muffler for a test stand?
 

If I rem. correctly about 7 or so years ago I saw an article in Model airplan news about how to make a test stand muffler/catch can out of a paint can, some cat littler and tubing??

Does anyone have any info on how to do this?
or what to use or some diagrams?
Will it affect the engines running any?

I have some old engines I want to fire up and see how they are doing, but the new neighborhood I'm in, if I were to do this in my garage..... Well they wouldn't "appreciate" it :D
Thanks!

Don't Recall
 

Is it possible to get to your local field before flying time and run the engines? That may be more practical. We can't fly before 9am for instance. I've gone there at 8 and done test running at times. Just a thought_bob

muffler for a test stand?
 

well, there engines that aren't mounted to any planes yet?
Besides it wouldn't be feasible/economical to do that for me...

I'd like to get it to where I can run up/test/break in engines at my house...

Test Stand
 

I do my running on a test stand mounted to 1/2 of a pallet. I bring it to the field when running in a new engine. It has to be before flying hours as we have a rule about breaking in at the field. I'll look around for what you're after_bob

muffler for a test stand?
 

Cool thanks!
I can't at the field because were close to a church, and we have an agreement with them that only at certain times can we do stuff...
Gotta keep the peace you know! :D

muffler for a test stand?
 

ok... some advice on how to "fake" it.

get some silicon tubing (the kind that is heat proof" about 12" long this is to allow the exhost to cool a bit before dumping it into the "silencer"

next take a metal tube I would say about 1/2" diameter about the length of a coffee can and drill 1/8-1/4 holes in it .. this is to disperse the exhast into the "chamber"

take a coffee can and mount the tube in the center with epoxy/jb weld/whatever so that its in the center. with the "intake" on the open end. cut the plastic cover to fit over the open end and punch 1/4" holes in it for exhast.

now we need to fill it with something to "break up" the sound waves.

cotton is good but will get saturated quick and need to be replaced...

Rocks (about 1/2" - 2" in daimeter should work.

play around with stuff and see what works best.

I made a (bad) quick scetch of what im talking about.

this should work but i make no promises :)

muffler for a test stand?
 

what about kitty litter? its absorbent but cheap

muffler for a test stand?
 

thats along the lines of what I was thinking off....
but let me ask you this, is that enough space for the gases to slow down/expand?

What if I were to put the tube going into a smaller can, drill holes around the exterior of the smaller can, put the smaller can inside the larger coffe can with the holed in the lid, and then fill in between the small can and coffe can with absorbent material?
think this would work better at sound dampening and not affect performance and not soak so much material?
:confused:

muffler for a test stand?
 

like i said... I'm just faking it (with my experiance with making "suppressors" for paintball markers)

try the smaller can idea... having more than one chamber should be a good idea. also maybe run a small tube out of the bottom of the inner can to a collection tank for the oil.

as for kitty litter.. you dont really want it to absorb the oil... cause that will decrease the dampening... maybe some in the inner can to prevent it from getting out to the outer can... then you can use some packed cotton.


as for restricting the flow as long as you provide enough hols and dont pack too much material into the cans it shouldnt be any more than the muffler does anyway.

another though... if you get it going good enough you can run a long tube outside and do your breakin inside. would be great for the winter.

I have a os.40 that needs to be broken in... I will try a few things and see what i come up with.

let us know how yours does.

muffler for a test stand?
 

i'm gonna go to lowes tomorrow to see what I can come up with.....
I was gonna run it inside anyway?¿
just leave the garage door open.....

off topic,
you make suppressors for paintball markers? I havea tippman 98 custom, with stock barell any suggestions....
pm me if you don't want to talk about it in the forums!
Thanks

muffler for a test stand?
 

half on/ half off topic.

i made a few .. they are not exactly legal to make and use in the us in certain places due to the.... interesting gun laws we have.

but the concept is the same.

the goal is to suppress the sound from a high velocity rush of air, or a "pop".

a paintball marker is one pop at a time... a glow fuel engine is many in a row.

to do this we need to provide a area to allow the expansion of the gasses but slow it so that it mixes with the outside air at a low velocity. eliminting the pop.

the can is the chamber in question and the fill (kitty litter/ rocks/ cotton etc) breaks the "wave" up and slows it down.

the other option is to give it multiple chambers to expand into (this is the theory behind the baffle in mufflers and why it gets louder when you remove it) this is also what suppressors on true firearms use, but many baffles and many chambers (having fired several suppress pistols and sub machine guns at a demonstration I can tell you that this does work rather well :D )

by having the 2 cans and the filler we are combining the two options and it should work well.


now off topic: suppressors on paintball markers are really not worth it. for your 98 I would get a better barrel which will make the gun perform better and quiet it down a bit, the 32 degrees "night stick" is my favorite and i have it on my Autococker and my Tippmann Pro-carb. and they dont cost a fortune to get.

muffler for a test stand?
 

Do your neighbors mow their lawns, run leaf blowers, let their dogs bark all hours of the day, saw wood for their new fence?

Fire them babies up. (Might be you'll spark some interest in the hobby rather than piss someone off :D ) It's not likely to be a daily thing. You might ask if there's a particular time of day to avoid (like for shift workers).

muffler for a test stand?
 

well its mainly just two neighbors....
The one I live next to and the one 3 houses down (head of our subdivision) And there both really good friends......
So far they have complained about my cars exhaust, my surround sound system, my old KX125 dirtbike when I was tuning the carbs, just about everything you can think of.........

What happens is they dislike something, they complain to everyone around us, then everyone around us talks about it, and then the rents hear about what everyone is talking about, and then is more hell for me...

When it snowed last year, I would be coming home at like 3-4 in the morn from work, and I would do nice little power slides up our hill counter steering the entire way up it (this was before my exhaust and my car was actually quiet) and we even got a complaint about that, What if I were to hit someone??
NO ONE WAS EVEN AROUND! so to keep the peace I'm being nice. :D

Keep in mind
 

With virtually any type of after muffler system no matter how carefully engineerd is going to alter an engines run characteristics and in most cases will increase combustion temps so you may want to keep that in mind and you won,t be able to expect that it run the same on an airplane as those kind of rigs.

John

Dampening Material
 

Hi All - Just for what it's worth. Instead of the kitty litter or cotton, try using semi loose steel wool. You can buy it by the bag cheap, it will form around just about anything, and with the oil clinging to it, it won't rust.

When it get's to soaked, replace it or clean it up in some solvent.

My 2 cents worth :D

Hope it works, I might try the two can baffle myself. Sounds like we live in the same neighborhood :p