blast gate positioning

[Grahamshed]

I am fed up of dragging the extractor around so I am finally getting round to piping the workshop ( ok, the shed )

At its basic level there will be something like 26 feet of 63mm piping with outlets to 6 machines. I know I will need a blast gate on the outlet to each machine but should I also put one just past each machine to stop the suction having to work any further along the system than it needs to ?
It may help to know that the extractor will be placed off a t joint part way along the system with machines to both sides..... although I could perhaps avoid this if necessary.

 

[wallace]

I don't think it would be necessary assuming your blast gates seal without suction loss. but I would change the t-piece your planning and use a Y piece. I have 6" piping and used a t-piece to a different run, this has quite a dramatic effect on suction.

 

[PAC1]

If you have a thicknesser 63mm is likely to block regularly. I struggle with 115mm at times. Just a thought others might use 63mm without problem!

 

[Grahamshed]

I don't think it would be necessary assuming your blast gates seal without suction loss. but I would change the t-piece your planning and use a Y piece. I have 6" piping and used a t-piece to a different run, this has quite a dramatic effect on suction.

Well that cuts the number of blast gates I would need in half.
I was thinking about the vacuum position while I was writing the original post and I could move it to the corner of the room so I had one continuos run along the wall to those machines then up across the roof to a couple of others on that side.
I dont have a planner/thicknesser and no plans to get one so I think the standard 63mm for the camvac should be enough.

 

[Myfordman]

Aim for the gate flow to be vertical or if they must be horizontal, make the gate open downwards.
Always shut the gate with extractor running. Both these precautions prevent compressed dust jamming the mechanism leading to leakages.
Once compressed, the dust is b*****d to remove.
DAMHIKT

 

[Grahamshed]

I will bare that in mind

 

[Togalosh]

I learnt a lot from this site

http://www.billpentz.com/woodworking/cy ... ing_design

esp about blast gate positioning, NO Tees & small bore tubing/piping

 

[custard]

I've never had much luck with blast gates. Even good quality, large metal gates with the slide opening downwards seem to get clogged with sawdust. On my latest set up it's designed so that the blast gates are removable for cleaning every few months as I've given up on making them self cleaning.

 

[Grahamshed]

That is an impressive site Togalosh. Thank you for the link.

 

[Togalosh]

That is an impressive site Togalosh. Thank you for the link.

No probs

If only I could source those filters I'd have a go at making my own air filter.

I am going to rejig my setup this week (hopefully) & run tests esp on the blast gates.

 

[Togalosh]

Update

Going on what Bill Penz suggested I've rejigged my set up & it's increased the Mbar reading by 50% at the furthest port - even with leaking blast gates..(for some daft reason I did not do a before & after air speed test though).

Also I rejigged my RAS dust catcher set up & that too has been massively improved.

I found my plastic blast gates to be clogged up & the aluminium ones to leak a lot - even when brand new. I will not buy anymore but make my own in future.