PD&D: You also experimented with several different
technologies for controlling the stepper motors used to
drive the printer and extruders. What were the problems you
encountered and how did you finally overcome them?
Reytblat: This was a long journey, and was ultimately the cause
of a large portion of the delay we’ve experienced in bringing our
machines to market.
Our goal was to build a machine with four extruders and with
larger than usual motors (NEMA23 vs. NEMA17), so we could
achieve reasonable printing speeds with a much heavier printer.
From the outset, we knew this would be difficult.
At the start, we designed our machine around an existing off-the-shelf Arduino compatible micro-controller. The board was
great, and the company behind it was even better. Alas, after
many months of trying we had to give up on it. We couldn’t solve
the problems of wiring, due to how the connectors were laid
out. It was far too expensive to produce, and it just couldn’t be
maintained in the field.
So the next approach we tried was to go completely in the
opposite direction. We partnered up with a great little custom
electronics house right here in New Jersey to design and
manufacture a complete, from scratch, fully integrated custom
controller that would have all the functionality we needed,
including all motor drivers, all on one board. That also took many
months, but in the end had to be abandoned as
Finally, we ended up with a combined
architecture which gave us the best of both
worlds. Our main controller is a large custom
Shield sitting on top of a standard, off-the-shelf
Arduino Mega micro-controller board. This gives
us the best of both worlds: a well-known, cost-effective, reliable central processor with plenty of
memory and I/O and a large-area custom board
which allowed us to organize our connectors
and other peripheral circuitry just the way we
In particular, it allowed us to drastically simplify
and reduce the costs of all the wiring in the
system, and at the same time improve our ability
to support our customers for a long time to
come. In the future, the modularity afforded by this approach will
enable us to upgrade the electronics over the years with excellent
backward compatibility and easy field installation. And our partner
company can still make it reliably for us right here in New Jersey.
PD&D: Your extruder’s design enables it to handle a very
wide range of materials, but you’ve already hinted at
developing other extruders which will allow your machines
to print even more exotic stuff. Can you comment on what
types of materials you’re aiming for and when you expect to
roll out those capabilities?
Reytblat: We have very high ambitions. We think we’ve figured
out how to 3D print with metal and with glass at a much lower
cost than possible today. We’ve already filed for a patent on the
former, and are working on the patent application on the latter.
If we’re successful in developing this technology, I think it will
revolutionize the industry by reducing the cost of metal and glass
3D printing to a level unheard of before. Stay tuned!
PD&D: There are rumors that you originally decided to
design a 3D printer to help you build a new type of rocket
engine. Are those rumors true? And will any of the new
extruders you’ll be working on be related to your rocketry
Reytblat: That is indeed how we started
on this journey. The metal extruder is exactly
what needed to do that. However, as so often
happens, the journey became the goal in and
of itself. And so these days rocketry is a hobby,
and 3D printing is the main focus of what we do.
When the metal extruder is done, I’ll certainly try
printing a rocket engine. But I think 3D printing
is now in my blood, so we’ll stay focused on it
for a very long time – it’s just too much fun! And
in particular, the approach we’re taking to it,
enabling people to print things they can’t print
any other way, is very satisfying. I really enjoy
coming to work every day and taking on the
challenges of engineering and manufacturing.
And I love our crew!
3DMonstr’s T-Rex 3D series offers build
volumes of up to 24 x 24 x 24”.
3DMonstr printers undergoing assembly at the company’s main plant,
located in West Windsor, N.J. All image credit: 3DMonstr.
Ben Reytblat, 3DMonstr’s CEO, poses with his creation.