Thank you for watching another Rainbow Aviation,
video I'm your host Brian Carpenter and today
we are out in the shop with the CNC press
brake experimenting with our latest idea 3D
printed press brake dies.
Today we will share with you our methods and
techniques that we developed to successfully
3D printing dies for our 20 tons CNC hydraulic
press brake.
But not only that, were going to take a look
at how we converted our cheapo harbor freight
3 in 1 press, roll,sheer, into a usable tool
for building aircraft.
Necessity is the mother of all invention.
Although not a literal translation from Plato's
Republic, he is the philosopher that's most
often attributed with this quote.
And I must say, it's still just as true today
as it was in 380 BC.
In my experience, there's no one that appreciates
and understands this more than those of us
that have small workshops.
Even though we work with a limited budget
limited space and limited materials, the one
thing that seems to be limitless is imagination.
Everything would be much easier if we just
had the same budget as NASA.
But it is because of these limitations, that
we are force us to stretch our imaginations.
Today's video and idea was born out of one
of those typical frustrations arising from
the absence of a very simple tool.
We were manufacturing bulkheads for the fuselage
boom assembly on the EMG-6.
Now, The development of the EMG-6 project
is always been on a very limited budget.
Coupled with a design philosophy that continually
tries to drive the cost of the development
and manufacturing down, presents a challenge.
The primary method by which we can reduce
the cost on many of the components, is by
manufacturing as many of the same component
as possible at the same time.
After all, the majority of the cost in any
of the components is the machine setup cost.
But with a project of this nature, where we
have very low sales volume, stocking a large
inventory is unsustainable.
Every dollar we put into inventory, is a dollar
taken away from the research and development
end of the project.
This being said, we still try on a regular
basis, to work in the principles of mass production.
We have designed the fuselage boom on the
EMG-6 to utilize the same material throughout
its construction.
We have also have designed into the majority
of the components, like the bulkheads, the
dimensions that result in setting up the CNC
press brake for the least number of adjustments.
The design of the individual bulkheads incorporate
flanges that are offset from the sides that
allow the upper and lower flange to be bent
first, and then the two sides can be bent
without setting up an additional set of dies.
There is literally only .020 clearance between
the upper and lower flanges and the press
brake die during the bending process.
This design corresponds with the design of
the fuselage sides allowing the upper and
lower flanges to fit snugly between the fuselage
boom side flanges.
We use this process on nearly all of the bulkheads
within the fuselage subassembly.
However bulkhead number 11 is the problem.
Because of the narrow dimension between the
two fuselage sides at this location, there
there is no room left for a upper and lower flange
between the fuselage side flanges.
As a result the flanges have to overlap the
flanges on the boom sides.
This results in, the final product with the
flanges bent so close together that there
is no room for the conventional bending die.
In the past, for prototyping and low production
volume, we can simply use the finger brake
and take the additional time necessary to
layout and bend the flanges using that tool.
However, this is fairly labor-intensive and
we could reduce the cost of the individual
component if we could use the CNC backstop
and bend the flanges in the same fashion that
we been all of the other bulkhead flanges.
This is actually quite simple, all it requires
is a bending die that will fit between the
two side flanges.
This will allow for the flanges to bend up
on the outside of the bending die.
The choice was to cut one of the longer bending dies.
I really didn't want to do that.
By a die that would match identical to the
existing die height dimensions and radius.
An Internet search came up empty.
I thought, only need to do is bend about thirty
of these bulkheads.
I have made them out of wood before
I've done that in the past and it worked great.
And then I thought, why not 3D print one of
these things.
That would be stronger than wood.
Even if it didn't work, the cost of the experiment
would be minimal.
so SOLIDWORKS we simply design the male died
for our exact specifications
we then extruded the profile to the width required to bend the specific
flange.
After we were done with that , we Exported the SOLIDWORKS drawing into an STL file
That STL file could then be imported into the Zortrax slicing program.
We then placed the part on the build platform so that the layers of plastic
would have the strongest orientation possible during the bending process.
We then selected the highest density available for the 3D Printing
And we selected a material Z-Ultrat which is one of the higher density plastics
with great impact resistance and good tensile strength. The next step will be to take the
file that we created in the Zortrax slicing
software and bring it out to the Zortrax M-200
3D printer. You can see the very close
infill pattern which is nearly as good as
printing in solid format. The infill structure
is a latticework of filament oriented at 45°
angles. This provides for an incredibly strong and rigid structure. And because of this high
density infill pattern it takes time for these
individual parts to print. once the part is
finished printing we can remove from the build platform useing a putty knife a small camp this
is done very gently with a light tapping motion to avoid any shock on the build  Platform. The hammer that we are using is literally
only a few ounces. The build platform will
remove easily from the part in the final product
is a high density plastic bending die ready
to be put into service. We built several different
types of dies for testing and for different
applications. Wwe can create dies of any with
an of any design with any radius we desire.
We can adjust the height of the dies to work
in conjunction with our steel dies, making
it possible to avoid adjustments in between
different bends. You can see the results on this die where we stopped the printing early
to show the infill spacing pattern. On this
end, we have faced that was attached to the
build raft and the platform. And on the opposite
side we can see the close proximity of the
plastic beads laid down at 45° angles that
create the infill structure. And after testing
more than a dozen different 3D printed dies,
we consider this to be a real option for the manufacturing
process. We use the dies the same fashion as we would a steed die.  And initially we thought that... well..  maybe aybe
these dies will have a pretty short lifespan.  But after all of our
initial tests we have been quite surprised.
Many of the dies that we have  manufactured hav bent up to a couple
hundred parts without any signs of wear whatsoever.
One of the added benefits, in comparison the steel dies, is the lack of marring, that goes on
with the aluminum parts that we are bending. One of our ideas was to use JB weld to repair any of
nicks on the dies as time went on. However, we
haven't had any need for this because the
wear is virtually nonexistent. I think the big key is that we have a die that is well within
the structural limitations for the material
that were bending. Most of these parts in this
video that we use on the EMG-6 electric motor
glider. Use primarily .040 thick
2024 T-3 aluminum. The success
that we've had with our 20 ton CNC press
brake has led us to experiment with another one
of our shop tools that normally sit idle.
We have a low cost harbor freight 3 in 1 press, roll,  and sheer. Although adequate for a lot
of nonaviation shops, the lack of a radius
die on the bending portion makes it virtually
unusable for building aircraft. We modified the
press brake portion by adding a piece of 1/4
inch plate steel in place of the male dies. And then we went on to manufacture both the
male die with a radius and a female die large
enough to accommodate the radius die plus
the thickness of aluminum that were bending. And although we have a great selection of
other sheet-metal bending tools in our shop. We have now put this one back into service
and use it on a fairly regular basis for simple
bending tasks. We've also been creating 3D
printed backstops that we can use when we
have repetitive tasks. By adding 1/4 -20
thread to the body of the female die,  we can insert a bolt and 3D print a stop that can
be adjusted back and forth by rotating. We
can consistently achieve tolerances within
a couple thousands of an inch. And it only
takes a few minutes to adjust the backstops.
If we have more than a few parts to bend it's
worth setting up a stop. To help in creating
consistency in the degree of the bend. Although
we could get much more sophisticated than this
using a block of wood and pieces of aluminum
as Shims, we end up being able to get consistency
in the bends that are nearly perfect. So.. There you have it... 3D printed press brake dies. You know we certainly
enjoy sharing our experiments and ideas from
the workshop. And we hope you enjoy them.
Keep in mind that we have a lot of other great videos
for you to check out.  And we keep making more
on a regular basis. So, go ahead and hit that subscribe Button.
And we will see you during the next one.
