Inconsistent hop

[Pewpewpetie]

Believe at last I have figured it out, the cylinder/piston head. I believe the o ring was to thick. Was creating a great seal, but wasn't allowing the ported piston head to vent on retraction, which then created a slight suction in barrel. So my guess is, if that bb hasn't left the barrel completely by the time the piston begins retracting then some of the air being used to propel the bb will be sucked back into the cylinder. Will be testing later once the winds and rain stop

 

[Pewpewpetie]

Also I have noticed that the piston isn't returning to exactly the same spot after each shot on semi.



View attachment 79300

 

[Lozart]

Are you running a cycle completion mosfet or precocking based on time?

 

[Pewpewpetie]

Are you running a cycle completion mosfet or precocking based on time?

No, basic mechanical trigger, 7.4v 25c  lipo,22tpa high torque motor with 13:1 gears, AOE corrected and sector delay switch

 

[Lozart]

No, basic mechanical trigger, 7.4v 25c  lipo,22tpa high torque motor with 13:1 gears, AOE corrected and sector delay switch

That'll be your problem then.

 

[Pewpewpetie]

That'll be your problem then.

What would you reccomend

That'll be your problem then.

I have another m4 with same build and have no issues

Should I put a standard gear set in

.

View attachment 79314

 

[Skara]

Well the energy output suggests it's a hop up issue. As you guessed, it's most likely the hop arm being wobbly/loose, or it could be the tensioner being way too soft.

The harder the tensioner (and stiffer the arm), the more repeatable the backspin.

 

[Lozart]

What would you reccomend

I have another m4 with same build and have no issues

Should I put a standard gear set in

.

View attachment 79314

Personally, I'd fit a Gate Titan or Aster but Perun V2 Hybrid would also work. Basically anything that senses the gear rotation to be able to stop it in the same place each time. That being said, it doesn't actually matter all that much unless you're getting feeding issues or you're trying to get accurate pre-cocking. Inconsistent hop is unlikely to be adversely affected by the piston not stopping in the same place.

I'd also get rid of all that bloody PTFE tape. There doesn't look to be much in the way of lubrication either (although that may just be the picture).

 

[Pewpewpetie]

Personally, I'd fit a Gate Titan or Aster but Perun V2 Hybrid would also work. Basically anything that senses the gear rotation to be able to stop it in the same place each time. That being said, it doesn't actually matter all that much unless you're getting feeding issues or you're trying to get accurate pre-cocking. Inconsistent hop is unlikely to be adversely affected by the piston not stopping in the same place.

I'd also get rid of all that bloody PTFE tape. There doesn't look to be much in the way of lubrication either (although that may just be the picture).

Had to use the ptfe tape for now as don't have any other o rings. Gona have to set it aside for a  Few days then try again. Stressful is an understatement

 

[Lozart]

Had to use the ptfe tape for now as don't have any other o rings. Gona have to set it aside for a  Few days then try again. Stressful is an understatement

Don't over think it.

 

[Pewpewpetie]

Don't over think it.

Haha bit late for That

 

[Pewpewpetie]

Finally I admit defeat, I've tried everything, 4 different rubbers, 3 different hops, 4 different nubs,3 different barrels and 3 different Air nozzles. Gun is very consistent now +-2fps but vertical hop is still all over the place. 2 out of 5 bbs hop too high , 2 will fly perfectly and then 1 will have not as much hop

 

[Rogerborg]

Classifieds -> never keen skirmished -> shoots like a laser.

 

[Adolf Hamster]

Classifieds -> never keen skirmished -> shoots like a laser.

"easy fix but i havent got the time"

the only possible explanation, and it might sound a bit stupid, but how are you going about setting the hop?

i've seen hops have dual "sweet spots" where if you start adjusting from off you get to the first spot with good hop, but if you keep adjusting eventually the combination of overspin/energy loss ends up at another point with what looks like about the right amount of spin but ends up with really crap consistency.

possible if you're starting off with big adjustments maybe you're missing the first spot and hitting the second?

 

[Pewpewpetie]

"easy fix but i havent got the time"

the only possible explanation, and it might sound a bit stupid, but how are you going about setting the hop?

i've seen hops have dual "sweet spots" where if you start adjusting from off you get to the first spot with good hop, but if you keep adjusting eventually the combination of overspin/energy loss ends up at another point with what looks like about the right amount of spin but ends up with really crap consistency.

possible if you're starting off with big adjustments maybe you're missing the first spot and hitting the second?

I wish it was that simple hahaha. Tried various hops, adjusting one click at a time and firing 5 rounds per click, costing a fortune in ammo now aswellmThe only thing i can think is that nozzle isnt seating bbs correctly, maybe some falling inside the lips? I really dont know anymore. The stress levels this gun has caused is unreal hahhaha. Really dont want to sell it as i love the unique look it has

View attachment 79417

 

[Pewpewpetie]

Also wondering if it xould be a tappet plate problem maybe angling the nozzle very slightly causing it to not enter the hop completely straight. Ill check when i next open it as i saw an article on it whilst searching every single page on Google hahahha

View attachment 79423

 

[Adolf Hamster]

the problem with that sort of thing is the consistency you're getting.

if the same rounds that are going through the chrono are also going all over the place (ie no changes to the setup between chrono/range shot) then it really shouldn't be an airseal issue.

you can get it with mags, if your testing on a half empty midcap or a hicap then go to test shoot on a stuffed midcap, the friction on the nozzle from the bb stack holds the nozzle back and gives temporary airseal issues.

 

[Pewpewpetie]

the problem with that sort of thing is the consistency you're getting.

if the same rounds that are going through the chrono are also going all over the place (ie no changes to the setup between chrono/range shot) then it really shouldn't be an airseal issue.

you can get it with mags, if your testing on a half empty midcap or a hicap then go to test shoot on a stuffed midcap, the friction on the nozzle from the bb stack holds the nozzle back and gives temporary airseal issues.

Been using hi caps wound fully. I think the only thing left is how tge bb is sitting before it hits the hop mound

 

[Lozart]

Here's an off the wall idea - is the end of the barrel clear of any obstructions? Does it behave the same way if you take the flash hider off for instance?

 

[Adolf Hamster]

Been using hi caps wound fully. I think the only thing left is how tge bb is sitting before it hits the hop mound

does it do it if you let the hicap unwind a significant amount?

ordinarily hicaps tend not to put that much pressure on, but it's not impossible.