Tm MP5 30rps build

[Dude666fx]

Evening all.
Looking at upgrading the ROF and trigger response on my MP5 and after doing lots of googling/research have ordered the following parts:

Shs 13.1 ratio high speed gears
Non braked airfet mosfet
Shs steel bushings
Shs steel bearing spring guide

Also in addition to the above will be swapping out the eg 700 motor for an ics turbo 3000 that i already had, already adjusted AOE and fitted deans connectors.
Using a 9.6v vapex battery not going down the lipo route just trying to see if it can be achieved this way.
I have a spare sector clip so will install that too to avoid feeding issues with the increased speed and have shims to smooth out the new gears being fitted.
The spring ill be using is an m120 but has had quite a few coils removed to bring it down to 325fps just hoping the harder spring in genaral will return the piston in time to be picked up again.

So im hoping after changing all this it will work perfect first time but i have a feeling it wont be that simple lol.

Should i expect to have to swiss cheese the piston or short stroke it? as im hoping to get away with out doing ether of these.


I dont really want any more than 30rps as will have to start upgrading more stuff and 30 or even slightly under is more than i need.

Another question i have is im using the xcortech x3300w chrono that has the programable burst fire mosfet will this interfere/upset the hard wired mosfet i am installing?

Many thanks

[Dude666fx]

Re: Tm MP5 30rps build

So I was hoping to reach out to you guys for help and guidance in this as have not tryed anything like it before. I have googled as much as I can find but not sure on a few bits.

[Sitting Duck]

Re: Tm MP5 30rps build

if your m120 had a coil or two cut to bring it down to 325 it is roughly a m100 now
the bearing spring guide will perhaps take it to 340fps

no I would not short stroke it just yet

however I'd see how she fires with a 8.4v and ics motor - it won't rip like crazy an PE
but best try 8.4v first to be safe

maybe with deans and 9.6v you might hit 25 but doubt if you will hit much past 20 on a ferrite motor

also went through loads of very similar stuff here recently so didn't wanna go over loads n loads all over again
your best bet might be to consider at some point a shs torquey mofo, m110-120 and with that in there then short stroke a couple of teeth
but suppose you can give it a go on 13:1 & ferrite motor with ya m100 type spring

[Dude666fx]

Re: Tm MP5 30rps build

Cool cheers for the info was thinking that with the cut m120 spring. Just taken the motor out of my ics and found no markings on it. It was second hand so possibly owner swapped out the turbo 3000 the only reason I was going to use it as a base was because I was getting 20rps from with just deans and 9.6v in the m16.

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[Sitting Duck]

Re: Tm MP5 30rps build

have a look into the motor spindle.....

if you see 2 x black magnets inside = ferrite

if you see two silver/chrome magnets then they changed motor foe a neodym one
(should be harder to turn by hand than a stock motor with black ferrite magnets)

some ferrite's can pull hi-speed gears or higher springs
but many struggle with a more beefy setup and get hot quickly or just fail to turn over properly
ok on stock gears @ 13rps but not much guts left in it for a higher speed setup
hence neodym's are the way to go but there are strong/not so strong motors as well as fast & not much faster than stock motors

shs torque are usually used for pulling 13:1's and m120's - not mega quick but plenty of guts to pull a stiff spring with 13:1 gears
check ya motor if you got silver/chrome neodym magnets in there

[Dude666fx]

Re: Tm MP5 30rps build

Thanks I'll definitely check it now I have that info as the build was designed around that motor. The m16 always had a high rate of fire I fitted deans to and that little extra blew the trigger contacts.

[Dude666fx]

Re: Tm MP5 30rps build

Plus have used it as a dmr with m120 spring and coped ok with that many times so led me to believe it was a turbo 3000. I read somewhere they put a 2000 motor in the British ones with a lower spring to run better than that way something to do with the u.s higher fps?

[Sitting Duck]

Re: Tm MP5 30rps build

ICS Sportsline M4's deffo run a bit quicker than G&G starters
and yup heard that ICS are alleged to have toned down UK compared to US or other guns

I found say a W-42 of mine was hitting say 16-ish rps on a 7.4v
where as a Raider was hitting 13rps on same battery - these are both stock - out of the box findings btw

tbh - ics infinite or turbo motors are still way unpowered compared to some absolute nutty mofo neodym's

Some of those will rip the crap out of a virgin stock gearbox until you prepare that box to handle such power
eg: AoE with sorbo/neoprene mix, radius box, shim as near to perfect as possible and fit a 3034 fet with 16awg
(v3 speed freaks can solder wires to motor if they must but not perhaps v2 owners)

if you really really wanna go mental you can get into 30's with a 7.4v lipo 25c+
using 12:1 gears and a really bad ass mofo motor, m120 SS 2 teeth - but don't ffs connect up an 11.1v 30c or PE will take place

As I said in other posts - about 25rps to 30ish is more than fast enough for me
Go too nutz and quicker wear takes place, hi-caps struggle blah blah blah

[Dude666fx]

Re: Tm MP5 30rps build

Might get a better motor see how things go. Just about to strip it down now and spend the evening shimmring the new gears maybe put the mosfet in if time. Don't want to rush this.

I'm using the non braked mosfet I have a guide sent with it but can't find much on installing them online plenty on the braked ones is it still a case of unsoldering the bottom trigger contact wire and putting it to the top one then putting the mosfet wire where the bottom contact used to be?

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[sj_asc]

Re: Tm MP5 30rps build

Regarding the MOSFET install, this is for an F-storm fet which follows the same wiring configuration as the Airfet.
http://forums.zeroin.co.uk/showthrea...ghlight=Jakeno

As for the existing planned configuration, the eg700 is a better base to work with if you are limited to that voltage, even if you were to stick with the stock ferrous magnets, the motor is capable of delivering good rates at 9.6v with that ratio so long as you can use a decent high output NIMH (I.e not mini type). You can dramatically increase torque with those by using neodymium magnets as said.

The ICS turbo 3000 motor offers more torque but significantly less rpm, and really should be avoided if you want to reach your target ROF - that is unless you are prepared to up the voltage.

Also what is your target FPS, and piston choice?

[Dude666fx]

Re: Tm MP5 30rps build

Looking for a fps of 325 the spring I have delivers around that in the m16 but it is an m120 with a lot of coils removed so still worried it may not return the piston in time. Just sticking with the standard tm piston see how that goes first. Don't mind Swiss cheesing it but am worried about short stroking and getting it right. Thanks for the mosfet guide sniperjesus this isn't the first time you have saved my bacon

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[sj_asc]

Re: Tm MP5 30rps build

Remember that the ID of the Marui Piston is slightly larger than that of most aftermarket Pistons, as such the walls are a little thinner. The safest tried and tested method of weight reduction is as below (taken from Mike at Hivemind)



This method does not cause structural integrity issues, and still allows for a sizeable reduction in weight. Bare in mind that the bulk of excess piston assembly weight is the head and its bearing block - ball bearings are not nescessary in the piston assembly if you already have them on the Spring guide.

Many people will probably try to deter you from using the TM piston, however it's actually a really well suited base for a mid speed SSG build at uk power levels.

With a lighter piston assembly, you can get away with a lighter main spring.

A guy that goes by the name of corvid on YouTube used to run some super quick and well thought out setups similar to what your target is, back long before the days of SHS, Lonex and many of these other brands we see today. He managed to run some pretty decent rates with the TM piston and Ferrous motors, back when neodymium motors wernt common place. He was also the guy that invented the AoE mod.

As for short stroking, it's essential that you remove the teeth from the pickup side of the sector gear to avoid interfering with Tappet to Piston release timings. It's only essential that you remove the corresponding teeth from the piston rack gear if the release tooth on the sector gear is enlarged (like TM's) - SHS's gear and most other after market gear aren't like this, so it's optional. The essential thing to remember with TM's piston is that if you are planning to short stroke that you need to bring the metal release tooth backwards, otherwise the gear will release on a plastic tooth and the lifespan will be almost non existent.

[Dude666fx]

Re: Tm MP5 30rps build

Wow he invented AOE mod. That's pretty impressive. Don't really want to go more than 30rps that's absolutely maximum. I was hoping the harder spring despite the missing coils will get it back in time but if I have to Swiss cheese will follow those pics for a guide as would like to keep structural integrete. I think I was thinking of the first picture in the mosfet guide have not seen the other method before hopefully just got enough wire for the first method as for the mosfet location is it a case of tapping it to the outside of gearbox where there is clearance?

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[Sitting Duck]

Re: Tm MP5 30rps build

You could still use the lower m120 spring AND SS and still get the same fps by using plastic spacers
G&G use a 5mm plastic spacer which saves a lot of weight over the old metal spring holder in piston or the bearing piston heads

Now you "could" use up to say a 10mm x 20mm diameter spacer in the piston if you are Shortstroking a couple of teeth off

DO NOT USE A 10MM SPACER AND A BEARING SPRING GUIDE WITHOUT SS 2 TEETH
The spring will almost certainly bottom out at a full 50mm stroke with that extra 15mm spring compression
(10mm spacer + 5mm aprox for bearing in spring guide)

Taking off 2 teeth equates to 2x3mm = 6mm final spring compression which you can claw back with a strong nylon spacer in piston 5 or 10mm
(use the piston bearing top race and collar when fitting if possible)

Only reason I never suggested this is you may as well get a £5 m110 or m120 or Element m115 spring and be done with it

Short Stroking I really only bother at say 25+ rps if she is running on too much to prevent double firing at higher speeds
(and avoid needing to use an ab fet - them Fire Storm or F-Storm fets are brilliant for the money if you can't be bothered to make ya own 3034)

[Dude666fx]

Re: Tm MP5 30rps build

Ok so spent a night shimmring the new gears until I was happy with it, spent the next evening sorting the mosfet location and soldering then reassembled the gearbox with sector clip, very cut down m120 bit with the steel bearing spring guide still had enough to keep it between that and the piston head.
Test fired and sounded great no shredding piston sound then it locked up then cleared with a full auto burst ( the gun did used to do this sometimes on semi so thought nothing of it)
Then it locked up again and wouldn't clear on full auto the motor went red hot straining so unplugged it by then it had gone midnight so had to hit the sack.

Done a bit of googling today on hi speed lock ups for solutions so gonna open up again in a bit to investigate.

The piston is locked right at the back of the gearbox likes it's stuck on the release tooth.

Do you guys have any ideas?

- - - Updated - - -

I'm thinking even though it's cut quite short the spring is still to strong for the new gears to pull back so maybe trim am m100 down to 325 fps and give that a try?