Fletty's new shed WIP ....or is it a retrospective??

[BobL]

To return to fletty's drum sander and it's dust collection ...

my suggestion

This is somewhat akin to sucking up a milkshake trough a large straw with the end partially blocked.
The gaps around the drum are just too constrictive and short of rebuilding the whole of the upper part of the sander not very much air will flow though those gaps.
It is still worth collecting some air from the top pipe but the lack of flow means more fine dust will escape from the gaps at the sides.

[fletty]

To return to fletty's drum sander and it's dust collection ...

my suggestion

Thanks Ian,
Ive been experimenting with 2 pack epoxy putties to to create the bell mouths and fairleads needed for an arrangement like the one you have suggested. I will probably make 2 new covers using the base of the existing cover, and 2 replaceable top decks. One top deck will have 2 X 100 mm outlets connected via 2 flexes to a single 150mm duct and the other will have a single 150mm rigid duct grafted directly onto the current base. As this 150 mm duct is wider than the base lm going to use the outer sections to draw air from outside of the housing and the centre, much larger, portion to draw air through the current base. The first can also be used to trial BobL's venturi and canopy suggestion.
Im also getting more and more entranced with the opportunities provided by 3D printing and IF I get my act together, it would be more than just feasible to 'print' and sell replacement drum covers for all of the drum sanders on the market.
It's an exciting World out there!

fletty

[DaveTTC]

This is somewhat akin to sucking up a milkshake trough a large straw with the end partially blocked.
The gaps around the drum are just too constrictive and short of rebuilding the whole of the upper part of the sander not very much air will flow though those gaps.
It is still worth collecting some air from the top pipe but the lack of flow means more fine dust will escape from the gaps at the sides.

I've been struggling to keep up with all my subscribed threads of late. Not sure if you made a sketch recommendation. If not what would or how would you recommend this be done. If you have already said what post do i need to go back to

Meanwhile I'll try and do some catch up

Ok just found it

Dave TTC
Turning Wood Into Art

[ian]

This is somewhat akin to sucking up a milkshake trough a large straw with the end partially blocked.
The gaps around the drum are just too constrictive and short of rebuilding the whole of the upper part of the sander not very much air will flow though those gaps.
It is still worth collecting some air from the top pipe but the lack of flow means more fine dust will escape from the gaps at the sides.

unfortunately, it is what it is.

in these sorts of drum sander, the drum is only supported at one end, the drum frame is a casting and if anything my diagram shows more space between the drum and the housing than exists in practice. I suspect that most of the make-up air enters from the ends of the drum either side of the work piece.

I know that all the ledges inside my sander are caked in fine dust.

[Sawdust Maker]

what if you had 2 x 4" ports on the housing

[wheelinround]

Alan Darrell's said his set up is similar to using a fitting like a room AC ducting like this. http://i00.i.aliimg.com/photo/v31/786360790/_font_b_portable_b_font_font.jpg
PORTABLE AIR CONDITIONER WITH FLEX DUCTS - AIR CONDITIONER

[BobL]

what if you had 2 x 4" ports on the housing

I sort of discuss this in post #121.

Irrespective of what is done using the existing housing these machines spill a lot of dust out of their sides so unless some air flow and hence dust capture is directed outside the housing it won't be captured.

Alan Darrell's said his set up is similar to using a fitting like a room AC ducting like this. http://i00.i.aliimg.com/photo/v31/786360790/_font_b_portable_b_font_font.jpg
PORTABLE AIR CONDITIONER WITH FLEX DUCTS - AIR CONDITIONER

A bell mouth hood would provide more air flow than this.

[BobL]

Check out these hoods used by the Corrimal Men's Shed
see Corrimal Community Men's Shed Cyclone Dust Collection System - Automatic Cyclone DC System


Some improvements could be made to these hoods but I won't go into these here.

[FenceFurniture]

How would a couple of fans go at pushing the dust back towards the housing for capture? Wouldn't get all of it, but may help?

[Chris Parks]

I would cut the side out of a length of 150mm pipe and cut the top out of the shroud and glue the two together and extract from the end of the pipe.

[BobL]

How would a couple of fans go at pushing the dust back towards the housing for capture? Wouldn't get all of it, but may help?

Unfortunately pushing dust whit a fan in anything other than ducting is like hearing cats and will just end up spreading it all over a shed.

There is a place for highly directional push such as from a compressed air nozzle but that's also best done with an existing directional air flow like within a hood.

[fletty]

Alan Darrell's said his set up is similar to using a fitting like a room AC ducting like this. http://i00.i.aliimg.com/photo/v31/786360790/_font_b_portable_b_font_font.jpg
PORTABLE AIR CONDITIONER WITH FLEX DUCTS - AIR CONDITIONER

I must admit that I was coveting one of these at my daughter's the other night BUT, when my nearly 3 year old grandson told me that the aircon was the only thing stopping him from "expiring", I felt pretty guilty!

fletty

[Pac man]

So apart from all this sub micron dust business what's going on?

[NCArcher]

There seems to be a sub micron amount of re-organisation.
Fletty have another G&T and get back to work. (I'll have a G&T with you on the 13th. I'm quite partial to a G&T.)
Do you have a heat gun? I think I have one sitting here if you need it.

[fletty]

There seems to be a sub micron amount of re-organisation.
Fletty have another G&T and get back to work. (I'll have a G&T with you on the 13th. I'm quite partial to a G&T.)
Do you have a heat gun? I think I have one sitting here if you need it.

You HEAT your G&Ts !

fletty