Tuning FX Impact Mk2/M3 - slower first shot - no reg creep - quasi-scientific analysis

[Seeker]

I was thinking about loctiting that peek piece just for the gun assembly process. If it's going to be a tight fit then it can move back and forth. Other thing is I may need to make it just a little loose to accomodate peek deformation once pressurized. It is really tough material but it may suffer from deformation a little.

 

[Seeker]

This is the negative of the plug made using melted wax.

The angle there is 118*. That is the angle of a drill cone. Maybe the angle is there just because a drill has it?



There may be no deeper meaning staying behind that cavity other than the drill point angle.

 

[nervoustrig]

I was thinking about loctiting that peek piece just for the gun assembly process.

If you decide to do that, be advised that most threadlockers have a methacrylate composition which will aggressively attack almost every O-ring compound imaginable…except the FKM type you intend to use. So I guess this is a warning if you end up trying different O-ring types or if anyone else gets motivated to experiment.

I’m anticipating that it may be difficult to apply threadlocker without getting at least some on the walls of the bore, at which point the O-ring would happily pick it up on its way to the destination.

The other potential issue is removing the PEEK part when the day comes you need to get it out, at least without damaging it.

 

[Seeker]

I agree. It would be much better to not to use any adhesive at all. I will try to do it so.

Yeah, I had a really bad experience with Loctite and plastic. I used it to lock a screw inside plastic thread. Silly me, the plastic part was melted. Nowadays, I would use Vibra-Tite VC-3 for that purpose.

 

[nervoustrig]

Yeah, I had a really bad experience with Loctite and plastic. I used it to lock a screw inside plastic thread. Silly me, the plastic part was melted.

Haha, my story was a shower head that kept loosening whenever someone adjusted the sprayer dial a few times. No problem, threadlocker to the rescue. It worked great for less than a week when it unceremoniously broke off. Turns out the nut was an electroplated plastic part made to look like metal and the threadlocker had eaten it for lunch.

 

[Airgunmann]

I highly doubt the cone is used to seal anything especially being the same angle as the drill bit I wouldn't even put the angle on the peek just keep a tighter dimension to out side wall and basically a press on fit of a few thousandths for the piece of peek that way if the peek does deflect some it wouldn't pinch

 

[Seeker]

I decided to place the cone on the peek so that the hole inside won't be defomed that match due to pressure induced stress. That peek element will have a plane to resist mentioned stress.

 

[Airgunmann]

Ok I understand do u have outer and inner dimensions if it works I'd like to make one for my mk2 but don't want to take it apart just yet 

 

[Airgunmann]

Length of it would be helpful to if it works which I don't see why it wouldn't thanks

 

[corny]

This is the negative of the plug made using melted wax.

The angle there is 118*. That is the angle of a drill cone. Maybe the angle is there just because a drill has it?



There may be no deeper meaning staying behind that cavity other than the drill point angle.

Plenty of flat bottom drills on the market. I use them all the time in production applications.

orherwise, 135 or 140 degree is the standard from production drills 

 

[corny]

Ok, got ya. It's doable.

However, not every user is able to do it.

Do you think it's also doable in a mass production using CNC?

Absolutely, no question about that. 
flat bottom drill would clean it up. 

 

[Seeker]

Testing soon.

 

[mubhaur]

Testing soon.

Great. Let's hope for the best . 

Bhaur

 

[airprsr]

My gen 1 Crown does the same thing. Not an issue for me I just shoot one into the ground if my first shot is going to be long range. Otherwise I just shoot. 

 

[Airgunmann]

Seeker any testing news yet ? 

 

[Vetmx]

I ordered that plenum piece so I don’t have to take either of my guns apart. When I get bored, I will hit the lathe. Going to build something along Nervoustrig’s idea with my own twist. It may be a couple weeks but I won’t abandon this topic. Even if I decide to do nothing and remain a shot dumper. Was just shooting last night at 100 and watched the gun go from zero to hero because I didn’t dump a bunch of shots. I don’t name my guns but if I did, Diesel might be a good name. Gotta warm the old girl up.

 

[Airgunmann]

I ordered that plenum piece so I don’t have to take either of my guns apart. When I get bored, I will hit the lathe. Going to build something along Nervoustrig’s idea with my own twist. It may be a couple weeks but I won’t abandon this topic. Even if I decide to do nothing and remain a shot dumper. Was just shooting last night at 100 and watched the gun go from zero to hero because I didn’t dump a bunch of shots. I don’t name my guns but if I did, Diesel might be a good name. Gotta warm the old girl up.

Diesel I like that got to get her warmed up

I plan on installing a peak piece and probably use a x ring quad ring was just hoping to see some results before doing so peek piece will be just to keep the oring out of the tapered area there and if it works out I may have to do my friends m3 also so maybe I should think about getting a m3 plenum for my mk2 I don't know keep us posted please

 

[Seeker]

Seeker any testing news yet ?

This weekend for sure. Stay tuned.

 

[Airgunmann]

Ok sounds good 

 

[Bigragu]

After looking at SEEKERS drawings, which I might add is great and kudos to him for pioneering all of this, tell me if I’m missing something-

SEEKER mentioned he would make the thru hole in the Delrin seal larger to accommodate the rod and guarantee no sticktion- got it.

Another o ring will go behind the back side of that Delrin piece, wether it be a standard buna o ring or X ring- got it

here’s my problem- where’s the seal? That back up o ring is not going to seal tight to the rod, no way. The Delrin, if made to allow movement as the plan, along with not crunch tight to the rod (then it’s back to square 1 with sticktion), then how is that sealing? 


i take back my input a page or so ago when I felt the duro nitrile back up o ring was the sealing o ring. I had not realized the front of the plenum end cap beak had a taper to it, but now that I see it thru SEEKERS sketches, it looks to me that taper was purpose built to wedge into that taper, which would squeeze the circumference of the PUR o ring, and that squeeze creates the seal against the rod. I also understand why polyurethane in a DURO 90 would be chosen for this as it’s just a tough o ring resistant to abrasion. The Leroy Brown of O rings. It’s unfortunate that the downside is the stick it gets against the rod, which is seen after a length gap between shots.



maybe another view into this is instead of a 2.84 ID o ring maybe the thickness of 2.62mm could’ve been less, enlarging the ID but not by much, to still create the seal but allow the rod to move more freely.



Tell me if I’m off base here on questioning where the seal against 110 to 160 bar plenum pressure would be. Maybe SEEKER can pop a drawing that shows in blue arrows the air flow or static pressure inside that plenum with the rod and both seals in view.



Tell you what, if this works, this mod should be named after SEEKER just like BSTALEY with his o ring mod on the marauder pistols