hop questions

[colinjallen]

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]

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.....

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.

 

[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]

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?

 

[Lozart]

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. 

True, but the ridges around the rubber are designed to combat that very issue.

The C-Clip is a crap design though, some sniper rifle hops already have grub screws for centring the barrel so yes it could work but you are introducing an additional point of endless fiddling to get things lined up properly. If the hop unit is made well then a tapered collet would probably work (you can get 3D printed ones for the Maxx hop units which would probably work for other hops too).

I have one of these in one of my Maxx units and it seems to hold everything properly steady (although it can be a bit of a pig to get in properly depending on your inner barrel sizes) https://www.airtechstudios.com/products/maxx-advanced-hop-up-chamber-inner-barrel-ring

 

[Lozart]

Appears they also do a universal version! https://www.airtechstudios.com/fr/collections/g-g-cm16-gc-predator/products/universal-advanced-hop-up-chamber-inner-barrel-ring

 

[Adolf Hamster]

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? 

most motors tend to come with pinions, and the majority of the time folk tend not to care too much about having the exact right pinion matching the exact right gears.

easiest way if you care for such things would be to try and match motor+gearing brand.

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) 

i'm a big fan of the maple leaf macaron+omega nub combo, ran it in many pews with excellent results. tan is fine for general use or green if you're the kind of lunatic who needs to be able to lift 0.48g at 1j......

iirc some specna units have the nub built into the arm? i'll let owners confirm that though.

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

bushings versus bearings, eh, i've never really paid much mind. bushings are going to be able to take more punishment and won't fail catastrophically like a ball bearing can, but bearings can be better for speed. some folk even mix and match with bushings on the sector then bearings on the idler/bevel gear.

shimming would be worth doing only if you feel like you can do it well, otherwise leaving it stock will be a relatively safe option. gotta keep good track of em though, nothing likes going walkies like a shim......

True, but the ridges around the rubber are designed to combat that very issue.

The C-Clip is a crap design though, some sniper rifle hops already have grub screws for centring the barrel so yes it could work but you are introducing an additional point of endless fiddling to get things lined up properly. If the hop unit is made well then a tapered collet would probably work (you can get 3D printed ones for the Maxx hop units which would probably work for other hops too).

I have one of these in one of my Maxx units and it seems to hold everything properly steady (although it can be a bit of a pig to get in properly depending on your inner barrel sizes) https://www.airtechstudios.com/products/maxx-advanced-hop-up-chamber-inner-barrel-ring

 the combat union design is pretty slick, it has a steel clip that slides in as normal (no actual tension just a neat fit) then a grub screw to lock the clip in place and a collet that screws in and locks the barrel absolutely rock solid.

that said, lot more space in an ak reciever to have a chunky unit with all that stuff on it, wouldn't be to easy to pull off in an m4.

 

[ak2m4]

Appears they also do a universal version! https://www.airtechstudios.com/fr/collections/g-g-cm16-gc-predator/products/universal-advanced-hop-up-chamber-inner-barrel-ring

Be interested to try that little wedge - does seem the simplest solution.  I just tried the locking nut that comes with the Retro Arms hop unit however it does nothing to keep the chamber and barrel aligned.

 

[Lozart]

Be interested to try that little wedge - does seem the simplest solution.  I just tried the locking nut that comes with the Retro Arms hop unit however it does nothing to keep the chamber and barrel aligned.

BZ Tactical have them in stock https://www.bztactical.co.uk/airtech-advanced-hop-up-chamber-inner-barrel-locking-ring-universal

Worth a try but be aware that it may need some "fitting". I needed a bit of kinetic engineering on mine!

 

[SoupyXo]

iirc some specna units have the nub built into the arm? i'll let owners confirm that though.

in my hop unit, it does have the nub attached to the arm, but im unsure if id need to change it, or if i can... regardless, there are too many options and not a whole lot of sense made in the item descriptions for the parts, which makes it that much more difficult to pick the right bits 

 

[Adolf Hamster]

in my hop unit, it does have the nub attached to the arm, but im unsure if id need to change it, or if i can... regardless, there are too many options and not a whole lot of sense made in the item descriptions for the parts, which makes it that much more difficult to pick the right bits 

tbh, if it were me i'd probably just replace the unit wholesale, but then i have a nasty habit of doing that to basically everything.

the curse of absurdly high expectations.....