GTA

Air gun Entertainment and reviews => Hajimoto Productions => Topic started by: Hajimoto on January 16, 2021, 06:27:47 AM

Title: Hatsan QE Stak Pak
Post by: Hajimoto on January 16, 2021, 06:27:47 AM



I own six (6) different Hatsan QE PCP's and never really thought about designing and producing an HP Stak Pak for them until now. My friend Duvalier in Puerto Rico, said "You really should design for this..." and I was like, "Yeah, why haven't I??"

Well introducing my 10 piece HP Stak Pak for all Hatsan QE PCP's. all the QE's have the same sized expansion chamber at the end of the shroud so this Pak fits them all.
(https://i.imgur.com/Hnz8sG9.png)
There are no modifications required as the shroud is already ventilated from the factory. You simply unscrew the end cap, remove the two felt-covered assemblies, remove the two aluminum standoffs and you're ready to go.


You insert my tension spring and then insert the baffles in the order I show. The different sized chambers in different locations in the stack break up patterns and forces the air to chamber and strip better. The differing chamber sizes help disrupt any harmonics that are created by a balanced flow so by the time the projectile reaches atmosphere, it is pushed by a much more laminar air stream.
The baffle chamber gobbles up the sound and makes the Hatsan QE much quieter.
If you have a Hatsan QE PCP, you won't regret snagging a set.


(https://i.imgur.com/3ybDwng.jpg) (https://hajimotoproductions.com/index.php/product/hatsan-qe-baffle-bundle/)


https://hajimotoproductions.com/index.php/product/hatsan-qe-baffle-bundle/
Title: Re: Hatsan QE Stak Pak
Post by: DrillDog on January 27, 2021, 08:58:03 PM
Do you have a video showing the db sound with factory ones first, and then with these ones?
That will help, because there is no point to get it without first see what is the report's change.
Thank you.
Title: Re: Hatsan QE Stak Pak
Post by: Hajimoto on January 29, 2021, 03:50:09 AM
Do you have a video showing the db sound with factory ones first, and then with these ones?
That will help, because there is no point to get it without first see what is the report's change.
Thank you.


No, I do not have a video that presents that. Because the sound change is more than just dB change and involved tonal changes, it is almost impossible for video capture devices to properly capture the changes. I have made several videos where dB changes were captured using smartphone applications or stand-alone sound meters but the results are only for reference as the testing equipment or app is not a calibrated instrument.


I typically rely on users to share their impressions and or experiences.
Title: Re: Hatsan QE Stak Pak
Post by: DrillDog on January 30, 2021, 07:21:24 PM
So you developed a product for specific rifle, and are selling it without first having any concrete data results to show?
Thanks anyway for your response.
Title: Re: Hatsan QE Stak Pak
Post by: Hajimoto on January 31, 2021, 08:00:24 AM
So you developed a product for specific rifle, and are selling it without first having any concrete data results to show?
Thanks anyway for your response.
I never said that I didn't develop the product and test it to be sure it offered some level of improvement. You also are fixed on only one aspect of the air stream management. I have always published that sound mitigation is only one of the benefits of proper air stream conditioning, you are obviously not aware of or pursuing those aspects so thanks anyway for your interest. 
Title: Re: Hatsan QE Stak Pak
Post by: huntr on February 08, 2021, 05:04:44 PM
I installed the QE Stak Pak on my Hatsan Flash today. I shot two different pellets. One that chronographs @ 1013 fps and the other is too fast to register on my FX wireless chrony, so 1099+ fps, and almost certainly supersonic from the crack. I'm sure it is exaggerated in my basement, but it does crack.

According to the dB Meter Pro app on my phone, the actual decibels were not reduced in my basement shooting area. However, the apparent sound when shooting the 1013 fps pellet outdoors was noticeably changed/ reduced. Previously it had enough of a 'pop' to it to make me uncomfortable ( neighbor-wise ) shooting in my backyard. Velocity was hanging in the same range, after installation, for a short 5 shot string.

I have no report on the effect to accuracy. My indoor range is only seven yards.

I did not shoot the fast pellet outdoors, in broad daylight, because I didn't trust it to not still have the audible crack and alert the neighbors. I'll try one or two around sundown when most people will be indoors.
Title: Re: Hatsan QE Stak Pak
Post by: DrillDog on February 08, 2021, 06:15:05 PM
I installed the QE Stak Pak on my Hatsan Flash today. I shot two different pellets. One that chronographs @ 1013 fps and the other is too fast to register on my FX wireless chrony, so 1099+ fps, and almost certainly supersonic from the crack. I'm sure it is exaggerated in my basement, but it does crack.

According to the dB Meter Pro app on my phone, the actual decibels were not reduced in my basement shooting area. However, the apparent sound when shooting the 1013 fps pellet outdoors was noticeably changed/ reduced. Previously it had enough of a 'pop' to it to make me uncomfortable ( neighbor-wise ) shooting in my backyard. Velocity was hanging in the same range, after installation, for a short 5 shot string.

I have no report on the effect to accuracy. My indoor range is only seven yards.

I did not shoot the fast pellet outdoors, in broad daylight, because I didn't trust it to not still have the audible crack and alert the neighbors. I'll try one or two around sundown when most people will be indoors.
Good to know, thank you!
Title: Re: Hatsan QE Stak Pak
Post by: Cableaddict on March 30, 2021, 03:42:52 AM

...... the sound change is more than just dB change and involved tonal changes, it is almost impossible for video capture devices to properly capture the changes. I have made several videos where dB changes were captured using smartphone applications or stand-alone sound meters but the results are only for reference as the testing equipment or app is not a calibrated instrument.

I typically rely on users to share their impressions and or experiences.

I can sort of confirm this, from my use with a different aftermarket QE baffle.  Mine is a ten-stage off Ebay, but the cones run the full length of the wide shroud area, and it does not have the spring that Haji provides.  Haji's idea seems superior, since it lets the shroud still send air back towards the rear vent hole.

-----------------

Anyway,  the baffles I have definitely lower the volume compared to the factory QE.  What is much more interesting & surprising is how they compare to a DonnyFl Shogun I recently purchased.  Being 1.6" x 8", I expected the Shogun to be incredibly silent.  It isn't.  While I don't hear any air-pop, I hear a very loud, bright ping from my hammer. I assume the entire barrel is resonating.   It's enough that I'm worried about the neighbors.

I put the QE system back on, and while I could once again hear just a tiny poof of air, the overall sound was both quieter, and a MUCH lower pitch.  I dunno if it's the baffles causing this, or it's the full shroud muting the sound of the barrel resonance. Or maybe it's because some air is directed backwards, inside the shroud, which an aftermarket moderator cannot do.


More testing needed,  but overall I believe factory shrouds are the way to go.  They just need to be designed better, or modded with offering like this one from Haji.
An added plus is that here in NY State,  hunting with a factory shroud is "probably" legal, whereas using an aftermarket unit is most definitely not.
Title: Re: Hatsan QE Stak Pak
Post by: Smbob on January 29, 2022, 11:41:37 PM
Good to know Hajimoto offers this! I have a Flashpup 25 and will be upgrading it soon with this.
I upgraded my Gauntlet 25 with his baffle stack and it made my Gauntlet much quieter and increased the accuracy too.