AOSC Forum Archive

Hey all,

I'm going to be building a DSG out of a CYMA MP5K, or CM041k. I've got a general idea of what I'm doing, but any of you techs with experience on these, please drop me some tips. I'll pretty much be gutting the gearbox, and dropping in siegeteks, SHS and lonex parts, etc.

You may have to do a little extra work to get the MP5K feeding properly, and you better not be shooting for anything above a CQB fps. That barrel is too short to support anything much higher than that.

Star_folder wrote:You may have to do a little extra work to get the MP5K feeding properly, and you better not be shooting for anything above a CQB fps. That barrel is too short to support anything much higher than that.

Planning on getting an adapter and 78mm suppressor extension, that should bring me up to around 200 mm ISh, so I'm thinking having it sit around 350 fps, ish.

I also plan on getting an apple airsoft meat tenderizer upper rail and front end conversion, then sticking a RDS of replica holo on top. As far as internals go, right now contemplating using a 14.8v lipo with a FT, 10:1 DSG gears, and m170.

As for the mags, I may get bigger ones and mod them, but the the cyma short mags are $8 on evike.

Trust me if you are running a 14.8 on 10:1 dsg don't forget to replace your pinion gear on your motor with a after market steel one, I chewed up 2 pinion gears and if i didn't have siegteks/riots my gears would be shot too.

Frost wrote:Trust me if you are running a 14.8 on 10:1 dsg don't forget to replace your pinion gear on your motor with a after market steel one, I chewed up 2 pinion gears and if i didn't have siegteks/riots my gears would be shot too.

Whenever I build the FT, I'll be putting a Riot Pinion on it.

TheInfidel23 wrote: Planning on getting an adapter and 78mm suppressor extension, that should bring me up to around 200 mm ISh, so I'm thinking having it sit around 350 fps, ish.

I also plan on getting an apple airsoft meat tenderizer upper rail and front end conversion, then sticking a RDS of replica holo on top. As far as internals go, right now contemplating using a 14.8v lipo with a FT, 10:1 DSG gears, and m170.

As for the mags, I may get bigger ones and mod them, but the the cyma short mags are $8 on evike.

Does that front end conversion have a thread addaptor for a barrel extension?

What are your goals for fps and rof?

Ok, after some consultation, I'll just be using a 11.1v lipo. Lot of mess when 14.8v of power is in play. So, revised list here.

11.1v 45-90c 5000mah lipo
Lonex A2
10:1 DSG
M170 spring

Of course, all the little things, like a MOSFET, new pinion (lonex is really soft), and some SHS compression parts are in order.

@starfolder, my goal is 70 rps. Whatever spring is needed to avoid PME is what will be installed, fps isn't really a concern, as in I don't have a set goal of where I want it to be. What ever it turns out as, it'll stay there.

As for that conversion kit, it just slips onto the outside after the front sight is removed. The adapter will clamp onto the existing outer barrel and carry through the kit to the suppressor.

I urge you not to build this! You can get the GB to cycle that fast, and maybe even cycle that fast sort of reliably... but you won't get the gun to feed. And you'll have problems left and right. Stay away from the 10:1 ratio AND DSG, IMO. Even 13:1 with DSG is waaaay overkil and is just a money pit.

I did a build with 10:1 DSG set up, and with a G&P Devil Jet M170 Motor, it wouldn't cycle on a 11.1v battery! I think I had a spacered M150 in the gun (on the heavy end by way of DSG spring options), but still, sooooooo much stress! On a 14.8v it would hit 76 cycles a second... but on a 11.1v it wouldn't even cycle?!?!

If you want a usable gun, I'd say closer to 18:1 gears.

70rps is tough stuff, feeding will be problematic, and it's probably a good thing you don't care about fps, because getting a consistent fps at that speed is even harder than getting something to feed reliably at that speed.

I also doubt you'll be able to get MP5 mids to feed that fast. You might be better off with 50rps for an MP5k

Star_folder wrote:70rps is tough stuff, feeding will be problematic, and it's probably a good thing you don't care about fps, because getting a consistent fps at that speed is even harder than getting something to feed reliably at that speed.

I also doubt you'll be able to get MP5 mids to feed that fast. You might be better off with 50rps for an MP5k

Well, 70 is a lofty goal, and I'm not certain I can reach that anyway, I may just do 14:1 gears with a JG blue at be happy with what comes out. If necessary ill go to the longer midcaps so I can space the spring out for stronger feeding.

Edit: gonna get 10:1 instead, and just see where it takes me with a JG blue. If its just too fast,I'll build a FT.

My last DSG P90 ran over 70 RPS when I used a 14.8v, but it did not feed and it was so powerful and scary sounding that I decided against ever trying to use it (assuming I could have gotten it to feed). Also, Yoda's ghost showed up and warned me of disturbing the balance of the force with it.

Well, many a development.

Supposedly the CYMA MP5k comes with the legendary torque motor that is as close to a FT as you can get. I won't be trading that out, at all. So whatever ROF comes out of using a 11.1v and 10:1 gears, I'll be happy with. Just found a super cheap one on some classifieds, so I'm going to pick that up for $60 instead of the $160 new , that's nice

Skywalker wrote:I urge you not to build this! You can get the GB to cycle that fast, and maybe even cycle that fast sort of reliably... but you won't get the gun to feed. And you'll have problems left and right. Stay away from the 10:1 ratio AND DSG, IMO. Even 13:1 with DSG is waaaay overkil and is just a money pit.

I did a build with 10:1 DSG set up, and with a G&P Devil Jet M170 Motor, it wouldn't cycle on a 11.1v battery! I think I had a spacered M150 in the gun (on the heavy end by way of DSG spring options), but still, sooooooo much stress! On a 14.8v it would hit 76 cycles a second... but on a 11.1v it wouldn't even cycle?!?!

If you want a usable gun, I'd say closer to 18:1 gears.

I'm not sure what else you had going on in your build, but this just sounds way off to me. I have a 9.6v NIMh that can cycle my dmr, and its only using 13:1 gears, JG blue, and M150. Either your battery or motor was shot, or something else is seriously wrong. Btw, I don't know if you meant LIGHT end, but M150's are rarely used, at all, in DSG's. there is just too much PME and too low fps.

TheInfidel23 wrote:

Skywalker wrote:I urge you not to build this! You can get the GB to cycle that fast, and maybe even cycle that fast sort of reliably... but you won't get the gun to feed. And you'll have problems left and right. Stay away from the 10:1 ratio AND DSG, IMO. Even 13:1 with DSG is waaaay overkil and is just a money pit.

I did a build with 10:1 DSG set up, and with a G&P Devil Jet M170 Motor, it wouldn't cycle on a 11.1v battery! I think I had a spacered M150 in the gun (on the heavy end by way of DSG spring options), but still, sooooooo much stress! On a 14.8v it would hit 76 cycles a second... but on a 11.1v it wouldn't even cycle?!?!

If you want a usable gun, I'd say closer to 18:1 gears.

I'm not sure what else you had going on in your build, but this just sounds way off to me. I have a 9.6v NIMh that can cycle my dmr, and its only using 13:1 gears, JG blue, and M150. Either your battery or motor was shot, or something else is seriously wrong. Btw, I don't know if you meant LIGHT end, but M150's are rarely used, at all, in DSG's. there is just too much PME and too low fps.

Yes, you have to understand this is an exponential scale here. Sure, a JG Blue can pull a M150 on 13:1. But 10:1 on a SPACERED M150 (Using Riot's spring guide spacer, look it up) is basically like trying to pull a M170 on 10:1 gears, or something like a M200+ on 13:1 gears. There is an exponential increase in stress by moving from 13:1 to 10:1 gears, as well as from M150 to M170 spring.

Now, in my build, I don't believe I ever got around to correcting AOE, and also, the Devil Jet motor isn't quite as torquey as the JG Blue. But still... My end all point here is this: you've gotten the advice of some people in SC who live and breathe airsoft and airsoft gun builds. I'm not at all saying that your 10 posts on this forum states anything about your amount of research elsewhere. But trying to push everything to the limit of ROF is just not worth the time and money invested.

Well, to your point, I have done a huge amount of research on other forums, and I'm confident in my abilities and skills. I've seen these kind of build perform fine, feed great, and then their users go out and wreak the field.

I am honestly just not understanding where you are coming from, though. Your build just doesn't sound rig to me. Even if its a G&P motor, it should have no issue pulling just an M150, especially using a lipo. I'm not trashing your skill, but it should not "just not cycle"