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View Full Version : DIY devolumizer or tophat mod agd automag juit style



juit
03-31-2016, 12:56 AM
I asked on the nation about the benefits and nobody answered me on the nation

so gonna do it my way & find some answers

this is an alternative method that the one on the nation

mount the engine on a drill "slow revs" cut until the orange gasket shows up
if its done with patience you wont mess up the gasket

92395

opened view

92396

Im using quick steel to make a cup face for better flow

92397

gonna try to use a hose for the other end

any ideas would be nice

Nobody
03-31-2016, 02:08 AM
Ideally, you don't want to use anything permanent. To me the benefits of this is not worth it. A 100 extra shots? Even 10% more is not worth it. You also need to have variable sizes to test with so you can dial in the gun for the velocity range. Too little volume and you won't get the velocity up high enough.

There is a reason why its not really done much, it can work but it is not great.

Tunaman
03-31-2016, 03:33 AM
waste of time

BigEvil
03-31-2016, 04:39 AM
waste of time

^ What this guy said.

captian pinky
03-31-2016, 07:11 AM
noone answered because there is not enough recorded data on it. The efficency insert works yes. The one that luke is selling is designed for hpa. When the pathway gets smaller it starts to act strange. multiple people are working on this on MCB. Personally i wouldn't have use epoxy for this. everyone that is working on this has been changing so many different things in the valve we don't want anything permanent yet. Most of us are doing the mod to use 12 grams if you are planning to use hpa when you are done you might want to rethink your direction.

Spider-TW
03-31-2016, 09:32 AM
noone answered because there is not enough recorded data on it. The efficency insert works yes. The one that luke is selling is designed for hpa. When the pathway gets smaller it starts to act strange. multiple people are working on this on MCB. Personally i wouldn't have use epoxy for this. everyone that is working on this has been changing so many different things in the valve we don't want anything permanent yet. Most of us are doing the mod to use 12 grams if you are planning to use hpa when you are done you might want to rethink your direction.

Besides 12gs, with small CO2 tanks, like 3.5 to 9 oz, it is handy. ~450 rounds out of a 9 oz is pretty neat. Going from 7 or 8 good shots to 15 or 20 on a 12g is a good deal. It's really kind of a complicated tuning method that works best when applied to a particular setup of gas, barrel, bolt, and bolt spring, in that order of precedence. Once you change one of those, you can loose your gains.

I would only devolumize on HPA if you were looking for the last few shots out of a particular setup with a small HPA tank. I would think it's kind of silly to devolumize a setup with a short barrel, but some people have to have that stubby barrel and want to get some efficiency back.

The worst part is that the power tube needs to be resealed and secured every time you fiddle with it. Once you get it set, it is best to leave the whole thing as is.

Devolumizing with a level 10 jacks up the operating pressure even more and with less room for improvement. Between HPA running higher pressure over CO2 and level 10 bolts using higher pressure than level 7s, the margin for improvement is not nearly as large with HPA.

Then you weigh all of that with getting a larger ninja super light tank that you can use on a bunch of your markers.

juit
03-31-2016, 10:02 AM
Wow , i didn knew it was a hot topic, what im runing is a 47/4500, but i only can fill up to 2500-2000 , so yes I need every single.shot I can get of that tank, with the ramp i got a boost of 10fps gain maybe is the weather or temperature, im just gonna seal it and test it this weekend, thanks guys for you input im always open to learn new stuff :)

BigEvil
03-31-2016, 01:10 PM
The severe downside of this is that it is brutal on the paint, which I believe was the reason why AGD expanded the dump chamber to begin with.

juit
03-31-2016, 01:18 PM
Ill keep an eye on that, i think the ramp is gonna be enough, i remember doing this on quests and the key was not to raise the pressure just to eliminate th wasted air

Spider-TW
03-31-2016, 03:11 PM
The severe downside of this is that it is brutal on the paint, which I believe was the reason why AGD expanded the dump chamber to begin with.

It is. The higher pressure gets a faster gas pulse, shorter bolt dwell, more bolt force, higher residual chamber pressure, etc., all relative to the amount of of volume reduction. So put paint type on the list of things you consider.

We had some paint on my son's pump mag that he kept popping in the barrel after he switched from a 14" AA barrel to the stubby minimag barrel and turned the velocity back up. He refused to go back to the AA, so I quit worrying about it. :argh: Over the few years he ran it on a 9oz CO2 tank, he worked it over very well. IIRC, we started with 8 nylon washers (~3/8" id) and backed down to 5 after he went to the short barrel, mainly because the piston would vent due to the increased pressure, which really kills your efficiency. :rolleyes: I'm pretty sure that was an older piston, implying it would be set lighter than a newer one in the first place.

juit
03-31-2016, 04:56 PM
forgive my ignorance but were did you put the washers?

blackdeath1k
03-31-2016, 05:46 PM
The severe downside of this is that it is brutal on the paint, which I believe was the reason why AGD expanded the dump chamber to begin with.

I've always wondered this. Mags are not the most forgiving on paint. I never could see how upping the pressure could possibly help with that.

juit
03-31-2016, 05:56 PM
I dont know if its gonna help but its shooting in 312 FPS +-3

ran out of air but it was shooting awesome

heres my baby with all its mods

:wow: 92398

Tunaman
03-31-2016, 06:45 PM
I dont know if its gonna help but its shooting in 312 FPS +-3

ran out of air but it was shooting awesome

heres my baby with all its mods

:wow: 92398

dont run it at 312...run it at 285-290.

blackdeath1k
03-31-2016, 06:55 PM
My markers are normally set 255-275. It's always appeared to be easier on paint. And what little distance lost is ALMOST never noticed.

juit
03-31-2016, 07:02 PM
yes I try to run them at 285 but the epoxy ramp that I made boost it to 312

it would be nice if some one build a tester to see at what PSI the can is running

Spider-TW
04-01-2016, 09:04 PM
You add washers to the dump chamber as an adjustable method of devolumizing. Large, 3/8 ID nylon washers can be ground on the OD a little to fit just right. When you don't want them anymore they come out easily.

Beemer
04-02-2016, 06:45 AM
Wow , i didn knew it was a hot topic, what im runing is a 47/4500, but i only can fill up to 2500-2000 , so yes I need every single.shot I can get of that tank, :)

4500psi fill every time...........:argh:

http://shoeboxcompressor.com/

Nobody
04-02-2016, 11:16 AM
Even if your field can not fill up to 4500psi, the inserts or devolumized chamber will only get you so much, maybe 10-20% more shots if that. There are other factors that lend itself to the number of shots that you can not really base hard numbers off it.

juit
04-02-2016, 12:06 PM
Im gonna buy the docs autococker adapter to bore to ball size match