at least 70,000 rounds through it, and it likely has hit over 100K by now. That gearbox looked practically new when I went over the gun at 70K. With maybe an inspection and regrease every 50K rounds or so, there is virtually no limit to its lifespan.

There is also very little deadspace inside that gearbox. The only area really is where the EL-001 board sits, and there is no load on that end of the gearbox.

Close, but not exactly.

It's way easier and electrically efficient to build a small motor that spins really fast with no torque than a motor with a lot of torque that spin slow.

Because the overall gear ratio is way larger than in normal AEGs, the small motor have almost no load and can spin-up to max speed instantly.
Because of that, the gears start moving at full speed at the same time and trigger response is increased.

We do the same thing in RC planes when running on brushed motors... because theses lack the instantaneous torque of brushless, we use a way faster motor with a reduction gearbox to get the same result.

I didn't want to do the math and explain all the details, but my post still stands as the result. :)

The 490a was designed to turn that planetary arrangement and an M170 cylinder at 22 rnds/sec. or about 1320 rpm. This is under load.

The only way to effectively change the gear ratio for more tourque and less speed is to replace the sun gear, which Systema did for the SuperMAX guns. They increase the OD and as such added more teeth. This is why you can't use MAX cylinders in a SuperMAX gun that have not had extra material removed from the sun gear track on the cylinder.

The 490a is a very powerful motor. I wouldn't be surprised if the no-load RPM was in the 35000 area. The weak point of the system though is the motor. Ones that work well will give years of service. Others die within weeks. But, there is a fix for that, and it was not a design flaw but a manufacturing one.

Whether it's a PTW or a high end AEG, if it has a computer, it seems to go through motors quickly lol

Hey Brad,not sure if you remember doing the ver. up kit in my PTW,but that had the newer style motor in it (Supermax 09 I think), It has Not had the "Motor mod" and it's still going strong,I'v been doing alot of full-auto for cover fire and it takes it no prob! When it flags I''ll get it mod-ed. That motor has alot of power,more so than the other motors I have!

Yes, that gear design is called near-perfection...it is the last sound many people have heard before calling their hit! It's a very distinct yet distinguishable sound on many playing fields!

I've had the same PTW gear box for five years. It's been re-greased once, and still looks like new. In fact the only thing I've had go is two motors in that time. Cylinders, mags, batteries, ...ect, all work like new. I'll never touch an AEG again.

I will say that Kevin's PTW is very efficient at turning battery power into kills.