Need an engineer here

ok first off im glad you folks like the post !

i dont see any problems with posting how to’s on this forum, it might be based in US, but is read by people all over the world where mods are legal….all my knowledge was optained while in denmark…where it was legal at the time

ok enough disclaimer here…some PM’ed me if i would make a mods….no…no and NO i will do nothing of the sort…

small spring with something wrapped around…idea….heres my thoughts….

a LDC with some material in it is better than one without….as long as you keep the material down so it doesnt take all the volume.

closed cell foam is not ideal as it takes away alot of volume, a fluffy material like speeker whool, is to fluffy and will be pulled into the path of the pellet bu the rush of air.

Felt IMHO is too dense, but it will help. and probably best choise.
Fleece where you burn the hairs a bit will work if you use something like curlers to keep it from being sucked into the pellet path

In denmark you can buy some PC soundproofing material made by Noise Control (german company), its a 2 layer fleece….top layer is too fluffy allmost like fleece from a fleece jacket…but second layer is somewhere between jacket and felt ….and this is the best material to date i have found….this material is open, has an adhesive on the back….and soaks up sound really good…..but i havent been able to find it here in the states which doesnt matter as its not legal to make shroud or cans here !

3m scrubbing thingys might work…its pretty open, and intertwined, but im afraid it might be too open….i have never tried it my self !

open material takes less volume than a closed material ! more volume less sound !

you can use springs, curlers, tubes with holed drilled through the sides to keep material out of the pellet path…spring are the best as they offer little resistance to the air before it enters the material…curlers look good also…tubing is probably the worst…but drill it like a madman so theres plenty of holes will work….the bigger holes the more flow….but also bigger chance of the material being sucked through the hole….its amazing how material i wouldnt have thought could make it through holes, springs and make it into the path of the pellet….IT IS VERY IMPORTANT THE PELLET PATH IS CLEAR, IF SOMETHING TOUCHES THE PELLET IT MIGHT SEND IT OFF INTO THE BAFFLING OUT THE SIDE OF THE SHROUD MAKING IT A POTENTIAL DENAGER TO THE SHOOTER AND BYSTANDERS !

someone asked about why i would put 2 or more washers spaced by oring after each other….well….a single walled baffle works ok….2 walls strips more air creating more back pressure keeping more air in the mod…less sound, that is why is use a whole stack of them at the end of the mod…to keep air in.

the first chamber is experiencing alot of pressure, and i would leave that with no material so to have maximum volume while making sure nothing gets sucked into the pellet path…also if your have the bushing drilled…material might block these holes…and when you get a spring make sure it wont block the holes either.

concave washers…in my experience means little, but it does help…too much trouble…..ceiling washers and the like fine if you can keep them aligned with thier odd shape

a cheap shroud…..Home depot sells a broom handle extender….has a blue handle on it…and the tube is rippled…….cut it to length so it reaches all the way back to the barrel bushing….now put a layer of gaffa around the tube until it fits perfectly into the frame…..take the handle…and drill a .308 sized hole through it so the pellet has somewhere to fly out….get a washer that fits inside the tube…the tube tapers slightly….get a dowel and hammer that washer as far forward in the tube as it will go….presto…one shroud 2$ 30 min to buy and make

i will try see if i can find the resonance formula, so we can calculate the best spacing og washers

Thanks for the post Cygnus, you said more than I had the balls to say.

Great info guys………..I did it all wrong 😳

Adam………are you using a shroud from Tony or the method that was just explained??

How can you get rid of the hammer noise???

Posted: Tue Oct 30, 2007 1:24 pm Post subject:

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for a shroud it can be a bit more difficult to baffel it, as there is no bushing to push against unless you run a spring or tubing all the way back to the bushing….the first chamber should start approx 2″ in front of the muzzle….and not be sealed off to the back you want to ustilize all that volume surrounding the barrel all the way back to the bushing.

Posted: Tue Oct 30, 2007 1:24 pm Post subject:

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First what Cygsx has layed out is dead on, your going to have to get some odds and ends parts and just start playing around. The 3″ first chamber is good and effective. If a spring is used make sure it is wide almost 1″ or a 5/8″ wrapped with felt or scotch brite pad muffler if you will. The parts from there on is where you should experimewnt with. I use copper tubing as spacers or PVC 1″, 5/8″, 1/4″.

As of now i’m working on a shroud design using what CygsX suggests PVC schedule 40 or Plastic electrical tubing, black/gray, 3/4″ ID for a pressure fit adaptor and 1″ ID for the shroud. The 3/4″ has to be turned down to fit inside the TSS frame and the 1″ ID shroud. The 6″ shroud will also have to be turned down as well to match the frame. Less then $5 spent on the 10′ lengths. I’ll work out a bafle system over the winter, but this should give you an idea. I saw the pics of your shop, save your money and work the details out yourself as far as a baffle system is concerned. I just need to figure out how to get my 6″ shroud drilled to 1″ID and i’m set, the outside is easy, chuck it and sand it. http://www.onlinemetals will do as well. I will figure it out in plastic tubing then do one in ali, or maybe stick with plastic as its quieter and may be benefical to sound dampening. Although Adam says his is quiet, then its quiet.

materials of a LDC….well 3$ for tubing, 5 for plastic parts, 2 $ for spacers 10 bucks…and so what, most people dont have a clue what goes inside, or how to space everything out ! this is where knowledge comes in….and that you gotta pay for !

Bulls eye Bill., 50$….hmm tube less than 3$ endcap 2$,, but then comes painting, making the endcap, mounting the endcap….and so fourth

bulls eye bill shroud does help, the thing with a baffel thats needed between shroud and frame is not entirely correct !

i have seen and tried that shroud, and it takes the bark out of the SS, as well as the condor, is it effective …uhmm its way better than nothing….can it be better YES just mount some baffels in that shroud and it will get much better.

so you want to make a your AF rifle more quiet, well heres the recipe

go to lowes or homedepot, by some washers 1″ outer diameter(for talon SS), .25″ hole, its in a plastic box and comes in 50 or 100pcs…or what ever washers fits your shrouds ID

go to the plumbing department, buy some 1″ OD thick rubber orings about 10 will be fine(if filling shroud get oring that fit ID of shroud)

now we need something to space out the washers, this can be accomplished in two ways, springs or tubing

one thing to keep in mind is the more volume is lost to stuff inside the less effective the shroud is going to get…..tubing…home depost sells a broom handle exstention, thats allmost 1″ OD, its more than 3 feet long and costs 2$, this can easily be sawed into pieces of desired lenght to space the washers….just got to use cut the tubing straight (use a saw box if your like me and cant saw a straight cut)

at the isle where you can buy loose screws theres usually some springs too, different stores different springs…so see what they got they dont have to match 1″ od perfectly you need at least one even if your going to use tubing….the longer your shroud is the more springs you need …you need as many springs as the lenght of your shroud to where it meets the barrel bushing

springs may need to be cut (dremmel is easiest, but a hacksaw can do it too)….to square off the ends heat end till red hot, and press against a flat non flammable surface, the whole spring will become very hot so use some plyers where you can get a good grip…now press against the surface and you will see the metal bending easily and it will hold that shape, try and the the end as square as the facctory made end…doesnt need to 100% square…but the more square the better

what to do with all this stuff

im gonna be talking about the SS here…..take off the endcap, and look donw into the frame and the barrel……you want the first chamber to be the biggest so grab a 3″ spring and drop it in there, now drop a washer, the an oring, then washer, next take your tubing or another spring, this should be less than the first chanber i would say 2″ drop it in….then a washer, then oring, then washer….next chamber should be smaller then the two previous say 1″ so drop a piece of tubing or spring, and then washer, oring, washer…now depending on how much space you have left i would just fill the rest with washers spaced with orings…the frame should so full that when you mount your endcap it should depress the spring a bit so everything is under tention.

and your done…go test shoot it !

stuffing a shroud is done in reverse compared to filling the SS with washers…as the SS is filled from the front and the shroud is filled from the back.

but it is same principle as filling the SS,

for a shroud it can be a bit more difficult to baffel it, as there is no bushing to push against unless you run a spring or tubing all the way back to the bushing….the first chamber should start approx 2″ in front of the muzzle….and not be sealed off to the back you want to ustilize all that volume surrounding the barrel all the way back to the bushing.

the hard part is to get the first washer about 2″ in front of the muzzle, spring or long piece of tubing back to the barrel bushing can do this, or you can try find a plug that fits inside the tube, to which you can mount a screw from the outside to keep it in place.

to make a plug theres several ways to do that….go shop in lowes/home depot see if the got something that can be used….i have seen plastic spacers for various things…that might be suitable…if the outer diameter is to large then mount it in drill and use sandpaper to “turn” the outside diameter down. the hole in the bushing should be large enough for pellet to pass, but small enough that your spring wont fit through it

wood can also be used…get one of those hole cutting drills that makes wooden “coins” and see if that fits…roundstock that fits can also be used…if they are a tad too small some electrical tape can take care of that, just wrap it tightly around

the assemble you stack of washer/oring/springs…and fit the bushing…remember to measure that its approx 2″ in front of the muzzle when everything comes together

how many chambers….rooms, baffels…should there be (not counting space between washers kept appart with orings)..i would say 3 chambers should do it, the size of the chambers should such as none of them have the same resonance as the other(look up speaker building equations)

you can experiment with wrapping the spring in felt/fleece, skubbing spronges…it works much like curtains in a house…imagine an empty house lots of echo….with drapes and carpet the echo disapears and noises are muffled somewhat….same thing in a LDC

Your right Adam. Even if your time is worth nothing, the machinery and tooling is big bucks,not to mention the ($$$) materials waisted screwing up while you learn. Of course accomplished machinist wouldn’t need to buy. Like you said,it can be done with basic tools,and materials. It may not look as pretty,but it will work.

Also try to rememebr that you aren’t necessarily paying for the materials, as much as you are paying for the experience and knowledge of the person performing the work! People think I charge a lot for an air conditioning service call when I charge $50 an hour, plus a $50 “ding dong” service call. BUT if you think of the schooling, training and >15 years of experience I have, and can fix any electrical/mechanical problem within an hour…that is not bad.
If you can’t do something, or don’t have the tools and knowledge to perform the task at hand, then paying someone who knows what to do and how to do it, (and would take 1/10 the time it would for you to waste $$$ and time and still not get it right) is the way to go.