Low FPS on recent project

[Pollynator_bravo2]

Evening folks

so I’ve popped a Titan ETU, m100 spring, eon gear box, eon piston and head, 13:1 gears, asg infinity 18000, into my nuprol defender. The fps looks a lot lower than I was expecting so I think I’ve screwed something up. The gate app isn’t picking anything out as a problem but it looks like I’ve missed what ever I’ve done wrong. Any help would be appreci


View attachment 95879



View attachment 95879

ated 




View attachment 95880
Also it’s on a 7.4v lipo 

 

[Pseudotectonic]

FPS same in semi and full auto?

 

[Fatboy40]

... so I’ve popped a Titan ETU, m100 spring, eon gear box, eon piston and head, 13:1 gears, asg infinity 18000, into my nuprol defender.

From the above I'm assuming you're using the same tappet plate + nozzle + hop unit as before? Also what was your previous gear ratio? (I'm assuming a stock Nuprol Defender so maybe 18:1?).

It would seem sensible to start with checking your air seal in general as, in theory, the parts used should not negatively effect anything (and I'm assuming that the GATE Eon piston head has a bearing, so the spring would be compressed further and that in itself will give a few extra FPS).

What FPS /. Joules were you getting on your chrono before and after?

 

[ak2m4]

Wouldn't let me open the video.  Most likely a compatibility issue with the Gate gearbox and hop chamber / Nuprol receiver.  Can be a sod of an issue.
 

Adding onto what @Fatboy40 said

1. What's the length of the inner barrel?

2. What's the cylinder type?

 

[Sneaky]

As above. Have you tried installing some of the original parts, bit at a time? Process of elimination, takes time but worth it. 

 

[Cain-c-123]

Another thing to check, if all else above fails. Is that the piston doesn’t bind. This will lower your fps dramatically and cause your gun to struggle cycling. With the 13:1 gearset and motor you have used. It does sound a little sluggish.

In comparison this is a set of 13:1 gears and a 22tpa motor with a perun mosfet on a 7.4 lipo. 
 

✌?✌? Hope you get it sorted buddy. 


View attachment 95926



IMG_2516.MOV

 

[Pollynator_bravo2]

FPS same in semi and full auto?

Not checked so I’ll do that ?

From the above I'm assuming you're using the same tappet plate + nozzle + hop unit as before? Also what was your previous gear ratio? (I'm assuming a stock Nuprol Defender so maybe 18:1?).

It would seem sensible to start with checking your air seal in general as, in theory, the parts used should not negatively effect anything (and I'm assuming that the GATE Eon piston head has a bearing, so the spring would be compressed further and that in itself will give a few extra FPS).

What FPS /. Joules were you getting on your chrono before and after?

Previously it fired at 310 fps. I’m not sure what the stock size spring and gears were but they were as brought 

As above. Have you tried installing some of the original parts, bit at a time? Process of elimination, takes time but worth it. 

Thanks for that. Good shout I’ll give it a go

Another thing to check, if all else above fails. Is that the piston doesn’t bind. This will lower your fps dramatically and cause your gun to struggle cycling. With the 13:1 gearset and motor you have used. It does sound a little sluggish.

In comparison this is a set of 13:1 gears and a 22tpa motor with a perun mosfet on a 7.4 lipo. 
 

✌?✌? Hope you get it sorted buddy. 


View attachment 95926



IMG_2516.MOV

Thanks. What does this look like when it binds and what should I check when investigating ?

I can also add that it started to drop range when it had been used for the second half of a game. After about 15/20 mins of play. 

 

[Pollynator_bravo2]

So the list of bits are as follows:

Gate EON V2 gear box

Titan Expert

ASG Infinity U-18000 motor

8mm Ceramic bearings

13:1 Cyma gears

EON tappet plate

Eon protector cylinder head 

eon power hybrid piston head

M105 Spring

unfortunately I can’t find the details on the cylinder View attachment 96025

 

[Badgerlicious]

Fitment with the gearbox perhaps? The delta series has a slightly thinner gearbox where the trigger unit sits, and is fitted in the body with some small pins that are moulded on the receiver. On my ak21 I had to do some filing which I could see causing issues with nozzle alignment. 

 

[ak2m4]

So the list of bits are as follows:

Gate EON V2 gear box

Titan Expert

ASG Infinity U-18000 motor

8mm Ceramic bearings

13:1 Cyma gears

EON tappet plate

Eon protector cylinder head 

eon power hybrid piston head

M105 Spring

unfortunately I can’t find the details on the cylinder 

how much did all that cost? 

 

[Fatboy40]

So the list of bits are as follows:

Gate EON V2 gear box

Titan Expert

ASG Infinity U-18000 motor

8mm Ceramic bearings

13:1 Cyma gears

EON tappet plate

Eon protector cylinder head 

eon power hybrid piston head

M105 Spring

Ouch, if you have a husband or wife don't let them find out ?

Just a GATE Titan BASIC, a Warhead Industries Base motor and a Maxx Model advanced trigger would have turned your Defender into a beast.

 

[Pollynator_bravo2]

Gate had a sale early in the year on their own website. Plus I brought in the polish currency which was very favourable so I didn’t pay anywhere near the cost if I’d of brought in the Uk. 
I will open her up this weekend and see if I can see what’s going down

Fitment with the gearbox perhaps? The delta series has a slightly thinner gearbox where the trigger unit sits, and is fitted in the body with some small pins that are moulded on the receiver. On my ak21 I had to do some filing which I could see causing issues with nozzle alignment. 

I have the eon cnc gear box now so no longer have the nuprol one

 

[Samurai]

Harsh truth is that you can keep shovelling money into it or you can give it to an airsoft tech who understands the details of how things work and will fix it for you.

 

[Badgerlicious]

I have the eon cnc gear box now so no longer have the nuprol one

What I mean is the nurpol gearbox is a weird shape so a more standard gearbox may not fit properly into the body without modification. 

 

[Pollynator_bravo2]

Fits perfect tbh sorry. The barrel length is 240 mm. I’m wondering if it’s the wrong size cylinder now. I’ve had it all

open and everything is free moving. 
 

I like to learn as it’s fun doing tech stuff but if I don’t figure it then it’s off to a tech I’ll go

View attachment 96126

 

[ak2m4]

that's what some people call a 4/5 cylinder or 70%, ideally for 240mm you should go with a 3/4 cylinder

 

[Pollynator_bravo2]

Ok thanks for this.  I’ll look at the old parts I’ve got as I think possibly the previous one may have been 3/4. If not I’ll swap it out. 

 

[Sneaky]

Harsh truth is that you can keep shovelling money into it or you can give it to an airsoft tech who understands the details of how things work and will fix it for you.

Very true. Something to bear in mind - having the correct cylinder is right, but also attention needs to be made to the quality of the piston head rubber. This tends to be forgotten. 
 

Learn from what you have found out so far, but when it comes to upgrades, like is more and bit at a time.

 

[Pollynator_bravo2]

So when I opened her up I found a couple of points. When the piston pulled back it on just exposed a tiny bit of the bottom of the tear drop cut out so it’s not getting much air in so to speak. The noise looks to be the pinion running on the wire retainer in the housing. 
got most of it reset only to repeat the fun of getting the spring loaded trigger and anti reversal latch back. I did buy some holders for them but they have disappeared so it’s waiting for more to be delivered. 
thanks for the help everyone 

 

[Pollynator_bravo2]

?‍
so after putting the old cylinder back, getting the pinion into the correct place………. We are now firing at 136fps and not at all when the hop is even slightly turned up. However I can feel a good air flow through the end of the barrel. 
mom guessing it’s not sealing to the hop/bucking very well. The only thing that wasn’t changed was the nozzle, bucking, hop, and barrel