Introduction : Cold Smoke Generator - Vent

This is an initial instruction on creating a vent for the smoke generator.

Part 1 - Vent

I have decided to break the instructions into a number of key parts which might just be useful components on their own. The vent is inspired by a well known bbq manufacturer.

Part 2 - Door

Part 3 - Pump

Step 1: The End Result.

This video shows the smoker during an initial test run.

Step 2: Parts

The aim is to use a few consistent parts

1 x M6 set screw 20mm long
1 x M6 nuts
1 x M6 washer
1 x M6 wing nut / butterfly nut
2mm x 110mm x 73mm sheet aluminium

**A gas canister or anything else that needs a vent**

Step 3: Tools

Think this is the minimum you will need

1 x drill (potentially electric)
1 x 20mm diameter hole saw (needs to be robust as cutting steel)
1 x 6mm drill bit
1 x 3mm drill bit
1 x angle grinder
1 x slitting disc
1 x hand file with flat blade
1 x hand file with a half round blade
1 x sharp scribe (sharpened nail worked)
1 x dividers or compass for drawing a circle.
1 x circular template (74 mm diameter paint tin)

Step 4: Cut Out the Vent

Cut out and bend into shape

As the aluminium is relatively soft, just use a sharpened scribe to drawn out the shape directly on the metal. Use the compass for dividers to scribe out the circle.
No simple options for this, but I tend to use an angle grinder with a slitting disc to slice the metal off in successive passes and then file down the shape.
Clamp the aluminium to a piece of wood or chipboard so you can cut through the metal against something flat.
At this stage you only need to drill a 3mm hole it the centre
Place the lug part in a vice and bend the larger part as this seems to be easier. doing this now adds a bit of stiffness the to shape and makes it easier to handle.

It doesn't have to be perfect, it will get coated in wood tar on first use.

I have added a DXF file of the outline.

Step 5: Vent Placement

Guessing where to place the vent

I used a paint tin to work out the best position for the vent
Move the tin around until it stop rocking (needed to grind off an embossed logo)
Draw around the tin
Place the vent into position
Make the centre point
Drill out the centre hole first with 3mm drill and then the 6mm drill
Then bolt the vent into position (align one of the holes it the top)
Drill the remaining 3 holes with the 3mm drill

This should mean that the vent will rotate with an even distance around the edge, which is what you need to control the air flow.

Step 6: Drill Vent Holes

Using the hole saw drill the vent holes

Remove the vent
Drill the three holes in the cylinder with the hole saw
File off any rough edges
Clamp the vent onto something flat
Drill the three holes in the vent
File off any rough edges

Step 7: Finished

Reassemble

At this stage I bent to vent by hand to follow the curvature of the cylinder. Just placed thumbs near the centre and bent the edge in the opposite direction working around the edge a few times.