Re: Shapemaker II ?

Date: Mon Feb 22 1999 - 21:07:43 EET

>I seem to remember something about a Shapemaker II project going on at the
>University of Utah as well. Has this system been commercialized yet? Any
>details out there??
>Chad Buchanan
>> JPSystem 5 is a desk top rapid prototyping system that was developed and
>> patented at the University of Utah (that's why I'm a little biased).


Yes! We're still here.

Perhaps I should give an intro/update to the list.

Shapemaker II was designed as a large object manufacturing technique.

The first version of the device used a 4 axis controlled hotwire cutter to
produce prototypes from thick (originally 1/2" to 2") layers of
thermoplastic foam. We have a custom software that reads *.stl files and
generates cutter paths to cut ruled surface (angled) edges on these thick
layers. The layers are manually stacked and bonded.

Using this technique we were able to create large prototypes relatively
quickly. For example:

Students from Civil Engineering produced a 20' mold for a canoe in 3 days
(working 24 hrs. per day)

We produced a 3' (48 layer) version of the Stratasys "head" in
approximately 8 hours.

We made a 5' by 5' by 4" airfoil section for a wind turbine that we later
covered with fiberglass, installed, and field tested successfully.

We have made patterns for composite tooling, etc.

The hotwire machine could make anything up to 4' wide by as long as the
material provided. The height limit depended on the operator's ability to
stack the layers.


The cutting accuracy was only +/- 0.25 inches for larger parts.

The cutter wasn't as fast as we would have preferred.

We were limited to very soft thermoplastic foam.

Our latest work:

We have recently replaced the hotwire with a waterjet and redesigned the
machine for closer tolerances.

The waterjet device is currently 2X faster than the old hot wire and will
soon be 4X faster.

The waterjet can cut denser materials including thin layers of solid
plastic and wood, although we have only worked with plastic foams because
they are very fast to cut and very inexpensive when building large parts.

We can typically control the accuracy to within +/- 0.02" within the sheet.
Remember, with layers, you can't do better than +/- 1/2 the sheet
thickness in the stacking direction. Accuracy can also be lost through
sloppy assembly of the layers and inaccurate calibration of the adhesive
thickness between layers.

We have the machine up an running and have actually built a large (roughly
12' by 10' by 24') part for a "customer".

About a commercial machine:

We are a research University. We are not in the business of making parts
or machines commercially. The technology has been patented and we are
seeking an industrial partner to license the technology. Until this
happens, we have established an avenue to have a small number of
demonstration parts made. If you contact me, I can route you to a local
company that will produce sample parts.

I have intended to announce this work to the list for some time, but I have
been terrified that we will get 100 requests for parts in the first week,
or even worse, there will be no response at all!!

We have new work going on involving variable layer thickness and combining
machining with layered manufacturing, but I'll save that for another day.



Charles L. Thomas
Assistant Professor
Department of Mechanical Engineering
University of Utah
50 South Central Campus Drive
Salt Lake City, Utah 84112
FAX (801) 585-9826

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