Thread: Installing my Dusty - WIP

That tin shed will make a nice harmonious thrumming for the neighbours

Originally Posted by woodPixel

That tin shed will make a nice harmonious thrumming for the neighbours

Try putting some outdoor carpet under the DC and the Shed.

Shed is right next to a 10ft bessa block wall and on the other side is a loading bay and car park. Block at the back has two houses. House at the back near me is storage, owned by the shop owner next door and the front house furthest is rented by a guy that works in the shop and is out till late I'll decibel it and if noise is excessive, I can always line it with batts

Originally Posted by BobL

Try putting some outdoor carpet under the DC and the Shed.

There's closed cell insulation strip between the pine frame and the lower base. I'll put some old carpet under the wheels on the base of the dusty
Thanks.

Shed and frame now bolted down and dusty installed. Noise levels are not bad. I'll get a Decibel meter tomorrow and get some readings. In the meantime, I shot a video.

https://youtu.be/OvK7I0LEDcA

As I am running some tests, I made a 150 to 125mm adaptor,

IMG_0261.jpg

I want to be able to return the dusty to standard so I made a new front section for a 150mm outlet.

IMG_0262.jpg

I have a mate that does a lot of plastic vacuum forming and he had a problem with vacuum loss. Turned out is was leaking through the ply and mdf sheets. He coated with sanding sealer and it fixed the problem so my adaptor has had three coats front and back.

The minor problem is that with the dusty in the shed I cant get to the impellor to change hoses because the filter almost fills the doorway so the filter assembly is going onto its own base so it can be removed for work on the impellor. Should be done tomorrow.

I see you have rounded the rim of the ply hole over, but more important than this is rounding the inner edge of the 150 mm pipe as this edge will offer much more resistance than the ply itself.

Now that the 150 mm duct is fixed in place is the time to run a round over router bit around the duct and ply edge. 38 mm if you have it other wise the biggest you have up to that size

LAppa.jpg

Also those screws should be counter sunk.
I do this by taking a long, narrow shank. CS tek screw and forming a reverse CS head on it with a dremel.
Then poke the screw through the hole from the inside of the duct and attach to a drill and run the drill while pulling on the screw.
LAppa1.jpg

It should be possible to recess those screw heads completely.
I've probably even gone too far on this one.
LAppa2.jpg

Thanks Bob. Still need to seal the pipe to the wood before rounding over. I have a right angle drive so I can use a countersink bit. It's a work in progress.

Lappa, stupid question, but for the big ring, did you simply stack a number of plywoods to make up the collar?

It looks very neat.

Thanks.
The large ring is 6mm ply and the collar is just 1 piece of 17mm ply. I was thinking of 2 x 17mm sections but 1 seems strong enough as the pipe will be supported.

IMG_0263.jpg

Originally Posted by Lappa

Thanks.The large ring is 6mm ply and the collar is just 1 piece of 17mm ply. I was thinking of 2 x 17mm sections but 1 seems strong enough as the pipe will be supported.

The combo of 17 + 6 = 21 mm limits the shape/size of any BMH (R = 38mm_.

On the generic 2HP mod I used a piece of 32 mm melamine and a piece of sheet metal from a washing machine and turned the BMH with a lathe


Two pieces of 17 mm and 6 mm = 40 mm which is more than enough for a 6" BMH.

Why doesn't the 5" inlet on the dusty have a 1 1/4" radius? Why doesn't the 3 hp unit at the men's shed 6" inlet have a 1 1/2" radius? I'd be interested on those with commercial woodworking machines letting us know the radius of the large 8" outlets on the machines dust ports - are they 2"?
Seeing the middle unbladed section of the impellor is only 5", going to a 6" inlet with a 1 1/2" radius surely must create more pumping losses than say a 6" pipe with a 1/2" radius?
Just asking and wondering

Originally Posted by Lappa

Why doesn't the 5" inlet on the dusty have a 1 1/4" radius? Why doesn't the 3 hp unit at the men's shed 6" inlet have a 1 1/2" radius? I'd be interested on those with commercial woodworking machines letting us know the radius of the large 8" outlets on the machines dust ports - are they 2"?

Commercial dust extractors don't give a rats excrement hole about any of this.
They typically bung a 10HP unit and 20" impeller on the end of their systems and as long as it meets the required but "outdated" OHS dust standard ( based on UK and US timbers) their legal backside is covered.
The result of all this is probably why most machines still using 4" dust ports with 400 CFM air flow rates.

Using a radius of curvature of half the radius of the duct is the supposed theoretical and practically ideal shape.
In one of my posts I refer to the research that establishes this.
That reference also says that as far as shape goes, a longer more trumpet like shape is supposedly slightly better but is not always as practical.

As far as the actual radius of curvature goes I'm a big fan of going with what what is already available.
I'm also a big fan of something is better than noting so even a small round over is better than nothing.
However if one has to build something from scratch and has the wherewithal then one might as well build it right.

Seeing the middle unbladed section of the impellor is only 5", going to a 6" inlet with a 1 1/2" radius surely must create more pumping losses than say a 6" pipe with a 1/2" radius?
Just asking and wondering

Its a good question but it didn't happen when I measured the 2HP with the 32mm runs over with the impeller running under low resistance - that's why I recommend trying a full 38 mm round over.
Pumping loses are more likely to happen under high resistance when the fan is operating near its cavitation point, but hopefully that's not the point there DC operations will be taking place otherwise there will be very little flow anyway.

Modification to the dusty so I can separate the filter assembly from the impellor and motor unit. This was an essential mod. as I couldn't squeeze my fat a$&@ past the filter unit to fit/change impellor hose fittings when the dusty was in the shed.

IMG_0264.jpg IMG_0265.jpg

Power now in the dusty shed and dusty back in the shed. Took some decibel readings WITHOUT the collection bag. It sounds noisier than before so I'll do another set of readings when the bag is fitted.

1 metre from dusty shed with door open, directly in front of door - 85.9 dB
1 metre from dusty shed with door closed - directly in front of door - 76.5 dB
1/2 metre to side of dusty shed - 73.6 dB
Back fence - 62.5 dB
Side fence with neighbours - 60 dB
Background noise with dusty off at all four locations - 58 to 58.7 dB.