VFC Scar-H upgrading problems.

[AnthB]

So I recently decided to give my new VFC a couple small upgrades because i felt it was not performing the way a VFC should. I went with a longer and tighter barrel 6.02mm , a m130 spring and some reliable metal piston. I wanted it to shoot 400+ with .25s.

Got my shop to install these pieces and I got a call saying it was ready. I go in to pick it up and he says to me alright lets test it before you leave. Kinda strange that it wasnt tested before hand but okay lets do this. Shots reading under almost 350 fps. So needless to say I was disappointed so I left it there to get re-worked on. While I was there some random guy came in and it seemed like he knew what he was talking about so I went with his recommendation and also picked up a modified hop-up. A week goes by and finally my gun is ready to be picked up.

Im in the store and the guy who worked on it and the store operator were telling me "I dont know why, weve never seen this. We cannot get your gun to shoot over 400. This is also after they changed the new inner barrel to one I didnt really even want ( more so because of the looks but thats just me. The other one looked more expensive but I wouldnt know regardless ) That new hop-up that "super pro" recommended to me will not go in a VFC so I dont know what that guy was trying to pull. I think they said they stripped one of my gears so they replaced that as well.

Once I get my gun home and hook up a freshly charged 9.6v to it. Thing will not shoot. So I call then he explains i'll need a Lipo. Sure why not. But why not tell me I NEED it before i leave. Whatever thats fine. So i picked up a 11.1v 1000mah 20c lipo and tbh I cant say im at all impressed with how my gun is working. I mean, he told me to not shoot on full auto just in case i ruin my internals but I guess my trigger finger is too fast because my gun will not cycle fast enough. So I goto full auto bursts but my battery runs too low to cycle after around 500 shots.

So my questions for you guys are -

- Why can I not get my gun over 400 fps with .25s?
- Is there a way to get a shorter trigger pull so it will cycle fast enough?
- What kind of battery will I need to be able to play more than a quarter of a game and will it fit ?

And finally

- Should I just switch back to a normal 110 spring with a 9.6 and call it a loss ? Im pretty new but I also read quite a bit and I have never even seen a gun that cant shoot 400 fps with .25s. Did I get a dud gun? A $550 lemon ? Let me know what you guys think.

[K3vX]

Just a note, 400 fps with .25 bb is too hot for the usual field, but that's another subject ;-)

It should not be hard to get that kind of fps. Usually, what is hard is to have a high rate of fire with that power. Since rate of fire isn't your goal, refer to the easy part.

Now, I don't know your tech, but he doesn't look very competent, and I'd refrain from seeing him again. Find someone that knows what he's doing, and that will deliver either a working product or a free service and your gun in it's initial state.

For the sluggish trigger response, it was to be expected, since you paired a stiff spring with what I assume is the stock motor, using weaker ferrite magnets. The alternative is using a motor with "neo" (I can't remember the exact name) magnets, which are both stronger and more efficient.

He told you to pick a stronger battery so you could overpower a motor that is too weak. He also told you to be gentle with it because well, it is a stronger battery afterall, and it will do more damage to your electrical circuitry.

You're wondering why? Because the original wiring is meant for a weaker battery, and it is a source of resistance, whih coupled with the higher voltage will heat, burn and altogether screw the gun again. The most common issue with a strong battery and no mosfet is called "trigger arching". I'll let you figure it, but basically it burns the trigger contacts after a while. The most popular way to avoid these issues is using a mosfet. A mosfet, simply put, will handle the electrical circuit when you press the trigger, instead of passing the current through the trigger itself. You can google mosfet for more info.

Typed on my smartphone, may contain errors.

[AnthB]

Ive heard of the mosfet wiring kits but it seems I can only order them and I'd much rather get them from a store so I can see them. Personal fault I guess. I do realize that the stronger battery with a stock motor and wiring kit would cause some problems but why wouldnt the tech call me and say "hey, this wont work well unless you do this , this and this." I would have said sure slam it all in and send me the bill. But that didnt happen.

Also we play on a private field . I really just wanted a harder, longer and more precise
shot. My scar H was actually down to 325 fps and for an outdoor gun that just doesnt sound right. They said that maybe my spring was compressed after a round of full auto. I dont think thats possible seeing as if I play on full auto that round I ALWAYS take the mag out and shoot a bunch of times in semi just to make sure everything is clear.

Also the tech says he always works on VFC and it should be a piece of cake. Said he's been a tech for so long so thats why I found it hard to believe that nothing could be done about my fps. It sounds like either this is actually a lemon or I just got bad parts. Not wondering why he told me to get a stronger battery. It was more of why did he wait till I got home with my gun to tell me I needed a new battery.

Im going to need to buy a backpack for the battery in this thing because 500 shots isnt even enough for like I said a quarter of a game. Im not sure what to do about any of this. Sounds like my VFC was a waste.

It's a shame because I wanted to bring my GnG mp5 in to get it fully decked out for indoor but how can I now?

[FirestormX]

From the sounds of what K3vX was saying, your gun isn't so much a lemon with bad parts, but that your gun needs more work done to it.

You've upgraded your spring, so you need to upgrade your motor in order to wind it. If you want to run your lipo, you'll need to get it rewired with something meant to handle it. While you're running the lipo, you should install a mosfet to prevent trigger arching.

[AnthB]

Well I am definitely going to be looking into a stronger motor and ideally a mosfet kit that I can find in a store near me. I would not be installing it myself. Where do you guys, if anyone go to get your guns repairs / upgrades in the GTA ? Along with that new motor should I be looking into more reliable gears for my internals ? I'm not really the type of player to dump ropes of bb's down field so I couldn't care less about how many it shoots per minute ( for outdoor haha )

[cetane]

so I couldn't care less about how many it shoots per minute ( for outdoor haha )

If you are wanting fast trigger response, you always get high rounds per second count unless you have a fancy MOSFET that can control motor speed to slow it down in auto

[K3vX]

Exactly, the trigger response depends on the rate of fire. This is because when you press the trigger, the faster the cycle is done, the lower the time between the trigger actuation and the BB leaving is. Now, with a neodymium motor, even with the stock configuration, you'll get a good rate of fire (and trigger response). If you do get a neodymium motor, you'll need to take a few steps to ensure everything isn't too strong, like correcting the piston's placement for maximum gear teeth contact (commonly called angle of engagement, or AoE). This will avoid that you strip the teeth on the piston, and eventually prevent the whole gearbox from cycling properly. There are other things, but I won't cover them here.

But a good technician will do this be default when working on a gun.

(Sorry if everything I say sounds like I'm rambling, I have this tendency to overexplain everything)

[AnthB]

Over-explaining is a good thing. I'll have to look into where I can buy these things. I'm still wanting over 400 fps and a good battery recommendation. Something that will fit but will also last more than 500 shots. Neodymium motor is a term I am not familiar with. I'll google it. Would that not be all of the higher end motors? I guess a better question would be, what are the high end motor companies and what should I be looking for when choosing one? Other than if it will fit.

[SuperHog]

Before you sink more money you should borrow a 11.1V Lipo and give it a test. The higher voltage could make that stock motor more snappy.

I have a VFC SSR which probably has the same motor. I am running a 11.1V with a MOSFET and stock motor.

Also your drastic drop in velocity could be from an air leak. Check your piston oring, nozzle seals and hop rubber.

[pestobanana]

Trigger response is NOT directly correlated to high rate of fire. Trigger response relates to the start up acceleration of the motor. For example a G&P M140 can reach the same speeds as some cheaper neo motors, but will never have the same trigger response because of the slower acceleration. Motors use magnets, traditionally ferrite magnets have been used, but recently stronger neodymium magnets have been used.

Who was this gun tech, he sounds like he doesn't know what he's diong. As for hop up rubbers not fitting in VFC, it's true. Some don't because the VFC hop up unit is tighter than most. You can FORCE some thicker rubbers to fit by cutting the end off and shortening it so the C-clip isn't blocked, but you still risk tearing the rubber.

There are lots of people that call themselves "gun docs" but are really just dumbasses that think they are, so take it to someone reputable on this forum. I've seen some that didn't know how to shim, lost a C-clip and super glued the barrel to the hop up unit, and one that didn't know how to adjust motor height.

Also, what about the stock performance were you dissatisfied with?

[K3vX]

Pesto is right, I should have been more clear. It IS correlated, but not directly. I was assuming a neo motor for my example, which means a lot of torque compared to ferrite, even from a "low torque" one.

OP, check airsoftstore.ca for aeg parts, they have a good selection and every item is well explained.

Also, yes, try a mosfet [and someone else's 11.1 (or buy one from hobbyking.com, the nano-tech LiPo are some of the best packs you can get for the money)] EDIT: I was asleep last night, I forgot you had a battery and SuperHog's response made it look like you didn't had one. It might help enough to keep the stock motor. I'd still check the mods I mentionned earlier about the piston.

[pestobanana]

Originally Posted by K3vX

Also, yes, try a mosfet and someone else's 11.1 (or buy one from hobbyking.com, the nano-tech LiPo are some of the best packs you can get for the money). It might help enough to keep the stock motor. I'd still check the mods I mentionned earlier about the piston.

I'm just going to add a +1 to check airsoftstore.ca, but a MOSFET will not fix your problem unless you have serious trigger issues, but that should not be the case. MOSFET's only improve trigger response and RoF if you have a seriously messed up trigger switch.

You said the gears were changed, were they shimmed properly? Does anything get hot when you're firing?

[AnthB]

I've already bought and used the 11.1v LiPo. It works well but the trigger response isnt where I'd like it to be. Also with the m130 spring i put in, I can only fire around 500 shots until the voltage drops and it wont cycle. From what I was told from the tech, there is NO air leaks and perfect compression. I really need to open up one of my old guns and start working on these things myself it seems.

[pestobanana]

As we've said if your tech can put in a M130 spring and still get you under 400 fps, and CLAIM there is no air leak, he doesn't know what he's doing because there clearly IS an air leak.

Is it a Mk.17 SSR? With a perfect air seal you can easily nag 450+ fps with .2g. With a M120 I get 455 in my M14 and 445 in my G36... With a M130 I'd easily push to 490 fps in my M14.

Something is definitely wrong here because my friend's SSR can run no problem with a M120 and a 9.6V mini battery.

[lurkingknight]

if the vfc scar H has a similar breakdown to their scar L, someone a lot more knoweldgeable than your shop or super tech that recommended you the bullshit hopup is going to be needed. The VFC's wiring is weird, some creative mosfet choice or installtion will be needed to get it working. This is a non standard gun 2 inches out of the gearbox.

As for your FPS issue, someone can't diagnose for shit. Either your cylinder is the wrong match for your barrel, your piston is not full stroking for whatever reason, or you have a massive air leak somewhere, or the spring in your gun is not a 130.

Your stock motor should pull a 130 spring just fine, it may need more power. borrow a 11.1 lipo from someone to try, but the stock motor probably won't like pulling a heavy spring like that long term.