Making a DMR

[The captain]

Hi Guys,

So i want to learn to tech. and i also want a DMR, so my plan is to make my Nuprol M4 into one. I know i need a MOSFET that i can programme to safe-semi-semi so i can class it as one. and i have a spring that will have be shooting at 450. but i know i have to take most of the gun apart to install this spring. So i was wondering if anyone can tell me what else is reccomended to make a DMR.

Any other Tech-ing tips would be greatly appreciated.

 

[Asomodai]

Technically you could just put a big whopping spring in it, cut down the selector plate and call it good. How long it will last would be the problem. This is what I have done for all my DMR's. 

Prometheus 6.03 Tightbore barrel matched to your current inner barrel length. 

Upgraded hop unit if possible.

Flat hop tensioner and prommy purple bucking. 

22TPA Neodymium motor paired with a set of 13:1 gears (Trigger response)

Basic Mosfet like an Acetech. 

M110-M120 spring depending on your local DMR site FPS rules. 

New Bearings or bushings for the gearbox. 

Decent piston. 

 

[Rogerborg]

I know i need a MOSFET that i can programme to safe-semi-semi

Er, no. As @Asomodai says, you can cut a bit off the selector plate so that it can't engage full auto.  See:

 

[The captain]

Technically you could just put a big whopping spring in it, cut down the selector plate and call it good. How long it will last would be the problem. This is what I have done for all my DMR's. 

Prometheus 6.03 Tightbore barrel matched to your current inner barrel length. 

Upgraded hop unit if possible.

Flat hop tensioner and prommy purple bucking. 

22TPA Neodymium motor paired with a set of 13:1 gears (Trigger response)

Basic Mosfet like an Acetech. 

M110-M120 spring depending on your local DMR site FPS rules. 

New Bearings or bushings for the gearbox. 

Decent piston. 

Okay, what dictates if upgrading the hop is possible ? also when you say upgraded hop unit do you mean a nub and a bucking ? or the actual cogs and the rest ?

and cutting down the selector plate required opening the gear box, ive never done that before, dont want to break the gun before im finished converting it.

I have the spring already. and what is a "Flat hop tensioner".

The prommy purple bucking says for fps under 400.

Sorry i got loads of questions man, im new to opening these beauties up and changing stuff, i have seen so many videos on how to actually do it, but i dont really know about parts and whats better for what job and why.

 

[Lozart]

Okay, what dictates if upgrading the hop is possible ? also when you say upgraded hop unit do you mean a nub and a bucking ? or the actual cogs and the rest ?

and cutting down the selector plate required opening the gear box, ive never done that before, dont want to break the gun before im finished converting it.

I have the spring already. and what is a "Flat hop tensioner".

The prommy purple bucking says for fps under 400.

Sorry i got loads of questions man, im new to opening these beauties up and changing stuff, i have seen so many videos on how to actually do it, but i dont really know about parts and whats better for what job and why.

Go read this: 

https://www.reddit.com/r/airsoft/comments/5g58ia/holy_grail_dmr_guide_updated_for_20167

If you're still set on going DMR you will have to open the gearbox regardless. 

 

[The captain]

Technically you could just put a big whopping spring in it, cut down the selector plate and call it good. How long it will last would be the problem. This is what I have done for all my DMR's. 

Prometheus 6.03 Tightbore barrel matched to your current inner barrel length. 

Upgraded hop unit if possible.

Flat hop tensioner and prommy purple bucking. 

22TPA Neodymium motor paired with a set of 13:1 gears (Trigger response)

Basic Mosfet like an Acetech. 

M110-M120 spring depending on your local DMR site FPS rules. 

New Bearings or bushings for the gearbox. 

Decent piston. 

Out of Curiosity, just how long would it last ? if i just get a new spring, nub, bucking, motor, barrel, and use a mosfet to lock to semi. No new Piston or gears or bushings. Are we talking a few thousand less shots before it gives out ? or are we talking itll fall apart in 500 shots ? also what is likely to go first when putting in a bigger spring ? im assuming the piston ?

 

[Asomodai]

Out of Curiosity, just how long would it last ? if i just get a new spring, nub, bucking, motor, barrel, and use a mosfet to lock to semi. No new Piston or gears or bushings. Are we talking a few thousand less shots before it gives out ? or are we talking itll fall apart in 500 shots ? also what is likely to go first when putting in a bigger spring ? im assuming the piston ?

How long is a peice of string? It depends how each part manufactured was QCed at the factory if at all. All the stock stuff in cheap rifles like yours are built to a low cost to perform well enough for the stock FPS. The more you spend the less chance of it it being a lemon. 

Just get it all done at once so you dont have to take it apart for a long time.

First thing to go is likely Piston, though I have broken more gears then pistons due to poor shimming. 

If you are going to replace the spring you have to take apart the gearbox anyway. 

 

[Tackle]

I would so say to get yourself a chrono, if your tinkering & trying to get to a particular fps you don't want to have to arrive on site & rely on their chrono, you might get turned away ?.

its prob the next thing on my shopping list, got a load of fettling to get on with, once I can hold my tools lol ?

 

[Wo1f]

I’d be lost without a chrono. Best £50 I’ve spent in airsoft. 

 

[Adolf Hamster]

I’d be lost without a chrono. Best £50 I’ve spent in airsoft. 

agreed, very useful, especially when mis-advertised springs are a thing.

 

[The captain]

@Adolf Hamster@Wo1f@Tackle I Have just ordered one, based on you guys's suggestion. thanks

How long is a peice of string? It depends how each part manufactured was QCed at the factory if at all. All the stock stuff in cheap rifles like yours are built to a low cost to perform well enough for the stock FPS. The more you spend the less chance of it it being a lemon. 

Just get it all done at once so you dont have to take it apart for a long time.

First thing to go is likely Piston, though I have broken more gears then pistons due to poor shimming. 

If you are going to replace the spring you have to take apart the gearbox anyway. 

Surely all gearboxes are shimmed well by default ??? Do you only worry about shimming if you change somehting ? or is it good to get in there and do it to any gun you have ??

 

[Asomodai]

@Adolf Hamster@Wo1f@Tackle I Have just ordered one, based on you guys's suggestion. thanks

Surely all gearboxes are shimmed well by default ??? Do you only worry about shimming if you change somehting ? or is it good to get in there and do it to any gun you have ??

Wishful thinking I am afraid. Hardly any gearboxes have been shimmed properly or the AOE corrected from factory. 

 

[E21A]

Surely all gearboxes are shimmed well by default ???

my Nuprol M4 

Lol 

 

[Wo1f]

You’ll be lucky to get a gun that’s shimmed well, never mind perfectly from the factory.  Some manufacturers are better than others, but every company has their lemons and perfect guns. 

 

[The captain]

damn, i guess ill need to shim it then. didnt realise they wouldnt come already done, seems like something that should be done. Any to do this the first time ??

 

[Lozart]

damn, i guess ill need to shim it then. didnt realise they wouldnt come already done, seems like something that should be done. Any to do this the first time ??

It will be shimmed, just not well.

 

[Rogerborg]

damn, i guess ill need to shim it then.

Well, maybe.  My £75 CYMA M4 was spot on, although I accept that was just down to luck rather than any sort of diligence at the factory.  If you're in there doing the spring anyway then you might as well clean out the China snot grease and do the shimming.  A pack of assorted shims is only a few £££ and all it needs is following one of the many video tutorials and some patience.

 

[Musica]

Well, maybe.  My £75 CYMA M4 was spot on, although I accept that was just down to luck rather than any sort of diligence at the factory.  If you're in there doing the spring anyway then you might as well clean out the China snot grease and do the shimming.  A pack of assorted shims is only a few £££ and all it needs is following one of the many video tutorials and some patience.

a broken clock is right twice a day.

 

[Rogerborg]

a broken clock is right twice a day.

Lies, I'm rarely right more than twice a week.