I mentioned the purpose of the groove in post #254 above, unless you are talking about a groove I’m not aware of. The groove I’m talking about is across the face of the angled sealing area.
Dave
Dave
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Huben Any issues or problems with Huben gk1 please share your experience
- Thread starter windowtintz
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Ok I thought you had it apart for service. There is only one groove on the valve and it’s on the angled portion of the valve. The angle part shown above the red line does the sealing.I haven't taken mine apart yet. Was hoping to learn what the top groove was, besides being a potential failure point. At the moment, mine is shooting at 37FPE average for a magazine with a 30MPa fill. (28.4 grain NOE slugs.) Rather not crack it open unless I need to. If needed (or when needed) I'll open it. Still in the honeymoon stage.
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Not that groove, the circular one on the top face. I understand the one on the angled sealing area.
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I see, I would have to pull mine apart to check. I’m not sure if it’s there from the factory or worn into it. I can’t imagine a purpose but that doesn’t mean there isn’t one.
Dave
Dave
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What does the top view look like? The flat face above the red/orange line? Is there a circular groove there? Or is the groove on the bottom circular face? Or is the picture that Stubbers posted not relevant? Part 21, the close valve spring stem should fit in the bottom of part 20, the plastic close valve. Is the groove due to part 21?
Basically, I don't understand what face is depicted by @Stubbers photo. So I don't understand where the circular groove is, or if it has a function.
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Simply not even sure what face the circular groove is in, top or bottom face. Can't understand why the groove would be in the top face at all. Not sure why it would be in the bottom face either.
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That *circular groove is on the bottom not the top of the valve. It’s not there on the spare plastic valve I have. It’s either something Huben just started implementing or it was caused by the metal driving into it.
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That groove / indentation isn't from internal forces of the guns operation? Hmmm, if not...interesting..
But my interpretation of the breakage is that it relates to the force that creates the shown indentation.
-Matt
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Does the groove correspond to the close valve spring stem flange part #21? Seems like it might, as the stem fits into that plastic close valve. Maybe the flange diameter is a little too small? Or the plastic is too weak?
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My interpretation is the indentation mark is the result of #20 seating onto #21 every shot cycle. If it's a machined groove that just happens to be at the same area such indentation would occur then perhaps coincidence, but being there is a reported breakage occurring from a user at this exact location where the two materials meet, I can't help but assume quite a bit of energy transfer is going on between the two materials (base of #20 and the 'seat' of #21).
-Matt
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Pretty much the same as I was thinking. If it was me, and who knows, maybe it will be me, I'd consider remaking the plastic piece and perhaps widening the flange on the steel part. I'd think having more contact area would spread out the force density. Hope I explained that clearly. Perhaps I'm not thinking about it correctly, if so, please help me understand more.
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Yes, that would be the part causing the indentation. It could’ve just been a defect in the material or a few other reasons. Adding a thin metal washer, the same diameter as the closing valve, would distribute the stem flange impact across the entire surface of the bottom valve face.
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My approach would be make that plastic piece metal and have a peek/plastic seat, or change the geometry of the existing plastic piece so its seat is more robust/thicker with a tapered transition versus a sharp edge, such as this:
Hard to draw with it so small, but think of the base of a bishop chess piece:
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It might be the print of the washer's edge. It's more like a Belleville washer. The cupped side facing the valve surface.
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Here is an image of mine. Mine has a smaller washer similar electrical ground wire washers.
Mine has no wear or groove present. It has a minor area that is discolored and very slightly abraded from the washer.
It appears that this end doesn’t take a beating under use. At least not to the extent to cause the recent failure.
Obviously mine uses a different washer. It displaces any energy over a smaller area and should have created a groove or indentation by now.
Dave
Mine has no wear or groove present. It has a minor area that is discolored and very slightly abraded from the washer.
It appears that this end doesn’t take a beating under use. At least not to the extent to cause the recent failure.
Obviously mine uses a different washer. It displaces any energy over a smaller area and should have created a groove or indentation by now.
Dave
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Did you find a washer in your GK1? Or is it just the imprint of stem? Simple fix might be a washer between the stem and plastic to spread the impact load. Increasing the diameter of the washer to about the seal size would reduce the impact force by 40 percent, roughly estimating. Or making the stem with a larger flange if you have that capability.
30 euro for a tiny bit of plastic seems like a lot, but at least it's available.
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Not having the trigger guard in front of me, I assume the closing valve stem enters a hole and meets the adjustment screw. You said the adjustment screw was adjusted out. Is it possible the stem got caught on the edge of the hole when you assembled the trigger guard? I’m not trying to cast blame here, just trying to figure out what would cause that kind of force on the bottom of the valve.
Can you take a picture of that part of the trigger housing?
Dave
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I see an indentation/wear...just smaller diameter than the failed one which is what I suggested as a fix in reply #256 , because the energy doesn't force that flange to flex with a smaller diameter washer/seat.
IMO due to his washer design, regardless of setup, that flange is taking a beating over time and you can see the cracks that started the failure, I highly doubt the failure happened in one shot cycle, rather over several as the fracture grew from not visible to the human eye, to visible, than grew in length.
Shown in red is where I believe the initial fracture(s) began, it would explain the flexing flange theory I propose.
-Matt
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