Product Design and Manufacturing
Introducing Mike Hilgendorf
Engineer / Product Designer including part & mold design of automotive, medical, electro-mechanical and fuel
Process experience includes: injection molding (including sample
start-ups), roto-molding, metal fabrication, plastic welding and fabrication.
Skills include: SolidWorks, Master Cam, AutoCAD, Agile, PDM Works, Injection mold
making, mold repair, molding technician trainer.
Training includes: RJG Decoupled Molding, part & mold
cost estimating, Lean manufacturing, DFMA, FMEA, BOM creation.
Plastics Part & Mold Design
Mike is an expert in all aspects of plastics manufacturing from part design
to mold design to processing and cell assembly. Injection molding is his forte`
and he has worked for some of the largest molders in the world. Mike has
relationships with several key manufacturers in the USA
and Asia. Doing it right the first time makes all the
difference! Mike can make sure you get the right designs and quality molds at
great prices which can make a huge difference in getting your project completed
within budget. Let his experience help you make the right decisions.
Rotational molding is another area of Mike's expertise. Often referred to as
roto-molding, the process offers low cost molds for large hollow shaped parts
such as tanks, floats, enclosures and cases. Many sheet metal products can be
redesigned using roto-molding allowing threaded inserts and metal parts to be
molded right into the part. This can save costly secondary assembly operations
while avoiding less reliable bonding or sealing operations. Ask if your product
is a fit for roto-molding.
offers contract designing services with over 15 years of experience bringing
products to life. Whether you need a concept design modeled in 3D or drawings
for manufacturing, he can help. Products can be made from plastics, sheet
metal, structural steel and more. Clients and employers have found Mike to be
skilled in creating cost effective, robust designs, mindful of easy assembly
examples can be seen below;
Case study #1
A fuel cell company
needed a plastic part with features that had never been done before via
injection molding. Several companies turned them away saying it was not feasible
when Mike was asked to take a look. The Noryl part was very thin (.025”)
and long, which was a challenge in itself, but they also needed a screen area
in the part consisting of 1320 holes spaced .012” apart in a specified
area. Holes needed to be .009 to .011” in diameter. See the photo below
of an actual molded part. Mike built the mold and ran the parts on the clients
own molding machine purchased for this challenge.
HOW DID HE DO IT?
The challenge of filling
a thin part was accomplished with a muti-gating design. Mike devised this
design without the aid of “Mold Flow” relying on his experience
instead of expensive software. Small “Viper” gates were created to
develop material shear as it passed through them, keeping the plastic molten
The screen (a field of
1320 holes) was a little more challenging and took some creative thinking as it
is impossible to flow Noryl the distance needed through the string-like cross
sections of the screen. An insert was created in the mold with 1320 cone shaped
pins tapering from .013 at the base to .008” at the tip. They were
produced by a staight drilled electrode using an orbital edm process that swept
farther around as it raised up on the pins. The
delicate pins could not shut off for fear of smashing the tiny ends so the pin field area was made thicker than the rest of the part. The
conical pins also protruded higher than the rest of the part but short of
shutting off against the top of the mold. Rather than having to flow plastic
through the strings to fill the screen area, this thickened area over the pins
allowed plastic to flow above the field and down between each pin with ease.
A secondary planing
operation was then used to cut the thick area down to the thickness of the rest
of the part exposing the field of tiny holes. Prior to this, parts were being
produced by machining plate stock to the desired thickness and circuit board
drilling the screen field. The machining process cost $64 per piece, but with
Mike’s mold parts were produced for < $1.
Case study #2
A Fuel Cell company
needed a manifold injection molded with internal curved channels like the
machined prototype pictured below. Zinc suspended in fluid was passed through
the manifold and delivered to each cell. To make the prototype they machined
two pieces and glued them together. Glue oozes into the channels and along with
gaps would trap zinc which eventually built up and caused a blockage. Molding a
one-piece part would be much more desireable but very challenging. Mike was
asked to take on this challenge and he accepted.
Mike decided that
“Lost Core” molding would be the best possible approach. This
process uses a technology that involves inserting a core (generally
of cast metal) into an injection mold, overmolding it with a thermoset A polymer-based liquid or powder that becomes solid
when heated, placed under pressure, treated with a chemical or via radiation.
The curing process creates a chemical bond that, unlike a thermoplastic,
prevents the material from being remelted. See thermoplastic. or
engineering thermoplasticA polymer material that turns to
liquid when heated and becomes solid when cooled. There are more than 40 types
of thermoplastics, including acrylic, polypropylene, polycarbonate and
polyethylene. ..... material,
and then melting or washing the core out of the part. PEEK was chosen as the
housing material and a eutectic core of tin / bismuth
was identified with a low enough melting point below that of PEEK. The resulting part is pictured
along with the prototype below. For more on lost core molding follow this link:
Case study #3
San Diego Company needed a quick turn around on 3 parts of a speaker assembly.
Concept designs existed that were not injection moldable. A moldable design and
100 parts were needed for a trade show in 4 weeks. Mike took the designs and
made the needed design changes in 4 days. Molds were designed by China sources
in 3 days under Mike’s direct oversight and molds were completed in 2
weeks. 100 pieces of 3 different parts were received in time for the
show… ANOTHER HAPPY CUSTOMER ! See part
photos & mold dwg below.