Need some help with correct sizes for Separator

[Mr.GfC]

Hi all.
I need some help in getting the measurements correct. I'm a Disabled VET and I have a hard time understanding the ratio's and basically anything other than simple math now. I've recently been able to acquire a Jet 1221 Lathe and in turning the handles for tools, I realized that I desperately need a dust collector/separator.
A friend of mine gave me a fan that has a 5-3/4" intake on the side.

Not wanting to stress the motor, I'll be using a 5-3/4' hose all around.
The thing is, I live in Lima, Peru. So there are a lot of things ya'll use, that I don't have access to. Like the adapters I've seen turning the hose into a rectangle-for attaching it to the separators. So, with this in mind, I drew this separator up in CAD.

I'm using a cardboard barrel I was able to get that is just big enough to accept x3 5-3/4" across and top to bottom, inside.
My idea is to remove the bottom ring and glue the barrel to a wooden ring that I can them mount on the collection barrel. By doing this, I thought I could mount the separator plate with 3 long carriage bolts to the separators lid, leaving a full open circle for the dust particles to drop into the collector-barrel.

My questions are:
1.   The exhaust tube:
a.   How far into the center of the barrel does it need to go?
In the drawing, I have it 5-3/4" from the bottom plate.
2.   The Bottom Plate:
a.   Is there an optimal distance it should be from the side of the barrel? The space between it and the wall-does it have to be a specific size?
3.   A Helix:
a.   I know that because the barrel is made from cardboard, I'll need to insert a 'strike plate' where the dust and chips hit the side, to keep it from getting torn up/eaten away.

So, would it improve the separation of the fine dust to also install a Helix to direct the airstream downward and should I run the Helix all the way down or just the length of one rotation?

[Schreck]

Kind of quiet over here.....
Regarding the bottom plate, it should be located within the separator and not extend down into the collection barrel.  You want to keep the spinning air in the separator, out of the the barrel.  I think locating the bottom plate an inch above the bottom of the separator walls would be about right.