Welcome to a new video.
This time we will make a metal dust collector.
Instead of using water for a spark trap, this dust collector will be made from
sheet metal and use a Thien Baffle to separate the metal dust.
The ingredients are fairly straight forward.
I am using a blower with a steel impeller, see a link in the description, 16 gauge sheet
metal and 1 in angle iron.
In part 1, Tony and I will be build the Thien baffle from the aforementioned sheet metal.
Unlike a cyclone separator, the Thien Baffle is much shorter and includes a bottom baffle
that allows the dust to drop out but prevents it from getting sucked back in.
You will see how it looks like at the end of this video.
In the mean time, the shop is not equipped with any sheet metal tools and I just gave
Tony a drill that was set on hammer mode.
That does not help.
However, while we don't have any real sheet metal tools, we make the best use of all the
tools we have at hand.
For the Thien Baffle, we need to create 2 24in diameter circles from the 16 gauge sheet
metal.
We are using a hole in the middle of the sheet metal to insert a guide pine.
Using the bandsaw, We almost cut a complete circle using a jig we cobbled together for
the bandsaw but stop short of cutting the complete circle to leave a race way for the
inlet.
As neither Tony nor I have much experience working with sheet metal at all, we are proceeding
very cautiously.
Fortunately, the badsaw cuts quite nicely and is also making it easy to maintain the
circle.
Since 16 guage sheet metal is fairly thick, I am somewhat worried about bending the walls
that will support the top and bottom circle we are currently cutting out.
While working on this project, I had looked into buying sheet metal tools but the smaller
sheet metal brakes and rollers are not rated for 16 guage sheet metal.
The tools that are are much larger, heavier and more expensive.
Alright here we are.
One circle is cut and where we stopped cutting is where the air inlet to the dust collector
will be located.
Tony is marking that part out now.
The size of the inlet will be 6in square which is the same dimension as the height of the
Baffle and big enough to not significantly reduce airflow.
For the Baffle to work, the compartment into which the dust will drop needs to be airtight.
Otherwise, airflow would move through the drop out in the Baffle and prevent the operation.
You will see how that looks like when I test it at the end.
I have good luck with a Thien Baffle for wood dust collection but getting an air tight sheet
metal compartment is a project I have no experience with.
Now, we are completing the bottom part of the Baffle.
At this point, the sheet metal for the top and bottom parts are still completely identical.
However, they will deviate soon after.
The top part of the Baffle will receive a 6in diameter circle in the middle where the
blower will be positioned and the bottom part of the Baffle still needs more material removed
to create the drop out.
Before we do that we need to cut a 6in wide strip of sheet metal that will form the outer
wall of the Baffle.
Since we don't have a shear, we mounted a guide on the Bandsaw table.
Let's talk about this 6in hole in the middle of the sheet metal.
Initially, we though we would use a circular hole cutter attached to a drill.
Unfortunately, my drill press does not have enough clearance, and stabilizing the drill
by hand seemed impossible.
Instead, we are cutting 4 1/2in holes and will use a sheet metal snip to create enough
space for a nibbler.
How convoluted.
Another option could have been using a plasma cutter but I no longer have access to one
and have not seen the need to buy one yet.
However, I am pretty sure a plasma cutter will be a likely future acquisition.
If you have any other ideas for cutting this darn circle, please let me know in the comments.
I really don't have experience working with sheet metal.
Fortunately, the snips work quite well and I should soon have access to insert the nibbler
which will nibble away at the sheet metal.
This is a good point in case for how proper tools can make everything move much faster.
While the nibbler works exceedingly well, getting the right turning radius took some
practice.
As a result, I am approaching the circle with multiple overlapping operations.
And there we are almost a perfect circle.
Well, a bunch of clean up was still required.
Draw filing is pretty quick to remove the sharp and jagged edges left by the bandsaw.
All this preparation is really just procrastenation to avoid bending the strip of 6in wide sheet
metal into a circle.
As it turns out, there is a reason that sheet metal rollers exist.
Without them, rolling thick sheet metal is somewhat difficult.
With this brilliant realization in mind, I proceeded to make myself a Frankenstein pyramid
roller.
It consists of three roles where one sits on the top and can be moved down to increase
the bending amount.
Ideally, I would have used a lathe and solid rolls but that was not an option in this case.
Instead, I welded something together from black plumbing pipe.
Yuck.
Nonetheless, it seems to get the job done and my vise grips constitute an almost perfect
crank.
What more could I want?
I occasionally check how close I have come to the right radius but in the end managed
to slightly over bend the sheet metal anyway.
It turned out that that was not really a problem and the jig I build for clamping took care
of removing gaps in the joint.
Usually when welding the clamping set up is the interesting part that makes for a successful
weld.
Here you see a circle cut from plywood that I am using as part of my clamping set up.
The cut corners from the plywood circle are placed on the outside and allow me to press
the sheet metal tightly together.
Welding sheet metal is another challenge for me.
I am using a stiching approach to prevent the metal from getting too hot and from blowing
through the walls with the welder.
By and large that seems to be going well although the weld beats are somewhat ugly and need
to be cleaned up later.
I am slowly working my way around the circumverence of the circle and reposition my plywood clamping
jig as needed to get access.
Inspecting the inside shows good penetration on the welds.
What I forgot to mention was that the strip of sheet metal I had cut was only 3 feet long
and not enough to make it all the way around.
That's ok.
I will just cut another piece and continue along.
To match the remainder of the circle to the inlet I will first weld in another wall.
Since I don't have a brake that will make joining the bent wall to the inlet much easier.
Again the main challenge here is how to clamp the piece in place.
For that I use some cut off square tube allows me to get everything lined up.
To bend the wall to the right radius my cobbled together frankenstein roller will have to
do the job.
I am still surprised how well it is working.
The main challenge in making it was to have the rollers well centered which I struggled
to do without a lathe.
When bending metal, it's never possible to bend the whole piece evenly and so the extra
length to give the rollers something to grab needs to be cut off.
After placing the sheet metal into my little plywood jig, welding everything together is
quite fast.
There we go.
The walls are completed and the only thing missing from the Thien Baffle is the bottom
with the drop out where the metal dust can fall into the collection bin.
The cut out is a 240 degree arc that stops at the inlet.
Since I want to use my circle cuttting jig on the bandsaw again, I need to figure out
where the cuts needs to be placed and where I need to make space for the bandsaw blade.
Creating the opening for the blade requires many small cuts due to the limited turning
radius of the blade I have installed.
Once the opening is there, cutting the remainder of the circle is fortunately quite easy.
At the moment, I am keeping a small tab to help with welding the bottom to the rest of
the Baffle and I don't know yet if I will remove it eventually or not.
Once I welded the bottom in a couple of places, I can go back to my little plywood pieces
to create a gap free joint for the rest of the wall.
As I have some rigidity in the whole structure now, I only need to insert one of the plywood
segments.
Previously, trying to clamp both of them with my parallel jaws clamp resulted in either
one or the other frequently falling down before I could put on clamp pressure.
Alright, the welding is done and only some clean up on the welds is remaining.
Now comes the moment where I can see if the blower fits on my sheet metal Thien Baffle
and give it a quick test run.
There is still a lot more work to be done but this is a good moment to finish this episode
by checking if the metal dust gets blown out or remains in the Baffle.
Remember the drop out is not in an airtight compartment, so I don't actually expect the
dust to disappear.
If you enjoyed this video, please subscribe to my channel and stay tuned for the next
part.
Another video I am working on and which I am very excited about is to visualize the
pattern welding process in swords.
I liked my visuals so much that I made myself a few T-Shirts.
If you like the design and would enjoy a t-shirt as well, follow the links in he description.
As always many thanks to those of you who follow me on Patreon and continue to show
their patience with my slow video production.
See you next time.