3D Printing a Yacht Hull Mold
from a 51-foot-long
yacht hull mold to
only a single mold
may be needed for
the manufacture of
larger vessels, such
The printed sections
of this test
mold are made of carbon fiber reinforced ABS from Techmer
PM. ABS was chosen because of its physical properties
and relatively low cost compared to other reinforced
Thermwood has already 3D printed a full-size pleasure
boat master pattern which has been used to produce
multiple production boat hull molds. While this demonstrated
the value of additive manufacturing small boat
tooling, much larger vessels, yachts for example, require
a different approach. In these instances, since only a single
mold is needed, it is desirable to print the mold itself
rather than print a plug or pattern from which multiple
production molds can be made.
To demonstrate to the industry how this might work,
Thermwood printed a 10-foot section from a 51-foot long
yacht hull mold. This rather unique mold design was
specifically developed for additive manufacturing. It is
printed in sections, each about five foot tall. These
printed sections are then bound together both chemically
and mechanically using high strength polymer cables
into two mold halves. The two mold halves then bolt together
to form a complete female mold for the yacht hull.
Each mold section has a molded in rocker. When the
mold is fully assembled, it rests on the floor on these rockers.
At this point, the mold can be rolled over to tilt about
45 degrees to either side, kind of like a giant rocking chair.
This allows for easier access during the layup process. A
set of molded wedges are clamped to the rockers to hold
the mold in the desired position. Once the hull has been
laid up and fully cured, the mold is rolled to level and the
printed wedges are clamped to both sides, holding them
level. Then the two mold sides can be un-bolted and slid
apart to release the finished boat hull.
Certain thermosets will work directly on the ABS
molded surface using just traditional mold release practices;
however, other thermoset materials are based on
solvents that can chemically attack the ABS polymer.
To prevent this, Thermwood has experimented with
several protective coatings. While it appears that this approach
will work today for certain thermosets, the ideal
would be to develop a low-cost polymer that is chemically
resistant to the other thermoset solvents and eliminate
the need for a protective coating.
These demonstration pieces were printed and trimmed
on Thermwood’s 10x10 foot LSAM MT, the smallest and
lowest cost additive manufacturing system currently available.
The entire mold section, made of four printed pieces,
weighs 4,012 pounds and required 65.5 hours to print.
For more information, contact Duane Marrett, Thermwood Corporation, 904 Buffaloville Rd., Dale, IN 47523, 800-533-6901, E-mail: firstname.lastname@example.org.