Systema Revolution gearbox info

[MadMax]

The PTW MP5 is quite an interesting piece of work. It uses similar cylinders to the M4 PTW but they are not completely cross compatible. The MP5 PTW has a larger cutout next to the sector gear window to clear the step gear. Because of the need for a larger cutout to clear the larger diameter step gear (larger than the M4 one) a M4 cyl doesn't work in a MP5, but it looks like a MP5 cylinder could go into a M4 PTW. It's possible that SystemA would simplify their inventory and only carry MP5 cylinders which are backwards compatible with the M4 line.

I'm kind of drowning in grenade planning these days. I really do want to post my reviews of ShotShow stuff, but I'm crummy with Photoshop (pics still need a little treatment) and there is a fair bit of writing to do still.

I'll try to start dealing with the photos and trickle out the writing editing my initial posts so at least you can drool over pics of some of the stuff I saw.

[mcguyver]

The concern I have is the nozzle o-ring. In current PTWs using Viton o-rings, they need to be replaced about every 10,000 rounds. The newer cylinders are using polyurethane, and so is the Revolution mechbox. There is no word on lifespan for those yet, but it will exceed 10,000 rounds for sure. But, to replace it, you need to tear the mechbox down.

According to Blackwolf from airsoftmechanix, the MP5 PTW cylinder is smaller in diameter than the M4 cylinder, and this is a real problem for cross-compatibility. Both he and Zilch from Systema Europe are sworn to secrecy (as it were), so no further info is available from them to be 100%.

[WarChild7]

Originally Posted by ILLusion

I was under the impression that the MP5 also used the "Revolution" gearbox, as initial reports indicated that the gearbox wasn't much more than a modified version 2.

The MP5 does not use the Revolution gearbox. I saw the MP5 at the Shot Show. You can see in this pic that the gearbox on the MP5 is different than the Revolution pics shown in my first post.



When I spoke with Wallace on Wednesday, he said the Revolution gearbox still has at least another month in prototype phase, followed by a couple months for tooling and production, so it's unlikely we'll see them on the market for sale before the beginning of Summer.

Oh, one more thing: the Revolution will be offered in two variants, a high-speed version (M100 probably) and a high-torque M120 version.

[MadMax]

Now that I look back at my pictures, I note that the MP5 cylinder does not have the shoulder diameter at the rear that's present on the M4 cylinder. It seems that the body diameter could be the same, but the absence of the rear shoulder would make the MP5 cylinder incompatible with the M4 PTW.

Tearing down a gearbox to replace the oring every 20k rounds wouldn't be too bad. It's not like we don't already often have to get into a gearbox that regularly. It would detract from the uber robustness ideal, but if you're running an insane M170 setup, it would still be a significant improvement over replacing a complete cracked gearbox. I'm hoping they've done their lifecycle testing and that the Revo is actually that fatigue resistant.

I'm hoping that one day SystemA will make a removable rear plate and remove all the metal that guides the piston. Continue the cylinder holding bore all the way back so you could slide out an entire piston-cylinder assembly from a MP5 through the rear of the gearbox. That would deal with the oring wear issues and take all the impact fatigue off the gearbox shell and put it onto the cylinder tube. The change would be easy as PTW cylinder tubes have the same outer diameter as the standard TM cylinder OD.

[mcguyver]

That o-ring could last even longer than 20k rounds, I don't know. The cylinders out there only became available last August, so for us, I don't know how many people have that many rounds through them from then until now. I know for a fact that Viton would be a poorer o-ring to use there, but all their new cylinders and rebuild kits come with the polyurethane anyway.

Originally Posted by m102404

Too bad they left one of the circuit boards exposed (blue horizontal one), I guess there just wasn't enough space.

The optical counter mech is neat, but won't grease, flung off the gear, land smack on the board? Maybe I should use less grease....

That blue circuit board looks like the heatsink for the FETs. A solid aliminum heatsink would be more mass than a cast alloy mechbox shell, and it eliminates the problem of opening the mechbox and having to disturb the FETs.

The sensor problem with grease contamination is not a new problem for the PTW. Even Gen 1 guns had this problem. Currently in the M4, you can remove the EL-001 board and clean then sensors in about 5 minutes (if you're slow), as well as clean out the holes in the sector gear. Being sealed up in the mechbox shell does not make this job easy.

[MadMax]

Maybe a hole could be drilled in the side of the gearbox. Run the motor at low voltage so it can't drive enough torque to overcome the preload in the mainspring which would define it's stop point so the peep hole lines up with the hole in the gearbox.

With the port in the gearbox and peep hole lined up, blowing out goo could be done with a duster can straw. Strategically placed holes could also be used to access the optoelectronics. A pair of opposing holes (on opposite box sides) above or below each sensor could provide direct access to sensor faces. Perhaps a bent shim of metal with a pad of felt glued to the inside face could be used to poke through the window and wipe the sensor face.

Maybe an entirely new lubricant could solve the gooing problem. Maybe painting on a coating of colloidal graphite could provide non gooey lubrication that would be easily blown off of sensor faces. Thrown off powder would be too small to occlude gear holes too.

I do find it a little goofy trying to detect a small drilled peep hole. There are lots of small processors that could count the sector teeth to derive sector position. The teeth profiles are nice and fat which make for unblockable optical flags. Also, with the teeth turned away from the sensors, a nice big gap is left to access the sensor faces with a Q tip through a hole in each gearbox side.

[mcguyver]

I don't think modifying the gearbox should need to be done. People will have to practice a maintainance set when using this mechbox. Clean sensors and sector gear holes, replace nozzle o-ring, relube nozzle o-ring seat and clean, re-lube cylinder. No regrease of gears whatsoever, to prevent sensor and board contamination.

All this should be done regularly, just like on a PTW (it only makes sense since it's the same systems for the most part), but the trick will be to know when this needs to be done. The nozzle o-rings used to be the weak link, but now that they have improved, the maintainance schedule can be extended.

Hmmm anyone want to buy a ptw? This would rid my missfeeding problems that have plagued my ptw.

[MadMax]

Actually I just shot off an email to SystemA hoping that they could add some tweaks like cleaning ports. Why not make it easy to clean sensor faces or sector peep holes. If they're going to provide a diagnostic LED feature, why not make it easy to correct some issues?

I was all over getting a MP5 PTW, but after looking over the Revo gearbox, I'd rather upgrade a CA MP5 and upgrade it with a Revo box. Decent metal body with consistent hop up, low cost reliable mags, and a plethora of TM compatible accessories like a SD forend and a sliding stock.

I'd put up with a breaking cocking handle any day if I could get the PTW avionics and gear group. I think I could hack in last shot cutoff with a magnetic mag follower that affects the inductance of a coil wrapped around the hop up stem.

[ILLusion]

Originally Posted by MadMax

Now that I look back at my pictures, I note that the MP5 cylinder does not have the shoulder diameter at the rear that's present on the M4 cylinder. It seems that the body diameter could be the same, but the absence of the rear shoulder would make the MP5 cylinder incompatible with the M4 PTW.

So then that would make it that much more compatible with real steel uppers... hmm.....

[WarChild7]

More Revolution info:

Scheduled to be released in time for the summer season of 2008, the Systema Revolution gearbox is the future top-tier solution for upgrading an AR-15 type AEG that uses a Version 2 gearbox. The Revolution is a drop-in fit for the Tokyo Marui M4/M16 series, and will fit most other brands as well, provided that they are made to a high enough standard and measurements close to Tokyo Marui. As with the traditional full gearbox upgrades from Systema, we are not expecting any issues using this with G&P and Classic Army receivers. ICS will not be compatible, due to the split design and modified receiver dimensions.

Compatibility with the V2 gearbox stops at the surface. The Systema Revolution gearbox mimics the V2 on the outside so it can be used with the common AEG, but an entirely different heart is beating on the inside. Note the extra beefy walls of this near gearbox, which is designed to withstand high powered springs for mind-blowing power levels unseen in traditional Marui-type guns.

ELECTRIC CONTROL UNIT

An ingenious trigger unit called the E.C.U. is integrated into the Revolution. As the trend is with high performance electric guns, the design uses MOSFET components to allow a smooth flow of electrons from the battery to the motor, and eliminate arcing and high currents from the trigger unit. Instead of a mechanical cut-off lever, the E.C.U. has an optical sensor to detect the movement of the sector gear at all times.

First of all, the optical sensor allows the factory-programmed chip to make the gun shoot once on semi, and once only. Even a quick tap on the trigger activates the cycle, which doesn't leave the spring half-cocked like a traditional AEG does. This feature was exclusive for the PTW, but now it is available for AEG users as well.

Because the E.C.U. "knows" the position of the gears at all times, it will always stop the firing cycle in the same spot. Adding more current or active braking (by reversed polarity) when necessary, the E.C.U. keeps the shooting cycle consistent shot after shot. This allowed to omit another small mechanical part, namely the anti-reversal latch. Less moving parts translates to fewer mechanical problems!

The E.C.U. makes a proper three round burst possible as well, instead relying on complex mechanical parts or an inconsistent timer system as seen in older designs. As with real firearms, the burst stops as soon as the trigger is released, even if three rounds were not fired at that point. In fact, this circuitry can allow programming any number of rounds to be fired automatically on each trigger pull. So a 6 or 7 round burst is possible though it's not clear at this point whether Systema will make that user programmable.!

MECHANICAL ADVANCEMENTS

The tappet plate is one achille's heel of a traditional AEG gearbox design. Why reinforce it when you don't even need one? Pioneered with the PTW, the Revolution gearbox has a new nozzle design; the loading movement is achieved with a flexible fit to the piston head. This makes the nozzle movement linear, and eliminates the old fragile part from the equation entirely. The nozzle is pulled back and released from an O-ring within the piston head as the piston moves. As a fine side-effect we expect the gearbox to be even more durable in the front, compared to the reinforced V2 gearbox.

The piston is considered to be the "consumable" part in any AEG. With the Revolution, this is addressed again with a PTW-style solution. By reducing the spring diameter, Systema achieved more freedom in the design of the piston. It is now an enclosed polymer part with an all steel tooth rack below, while other metal tooth piston designs have been open from the "belly" to allow sufficient space for the tooth rack. As a result the spring does not rub against metal, and the tooth rack stays on under the load of even the strongest springs. An in case you were wondering, this is not the traditional red cylinder offered by Systema in the past for regular gearbox upgrades. This is the same super strong piston (which also happens to be red color) used in the PTW MAX guns.

THE REVOLVING REVOLUTION

As the gearbox was improved so far ahead compared to a traditional design already, Systema decided to make the gear train their way, instead of reinforced parts following the Tokyo Marui form. The gear train consists of four gears to transfer the power from the motor to the piston. The sector gear has a slightly larger module (tooth size) to engage the piston, and is fitted with 7 mm bearings for strength. Two spur gears and a bevel gear are machined to tight tolerances with a smaller module to reduce gear noise and improve efficiency. These three gears are supported by two 6 mm ball bearings each, and allow a wide range of gear ratios to be developed later on.

Because of the additional gear in the gear train, the motor was redesigned to run in reverse. While a DC motor would turn the other way simply by reversing polarity, it will not give peak performance in the "wrong" direction. The motor of the Revolution gearbox features superbly strong Neodymium rare earth magnets, ball bearings, a steel pinion and hand-wound armament for the highest performance money can buy.

Is this thing still alive? launch was supposed to be march/april.

[panda86]

I was trying to do some research on it, and they are still developing it. Might be late summer release.

Does anyone know what FPS to expect from the Revolution?

[AngelusNex]

I'd imagine they'll sell different spring strengths.

[.:Seaforth:.]

God damn it I am holding off on upgrading my m4 so I can buy one but it is taking sooo long