There is already some great information out there about 3D printed tools for press brakes,
however I haven’t seen anyone using these
together with a vise.
Unsurprisingly this also works great.
The punches and dies take up little space,
are cheap to make and can be printed in whatever
size and shape you need which makes them
perfect for hobby use.
Being able to fairly accurately bend sheet
metal is a great addition to capabilities
of a home shop and therefore I would like
to share some of my experiences with you.
Obviously the first thing you need is a vise.
Mine has seen better days, however it should
still do the job.
A small vise like this one right here can
work too, however the size of you parts is
going to be somewhat limited and same goes
for the force you can create which directly
translates into the thickness of the material
you are able to bend.
The dies and punches need to be printed fairly
solid.
I am using 5 perimeters with a 0.8mm nozzle,
80% infill and 0.2mm layer height.
For shapes like these, PLA or PETG on itself
should be strong enough, however for special
shapes like this gooseneck punch you might
want to increase its strength by reinforcing
it with steel wire, like I showed in a previous
video.
Of course this also depends on the force you
apply on the tool, however you definitely
don’t want PLA to shatter under heavy load
right in front of you.
This brings us to the traditional safety instructions:
Do this at you own risk and definitely wear
safety equipment.
The maximum thickness I have tested so far
are 3mm in aluminum and 1.4mm in steel.
These values are definitely not the final
limits, however I right now don’t have any
thicker material at hand.
Even though the length of the dies and punches
is limited to the size of the vise jaws, making
longer bends is no problem.
By just gradually creating the bend while
moving the part back and forth we can not
only get a pretty accurate 90 degree angle
but it also looks very uniform.
Modeling the dies and punches in Fusion 360
is fairly straightforward.
It’s basically just one extruded sketch.
Make one side to fit right onto your vise
jaws and draw the shape of your punch or die
on the other side.
Make sure that when mounted to the vise, the
center point of the punch and die line up.
In order to quickly exchange tools I went
with magnets to fix them to the vise.
First I used 10x2mm disc magnets, which are
way too weak, and then switched to 15x10mm
disc magnets.
These fix the tools fairly nicely, however
you have to be extra carefully not to get
anything magnetic next to them.
Therefore I would recommend to just go with
multiple smaller ones.
Create some pockets in your 3D models and
use glue to fix the magnets after printing.
Depending on the cleanliness of your shop
and the material you are working with, you
might want to fully enclose the magnets or
at least put some tape on them, so they don’t
collect all the steel chips that might be
present.
So far I have been doing what’s called air
bending: This means that the part contacts
the press on three points.
The bending angle is controlled by how far
you push the punch into the part and the distance
of the other two points controls the radius
of the bend.
A bigger opening will give you a bigger radius,
however I haven’t found an easy formula
to apply here.
The other two bending techniques for press
brakes are bottom bending and coining.
I won’t go into detail about those, as they
are a bit more complicated, need more force
to create a bend and the tools cannot be used
as versatile as those made for air bending.
In most cases you want to use such a V-Punch,
as it offers the most stability.
If you need more clearance, you can switch
to a goose neck punch.
Here you can also see a perfect example of
springback.
This punch has exactly 90 degrees, but after
releasing the pressure from the part
it springs back a few degrees.
So in this case the punch needs to have a
smaller angle, roughly 2-4 degrees less, to
create an exact 90 degree bend.
Obviously we could also use a much sharper
shape and just control the bending angle by
how far we push it into the part, however
this is going to require a bit more attention
and trial and error to create a perfect right
angle.
In order to get an accurate bending radius
we can use a punch with the same shape as
our part, like this one with an 11mm radius.
Keep in mind that there is actually a lot
more to consider when you want to create very
accurate bends.
However this would be out of the scope for
this video and I wouldn’t be the right person
to explain that to you.
But as I said in the beginning, for a home
shop guy this should be good enough for most
use cases.
The project that got me started with all of
this was actually the need for some custom
handle strips for a drawer cabinet.
This is 1mm steel and I need to add two 440mm
long bends which means that there will be
a lot of back and forth involved.
Even though the part is more than three times
as long as the tools, the bends still look
nice and uniform.
You can see some marks from the area where
the part contacted the die, however these
could be polished away fairly easily.
This is also an advantage to cheaply made
steel tools, which often create much more
noticeable marks.
Don’t worry, I am going to install some
nice front panels later, but now I want to
play with my new toy.
Hold on, let me try something
I have seen online.
