SYSTEMA m170 gearbox set

[doc_pathfinders]

Lo all,

i wanted to just put a few comments down now about something i picked up a few weeks ago..



as well as a Neo Strike chamber HOP unit

i'll put up pictures that i took later, but first of all i'll add a few comments:

the finish on this gearbox is great, a very fine phosphate i would guess..
the MOSFET is interesting, i have the newer (and better i would guess) Single mosfet unit rather then the older Double units (the double's were known to have problems)

i have been running this in my SPR MK12, and after a long rough start it's pumping out 160 M/S with my 0.25's

Problems:
Fuse, it has a 35 amp miniblade-type fuse, this has gone after looong strings of semi automatic (i would guess it's about 30 seconds to 45 seconds of constant semi, it's just pulling too much current) while this was only found in testing (i don't intend to put anyone in hospital, but testing properly involves harsh testing) it's still a point of concern that maybe at some point during a firefight your gun might stop. the mosfet unit casing gets quite hot (from the mosfet) and i was thinking of using some arctic 5 heatsink compound i have here on it to increase the rate that heat can be transffered to the heatsink, anyone have any ideas?

putting the spring in!
the included instructions call for the box to be dis-assembled and the motor height adustment be done with the handle attached to the remainder of the gear box.. otherwise the bevel gear might sustain damage in moments, add into the fact that i can see some difference in the bevel gear included on the Provided magnum means you need to be sure what's going to happen when you pull the trigger that first time!



after a couple of weeks of problems with a 'POS' DBOYS body, and a subsequent swap to a classic army one i had around, i finally realised that i was onto a real winner, the trigger response is great, i ran it with a couple of old 3300 9.6v NiMH batteries at first, blew a fuse and changed to a 30 amp (down from 35, all they had at the time) and it went well on a big 2200 11.1v lipoly where it's been tested and finally gotten working.

i'm amazed that a 9.6 could pull back a m170 and the rate of fire wasn't bad at all.

also, watch out about the screws in the gearbox, after a while of testing i noticed that the screws were very loose, loosing a screw in a while loose!

so a dab of loctite (blue) is advised

full review to be submitted later, with pics.

[Guges Mk3]

M170...geez.

Did they radius the front of the mechbox to destress it?

[doc_pathfinders]

yep,

to be honest, i'm amazed that it can work so well.. it feels like a TM stock.. buttery smooth.

the piston is polycarb full-tooth, not all teeth are metal, spring is evil to fit (has a life of it's own!) the spring guide is basic metal (no bearing) but the bore-up kit piston head was with bearings.

shimming was good, not perfect but not bad and i feel that their was a little too little grease where grease needs to be. the gearbox housing feels quality, some reinforcement where it needs to be but not so much towards the back (in reality a gearbox is only going to go at the front, so it's where it needs to be.

[doc_pathfinders]

the systema magnum that comes in the box has what i believe to be a different bevel gear, the motor has been able to pull back that m170 spring when using an old 9.6 battery. before i built i played with the motor for a bit, the magnets are VERY powerful, even moreso then the guarder infinite torque motor... the last time that i blew the fuse in the field i realised that the motor had become a tad warm, even through the bulky SPR style grip.

[Azathoth]

See it's stuff like this where I keep on asking myself WHY are people putting sorbo's into their guns when a factory built gearbox with M170 goes for 100,000's of rounds without breaking.

A friend went the Systems M170 round downgrade spring and there is no difference between his gearbox shell and Mine which was the M120.

[Styrak]

These are Systema gearboxes....not stock TM or other mechboxes...

[doc_pathfinders]

does anyone want pictures of the bare MOSFET unit (with/without the heatsink on)?

if anyone does, let me know now so i can take the stock off etc etc...

as i said before, i have the single mosfet unit version, not the older troublesome dual unit..

(could it be that the lower current versions were the double and the high current versions were single until they realised the problems? just a thought)

[zone 69]

Originally Posted by doc_pathfinders

does anyone want pictures of the bare MOSFET unit (with/without the heatsink on)?

if anyone does, let me know now so i can take the stock off etc etc...

as i said before, i have the single mosfet unit version, not the older troublesome dual unit..

(could it be that the lower current versions were the double and the high current versions were single until they realised the problems? just a thought)

OK post up some pic's I like to see one up clouse.

Put a coin in the pic so i can judge the size of it.

Thank's

[doc_pathfinders]

Ok, here are some real close-ups..

please note, this is from another gearbox i had arrive today (m150 spring, but the MOSFET is the same, take my word on it)

[Guges Mk3]

Can I have a picture of the front of the gear box from either the left or right side. Right where the cylinder seats into the mechbox, please.

[doc_pathfinders]

next time i take down the rifle i'll get you those pictures

[Guges Mk3]

TYVM.