Thread: Thoughts welcome on controlling dust...

Anyone had any experience with

https://www.gregmach.com/product/pro...ust-extractor/

It claims 1900cfm, 18" wg, and 355mm impeller..
From reading, that ought to be a better deal than the otherwise universal 300mm blower.

Slightly dearer, but not much, @620

No indication of filter size, but I'll have it outside the shed anyway.


Russ


Russ

Originally Posted by russ57

Anyone had any experience with
https://www.gregmach.com/product/pro...ust-extractor/
It claims 1900cfm, 18" wg, and 355mm impeller..

14" impeller is V good but seriously doubt the 18" and 1900 cfm claim.
At 50Hz those impellers can at best deliver about 10-12" of vacuum.
Notice the web pages says 1900 cfm without the bags!
Once 6" ducting is hooked up it will be even less.

From reading, that ought to be a better deal than the otherwise universal 300mm blower.

Definitely better.

Better still would be to check if the motor could be configured for 240V 3Phase operation.
Then you could drive it via a $200 VFD and spin the motor back up to its original 60Hz (north American) speed and this will give you 20% more air flow..
This assumes you are OK working with mains to hook up the VFD yourself -if not the added cost of a sparky could be $$$.

Slightly dearer, but not much, @620
No indication of filter size, but I'll have it outside the shed anyway.

Those nylon filters are not as good as needle felt but as you say locating it outside the shed so it doesn't matter.

My approach to dust collection is, I have two 3hp Jets. Both use plastic bags on the lower end, to collect dust. One has two canister filters on top and the other has two one micron bags. I also have a HF "2 horse" unit with a 1 micron bag. The little HF unit tends only my miter, since it's other main duty is, vacuuming the yard via a Super Dust Deputy [SDD] (I modified it and the SDD to make them easy to tote to the yard during pine cone chases).

The SDD ties to the canister filter unit and tends two lathes, an 8" jointer, the table saw, a planer and a router table. For the record, the canisters trump the bags for flow.

I used gasket foam like you use between a camper and the bed of your pickup around where the bags seal to the collectors, to get better seals around all the bags. Before I did, there were dust trails all around the collectors where the bags tied to them, but that problem went away with the foam installed.

I had used Y's and gates to control flow to different machines, but canned that idea when I saw the draw drop noticeably. Instead, I use permanent hoses from each machine and they are all suspended from the ceiling (at about the level of the SDD input), via simple pulleys. It takes me no more time to swap hose than it did to close one gate and open another, and I don't suffer the loss the Y's and gates caused.

For sanding, I have a sanding table, which I installed sides, back and top on, using some nylon I had laying about. I use it religiously. Because the table is forced to draw air only from the front, you can work at the front and watch the dust get pulled back into the unit. I even use it to router small projects from time to time.

For buffing, I scored an Air Handler off craiglist for one hundred dollars. It has a small squirrel cage, which pulls all the tossings from the buffing process down and through an 11 Merve filter. So, yes, squire cages have their uses.

Over my simple copper plating operation, I have a variable speed, in line fan unit, which exhaust directly outside.

My collectors keep the floor clean via 4" hose and wand. Thanks to the SDD, sunglasses may get bent a bit, buy are not rendered trash, and I no longer have to worry about what solid objects are doing to my impeller.

I plan on moving one of the big collectors out to the garage side of the shop and will have just the SDD inside. When I do, I'll raise it about four or five feet, so it doesn't have to pull off the top of the SDD from the ground level. I will also add a squire cage for those times I want to blow out the shop. I had that set up in the past, long before I had my first collector and it did a great job of vacating dust my electric leaf blower tossed into the air. The "garaged" unit will be in a large box so I can return the air to the shop, since our summers see many three digit days and our winters are cold enough I want heat and that kind of air movement would dent the efficiency of the HVAC.

Here is the nameplate off the motor of the Gregory machinery 3hp dc.

Does this look like it could be used with a vfd?

Pushing it a little harder to get more flow seems like a good idea.

Russell

Russ

Originally Posted by russ57

Here is the nameplate off the motor of the Gregory machinery 3hp dc.
Does this look like it could be used with a vfd?
Pushing it a little harder to get more flow seems like a good idea.

Can't tell from the info in the photo.
Next step is to open up ad take a photo of the motor connection box.

And there is the rub.
If I buy it, and can't use a vfd, then I have an expensive exercise to replace the motor with one I can use

Or do I just get the single phase and do the best I can?

Russ

Originally Posted by russ57

And there is the rub.
If I buy it, and can't use a vfd, then I have an expensive exercise to replace the motor with one I can use

Welcome to VFD Lottoland.

Or do I just get the single phase and do the best I can?

Yep - that's about all you can do.

So, I've ordered the single phase.
Landen from Gregory machinery was very helpful but couldn't find a shot of the motor wiring.

Next question, after it finally arrives..
It will be about 5m from the main dust sources. Plus some bends
It has a 200mm inlet. 200 ducting (spiral) is not eyewatering but the fittings are... Eg, $40/m for the duct, $125 for a 90deg bend...
So I wondered if hvac fittings would work? I'd be staggered if they fit perfectly, but a bit of tape should do the job.
Actually, they have solid ducts as well so maybe they should fit..

I'll run in 200 from the dc under the floor, then reduce to 150 and 100 as required.


A lot cheaper...



Russ

Originally Posted by russ57

It has a 200mm inlet. 200 ducting (spiral) is not eyewatering but the fittings are... Eg, $40/m for the duct,

Humm. . . . .That makes it 5x more than 6" PVC pipe, and ~2x the cost of 9" PVC.

$125 for a 90deg bend...

That's 4.6x the cost of a 9" 90º bend, and 11x more than a 6" 90º bend.

It's all eye-watering to me.

So I wondered if hvac fittings would work? I'd be staggered if they fit perfectly, but a bit of tape should do the job.
Actually, they have solid ducts as well so maybe they should fit..

HVAC are designed for low pressure and moderate volume and do not usually need to be aerodynamic and so may be extra turbulent when run under DC conditions..
To get around this you could go to 12" ducting but then the air speed will be so low the sawdust will fall out of suspension.

It's dead easy to make your own almost aerodynamic 90º elbow from some sheet metal or plastic and MDF.
When I find the link that shows how to I will post it here.
Mens Shed Dust Collection

I'll run in 200 from the dc under the floor, then reduce to 150 and 100 as required.

With only a 3HP DC I doubt it will move enough air to maintain a high enough air speed to keep the saw dust in suspension inside the 8" ducting.

Add to that stepping the 8" down to 6 and 4" means the air speed definitely won't be high enough high enough in the 8" duct.

Unless you have a need for more than one machine running at the same time, then the $ spent on a 8" trunking line is wasted and won't get you any more flow unless you take the 8" direct to a machine. Even then the 3HP is just not going to pull enough air.

The added complication with 8" is your will need 8" to 6" Y transitions. These will also be eye watering if you buy them because they will need to be custom made as the standard imperial metal ducting is not the same size as the PVC.

A hankie for the watery eyes because you aren't alone. In my search here in the Great White North the PVC 8" to 6" wye at one place was quoted to me at $360Can because they are custom made and I wanted 8! I'll be making rectangular.

Pete

Originally Posted by BobL

Humm. . . . .That makes it 5x more than 6" PVC pipe, and ~2x the cost of 9" PVC.


That's 4.6x the cost of a 9" 90º bend, and 11x more than a 6" 90º bend.

It's all eye-watering to me.


HVAC are designed for low pressure and moderate volume and do not usually need to be aerodynamic and so may be extra turbulent when run under DC conditions..
To get around this you could go to 12" ducting but then the air speed will be so low the sawdust will fall out of suspension.

It's dead easy to make your own almost aerodynamic 90º elbow from some sheet metal or plastic and MDF.
When I find the link that shows how to I will post it here.
Mens Shed Dust Collection


With only a 3HP DC I doubt it will move enough air to maintain a high enough air speed to keep the saw dust in suspension inside the 8" ducting.

Add to that stepping the 8" down to 6 and 4" means the air speed definitely won't be high enough high enough in the 8" duct.

Unless you have a need for more than one machine running at the same time, then the $ spent on a 8" trunking line is wasted and won't get you any more flow unless you take the 8" direct to a machine. Even then the 3HP is just not going to pull enough air.

The added complication with 8" is your will need 8" to 6" Y transitions. These will also be eye watering if you buy them because they will need to be custom made as the standard imperial metal ducting is not the same size as the PVC.

Thanks Bob, you just saved me a fortune, as well as a tricky installation.
I was thinking 8" for 2 reasons, because the dc has an 8" inlet, and because I thought that would make up for the long run, providing lower resistance for part of the run. But I think I follow that the reduction to 6" will reduce the overall air flow, and the speed in the larger diameter will be too slow to keep the dust, especially guess bigger stuff, in 'suspension'.
(The 8" hvac poly fittings are pretty cheap though)

Any recommendations from Victorians as to the best place for fittings and pipe? The online supplier in wa seems pretty good, and freight was around $55, but buying from Perth seems counter-intuitive.

Ps, I'm thinking the hvac 'boots' would make good collectors.



Russ

Ps, I'm thinking the hvac 'boots' would make good collectors.

A BMH is superior in terms of collection and air flow and costs next to nothing to make if you have a lathe and hot air gun.

So, my Christmas gift arrived today...
1 off 3hp dust collector...Gregory machinery were great to deal with.

I have projects lined up till next Christmas, but somehow I'll squeeze installation of this in..

Any good sources for 150mm pvc and fittings in Melbourne?

Russ

So, I think I have a clear day or 2 to install.
I had planned how to run the ducting under my shed from a cupboard outside.

As I was starting I realised I could save a couple of 90 bends, but I will need to make a bend of maybe 15 degrees instead.

Has anyone used something like this
https://www.pacificair.com.au/ductin...pandable-150mm

But I might be better off just using 150mm flex hose, because I can use that to connect to saws etc as well, I don't think the semi flexible would hold up..

Any suppliers in Melbourne? I think timbecon may have it but they are the other side of town.
Hafco don't seem to list it, nor leda.

Regards

Russ