The first two videos in my rollation
series have been very well received. I've had a lot of requests to see a
transition between a round and a square. So I've made a form for that. This is a six inch diameter disc,
and this is a six inch square base, and I've spaced them three
and a half inches apart. So I'll use the rollation technique again
to make the pattern to create this part. And I'll be using an improved
process to create the pattern. Some of my viewers have had great suggestions
for fine-tuning the rollation process. One of my favorites is putting a little
rubber cement on the edges of the form, so when you roll it across the pattern
paper it's much less likely to skid. That really helps a lot, and
in my previous videos I used a pencil to trace along the edge of the form. That works, but there's a much
better way which I've come to prefer. What really works well is to use a thin layer
of aluminum foil on top of your pattern paper. So I'm going to use spray adhesive
to hold the foil to the paper. Just a light coating of adhesive is all it takes. And I'm going to let that dry for a minute. So now I can lay down the aluminum
foil, and I'll just roll it out. So this gives us enough material
to make a lot of patterns. I'm going to make this from two pieces of metal, so there's going to be a welded
seam in two of the corners. So when I lay this out I need to capture
the pattern all across two sides, plus a little extra to get leverage for bending. So let's start with this up on the corner. I'm going to roll it away from me first. Then we'll roll over to the next position. And I'm going to mark the
center points on the round disc. Now we'll roll back the other way. I'm also going to tip this up on edge, so it makes a nice crisp impression
on the back side of the form. Okay so now I can cut this out. So there's our pattern. Using a square, I'm going to draw a line to the center of
each of the quadrants I marked on the pattern. Now I can trim the excess off the ends. So using this pattern I'll cut out
two blanks from 20 gauge steel. I cut two blanks of metal, and I added
a quarter inch extra material to the top to give me some wiggle room. The base of the form is three quarters inch thick,
and I want the part to have a flat area to match. Also I need notches at the corners to
accommodate the forming I'll be doing. So I've drawn a line three quarters
inch away from the bottom edge, and made notches that meet the line, and then I've drawn lines that
will meet the notches on the disc. So this disc has quadrants marked on it, and
more notches halfway between the quadrants, and each of these lines comes right
up to meet one of these notches. So I've drawn radial lines on a piece of paper and you can see that if a slight
bend is made on each of these lines, it will create a bend that
matches the form precisely. It's time to lay out the bend line on our blanks. I want to be efficient with
this because we have two blanks, and each blank has three areas where
it needs a radial pattern of lines, so I want to do one layout that I
can use for each of these corners. So I'll show you the process I'll use. First of all I'm going to use a scriber
to put a point right at the base of this where all these lines will converge. And then I'm going to draw a line on the blank that goes from that point right
out to the edge of the metal. I'm going to continue that line
onto the paper behind the metal. Let's do that on the other side. So we have an angle here close to 70 degrees. I want to divide this into eight equal parts, and it's a little bit tricky to
do that with measuring devices. I mean if we divide 70 by eight that gives
me roughly seven point something degrees for each increment, and it's hard to measure angles
that small with simple tools, so I'm going to do this a different way. I'm going to project these lines
to the point where they meet. Then I'm going to use a compass, and I've put
a felt tip marker on the nose of this compass. And with this compass I'm going to draw an arc
some arbitrary distance away from the apex. I'll make this a fairly large arc. And then using dividers, I'm going to
divide this into eight equal segments. So let's take a stab at this. So that's a little bit too big. I'll
close it down a little bit try it again. I need to go just a little bit larger. I'm just about there. Okay we got it! Eight equal divisions. So I'll use my felt tipped marker
to mark these on the paper. You could actually get better precision
using a sharp pencil for this. I'm using a pen so it shows
up on the camera better. Okay so there's our eight equal divisions. And now I'll draw lines from this apex
through those points I've just laid out. So there's our layout - eight equal divisions. So now we'll put the apex of this notch right on that point, and line up
these lines with the longer lines. And now I can find the point on the edge of
our blank where these lines need to meet. And the reason I'm doing it this way
is because you can see that the space here is much wider than the space here, even though the angle between them is equal. So let's continue our layout. So we have all the bend lines on
this corner let's go on to this one. So I'll do the same layout on the second
blank, and then we can start bending. I'm using the same bending fixture
I used in the last rollation video It's really simple. It's just two
inch and a half cold rolled steel bars clamped together with a spacer between them, and the spacer is just a little bit
thicker than the metal we're bending. So all I have to do is to slide this into place. I want to get the corner of this top bar
right at the base of the notch in this part, and then I'll use Vise Grips
to apply the clamping pressure. And to make the bend, all I need to do
is to press up on this little end here. And I have to move in one direction with this
fixture, I can't back up and redo something. So I want to check my progress pretty
frequently and make adjustments if I need to. So I'm just guessing about how
much each bend needs to be, and pretty soon I'll check it on our fixture. Everything that I'm bending
right now will get cut off, but it's nice to have that extra material just
for the leverage I need to make the bends. Okay, so let's try this on the fixture
just to get some sense of how I'm doing. So the radius of curvature actually looks pretty
darn good, so I'll continue with this process. Okay we're just about to the center of the bend. Then I'm going to try this whole
corner into place on our fixture. Looks like it's over-bent a little bit. This is over 90, so I'll open that up a
little bit, get this corner to be 90 degrees, then stick that on the fixture. And it's actually matching that
curvature very very very well. So I may adjust that later, but that's certainly
good enough for now, so let's keep moving. So we'll put this back into the fixture and
start making the bends going to the next corner. Let's check our progress again.
We'll try this on to our fixture. So I've made the bends a little
bit sharper than they need to be, but it's not too hard to fix that. All I need to do is just press
them out against a flat surface. So it looks like it needs a little bit
more bend right where I'm placing my thumb. I'll tighten that up a little bit and it's pretty
good - probably good enough for where we're at. I can fine tune this later, but I want
to continue with the bending for now. Okay we're coming up on the
last bend on this corner. So I can see I've gone a little bit over 90
degrees, so I'll straighten it out on this side. And then try it on our fixture. And it's a little bit over bent
in the area between my fingers. So I'll put that against a flat
surface and press out on both sides. I'll try it again - it needs a little
bit more unbending in that corner. And this has gone under 90,
so I'll tighten that up. I'm going to use a hammer now to tap in. Just a little bit more angle right in the corner. So that's fitting super well, so I'm
going to go right on to the last corner. So there certainly are better
ways to make these bends. If you have a bending brake,
of course that's how you do it, but I'm designing this video for people
who may not happen to have a bending brake. They're rather expensive tools, and I think you'll see that we're going
to get a pretty decent result in the end. So I'm going to trim this now. I'm going to make a cut from this
corner right to the center of this bend on both sides, and then I'll do
the forming on the second part. So both pieces are fitting
the form very nicely now. Here's the piece we just formed, and we'll
put the first piece into place on top of it. And they really fit together pretty well. So there's a lot of overlap on these corners. There's a couple of inches overlap, so
I'm going to remove much of this waste to get them to nestle together as snugly as I can, and then I'll scribe these
corners for the final trimming. Everything's clamped up tightly to the form, and I'm very happy with how
things are fitting together. So now is the time that we'll scribe
these edges for the final trimming. So I'll pull everything up tight
scribe one line on both sides. So now I'll trim it for the final time
and we'll tack weld the parts together. Let's talk about the machine setup for steel. First of all, I'll switch
from the AC mode that I'm in to the mode for steel, and
this is DC electrode negative. And to make a puddle on 20 gauge
steel takes at least 35 amps, but I like to set the machine hotter than
that, so I'm going to go up to about 50. And that way with the foot pedal I can give
myself a little extra boost if I need it. So that's all we need to do
for the machine settings. Let's take a look at the argon regulator now. I like to set the argon flow to 12
to 14 cubic feet per hour for steel. So I've trimmed the edges and everything
is clamped back up on the form. The fit up is beautiful, so let's
put some tack welds on this. So that's enough tacks to hold everything. I'm going to take it off the form. Now I'm going to work each
of these tack welds with a hammer and dolly to make sure
the metal is perfectly level, then I'll finish the welds
off the form, dress them, then we'll do the final checking for
fit and trimming back on the form. I'm using a homemade post
dolly to fit inside this, to enable me to level the
metal around the tack welds. Okay, it's time to finish weld this part. And I have two more corners to finish up. Okay I'll dress these welds,
and we'll do the final tune-up. I'm going to cut the welds down
with 50 grit abrasive first. Then I'll use 120 grit to get it smoother. Then I'll rotate it to the next side. I'll go back to the 50 grit. Then I'll go back to 120. I'll roll it over to the next side. Back to the 50 grit. And then the final step is to
switch this to orbital mode, and go over the whole surface
with the orbit sander. So we're just about done with our transition. The last step is going to be to trim this top
edge down flush with the disc on our form. And it would be easy to scribe this on the inside, but it would be difficult to see that scribed
line because of the funny angle in here, so I want to find a way to scribe the
outside, and I have a plan for that. I've made a little tool. It's just
a piece of metal with a notch in it, and the notch can fit down over this
flange, and then I can mark the outside. So I'm going to put some Dykem on the outside of
this so I'll have a high contrast line to trim on. I'll give that just a minute to dry. Okay, and now I can scribe
around the outside edge of this. I'll just rotate the part. I think that'll
be easier than trying to move the tool. So there's our scribed line. Let's pull this off the form. And I'll trim right on that line. So I'll put this back on the
form and we are good to go! So the part cleaned up very nicely. I've got a very snug fit on the form both top
and bottom, the welds cleaned up perfectly. I'd call this one a success! So again this, is a great example of a part that
you can lay out using the rollation process. I hope you're enjoying my videos. I invite you to like, subscribe, and click the
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