Systema Hop Unit in Celcius MX2 (2011)

Just thought I would share my experiences with you...

After comparing the Systema PTW hop unit with the Celcius version I preferred the build quailty of the Systema so decided to try a swap out.

It turns out that the Celcius hop unit is about 0.5-0.7mm smaller than the Systema one and as such the Systema unit will NOT fit without modification.

The systema has a powder coating so if you file/sand this down you can get it to fit, however I think my systema hop now sits about 1mm further forward and subsequently so does the cylinder which has lead to the gearbox hamming occasionally... time for a swap back me thinks!

Thank you for the information! It`s people like you we need on the forum,that shares experiences and trials and errors so others don`t have to. Gratitude!

I was also thinking of something like that, but glad I didnt follow up and got myself Systema hop up/cylinder. I guess best option would to stick to original ctw parts.

What about sticking ptw springs inside the ctw cylinders - would they perform better?

Not looking at size or anything else, would systema cylinders be any better than their celcius cousins?

Thanks, great learning.

Thanks guys,

I'm planning on excessively tinkering with my CTW so expect lots more updates!

I've ordered 2 new Celcius hop units from AsiaRsoft and also the after market Deep Fire hop packing and hop adjuster. I'm going to see if these fit.

I've also ordered a Deep Fire 6.02 barrel (which has the chamber sleve build on) as tbh I'm not that impressed with my Reformation II barrel The hop key alignment is out by 0.8mm and there is some scoring down the barrel (might just be the manufacturing process) but I crave consistent accuracy!

Delta Cypher wrote:Thanks guys,

I'm planning on excessively tinkering with my CTW so expect lots more updates!

I've ordered 2 new Celcius hop units from AsiaRsoft and also the after market Deep Fire hop packing and hop adjuster. I'm going to see if these fit.

I've also ordered a Deep Fire 6.02 barrel (which has the chamber sleve build on) as tbh I'm not that impressed with my Reformation II barrel The hop key alignment is out by 0.8mm and there is some scoring down the barrel (might just be the manufacturing process) but I crave consistent accuracy!

Why aren`t you happy with the barrel? Mine is consistent after i wore in my hop. But i also am gonna do a hopup mod. So this will be interesting.

I was having trouble with my new ctw hopup packing, it was causing balls to mis-feed into the bottom hole of the hopup unit from the clip because of a packing issue, which lead to chopping...

I don't have CTW parts available, so I dropped in a PTW hop up unit without modification *. I measured the units and compared almost everything. Most of the dimensions were within .001 " to .005" which was surprising to me.I didn't see the positioning issue with the PTW unit being to far forward.Especially a whole 1mm. Mine was ~.008" rearward actually.

*The Only thing that did not work from the PTW to the CTW is the brass PTW packing base, The CTW has a small counter bore to accept the barrel where as the PTW's base does not (this causes a barrel key misalignment) However, I was able to use the CTW Packing base with the CTW packing and all the other PTW components and CTW barrel.

*The powder coating on the PTW didnt cause an issue for my CTW, it actually dropped right in the barrel, it feels just slightly tighter than the CTW but did not require any excessive force to install.

I tested the gun, and did not have any issues like the other guy that originally posted this had with his attempt.

I wonder if the tolerances in CTW's are such that this my work on some ctw's and not others?!?!

i tried the PTW blue cylinder into CTW MX2, its cant fit..too tight!!
and PTW springs inside to CTW cylinder it fine as i tried M110 and M130.

I bought systema chamber og deepfire hopup parts.. all fits good and the barrel is correctly aligned with my chamber,BUT.. i have to sand of the powder coat.. no way its fitting inside the outer barrel... sighs..

I've played a bit with some systema hop-up parts and a few barrels.

The U-shaped barrel end, where the hop-up sits, is longer on the CTW's barrel, and fits into a countersunk area on the CTW chamber packing. A systema barrel with systema packing will line up just fine in the CTW hop chamber.

Systema's hop chamber offers a visibly larger opening for feeding BBs, but it's 0.3 mm shorter towards the cylinder. You can test this by pressing a hollow hop-chamber to the front of a CTW cylinder. While a CTW chamber will slide in and out the nozzle, with a systema chamber you'l feel a tiny bit of spring compressing - it's the nozzle spring.

I was able to solve this by cutting a washer from 0.25mm thick plastic sheet, and place it inside the groove on the piston head. It's 19mm outer dia with a 10mm inner hole for the nozzle. Held in place with two drops of superglue, so it won't disappear if I'm cracking the gun out to clean the barrel.