VFC 417 DMR Build

[Hectic]

Okay so i grabbed me a 417 now I am going to build a DMR type rifle out of it. Here is what i have in mind but also have some concerns.
SHS 13:1 gears (not going for rof, just trigger response. Will have the merf set to 30% rof if i cant semi lock it somehow)
SHS blue piston 14 metal tooth
stock spring (m120-130ish)
Merf 3.2
11.1v 15c lipo (may custom make a bigger one, can fit 2 buffer tube lipos in the 417, 22.2v anyone? Lol jk)
piston head (pom)
Sorbo pad
455 or 509mm inner
smooth hop rubber, bridge tensioner..

My concerns, will the gears, piston withstand the 420+fps?
or do i need to go lonex piston (no stock atm) and some sigtek gears?
I i can get it around 420-440fps and 25+rps (before reducing it with the fet) id be happy, lookin to get near instant trigger response and the ability to run .36-.40 bb's for longer range engagements.
Thanks in advance tech gurus!!

[Shamusodoofus]

You shouldn't have any issues with this set up. I personally run a similar set up, except I run Lonex 16:1 gears (Firing 450~ FPS with a Modify M120). The 11.1V LiPo should power the motor sufficiently. The only thing you may want to consider is getting a battery with a higher C rating, maybe somewhere between 20-25C if possible. Another thing of note, which I'm sure you're already aware is to make sure the gears are properly shimmed and AOE is corrected. Assuming this is done you really shouldn't have any problems with the set up.

Siegetek gears are pretty overkill unless you're building an insane FPS or ridiculous ROF build. If you're looking for gear durability/longevity then I say go for it, but for your purposes and build it would be largely unnecessary.

You may also want to consider running lighter BBs, personally I've found that at 450 FPS .32g BBs ideal for range and accuracy.

[Hectic]

Thanks for the input! I figured with what i read that those gears tho cheap were prety solid. And i like the piston cause its pre lightened and cut a little thinner to fit the vfc gearbox.
I found on oldschool style hop ups .32 was about as heavy as I could run but with flat or R/iR hops they can lift .43's no problem just they take way to long to travel to target. At 500fps .40-46's have a reasonable flight time and .36's seem to blaze their way to the target.
I figure if im around 450fps .36's will likely be the max and .40's would be okay on a breezy day but not optimal.
also alot of it has to do with the cyl/barrel volume.
A short ish barrel (thinkin on going 455 not 509) with a full cylender is over volume, add a heavy bb that takes longer to travel down the barell uses the extra volume absorbs more energy and so has a longer effective range. Obviously every gun is different and itll always take testing and tuning to get the perfect balance. I got alot of hours doing that with my bolt action lol.

[Spike]

If you can fit 2 lipos in your stock, I would suggest you running them in parallel. You will absolutely murder the bejesus out of a 15c discharge battery with that setup (anyone who doesn't believe me, try it with a lipo alarm or a watt meter, it'll start dipping below minimum voltage really, really fast when shooting in semi).

600mm barrel is overkill. How long is the outer barrel? Just go with that length.

[Hectic]

Not 600. 509 or 455 lol i see my typo.
think the stock one is close to m4 length 370ish but ill he putting either a 16 or 20inch front set on it so just getting the length right for that.
im curious about running them parallel. Does that not just increse the capacity or will it also up the discharge?

[Wardlord]

Originally Posted by Hectic

Not 600. 509 or 455 lol i see my typo.
think the stock one is close to m4 length 370ish but ill he putting either a 16 or 20inch front set on it so just getting the length right for that.
im curious about running them parallel. Does that not just increse the capacity or will it also up the discharge?

Parralel will give you same voltage but double capacity.

[Spike]

Ah ok, that's better.

Running in parallel will double both the discharge rate and mAh capacity. Both batteries share the strain of the system instead of one, so it puts less wear and tear on the batteries.

Ever notice how pretty much everyone's stock tube lipos are poofy? Because most builds are too much for them.

[Hectic]

okay so first find some better C rating batteries then run em in parallel.
what about just increasing voltage to 14.8 or 18.5 or thatll still be an issue of not enough C?
edit didnt see the above post.
okay so thatll give me 11.1v 1600mah 30c seems like that could run one heck of a spring on any gears lol.

[pestobanana]

R hop or bridge hop the barrel

Get a 22 TPA high torque motor
SHS 13:1 gears

Get rid of the Gate FET, put in a smaller and more durable 3034 FET
Get rid of your shitty Li-Po, get some better 25-50C buffer tube ones

This is the 417 DMR I sold a while back:
http://www.airsoftcanada.com/showthread.php?t=169121

[Hectic]

i run bridge hops exclusively now. I like the performance and easy install lol.
are there easily available 3034 fets that install easily like the merf stuff?
and is that like a lonex a2 or a JG blue motor?

[pestobanana]

I don't get what you mean by easy. MERF installation is annoying because of all the signal wires. Its simple enough for me.

http://airsoftcanada.com/showthread.php?t=169957

22 TPA is ZCI HT, Chaoli Blue (comes in some Chinese guns like JG, CYMA, A&K etc.)

You would have better trigger response with a ~16TPA motor like SHS HT, but then you may run into feeding issues without a delayer. With a delayer you will likely run into FPS consistency issues due to tappet pre engagement.

[Hectic]

Cool thanks.
i didnt find the merf too bad to install. Especially with the 1 signal wire method. it installs the same as your thread shows. Reason for choosing the merf is for the rof controll. looking at the design on the selector i cant see a simple way to semi lock. But at 30% rof ill be able to semi faster than full auto so that should be good enough for most hosts i deal with.

[EOD Steve]

The general rule of thumb you have to ask yourself about Siegetek vs SHS or whatever else is: do you want to gamble with Chinese gears? I've had great success with Siegeteks and one set is going North of 40k rounds now with very minute wear.

The only time I have seen them fail is due to gross installation error or improper parts-matching (VFC lower gear train with Siegetek DSG or some other fucked-up "budget" measure)

SHS piston is fine, but with SHS, you never know if you have a good batch or bad batch, so why gamble? I got tired of going the cheap route and now put Lonex reds into all of my guns. Short of a preengagement event or a jam, I have not been able to destroy one in my high-power testing (540fps+). Pestobanana can comment on durability on high-speed builds.

Back when I was still with the Store, dealing with after-sales support, it became apparent that there was a correlation between the 2-wire method of installing Gate FETs and them blowing up. Not sure if it was due to gross installer error due the the perceived installation difficulty if 1 more wire or something actually electrical, but I never saw merit in the 2 wire method.

[pestobanana]

Siegetek vs SHS... I use both. SHS is "good enough" for most applications, Siegetek is very good, but you really won't benefit from having a set unless you've already optimized every other part of your gearbox. And you have to be good at shimming, there is no point in spending that much money on a gear set and shimming it in poorly. Once you start to extremely high stress builds, Siegeteks are the ONLY choice. I've seen a broken 14:1 step gear before, it was missing two teeth. That was caused by grossly negligent installation by several "techs" and a year or so of running a M170 in a DSG over 50 RPS.

Lonex pistons are the best general purpose pistons on the market. The racks are the hardest I've seen, and the material is dense but flexible. I've never seen one fail from anything except pre-engagement due to jams. Even then the steel teeth and pickup tooth are fine.

The two wire method causing failures is probably just user error, the signal wires shorting or something. All the second wire does is it connects to the positive lead inside the FET.

[Hectic]

Okay so this is my list of stuff.
SHS 13:1's
lonex red piston (gonna lighten it a wee bit.)
sobo buddy kit 70D From ASC
lonex pom piston head
modify cyl. No hole
madbull 6.03×455 inner
(with that^ combo i will run .36's should be near perfect for volume)
Modify flat/promy bridge franken hop (i have in my 400fps gun and love it)
gonna hit the rc store and find a good lipo i can fit in the buffer tube with a merf. Im stickin with merf just cause i have 2 and all my other guns are alrdy wired for it.
gonna shoot for 11.1v 2xxxmah 30c or more.
going to run the stock motor see how that goes and if it sucks or dies ill buy a lonex or zci
Now how is the quality of the vfc springs. Will they maintain the fps for a while or soften up fast? If they kind of suck what should i use for a 420-440fps setup m130?