Metal project enclosures can be costly and sizing can be confusing, but it
doesn't have to be, so let's take a closer look at how to make metal project enclosures.
This is Cosador, Johnathan here, there's heaps of different types of
project enclosures, but metal has unique properties. It's strong, it can take a hit
and it can handle high temperatures. It's electrically and thermally conductive
which can help with electromagnetic interference reduction and heat
dissipation, and metal enclosures can reduce noise emissions and guard against
external noises. But, which type of metal? galvanized, zinc, alloy aluminum or
stainless steel really depends on environmental conditions like weather
heat and chemical resistance, but in this episode I'll be making a metal project
enclosure out of .55 mm including sheet metal.
So, the next question, how big or small must be? the size of the project enclosure must
be considered, I lay out all the internal components on a flat surface and arrange
them with consideration of future access in mind until I have a suitable
configuration, then I think about how much clearance is necessary around all
of the components and on top of that I add a little extra room for flexibility,
and lastly I need to consider any mounted switches, panels or cable
penetrations and if their positions are going to affect the internal components
and whether more space should be added. So, I want to make a project enclosure
that's 400 mm long, 200 mm wide, and 100 mm tall.
I'll split the box into two sections, the top cover, which will cover
the top and the two long sides and the bottom section, which will cover the
bottom and the two short sides. On this section, I'll add tabs so I can attach
the top to the bottom. I need to transfer my plan to the sheet metal so I need to
make a stencil and stencils are great because it allows me to replicate my
markings without redoing the measurements, so I managed to find this
giant roll of paper in the garbage, but butchers or packaging paper is ideal,
baking paper or even sticky taped printer paper will do. I measure out the 400 by
200 and the 100 by 200 mm boxes and then add the tabs afterwards.
I've done this with gray lead and for precision that's best, but for the video
I've used a marker to give a little contrast. The tabs are 25 mm
long and I've put them on each edge of the bottom section of the enclosure.
Where the sheet metal will fold, I've removed the corner by 30 mm,
this is because when the sheet metal folds, I don't want it to be a true mitre
or the tabs may interfere with each other and present a fold that's less
than 90 degrees, and for the top I've made it 405 mm by 202 mm
by 105 mm for a bit of allowance on the inside so the bottom
section slides in freely, also I've given allowances on the other measurements to
provide an overhang on those edges that may be trimmed off later, I name the
stencils and I cut off any excess overhanging paper. Now, I have the stencils
made I need to transfer them to the sheet metal, so I put the sheet metal on
the workbench and I place the stencil so that I don't waste sheet metal, and with
some masking tape I secure the stencils to where I wish to transfer the
measurements.
With the scribe, punch or even a hardened metal screw and a hammer, I find
where the lines intersect, I give it a gentle tap and leave a small indented
dot on the sheet metal and I do this for each of the intersecting lines. I remove
the stencil and carefully join the dots with the marker or pencil and I do the
same for the other section.
Now, I have all the markings, it's time to cut it out. For this, I'm going to use
some metal shears and I'll start with the top, first I cut out a rough shape
about five mm away from the markings, close enough so that I will not
waste too much material, this will enable me to cut a line in finer detail because
the thinner strips of sheet metal curl away better from the shears. Now on to
the bottom, I first do the rough cut, then I go around the basic shape by passing
the diagonal notches, then when I cut the notches, I do two separate cuts varying
slightly off the line leaving approximately 1 mm in the
middle, this is important so that each side doesn't interfere with the other
during folding. I bend it a few times and I snap it off and I do this for each of
the notches, then I snip off any external corners and soften any sharp edges with
a file. Now everything is cut out, it's time to fold everything, I prioritize
folding top to bottom and visible to non visible and reorder to make it easier
but not change the quality of the folds. If you would like more information about
bending sheet metal please check out my other videos, I'll put a link in the
description and add a card to this video.
Now I have the two sections folded, I need to check the fit making sure that
the bottom sections tabs seat well on the top section. Sometimes external
corners can interfere with the inside of folds and they may need to be adjusted
for a better fit. It's time to put this together, I select some sheet metal
screws and a couple of drill bits one bigger and one a little smaller than the
screws thread. I mark out the places I wish to put the screws on the top
section making sure that they will intersect with the tabs on the bottom
section and making sure that the sheet metal is firmly held or clamped down
with the larger drill bit I drill a hole on each of those marks, then I line up
the two sections again and through each of the holes I put a mark on the tabs of
the bottom section, then with the smaller drill bit I drill the holes on each of
the marks on the bottom section, and I check that all the screws go in and
everything is lined up. Now, it's time to shore up the enclosure a bit and fix any
little problems or imperfections, if there are any mistakes now is the time
to fix it. I'll knock out any dents and trim off any overhangs that are
unnecessary and sand any bits that may make the finished product look better.
For painting, I give them a good clean, then I give them a coat of paint on the
external parts of the enclosure and any visible edges, I let it dry and I screw
it all back together and it's done.
Ok, the evaluation, it's not perfect the cuts
and folds really could have been given more time, but that isn't always required
and function at times is more important and most definitely its strong, to size
and it will serve its purpose.
Sometimes we can't get a measurement right or make
exactly what we want the first time around,
but that's not necessarily the sign of a novice, it's the sign of prototyping and
making something new, and if this was useful to you please like subscribe and
turn on notifications and if you would like me to do a video about something
else just comment below, thanks for watching and remember guys
break it til you make it!
and I'll see you next time