[Mr.Chips]

I have seen a few Skirts in my day but this one is a little different.

It isn't mounted to the router but to the Z Axis fixed base. You would adjust the height for the right interference to the top of the work. And it would remain at the same height all the time. The skirt wouldn't collapse and make gaps as the router moved lower. This would be most useful on flat surface work.

What do you think?

Hager
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Thanks everyone for your comments, I have added them into this original posting.

PROS:
* Not in the way when changing tools.
* A better seal because it maintains the same optimum height no matter how deep you are cutting, which can cause gapping.
* Easy on and off

CONS:
* Material hold down clamps higher than the bristle area would have to be avoided.

[dertsap]

thats a pretty good idea ! i can see benefits to that type of setup , changing the tool being one

[wcarrothers1]

That is a good idea. Since my gantry Z is setup oposit I don't have anything solid till back up on the Y. But lots a people have their Z like the picture making this possiable. I'd say it could be an improvement long as you don't reqire the skirt to move in order to avoide stuff like clamps around the work or something like that (which could be avoided while riding with the router).

b.

[martinw]

I have seen a few Skirts in my day but this one is a little different.

It isn't mounted to the router but to the Z Axis fixed base. You would adjust the height for the right interference to the top of the work. And it would remain at the same height all the time. The skirt wouldn't collapse and make gaps as the router moved lower. This would be most useful on flat surface work.

What do you think?

Hager

Dear Hager,

I think this is an excellent idea. If you consider how hand-held router dust extraction works, the tool moves into the work-piece through a "collar" that is at a fixed height compared to the top surface of the surface that has to be cut. The collar extracts the dust very well.

However, if you want to do "stuff" that makes the top surface of the work-piece somewhat less than flat, we have problems.

My guess is that you are correct. It will usually be the case that the wonky surface of the work-piece will always be better sealed, as regards dust, by a fixed shroud rather than a mobile one on the Z axis. After all, the Z axis will always be moving vertically greater distances than the profiles of the workpiece , and that suggests that a shroud that is not driven from the Z axis will work better.

Just a thought, errh, probably badly expressed...

Best wishes,
Martin

[martinw]

Sorry, quick correction..

By "fixed", I mean a shroud that could be adjusted vertically for each job, as originally suggested.

Thanks for your patience,

Best wishes,
Martin

[dertsap]

the more i think about it , i like the idea of having something like that because it can be setup to pop it on pop it off which is simple and i like to keep things simple and convenient .
when i'm cutting wood and especially mdf it would be nice to have the dust extraction but i haven t added one because it would be in the way when im cutting aluminum , something like that is perfect

[martinw]

Somebody on the Zone came up with the idea of fixing dust shrouds with magnets.

Easy to fix, and easy to remove. Brilliant. Do a search.

Best wishes,
Martin

[Mr.Chips]

Thanks everyone for your comments, I have added them into the original posting above.

PROS:
* Not in the way when changing tools.
* A better seal because it maintains the same optimum height no matter how deep you are cutting, which can cause gapping.
* Easy on and off

CONS:
* Material hold down clamps higher than the bristle area would have to be avoided.

[Mr.Chips]

I went to the dollar store today looking for a broom, brush, or what ever to use the bristles, and I thought about a vacuum cleaner upholstery brush. See photo below.

Simply cut off the top portion and glue it into a box. The circular brush would surround the bit and focus the suction. Drawing below, but not to scale.

I know most of the Dust Skirts I have seen have had the Skirt part as large as the shoe, but is this necessary?

Any comments on this type Dust Shoe/Skirt?

[BobF]

I bought a router mount bracket from K2. It has a 1/2" hole drilled vertically through a corner of the bracket. The purpose is to mount the dust shield. The shield is attached to a 1/2" rod that slips up through the hole and there is a set screw to hold it in place. This is easy to remove and easy to set the height of the shield. You may want to adapt that idea.

[Mr.Chips]

Let me rephrase the question.

How well do you think a 2" diameter Dust Skirt would work?

Has anyone tried one this small?

Thanks
Hager

[Buzz9075]

One thing to keep in mind if you are using a smaller dust collect it is not like a vacuum. This is what I have been told by the local store where I got my dust collector, if you reduce the size of the vacuum hose you reduce the suction capability, so what I have been doing with all my designs is ensure at no point does the cross section of the air path go below the size of the cross section of my 4" vacuum hose. So when you design your head if you using a dust colletor you want to try and keep the paths moving the through your head design equal or very close to the size of the vacuum hose it self. For example area of a 4" hose is 12.56 sq" or a path 6 * 2.1" or 12.56" * 1". If you are using a shop vac this is not the same.

It is rather easy to prove, take a piece of card board and cut a 2" diameter hole in it and place it over the end of you dust collection hose. If it acts like a vacuum you will get more suction through this hole than you do through the 4" hose itself.
I have never tried one at 2" all mine are much larger. As your hole is not permitting the router to go through the vacuum head make sure you test with shorter cutters to ensure they will make it deep enough, for example my 1/16" cutter are much shorter than the rest of my cutters.

Buzz

[BobF]

Buzz is right.
Dust collectors have a low static pressure in the range of 4 - 12 inches of water for most. A good shop vac can have as much as 100". This is why a vacuum feels stronger when you reduce the area and dust collector does not. The dust collector is designed to move lots of air, not create high pressure.

[Mr.Chips]

One thing to keep in mind if you are using a smaller dust collect it is not like a vacuum. This is what I have been told by the local store where I got my dust collector, if you reduce the size of the vacuum hose you reduce the suction capability, so what I have been doing with all my designs is ensure at no point does the cross section of the air path go below the size of the cross section of my 4" vacuum hose. So when you design your head if you using a dust colletor you want to try and keep the paths moving the through your head design equal or very close to the size of the vacuum hose it self. For example area of a 4" hose is 12.56 sq" or a path 6 * 2.1" or 12.56" * 1". If you are using a shop vac this is not the same.

It is rather easy to prove, take a piece of card board and cut a 2" diameter hole in it and place it over the end of you dust collection hose. If it acts like a vacuum you will get more suction through this hole than you do through the 4" hose itself.
I have never tried one at 2" all mine are much larger. As your hole is not permitting the router to go through the vacuum head make sure you test with shorter cutters to ensure they will make it deep enough, for example my 1/16" cutter are much shorter than the rest of my cutters.

Buzz

Those are very good points Buzz, currently I am using a shop vac with a 2.125" ID vac hose.

With a 1/4" Bit length 2 1/2" + the Bit chuck 1 1/4" = 3 3/4".
The brush has aprox. 2" bristles + cutting depth of 3/4" + box verticle height of 2" = 4 3/4".

So the 3 1/2" body of the router would have to go down into the vacuum box a depth of 1", when cutting 3/4" deep, and further when cutting deeper.

The desiding factor would be when the bit chuck went into the 2" skirt area it would start restricting the air flow as in your example and would reduce the suction.

So in summary a 2" brush is too small.

Thanks for commenting and bringing this to my attention, OK on to plan "B"


and the verticle height of my vacuum

[LeeWay]

I designed one similar to this that was stationary when cutting, but adjustable in height. It worked pretty well until I quit using the little vacuum table I made and started using toggle clamps for hold downs.
My vacuum pump was an old air conditioner and when the parts were perfect, it would work fine, but just not enough vacuum pressure to use it with imperfect parts. This machine mainly cuts lexan though, so no dust flying around anyway.

[Mr.Chips]

I designed one similar to this that was stationary when cutting, but adjustable in height. It worked pretty well until I quit using the little vacuum table I made and started using toggle clamps for hold downs.
My vacuum pump was an old air conditioner and when the parts were perfect, it would work fine, but just not enough vacuum pressure to use it with imperfect parts. This machine mainly cuts lexan though, so no dust flying around anyway.

Yes toggle clamps are very handy and easy to use but do get in the way with this type short bristle shoe system or any type for that matter.

I see your brush height is nice and short allowing for a thinnner overall height of the shoe, and it looks like you cut out the top of the shoe to allow the lower body of the router enters the shoe for max cut depth.

I still like this idea of a fixed shoe height. So not ready to give up yet.

Do you have some close up photos of your shoe?

Thanks
Hager

[LeeWay]

I'll try to take some better shots of it. I also used the brush around the top hole so the hole was just large enough for the collet to fit through. It really worked well, but I was also using a pretty big dust collector. Just a 2.5" hose though, so it would have worked just as well with a shop vac.

They sell this brush with longer length inserts. About 1" long. These are 5/8" long. Just standard door sweep.

[Mr.Chips]

They sell this brush with longer length inserts. About 1" long. These are 5/8" long. Just standard door sweep.

Where is this available HD?
hager

[LeeWay]

You may find it at HD.
I get it from McMaster Carr.

Page 1227 in the catalog.

[Mr.Chips]

You may find it at HD.
I get it from McMaster Carr.

Page 1227 in the catalog.

Thanks for all your suggestions Lee.
This looks like a good and easy way to go.

Hager