Outside cuts on sheet metal are similar to inside cuts, but they're not the same
and after making "how to make metal project enclosures", I was going to make a
video that included how to make middle project enclosure penetrations, but then
I received a comment from Hammas Majeed and I hope I said that right.
very very nice and useful videos specially for my kind of projects.. but
where is the cut for the LCD. which starts from center and not from the
corners. I waited for it to end of video..
:p
I'm really thankful that you watched
'til the end of the video and I'm grateful that you took the time to
comment and with this in consideration I thought that it's a subject that's worth
looking into by itself. So this is how to make inside cuts on shee t metal by hand
This is Cosador, Johnathan here. So, there's a multitude of reasons why you
would want to put an inside cut on to sheet metal, whether it be for metal
project enclosures or any other type of penetration, and cutting from the inside
outwards is not the same as cutting from the outside in and it takes a little bit
of out-of-the-box thinking. Now, I'm not against power tools and a jigsaw or a
rotary tool is definitely up for the task, but for the sake of doing the
basics, I'm going to do this by hand, so that means only hand tools and no power
tools, I'd like you to think about that and just keep watching, so let's get
started, I need to put some lines onto the sheet metal and this is going to
represent where I want to cut them, even though they're not measured I'm going to
aim to cut on the inside of the line. If you'd like more info on marking up,
please check out my other sheetmetal videos, particularly the bending and
metal enclosure video. I'll put links in the description and a couple of cards on
this video. Now, I have the sheet metal marked up I'm going to cut these with a
couple of different methods. First up the metal shears method, and the question is
how do you put a hole in to sheet metal without a drill, common sense would
dictate a punch, but really it's possible to make a hole with anything that's hard
and sharp enough, and I'm going to use a piece of 25 mm by 25 mm
angle and a hammer just to prove a point. Once I've made
whole that's big enough to pass the shears into, I cut out words in a spiral
pattern, I find cutting from the center outwards minimizes errors and deformation.
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Once I get close to the line, I cut onto the edge of the line where it is
accessible by the tool,
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when I'm doing these cuts it's easy to see the
limitations of metal shears, because metal shears are typically right-handed
or left-handed and that's not which hand you use them in but it's the orientation
of the cutters. But there's a way around this with metal shears, I rotate the
metal shears into an upside down position and I cut the remaining corners
from underneath
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and it's done. With the metal shears, I can get close to the line
but the shears do leave marks and deform the sheet metal, but this is not a huge
problem, I'll show you how to fix this later in the video so keep watching.
Now method two with a chisel, I know that there's a lot of people out there that
are going to say Johnathan, what are you doing? but hang on a second. I'm not
saying to use your best woodworking chisel, but maybe one that you don't like
very much and if you just can't do that to a chisel consider finding a bit of
hardened metal, sharpen it up and use that. With the chisel, I don't need to
start with the hole. I just go straight up to the line, I slightly angle the
chisel and I gently tap it with the hammer, making small cuts along the line.
This piece of sacrificial timber that I have underneath is a little bit too hard
and I'm having to put a little too much force to punch through, so I swap it out
for a softer a bit of ply and I continue cutting the sheet metal, paying attention
to the edge of the line and keeping inside the corners, I do this with each
side of the square.
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and I make sure that the offcut is detached, and it's done. The chisel method
is great because the chisel and the hammer are the only tools that are
required to cut the material, however it does to form the sheet metal
significantly more there metal shears, but it can be fixed
which leaves us with finishing. I'm using a flat solid piece of metal I place the
sheet metal on top and I gently flatten any of the deformed parts I move around
the square ensuring that it's all flat and checking both sides. Now I'm happy
with the flatness of the piece, I'll file to the line, this might take a few passes,
but I'm not trying to take all of the material off at once I just want to meet
the line. Now I've got to the point where the part looks flat and it's filed up to
the line. When it's shiny like this, it looks perfect, but let's check the
quality of this cut. I spray on a bit of black gloss and I help it dry a little
bit. Now I can see that the edges are still curved in a little bit, if I
required better quality than this, I would need to check flatness with a rule
as I'm flattening it, but this quality is good enough for me because most mounted
parts have edges or bezels that hide all of these errors. So which method is
better and when would I use each? It's clear that the shears do a better job
solely because less labour is required and I could quite easily do this if the
material was folded, but the shears have a major limitation their size, whatever
hole I cut I need to be able to fit the shears into and this is where the chisel
method is superior, with the chisel method I can punch the required size and
file what remains. So, really which is better is dependent
on the task at hand.
Whenever we do something, we want to do it the right way
and it's important to remember that the right way is your best available method
and if this video was useful to you please like, subscribe and turn on
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and remember guys
Break It til you make it!
and I'll see you next time