hop questions

[SoupyXo]

so i saw a thread a while ago about hop setting, but its disappeared... 

my aeg seems to send bb's to the right after about 15 feet, and it sometimes has feed issues, not too often but still has feed issues every once in a while (its a windy uppy mag, so that could be the issue with feeding) 

how would i go about correcting the accuracy on it (specna arms c17 core bone stock) so it fires dead straight and on target? 

 

[EDcase]

I believe the hop rubber is slightly twisted off centre.  You'll have to take out the inner barrel and open the hop unit to re-seat it.

Make sure its undamaged and clean off any oils or dirt.

 

[RostokMcSpoons]

I've had the same thing.

Have you already taken it apart?  Just wondering if there's a chance you put it together again with something misaligned...

Alternatively there is a chance the lip at the rear of the hop rubber has been split and is impinging on the rear of barrel, forming a lip or nub that causes side spin.  

 

[SoupyXo]

I've had the same thing.

Have you already taken it apart?  Just wondering if there's a chance you put it together again with something misaligned...

Alternatively there is a chance the lip at the rear of the hop rubber has been split and is impinging on the rear of barrel, forming a lip or nub that causes side spin.  

i have taken the inner out before to check the hop rubber and nub, they looked ok so i cleaned them and popped them back in, and it seemed to work ok, until i noticed it was actually sending the bb's off to the right while i was ADS shooting at targets (cans and some old garden lights lol) in the garden the other day..... i was thinking about getting a maple leaf anyway, just not sure which one id need, and not sure which nub to buy either

 

[Adolf Hamster]

Consistent curving off to the right is the hop mound being off-square

This is commonly one of 2 things:

-The nub is uneven/off centre in the chamber (the arm may also be off centre/square depending on the quality of the unit)

-The bucking is rotated slightly off-centre either because its not square on the barrel or the barrel itself is off square.

Pull the barrel/hop unit, turn it on a bit then look down the barrel, it'll be obvious how its sitting relative to the feed tube on the hop.

 

[SoupyXo]

so i had a look at the hop rubber again and it had a little divot in it, sort of like it'd been sat in there with pressure on it toward the rear of the rubber, and it was kind of oily too... cleaned and re-seated it, will test it soon 

 

[SoupyXo]

further update - still got sidespin to the right... nit sure if the hop rubber is farked and i'm getting very annoyed at the semi auto getting stuck, so i think i might be buying a warfet for pre-cocking, a maple leaf macaron, and the associated nub... airsoft is fun

 

[Adolf Hamster]

No active breaking mosfets involved? Thats a pretty common cause for semi lockups.

Did the hop look square in the barrel ok before install? It can be subtle, and often it might look fine in one position only to become not fine when the hop is adjusted.

 

[SoupyXo]

No active breaking mosfets involved? Thats a pretty common cause for semi lockups.

no, its just in the standard ''battery to trigger to motor'' setup currently, nothing fancy... i use 7.4v lipo, so warfet for pre-cocking (no active braking) with a warhead 20k rpm long shaft base brushless sounds good to me

Did the hop look square in the barrel ok before install? It can be subtle, and often it might look fine in one position only to become not fine when the hop is adjusted.

it seemed fine. the hop was way off when i put it back in and it sounded like it was struggling to fire, but i adjusted it and it sounded like it did before, and still presented the same sidespin issue...  somewhat lost as to what to do with it, but learning isn't a bad thing

 

[Adolf Hamster]

no, its just in the standard ''battery to trigger to motor'' setup currently, nothing fancy...

maybe a little too quick on the trigger?

so warfet for pre-cocking (no active braking) with a warhead 20k rpm long shaft base brushless sounds good to me

on 12:1 that's a nice combo, snappy in semi but nothing crazy in auto, i was getting ~18ish rps out of that build but the trigger response would fool ye into thinking it was much faster.

it seemed fine. the hop was way off when i put it back in and it sounded like it was struggling to fire, but i adjusted it and it sounded like it did before, and still presented the same sidespin issue...  somewhat lost as to what to do with it, but learning isn't a bad thing

not unusual for hop completely off to have firing issues, it's one of the reasons i take exception to sites that insist on chrono'ing that way because you can get some weird readings.

only cause for sidespin aside from the hop would be something like dirt/deformation in the barrel, or the bb clipping something (typically suppressors) on the way out, although usually that's a lot more dramatic.

 

[SoupyXo]

maybe a little too quick on the trigger?

on 12:1 that's a nice combo, snappy in semi but nothing crazy in auto, i was getting ~18ish rps out of that build but the trigger response would fool ye into thinking it was much faster.

very very likely, but warfet + warhead + pre-cocking = no problem, and i get the added bonus of better trigger response.  while im in there fettling and fitting the warfet wiring, i can spin the cylinder so the gap isnt visible, to really do a neg airsoft and fucking piss the wankers off XD 

not unusual for hop completely off to have firing issues, it's one of the reasons i take exception to sites that insist on chrono'ing that way because you can get some weird readings.

only cause for sidespin aside from the hop would be something like dirt/deformation in the barrel, or the bb clipping something (typically suppressors) on the way out, although usually that's a lot more dramatic.

from what i can tell by the old eye chrono, its still whipping them out at about 300fps, and chucking them a good 120 feet, just with a hectic side spin to the right..... let the good old ''never wrong'' site chrono tell me im hot... ill laugh and agree, and then say ''i know i am, but this is mostly stock'' while pointing at the aeg lmao 

 

[Adolf Hamster]

very very likely, but warfet + warhead + pre-cocking = no problem, and i get the added bonus of better trigger response.  while im in there fettling and fitting the warfet wiring, i can spin the cylinder so the gap isnt visible, to really do a neg airsoft and fucking piss the wankers off XD 

it is still possible to trip up the warfet, although not as easy as a mechanical trigger. you'll get the feel for it regardless.

ahh yes, spinning the cylinder. tbh from all the messing around i've done i've tended to find aeg's are that badly sensitive to overvoluming, on the likes of an hpa you do gotta get it right although thankfully on those platforms it's also very easy to get it adjusted perfect for the ammo you're using.

as a general rule sticking with stock ain't too far off.

from what i can tell by the old eye chrono, its still whipping them out at about 300fps, and chucking them a good 120 feet, just with a hectic side spin to the right..... let the good old ''never wrong'' site chrono tell me im hot... ill laugh and agree, and then say ''i know i am, but this is mostly stock'' while pointing at the aeg lmao 

chrono is a useful tool for tinkering, worth getting one if you don't have one already.

it's a good way of measuring the quality of air seal and to some extent expected accuracy (at least the factors relating to consistent velocity).

 

[Badgerlicious]

As an aside, you won't need a mosfet with the warhead motor, they are insanely snappy as is, and have built in active brake and low voltage cutoff. 

Also, are you able to shine something into the hop chamber or down the barrel to check alignment? That could be an issue. 

 

[SoupyXo]

As an aside, you won't need a mosfet with the warhead motor, they are insanely snappy as is, and have built in active brake and low voltage cutoff. 

im not going to be using the active braking anyway on the warfet, i just want the pre-cocking and fire mode selection for full auto so i can get 3 round burst instead of full auto, and the warhead is literally just because i dont like brushed motors

as for the alignment, it seems to be ok, but i dont know really what im looking at, or what im looking for... as mentioned, the hop rubber looked ike it had a divot or a pressure mark in it as if something was resting on it for too long.... maybe thats the issue? 

 

[Adolf Hamster]

as for the alignment, it seems to be ok, but i dont know really what im looking at, or what im looking for...

the alignment can be very subtle, if you're looking down the barrel through the back of the hop unit you'll get a picture like this:

View attachment 91750View attachment 91752

left is misaligned and would curve shots off to the left, right is perfectly centered. of course you have to eyeball it based on the feed tube cos you can't cheat and add an imaginary line like i have on those images.

as mentioned, the hop rubber looked ike it had a divot or a pressure mark in it as if something was resting on it for too long.... maybe thats the issue? 

a deformation in the mound of the bucking would do that, some do have intentional shapes (eg the pdi w hold looks like a normal bucking with a v cut in the middle), but it's possible for wear/damage to do something similar which if off-centre can affect the spin and hence cause curving.

 

[SoupyXo]

the alignment can be very subtle, if you're looking down the barrel through the back of the hop unit you'll get a picture like this:

View attachment 91750View attachment 91752

left is misaligned and would curve shots off to the left, right is perfectly centered. of course you have to eyeball it based on the feed tube cos you can't cheat and add an imaginary line like i have on those images.

a deformation in the mound of the bucking would do that, some do have intentional shapes (eg the pdi w hold looks like a normal bucking with a v cut in the middle), but it's possible for wear/damage to do something similar which if off-centre can affect the spin and hence cause curving.

ill pop the hop rubber out after i see if its off centre, and ill get a picture of it

the hop rubber is really oily, I'm not sure why but it feels slick... opened the gearbox the other day and that was caked in blue grease so I've cleaned and re-greased that with abbey silicon...

anyway, you can see the damage that's apparent on the hop rubber, and the divot that's there... that could be an issue right? 

View attachment 91753

View attachment 91754

 

[RostokMcSpoons]

I'll defer to the more experienced / expert members of the forum, but any damage anywhere can't be great...? 
I'd be most interested in seeing this part of the rubber from another angle (90deg to this view) to make sure there's no damage to the lip

View attachment 91755

 

[SoupyXo]

I'll defer to the more experienced / expert members of the forum, but any damage anywhere can't be great...? 
I'd be most interested in seeing this part of the rubber from another angle (90deg to this view) to make sure there's no damage to the lip

View attachment 91755

the ends are fine, its just that little dip in the larger part... but, i did buy it ''new'' from ''that retailer'' .... so it wouldn't be surprising if it wasn't new ...

in saying that, when i was cleaning the gearbox of all the blue shit, i checked the air seal on the piston and it felt like a hotdog in a hallway... 

 

[Adolf Hamster]

the hop rubber is really oily, I'm not sure why but it feels slick... opened the gearbox the other day and that was caked in blue grease so I've cleaned and re-greased that with abbey silicon...

oil won't help it's lifting capabilities (although usually that tends to be temporary, after a few mags it'll have worn down to fresh rubber)

anyway, you can see the damage that's apparent on the hop rubber, and the divot that's there... that could be an issue right? 

you mean the indentation on the outside? that's pretty normal to see, it's the result of the rubber being constantly pressed down by the nub when it's in the gun (because the vast majority of folk myself included don't turn their hop units off at the end of a game day). that in and of itself shouldn't be anything to worry about.

what matters is the mound inside the rubber if it has any damage to it would cause curving.

 I'd be most interested in seeing this part of the rubber from another angle (90deg to this view) to make sure there's no damage to the lip

lip damage would generally cause an air leak resulting in fps inconsistency, although it is worth checking the lip and the bucking in general for tears.

 

[Rogerborg]

the alignment can be very subtle, if you're looking down the barrel through the back of the hop unit you'll get a picture like this

It's amazing how many guides and techs don't mention this.  The c-clip on the hop unit only holds the barrel in approximately the correct orientation and I've become mildly obsessed with making tiny rotations to get the mound centred.  Hop off, rotate the barrel a smidge, hop to full, eyeball, and repeat until your OCD is satiated.