Re: Inexpensive alternative to other RP processes???

From: Glen Young (
Date: Thu Sep 14 2000 - 15:27:21 EEST

We use one and have replaced using an LOM to create models for our casting process. Our working range is a bit larger than the one mentioned in the article. When we run our twin 5' x 5' tables in tandem we get an effective 5' x 10' x 42" working envelope. Considering you can run larger parts for a longer "unattended" period of time, it becomes quite cost effective. Although our machine is quite a bit larger, the concept is the same, plus we enjoy being able to run a wider variety of material in our machine, including aluminum.
To see the machine, check out Quintax's website and look under their "HD" router. Ours was outfitted with a 40hp Colombo spindle - and is a 5 axis machine, rather than a 3 axis. Can't say enough about their products.

Although the programming time is lengthier compared to using STL files in an RP machine, the actual runtime can be considerably shorter. This is also reduced considering you don't have to piece everything together. We currently use Delcam's Powermill for most of the programming of our models. It still uses the STL format, and we can automate a large portion of the programming through the use of macros.

Glen Young
Lakeland Mold Co.

>>> "SiderWhite" <> 09/13/00 10:59PM >>>
Anybody tried this equipment (gantry router) as an inexpensive alternative
to other RP options and if so, how did it work out for them?
Check out the article below or at:

Best Regards,
Glenn Whiteside

September 2000 A Gantry Router Helps
Reduce Prototype Costs

An industrial design firm used out-of-the-box thinking and found a way to
produce prototypes at about half the cost of conventional SLA and CNC

Choosing a Prototyping System
Implementing the Gantry Router
Gantry Router Becomes Coordinate Measuring Machine

Anderson Design found that this gantry router from Techno-Isel cuts
prototyping costs in half.

Anderson Design Associates, Plainville, CT, is a general-purpose industrial
design house with clients in a variety of industries, including toys, tools,
appliances, heavy machinery, and medical equipment. The company's services
include conceptual design, focus-group research, engineering, purchasing,
and manufacturing support. Preparing prototype models for client review is a
critical part of the product development process at Anderson Design. Until
recently, this was done by hand using urethane foam. The company had no way
of generating models from its Pro/ENGINEER CAD data unless it went to an
outside service. When Anderson Design decided to bring this capability
in-house, management investigated a variety of options.

Company officials found that the initial purchase price of a gantry router
was less than one-fourth that of stereolithography apparatus (SLA) or a CNC
milling machine, and that its day-to-day operating expenses are
significantly less as well. The router's working area is larger than that of
conventional milling machines, and it delivers more aesthetically pleasing
surfaces than SLA. Anderson Design also uses the router as a coordinate
measuring machine. Benefits to clients include a shorter design cycle,
faster turnaround, the ability to evaluate more design options, and lower

Choosing a Prototyping System

Anderson Design first considered SLA, a commonly used method of producing
prototype models, but determined that it had several drawbacks. First, it
was not suitable for all parts. Aesthetically critical parts with complex
surfaces, for example, couldn't be produced with SLA since this technology
makes tiny steps or facets in a curved surface. Second, the least expensive
SLA system cost about $100,000. Third, that system had only a 12-inch by
12-inch by 10-inch-high working area. Many of Anderson Design's projects
would require parts made in sections and bonded together. This is a
time-intensive and costly option. Finally, because operating expenses are
high, SLA models cost nearly twice as much to produce as foam models.

The firm also considered a traditional CNC machine. These machines, made by
companies such as Bridgeport, start at $50,000, not including the CNC
programming software. To get a model with a large enough working area,
Anderson Design would have needed one of the larger machines costing at
least $100,000.

A chance encounter led the company in a different direction: An
advertisement in an industrial directory described a new breed of gantry
router that interfaced with CAD systems, had a large cutting area, and was
offered at a relatively low price. Anderson Design decided to purchase that
machine: the Techno Series III from Techno-Isel, New Hyde Park, NY. The
price was less than $19,000 and the machine operated from Mastercam CNC
programming software (CNC Software, Tolland, CT). Its working area of 24
inches by 36 inches with a Z-axis height of 6 inches was large enough for
most of the firm's projects. The gantry router could also handle all the
materials Anderson Design needed to cut.

The gantry router's accuracy ensures that the models are faithful
representations of the designs created on the computer.

Implementing the Gantry Router

After purchasing the Techno machine and related equipment such as clamps,
tools for installing clamps, lighting, vacuum systems, cutting tools, and
software, the total cost of bringing automated model production in-house was
approximately $40,000. Within three days of installing the Techno system,
Anderson Design was billing clients for work done on the gantry router. This
was largely because the Mastercam software was easy to learn. Although
originally designed for metal working, Mastercam is also well suited for
industrial design models because of its ability to generate the most complex
contours with little programming effort. Mastercam includes IGES, DXF, and
CADL converters so that geometry can be uploaded from many CAD systems,
including Anderson Design's Pro/ENGINEER.

Although the Techno machine was designed for production routing and drilling
on a wide variety of materials -- including wood, plastic, MDF, solid
surfacing materials, and nonferrous metals -- Anderson Design has used it
mostly for cutting models from 7- or 15-pound density polyurethane foam, or
#35 or #65 Ren Shape. Typically, 4-inch-thick sheets of 4-foot by 8-foot
foam are used, although a few polycarbonate parts have also been made.

The machine's 0.0020-inch resolution and repeatability and 0.003-inch
absolute accuracy ensure that the foam models are faithful representations
of the designs created on the computer. This is critical in an industrial
design application because the models must give the client an accurate
likeness of the eventual end product. The Techno machine's accuracy is the
result of several features inherent to the table, such as the use of ball
screws and servo motors. For example, anti-backlash ball screws permit
play-free motion that makes it possible to produce accurate circles and
inlays. The ball screws have excellent power transmission due to the rolling
ball contact between the nut and screw. This rolling contact also ensures
longer life and greater rigidity during the life of the system because of
the reduced wear as compared to ACME screws and nuts, which have a sliding
friction contact.

Gantry Router Becomes Coordinate Measuring Machine

The resolution of the Techno machine has allowed Anderson Design to use the
system in unanticipated ways. Many of the firm's projects involve new
products that must interface with products already on the market. The
existing product may not be made by Anderson Design's client, which means
that the industrial design team doesn't have access to the product's
documentation or CAD files. In these situations, the designers go out and
buy the product and then figure out how to design an interface to it. 3D
digitizing offers one method of capturing the surfaces of the product for
use in the CAD system, but Anderson Design has found most digitizing
techniques to be impractical. Laser reflective scanning, for instance,
generates too much information for the designer to work with since it
captures thousands of x, y, and z coordinates. It is impossible to fit a
surface through all these points, so much of the data is eventually

Anderson Design found a better way to get surface data into its CAD
system -- by modifying the Techno machine to function as a coordinate
measuring machine (CMM). After securing an object to the machine's table,
just as if it were going to be milled or routed, an operator manually moves
the machine's crosshead until a flexible touch probe positioned in the tool
holder touches the object. The machine's display shows the x, y, and z
position of the probe at that point. This value is recorded manually. After
the designer has captured a number of points, they are entered into the CAD

The benefit of this technique is that a designer has complete control over
the number of coordinates that are recorded. Anderson Design has found that
between 70 and 80 planned points give a better indication of the surface
than the thousands of points that are captured with a laser scanner. Once
the 70 or 80 points are indicated in the CAD system, the designer uses them
to guide the creation of the existing object's surfaces. This use of the
Techno machine once saved Anderson Design six months -- the time normally
required to go through the legal process of obtaining drawings for a
particular product. They simply bought the product and captured its
coordinates in three days.

In approximately 300 hours of operation, Anderson has had no problems with
the Techno machine. This is partly due to the strength and rigidity of the
table, which is constructed from extruded aluminum profiles that provide
easy clamping capability. The machine also has four ground and hardened
steel shafts and eight recirculating bearings in each axis. This shaft and
bearing system produces very smooth, play-free motion and an extremely rigid
system that produces high-quality cuts. For Anderson Design, PC-based CNC
has proved to be an affordable, practical, and accurate option for the
production of industrial design prototypes, as well as a good coordinate
measuring machine from time to time. To the firm's clients this means
shorter lead-times, lower costs and -- most important -- better designs.

This article was prepared by Tim Van Leeuwen, Engineering Manager, Anderson
Design Associates, Plainville, CT.

For More Information
Contact Techno-Isel, 2101 Jericho Turnpike, New Hyde Park, NY 11040. Phone:
516-328-3970 Fax: 516-326-8827 E-mail:

For more information about the rp-ml, see

For more information about the rp-ml, see

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