Hey,Guys. Needed a muffler for the new dust collector installation, but it had to be a certain length - so I made one. Here's some pictures.
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Hey,Guys. Needed a muffler for the new dust collector installation, but it had to be a certain length - so I made one. Here's some pictures.
Where is the piece that directs the air/gas into the packing material and slows the it down to create a muffled effect, all I see here is a straight pipe type muffler which is not that effective, do you plan on using a piece in the middle of the muffler to redirect the air flow to the outside in to the packing material..
Hey, Geezer. There is no piece (initially anyway) most of these types of mufflers are open flow-through just like a glass pack muffler for autos. Much of the sound pressure wave is diffused by being exposed to the "softer" environment, much like a room filled with draperies versus a bare one. The difference in sound level is dramatic, at least with the store bought ones and they are so much smaller than this one. The last one that I saw this size (this one is 7" diameter) was on a 15hp bagged dust collector and this one is only 2hp. Even at this stage I use the airgun to blow air straight through and the sound difference between in and out is appreciable.Quote:
Originally Posted by geezer
The Borla muffler I used on my car is similar with the straight through effect. Well mine does have a curve in it, I can see through it and its still far quieter than not having it. My resonators are also this design.
It's a resonator. Rather than a muffler in the classic term. Although some would argue that a resonator is one type of muffler, I disagree. The expanding gas should flow through the "soft material" slowing it down, hitting the outside wall and reflect back into the incoming wave. This theoretically should cancel out the waves and quiet down the sound. The materials and distances are carefully calculated for the particular application and are not picked at random from the air, as I had once thought. If there is a phase mismatch between the reflected and incoming waves you get some odd affects acoustically. Like a drone at certain RPMs where there's mismatch.
Actually the resonator is tuned for a certain frequency and very inefficient at most others that are out of it's range. Some cars like my volvo use 2 resonators to cover a portion of the low and high RPM bands. So to cut those out of a 6 cylinder turbo and maybe replace it with an aftermarket one will make the note loud and very annoying. But if loud and annoying is what you're going for, then go ahead. I've learned my lesson already. :mad:
Almost every motorcycle muffler is made that way. They work fine, except for one or two specific rpm's that give you a drone. If you really want to quite it down you can put a baffle in the end. Basically weld on an end cap with a piece of tubing sticking about half way down into the muffler. Once the air gets to the end of the muffler, the end cap will force it to go back down into the standpipe to exit and increase the noise reduction properties of the muffler. Only downside is that it increases backpressure, but if its sized large enough that shouldn't be a problem.
Yeah and to my dismay a lot of the cruiser crowd like them like that. Seems the superbike crowd is getting there too. The louder and more abnoxious the pipes the more money they'll pay for it. I have 2 CX500, one of which has a supertrap with 3 baffles in it. The other one has HD Sportster cans I got for free when my neighbour "upgraded". lol Well as much as I hate hearing him come home at 1 AM, l love the quiet rumble of those stock HD cans on the vintage Honda.
But back to exhaust talk! Theory has it that the most important variable when trying to tune the exhaust is the mean peak efficiency of the expanding gas that's exiting the cylinders. This is the measure of the amount of work / power the gases can exert and is measured by temperature drops of the gases. Lets say you have a perfectly insulated and uniform vessel where the exhaust pulse temp can be maintained. That pulse will have roughly the same amount of velocity exiting as it did entering the vessel. Controlling the temperature and volume of the gas is the function of an exhaust system. Baffles create turbulance and disperse the waves allowing more surface area to cool the gases therefore slowing it down and altering it's frequency. That's why you see a lot of tuners wrapping their headers in order to concerve exhaust velocity when trying to maximise the scavenging affect on oversized pipes.
Anyways, sorry for the book. Nice resonator!
Thanks again for the good words, guys. Interesting technical talk about mufflers and resonators, just shows the depth of knowledge we've all come to embrace, make a living from, and share. I didn't get quite so deep in the design of this . . . we'll call it a, "sound attenuation device," I simply made it as large as I could considering the space that I have to shoehorn it into. Finally got it into position and a run-up of the collector revealed that you could stand beside the machine and still have a normal conversation. I'm happy with the results. You can almost hear the difference it make as the collector comes up to speed, which is the only time there is any variable in the rpm and building of the sound. And I still have the business end open with no ductwork in place yet (yes, it's pulling max amps) so most of the noise we're hearing is inrush. I'll post a few more pictures when the system is substantially complete. I'm making my own ductwork - and it will be square in cross section rather than round. I can't wait to read all the comments that will bring.
All the best, Don
All the best, Don
I wonder if the relatively steady airflow makes the 'sound attenuation device' design parameters more forgiving. Either way, glad to hear it works well.
A dust collection system is on my to-do list, so I'd love to see some pics when you get them.
I'll get some pictures up when get it all online - painting the initial branch of ductwork today. Welded it all together with my new 250EX, except for a few hit here and there with the mig. I simply "fused" the edges together with the tig.Quote:
Originally Posted by redbeard
Hey, Guys - here are a few pictures of fabricated parts for the dust collector system and routing hood -
All the best, DonAttachment 9177Attachment 9178Attachment 9179Attachment 9180Attachment 9181Attachment 9182
That looks extremely nice.Quote:
Originally Posted by dawjr32223