Hop Unit Build Help ( pictures )

[Auto Freak]

Hi there. I am building a hop unit as it came all seperate. I have it built up but I was wondering what this thread is for ? It goes into the hop unit and the only thing that I can think of is that it locks the arm in place or something like that ?

[MasterGouken]

Re: Hop Unit Build Help ( pictures )

Normal hop units have a nub with a spring on, pro win hop ups have this screw thread. I assume you can just use a biro pen spring on it, thats what i have done with mine. Maybe the screw can be loosened/tightened to optimise the hop up's location inside the upper receiver/outer barrel.

[Auto Freak]

Ok cool, does it need to be spring loaded ? I assume that it does to keep it from rattling about ? Biro spring..... good thinking

[frostyairsofter]

Re: Hop Unit Build Help ( pictures )

is that not just simply for spacing? when you stick it in the upper receiver in butts up against that?

[badger906]

Re: Hop Unit Build Help ( pictures )

the spring is designed to keep a constant pressure on the hopup pushing it back into the air nozzle. You'd have to do a fair bit of trial and error using the grub screw method.

[Auto Freak]

Finished !!

[dave38x]

Re: Hop Unit Build Help ( pictures )

Oooo, such a pretty hop unit - ordering one when the student loan gets here

[Auto Freak]

Oooo, such a pretty hop unit - ordering one when the student loan gets here

No need to waste good drinking money from your student loan :D They are not expensive, this cost me around £20 including P&P

[dave38x]

Re: Hop Unit Build Help ( pictures )

Haha, i'd agree with you but ive just bought the parts to rebuild my gearbox, and i intend to buy a tightbore, this hop unit and a cheapo free float RIS for my m4, so the beer money will have to be dug into for some of it!

Oh, and probably the swanky new G&P Self retaining pins as well!

[Auto Freak]

Oh, and probably the swanky new G&P Self retaining pins as well!

oooooo, tell me more ??

[dave38x]

Re: Hop Unit Build Help ( pictures )

Site in the far east has them, 8 usd.

Basically the rear pin is held in by a spring clip, you insert the pin into the lower and then fit this clip over it, it has slots to retain the pin both fully in and almost completely out of the lower. Front pin is a little more complex, basically you either need to have a receiver with the right hole or drill one perpendicular to the pin in that bit of material on the right hand side of the lower. (It's just behind where the head of the front pin sits). You then insert a spring/follower into this slot and push your pin in. The follower engages in a slot on the pin and locks itself in place fully in and out.

Rather excited, should do away with having to piss about with allen keys!

[Auto Freak]

Im confused. On my both my G&P's, I just have a front and rear pin that pushes out. No allen keys needed

[dave38x]

Re: Hop Unit Build Help ( pictures )

Cheaper guns have pins with bolts screwed into the other side as the pins are too loose (tight tolerances = higher cost of manufacture), or the pins are replaced with pins of that sort as the stock pins wear. Anyway, self retaining pins = bonus all round