Systema PTW Basic Info and FAQ

[mcguyver]

I guess you should specify if you have the 490 motor or not. With the 480, routing wiring was not as critical, as the brush hoods are different and the brush leads are routed in a different fashion as well.

A note on soldering, go easy. You don't need to heat the terminals up until they're blue and you only need a bit of solder. Don't goop the shit on.

If you have a 480 motor, the bearing is necessary to adjust the motor height. It is not required for the 490, as they are not adjustable.

[Scarecrow]

Originally Posted by mcguyver

I guess you should specify if you have the 490 motor or not. With the 480, routing wiring was not as critical, as the brush hoods are different and the brush leads are routed in a different fashion as well.

I have a motor and it spins when you pull the trigger (grin).

How do you tell what model motor you have?

[mcguyver]

Silver motor frame and green rotor (with either 11t or 14t marking) means 490 (11t for "a" and 14t for "b"). Black frame with bare copper-coloured (or close to it) rotor is 480 motor. These days, it makes a difference, as they are designed differently and different installation procedures are necessary.

[Fox Hound]

anyone know if i can use AEG gas blocks for my PTW barrel? looking for the vltor gas block and the real one is 60$ vs 12$

[mcguyver]

Yes, you should be able to use them. I have used King Arms PRI flip-up sights meant for AEGs, as well I have a G&G GR-25 gas block on my M16 at the moment.

My M16 barrel measures 0.725" outside diameter.

[Fox Hound]

why are the m4 cylinder's not compatible with the M16 ptw? Is it because of the barrel length?

if this is so i guess i can't put in a M16 inner barrel on my m4(with silenser) without changing the cylinders?

[mcguyver]

Originally Posted by Fox Hound

why are the m4 cylinder's not compatible with the M16 ptw? Is it because of the barrel length?

M4 cylinders are not immediately compatible with some M16 models, mainly Gen 1 and 2 M16. The cylinder lock of Gen 3 and newer is on the cylinder itself, while on the older M16 it is on the buffer cap. You either need to install a Gen 1 or 2 spring guide onto an M4 cylinder, or better yet, replace the stock tube, and spring guide with a MAX stock pipe kit. Jugglez has them for $150. This way, you can buy all new cylinders at any time, and use them in the M16.

The M16 cylinders have been discontinued for some time now, but there may be a few floating around out there.

It also bears mentioning that Gen 1 used a larger hop-up I.D. than newer guns use. So, you would also need to install a new cylinder head (complete with nozzle) on the older cylinder to be able to use it in a newer gun.

[Fox Hound]

what about the barrel length? Can i still use a m16 inner in my m4 barrel?

[mcguyver]

The M16 cylinder does have an increased air volume, as it's cut only once at the rack gear, where an M4 cylinder is cut twice.

Look at your M4 cylinders, you can see alot of the rack gear. M16 cylinder shows 2 tetth only and is cut once for the sector gear.

If you're concerned, don't put an M16 barrel in the M4. Performance benefits would not be worth the cost. Or, if you must, do it and stick to semi-auto only, but it may not be sufficient.

I use an M4 M150 in my semi-only M16, and my velocity with that cylinder went from 455 FPS (with 0.25g BBs) in either M4 to 482ish in the M16 and I gained another 15 fps going to a real steel reinforced upper.

[jameskersten]

Well, its official, I became a victim to another bunk 490 motor failure yesterday. This is the 2nd failure of the 490 in my gun. The first right out of the box it was bad. The 2nd came to a head yesterday. About 2weeks ago I noticed a bit of an odd whine from the gun on longer sets of burst, the noise sounds like the typical low battery sound so I changed battery, didn't fix anything, noise still there. So I started to do my research and reliezed its possible I have another motor failure coming. Luckily I have a spare 490b in our "PTW kit" in case so I went on with my playing. Did a milsim last saturday, gun ran ok as long as I didn't make extended bursts or it would start to hear the whine noise but as soon as I stopped firing for a second the noise was gone until I did the extended burst again. Only hickup for the day was a result of a bad bb that got jammed in the hopup and such caused the fuse to blow and at one point the gun only first in burst but it was raining so I counted that to moisture in the gun.. Easy fix. Fast forward to yesterday. Instead of having a game day a few of us with PTW's figured it would be a great day to attempt a few maintenance things (cylinder rebuilds, hopup rubber replacement,etc). My gun ran ok, at first it didn't want to fire in burst, semi only. After a few dozen rounds it started to shoot on burst again and everything seemed ok so I put another 250-350 rds through it with only issue being every so often it wouldnt fire.
Well I then decided to take a problem mag I have apart to try and remedy issue of not feeding well, well I took it apart and fixed it up. Put it back into the gun and give it a few rounds to test it out. Well after about 5 burst through my gun it just stopped. I thought it might be related to some water in the electronics from the milsim so I checked the fuse and took the gun apart. Everything seemed ok so I figured I would try my spare 490b. Sure enough, it fixed all the problems I have been having with my PTW. In fact the gun sounds so different now, maybe I got use to the old motor going it or be it slowly just deteriated, either way, its got the nice crisp snap again that I love so much.
Anyways I thought I would share my story,maybe someone else is facing the same issue.

[mcguyver]

So, what have you guys done with your motors? I'm assuming you have them set aside for any future rebuilding or repair?

Have you guys tried to clean up the commutators with a comm file, and then replace the brushes with a hard stand-up brush from an RC shop? This seems to be a common way to fix those that can be fixed, as brushes cost about $6/set.

It appears that Systema has used very soft brushes in the 490's manufactured after summer/07, and replacement with a harder brush, coupled with filing of the comm points to remove contaminants and smooth out pole transitions has led to some good success. A comm file will run you about $6 at a hobby shop, and it's worth a try to salvage a $150+ motor.

[jameskersten]

thanks for the advise, I will give it a try. i did have a spare 490b that i bought back a few months ago so my gun is not down at all so i not overly concerned right now but I wouldnt mind trying your idea out and see what comes of it.

[mcguyver]

I goofed. They should be stand-up brushes, not lay-down.

http://www.systema-europe.com/Forum/...?TID=1651&PN=3

[swatt13]

im haveing a a problem with a few of my mags not feeding well, you mentioned you remedied this james, how so? i didnt really mind it at forst as it wich funny needing to tap the mag off your helmet to seat the bbs propperly, but needing to do it after every burst gets old real quick. esspecially when you "life" depeneds on it.

[jameskersten]

Mine was case of a cross fed bb down near the follower so I just took mine apart and removed the cross fed bb in the mag. It was really simple, I can't tell you for sure 100% its fixed completly cause I didn't get a chance to run too many more rounds through the gun before we called it a day but i did notice even loading those mags it was very different then before. It felt like there was lots of resistance before where is now there is only the normal resistance of loading.