Thanks for your reply!
I know, that higher voltage does more stress to the mechanics, but I asked, if the electronics can handle this with ease due to internal voltage regulation or does this reduce their lifespan either?
As your hopup suggestion is 3D-printed, I’m currently experimenting with several designs and print them either. If I can’t ensure a better performance with my own printed parts, I’ll rely on yours. 
Just measured the both HPG700 mit the chrony:
Reasonable 220-230 fps, too. Not bad.
But the P90 feels way more solid and satifying in hand.
The battery is empty after 4 mags and became warm. Not too hot.
I used the better LiIon-battery (two of 18650 size) of the HPG, which fits into the stock with a bit fiddling.
A bit annoying: round about 20 bobbles remain in the “empty” mag and can’t shot out due to the mag design.
I printed a plugin hopup for the HPG 700 and tested it today a bit:
The results are better, than I hoped for. Works like a treat.
Despite that, I printed just the thread of a hopup for the P90 in PETG to tune in the right size. With my new direct extruder Smart Orbiter V3, the quality is top notch:
It’s a bit of an unknown if an 11.1v lipo will cause circuit problems with these. 
A Bing Feng with a MOSFET is a fairly new thing so it’s a bit of a mystery, but these days if the manufacturer says that it’ll run 11.1v you’re usually okay. That said, in the past some MOSFETs in so-called 11.1v compatible blasters were notorious for burning out on the higher voltage. Bing Feng haven’t really offered any blasters with FCUs before so you’re kind of in unchartered waters here. 
Going up to 11.1v will increase your rate of fire but won’t change your FPS.
It’ll be interesting to see how that MOSFET fares on an 11.1v battery. If it’s solid it would be a good candidate for transplanting into other blasters. I still run an early BF P90 on 11.1v occasionally (no FCU), they’re a fun little unit for sure. 
As the rpm is fairly enough for me, I’m not so keen to place a 11,1 V battery in it. But a decent spring tuning may be applicable.
I’ll disassemble the whole unit to see, what’s in there. Sealing up the cylinder/plunger, greasing it properly, etc.
The hopup came out of the printer in very decent quality. Testing must wait till tomorrow, because I’m at work today.
BTW: what kind of grease do you suggest? Silicon grease, Lithium based or something else? Remember, it has metal gears (hopefully)
This one would be good for metal gearbox
Thanks for reply!
As you sell a bunch of different gellet types on your website, I would like to ask, which one has best quality, e.g. most uniform size, best shot from the P90?
This one is a great choice,very nice and stable quality.
Now THAT, my friend, is the million dollar question. 
Gel consistency has been all over the place like gastro at a kebab festival for a while now…
Gel brands that were once consistent in size are so variable between batches it’s like a lottery now. Everyone in here will have their favourites and there’s no doubt that if you’re chasing top performance from your gels you’re going to have to go down the rabbit hole of controlled growth times and size sorting the finished product with a sieve.
A forum search for that topic should give you plenty of light reading entertainment for some time. 
For your P90 with it’s 250FPS super hard gels are probably not necessary, the Ausgel Armourtech range, greens or pinks, would work well. I’d avoid LDT Heavy Milkies… they grow quite large and on a lower powered blaster would give you a fair few barrel jams.
Hi there,
I recently designed some Hopups with and w/o threads. For the P90 and HPG-700. Both with and w/o a second adjustable tongue.
The knurled wheel is used with M3 screw and nut to adjust the upper tongue without the need for an inbus key.
If the hopup is equipped with a second tongue, it can be adjusted either with a knurled screw or, I suggest, with a grub screw, as it is tuned only once.
First tests with several prototypes are very pleasing.
When I fully tuned in the system, I’ll publish the files at Thingiverse and Printables, if you are interested.
I print them in PETG, 0,1mm layer height and slowly. With my new direct extruder, the quality is outstanding. Much better than most of the commercial available printed hopups, I’ve seen on several websites.
I plan to add a tracer unit clipped under the hopup. Therefor I designed these large holes, where the LEDs shining through. I received the 1W UV-LEDs yesterday together with step-down-buck converter and tiny little microcontrollers. My idea is, to light up the tracer only when gellets fly by. So, I need the detect them with a light barrier. As mentioned before, I did this for a Nerf Stryfe. But I think I can compress the electronics into a little box underneath the hopup.
Very cool design. I have designed and printed my own hopups for a while now, well really it is just one design that worked and it gets modified to suit different blasters, inner and outer barrel length combinations etc.
My main tip is, don’t do the bottom tongue until it works with just the top tongue. Actually I went away from the bottom tongue altogether, as a good top tongue design will work pretty well, be far easier to tune, and less to go wrong with the print. I also use cheeky designs to make the seems go where I want them to be to print easier and keep the slicer from making the nozzle cross the gel path through the center.
It is a bit of trial and error, but don’t be put off if it doesn’t work like you hoped, small changes of the tongue and how it centers and holds the inner barrel make all the difference.
when is it available to the public?
Interesting idea. Be great to see how it turns out.
As mentioned above I’ve had varying success with printed top and bottom tongue type hopups but real good results with top tongue only. So run top only now.
Once start getting over 300fps and hard gels top and bottom type break the tongue in short time. Top only type last me a lot longer with great performance. Just my bit of experience. DKJ10 are a great printed top tongue only hopup.
I’ll agree with the “top tongue only” design with 3D printed hop ups… they’ve always worked for me.
Had a TacToys branded 3D printed hop up once… top and bottom tongue jobbie.
The print quality was so poor it actually worked better upsidedown. 
@Pequi nice looking design on that P90 hop up.
I modified the outer design of the hopups a bit and ask you, which one you prefer more?
My son and me do like the second version most…
Function is the same. Every design comes either with one or two tongues.
I didn’t have the chance to test the two tongue version so far. But with one tongue only, it performs really good!
Still waiting, for the B709, for the P-90 v5…
Got email confirmation, its still in the works…
This is taking awhile…
It will gov is in grind down due to eofy coming everything grinds to a halt. Busy crunching numbers they don’t understand.
Sounds like they don’t understand anything.
Despite the hopup I designed and is almost ready for publishing, I designed a speedloader spout for PET bottles, which works really well:
https://www.printables.com/de/model/922129-speedloader-spout-for-gelblaster
