Re: Inexpensive alternative to other RP processes???

From: Glen Young (
Date: Fri Sep 15 2000 - 22:24:47 EEST

Prof. Bernard,

It's integrated to the point that the CAD files are usually STL files and the same software that we used to cut up and/or nest models for the layer manufacturing process, is also used to prepare the files for milling. Although we could make undercuts in our LOM, we get around this by making multiple pieces in the mills/routers and joining them back together.

Is this an alternative? For big models? - yes. For small models? Who knows. There's nothing like sending an STL file to a machine and getting a complete part.


>>> Alain BERNARD <> 09/15/00 01:05PM >>>
Dear Glen,

Am I right if I say that your solution is an integrated CAD/CAM environment
for rapid milling in 3 to 5 axis ? Is there an alternative for layer
manufacturing techniques or a combinaison of both (milling and layer
manufacturing) ?

Best Regards,


A 07:27 14/09/00 -0500, vous avez écrit :
>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
>For more information about the rp-ml, see
Prof. Alain BERNARD Tel : + 33 (0)3 83 91 27 29
Professeur des Universites + 33 (0)3 83 91 20 09
CRAN ESA CNRS 7039 Fax : + 33 (0)3 83 91 23 90
BP n° 239, 54506 - VANDOEUVRE Cedex - FRANCE
e-mail :

For more information about the rp-ml, see

For more information about the rp-ml, see

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