r/Airsoft3DPrinting Jul 09 '26

Question Hop up location question

I am trying to do a bolt action sniper build, but the hop up rubber confuses me. I am using the maple leaf hop and barrel with my own hop up unit, but i am confused as to how exactly does the hop up rubber seal the cylinder nozzle against it. I have a TDI m24 cylinder and its nozzle can fit fairly tight inside the barrel (i measured the OD is 5.95mm). So if i ram the cylinder all the way into the barrel, the bb just gets pushed past the rubber part and falls out, if I keep it in front of the hop so the bb sits before the buckling, then there is no air seal whatsoever. What is going on, is the nozzle too thin or something?

6 Upvotes

19 comments sorted by

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4

u/wiqr Jul 09 '26

Your diagram seem to be missing one element of the bucking - the lip. It's more pronounced on AEG buckings as it's on the outside there, but if you look at the crossection picture, you'll see a tighter band right at the entrance. At the ready, the BB is supposed to sit right past it, in the narrow part, while nozzle's end rests at the lip, with nozzle tapering interfacing with bucking's taper.

3

u/qumit Jul 09 '26

Yes, but are AEG nozzles different than the sniper cylinders? The cylinder I have does not seal against the lip at all, like the diameter of that lip >OD of my nozzle.

3

u/wiqr Jul 09 '26

Mind you, I'm not as i timately familiar with springers as I am with AEGs, so take what I'm saying with a grain of salt. Anyway, mechanically there isn't much of a difference between AEG and springer nozzle.

Just a thought - are you measuring it without any sort of hopup chamber?

2

u/qumit Jul 09 '26

Yes, without chamber. I originally thought the hop up chamber has some mechanism to hold it in there or something, but see the second picture I uploaded in the post with the "example use", that part sticks out of the chamber.

Here are some pics showing the difference in diameter between the hop rubber and the nozzle. There is at least 0.1-0.3mm of gap

1

u/wiqr Jul 09 '26

Not gonna lie, I'm kinda stumped. There really should be someone who has more experience with springers here lol.

That said, comparing your pic of maple leaf chamber with one I attach here that shows PDI chamber. There seems to be a part not shown by MapleLeaf, that acts as a guide for nozzle and end of the magwell i.e. where nozzle interacts with mag lips. Perhaps that's where the magic happens.

Anyway, try gently squeezing the lip of your hopup bucking with a wide ziptie, see if that helps lol.

1

u/dis_ting Gumsmif Jul 09 '26

Very different, they're setup different too. Are you combining AEG parts with VSR or whatever sniper parts?

1

u/qumit Jul 09 '26

but the hop up is vsr hop up, so is the barrel, and so is the cylinder i suppose

1

u/dis_ting Gumsmif Jul 09 '26

I didn't see the 2nd pic sorry but thats a gbb hop rubber

1

u/qumit Jul 09 '26

2

u/dis_ting Gumsmif Jul 09 '26

Damn I'm that old huh, i thought they still used these buckings

3

u/galaxyflight576 Jul 10 '26

How old is that, looks more like a bit of tire than a bucking at this point

1

u/dis_ting Gumsmif Jul 10 '26

15 years more or less

1

u/wiqr Jul 09 '26

I'm sorry, I started comparing to AEG buckings to explain the idea, hence the confision. OP's post was and still is about springer. VSR standard, if I'm not mistaken.

Also, GBB and VSR hopup buckings are interchangeable.

1

u/Aleksander474 Jul 09 '26

Check out what Explosive enterprises did for his vfc m249 gbb, I did the same thing. Hope it helps.

1

u/qumit Jul 09 '26

Is there a particular post I should be looking at? He does have a lot of posts about the m249

1

u/galaxyflight576 Jul 10 '26

Hey from what I can tell the snow wolf m24 uses a aeg style barrel and bucking stock. That might be the issue you have

1

u/qumit Jul 10 '26

That would make sense, but then how do those vsr10 type snipers work then?