hop questions

[Guest 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.  

Edited June 3, 2022 by RostokMcSpoons

[Guest SoupyXo]

16 minutes ago, RostokMcSpoons said:

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

Edited June 3, 2022 by SoupyXo

[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.

[Guest 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 

[Guest 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.

[Guest SoupyXo]

10 hours ago, Adolf Hamster said:

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

 

10 hours ago, Adolf Hamster said:

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]

9 hours ago, SoupyXo said:

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

 

maybe a little too quick on the trigger?

 

9 hours ago, SoupyXo said:

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.

 

9 hours ago, SoupyXo said:

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.

[Guest SoupyXo]

 

16 minutes ago, Adolf Hamster said:

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 

 

20 minutes ago, Adolf Hamster said:

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]

5 minutes ago, SoupyXo said:

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.

 

8 minutes ago, SoupyXo said:

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. 

[Guest SoupyXo]

On 06/06/2022 at 14:39, Badgerlicious said:

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]

1 hour ago, SoupyXo said:

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:

 

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.

 

1 hour ago, SoupyXo said:

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.

[Guest SoupyXo]

14 minutes ago, Adolf Hamster said:

 

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:

 

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? 

[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

[Guest SoupyXo]

6 minutes ago, RostokMcSpoons said:

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

 

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... 

Edited June 8, 2022 by SoupyXo

[Adolf Hamster]

32 minutes ago, SoupyXo said:

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)

 

33 minutes ago, SoupyXo said:

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.

 

22 minutes ago, RostokMcSpoons said:

 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]

1 hour ago, Adolf Hamster said:

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.

[colinjallen]

48 minutes ago, Rogerborg said:

 

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.

Many a happy hour has been spent doing this.

[Floperator]

As someone who spent last night doing just this, after popping in a 60 deg. Macaroon, how do you make sure it *stays* in position?

[Adolf Hamster]

1 hour ago, Rogerborg said:

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.

 

Yep, whats worse is that twiddling the barrel doesnt strictly move the hop bucking at the same rate as the barrel (cos it can stretch), ends up not quite centred over the barrel window even if its centred to the hop. Maddening!

 

This is one of the things that differentiates a good hop unit from a bad hop unit, the centering of the window over the barrel, being a good fit for seal but not too tight, the c clip holding the barrel even closer to square.

 

Only hop unit i've met that does this perfectly is the combat union ak unit, but then that thing is ridiculously overbuilt with the pricetag to match.....

 

10 minutes ago, Floperator said:

As someone who spent last night doing just this, after popping in a 60 deg. Macaroon, how do you make sure it *stays* in position?

 

Usually they tend to stay in position relatively well, outside of installing the hop/barrel unit into the reciever theres not much load on the barrel aside from being pushed straight forwards.

[Guest SoupyXo]

so, if im replacing the motor, ill need a pinion gear for it, how do i select the right gear for the motor and gears in the gearbox? 

which hop rubber should i buy to replace the one i currently have, and which nub would i need for it (stock blue specna rotary hop unit) 

and would it be better to replace the bushings with bearing style bushings and re-shim it while im doing all the work? 

 

[ak2m4]

19 hours ago, Floperator said:

As someone who spent last night doing just this, after popping in a 60 deg. Macaroon, how do you make sure it *stays* in position?

 

It is indeed a problem.  The wall thickness of a Macaron edges on the thinner side as well so there's even more scope for the bugger to move around. 

 

I wonder if if could use 3 small grub screws?  Think it would work?