Monolithic baffle stack

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Mtdew
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Post by Mtdew »

HotGuns wrote:
Is it even worth drilling the mouse holes or is it quiete enough without them ?
It would be a waste of volume if they were not drilled.
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Post by HotGuns »

If it adds no reduction in sound, then it would only add to the cost of production wiuthout any increased benefit. Its not all about volume anyway. Some of the smallest cans have the best sound reduction.
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Post by paco ramirez »

HotGuns wrote:If it adds no reduction in sound, then it would only add to the cost of production wiuthout any increased benefit. Its not all about volume anyway. Some of the smallest cans have the best sound reduction.
Why wouldn't it help sound reduction?
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wolf
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Post by wolf »

HE HE :twisted: You could make that out of a square stock and a square tube
you could even offset the bore to keep the can clear of the sights
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Baffled
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Post by Baffled »

Update: I sleeved the first chamber in steel for strength and to help keep erosion at bay. I used a very tight 1/8" roll pin so that the sleeve will not move and misalign its bore holes with the rest of the stack.

I drilled a series of mouse holes on one flank only for now, 3/16", oriented in such a way as to proceed from the peripheral cuts and from there, BARELY contacting the bore hole.

Before the mouse holes - A string of 5 shots with CCI blazer .22 ammo out of a 8" bbl produced a dB reading between 71 and 74 on my cheap radio shack meter, with the meter about a foot away from the can, on a perpendicular axis. I'll get a few more readings witht he mouse holes.

I'm happy with it. It's doing a good job, and will be super-easy to maintain.
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Post by GANADERO »

HELLO MATES this is my silencer but i need help me my silencer Not greatly reduces the sound :D :D :D :D

Image
By ganadero, shot with FinePix A350 at 2007-12-17

Image
By ganadero, shot with FinePix A350 at 2007-12-17

Image
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Post by GANADERO »

wat is yours opinion mates what is the problem :D :D :D

i have more picts mates
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Mtdew
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Post by Mtdew »

The web between your holes is too wide, you should of spaced them closer. you lost a lot of internal volume.

Honestly as I posted earlier, the design is basically a inefficient flat washer design. You need volume w/ a inefficient design.

whats the dia of the stack? it looks small.





edited for typo
Last edited by Mtdew on Mon Dec 17, 2007 6:32 pm, edited 1 time in total.
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Post by poizzin »

GANADERO wrote:shot with FinePix A350 at 2007-12-17
to help with your focus problem
Try turning on the macro - {the little flower symbol on the menu} for better close up picture. Or move the camera back and use zoom to get in close. that should help
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GANADERO
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Post by GANADERO »

hello friends one more time this is a pict whit a dimentions friends


Image :D :D :D :D :D :D :D
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Post by RoninDan »

That staggered stack is really nice!
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Post by HotGuns »

Honestly as I posted earlier, the design is basically a inefficient flat washer design. You need volume w/ a inefficient design.
Actually...its not even close.

Notice that the hole in the baffle is round,a washer is flat. Since sound expands more like a bubble, than a stream the round vs .flat works much better... but on a .22 even a flat washer design can work pretty well.

GANADERO..

Your center hole may be too big. As already stated, your design wastes too much space in between the baffles. Tighten up the distance and go with start with a .250 hole. If you have good alignement, it shouldnt be a problem. If things are a bit out of concentric, you'll have to go bigger.
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Mtdew
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Post by Mtdew »

HotGuns wrote:
Honestly as I posted earlier, the design is basically a inefficient flat washer design. You need volume w/ a inefficient design.
Actually...its not even close.

Notice that the hole in the baffle is round,a washer is flat. Since sound expands more like a bubble, than a stream the round vs .flat works much better... but on a .22 even a flat washer design can work pretty well.

.
Well i'll disagree w/ you

How many commercial can designs (current or in the past) have CONVERGING baffle walls? Like the front of each hole it this design.

IMHO this design is actually worse that a flat washer since there is less turbulence and flow disruption.
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Post by Baffled »

MtDew, my staggered stack is performing VERY well. I have heard flat washer designs, and this one is much better. My K-baffled CAC-22 is significantly louder, although to be fair, the volume difference is large.

I would have gone with a more conventional stack in a heartbeat, but this one gives me a huge advantage in the disassembly/cleaning department. My goal is large volumes of automatic .22LR fire. Because of the air gap between the stack and the tube, I can fire thousands of rounds without having the stack glue itself into a nasty, solid mass.
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Post by Conqueror »

Here's my design for a mono stack. Similar to Baffled's, but with larger coaxial chambers for increased volume. I also cut the "mouse holes" straight with a larger endmill, which leaves a sharp ledge in the round chamber which should "cut into" the swirling gas like the ledge on a coach's whistle, helping it flow quickly into the coaxial chambers.

Image

I wish I still had access to a machine shop, I would gladly Form 1 this stack to try it.
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Mtdew
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Post by Mtdew »

Baffled wrote:MtDew, my staggered stack is performing VERY well. I have heard flat washer designs, and this one is much better. My K-baffled CAC-22 is significantly louder, although to be fair, the volume difference is large.
Sorry I wasn't clear, i'm only talking about non staggered symmetric (all holes in the center line of the bore)

The staggered design has much more potential.
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Post by RoninDan »

There's one problem i could see with the extra ports and mouse holes.
Wouldn't they get filled with crap after some use and make it hard to get it out of it's tube?
Sleeving the whole unit would make sense..
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Post by Conqueror »

If I were using this type of stack in a can, I would not thread the stack itself. I would simply put it inside the can and hold it in place with the endcaps. Remove both endcaps and hammer the stack out with a wooden dowel or something. Should be easier than trying to screw out a gunky stack.
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Post by Baffled »

Update - more testing.

I added mouse holes along just one of the two possible sides of the stack. The diameter of the holes is 3/16"; where they merge in the bore is such that the mouse holes just touch the bore holes, forming a sort of "figure 8." This improved the can significantly. The original 5-shot string which averaged about 73 dB on my Radio Shack meter dropped to ~68. It is noticeably quieter too first round. The Radio Shack meter measurements are purely relative, meaning I use it to compare within my own system.

It is at a point now where I don't want to jerk around anymore except for finishing, which is going to be a manganese park. I still have not tested for accuracy yet. Unless the accuracy is absolutely gross, I am going to leave it alone because it is doing so well. It is a part of a bullet-hose system, not a varmint gun.

When it's done completely, I'll post some additional pics showing the mouse holes, and the whole can put together.

Conqueror - I LIKE that "coach's whistle" cut. The way you have them placed is perfect, I believe. The gas does a 180-degree bend and jetc out the cuts. Very nice, and I'll bet it'd work great.
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Post by Conqueror »

Seeing your photos helped with that idea, otherwise I wouldn't have been sure that the gas really would spin around in the chambers.
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Post by HotGuns »

IMHO this design is actually worse that a flat washer since there is less turbulence and flow disruption.
Then explain to me why mine works better than any comemrcial design that it has shot against. Since its worse than a flat washer design, why is quieter? Please elaborate and explain to me why I need to chunk it.
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wolf
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Post by wolf »

Conqueror wrote:Here's my design for a mono stack. Similar to Baffled's, but with larger coaxial chambers for increased volume. I also cut the "mouse holes" straight with a larger endmill, which leaves a sharp ledge in the round chamber which should "cut into" the swirling gas like the ledge on a coach's whistle, helping it flow quickly into the coaxial chambers.

Image

I wish I still had access to a machine shop, I would gladly Form 1 this stack to try it.
Hmm , it would be interessting to try it both ways ,,just to see in what order it wound work best
Theory is one thing ,to have done a test is a other thing

Wish a lathe for cristmas to make one :wink:
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Post by Baffled »

Further update: I had a chance to compare this can to another F1 can. This can was slightly larger, and had a very elaborate and complex Omega-style baffle stack which was executed very well. This new staggered monostack was distictly quieter. It wasn't even close. I don't say that to blow my own horn, because the concept is not mine. I have nothing to prove and no agenda. Guys, this stack works. I don't know how sensitive it is to variations in the mouse holes or to dimensions... hopefully, not much.

FWIW, this stack is 1.250" dia X 7.2" long. The holes are 3/4", spaced 0.750" along the X-axis, and offset from the centerline 0.156". The annular cuts were made with the same 3/4" end mill, plunging into the stock for a distance of 0.220" from first contact; OR +/- 0.781" right and left of the centerline.

I'd love to see another one executed to see if this is not a fluke.
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Post by mpallett »

Baffled wrote:Further update: I had a chance to compare this can to another F1 can. This can was slightly larger, and had a very elaborate and complex Omega-style baffle stack which was executed very well. This new staggered monostack was distictly quieter. It wasn't even close. I don't say that to blow my own horn, because the concept is not mine. I have nothing to prove and no agenda. Guys, this stack works. I don't know how sensitive it is to variations in the mouse holes or to dimensions... hopefully, not much.

FWIW, this stack is 1.250" dia X 7.2" long. The holes are 3/4", spaced 0.750" along the X-axis, and offset from the centerline 0.156". The annular cuts were made with the same 3/4" end mill, plunging into the stock for a distance of 0.220" from first contact; OR +/- 0.781" right and left of the centerline.

I'd love to see another one executed to see if this is not a fluke.
I'd like to see how it would work in a 1" x 5" tube.
Over weight Telco guy with a FFL/07 for hire :)
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Post by 3101 »

mmmm, Matthew, that seems like a question you already know the answer too.. 8)
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