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sensors-ultrasonic 582 Ultrasonic Distance Measurement In 1947 American test pilot Chuck Yeager broke the sound barrier. The plane he was fly- ing, Glamorous Glennis (today on exhibit at the Smithsonian in Washington, D.C.) flew faster than sound waves can travel through the air. Sound travels at about 1,130 feet per second at sea level. While temperature, humidity, and atmospheric pressure change the speed of sound, for general purposes we can con- sider it a constant and use it for distance measurement. For years, the fancier Polaroid instant cameras used an ultrasonic focusing system to ensure clear, sharp pictures. Their ultrasonic system worked so well the company was able to make a tidy extra profit on sell- ing the sensors to other manufacturers (Polaroid recently sold the ultrasonic business unit). Theory of Operation To measure distance, a short burst of ultrasonic sound—usu- ally 40 kHz for most ultrasonic ranging systems—is sent out through a transducer (essentially a fancy term for a speaker). The sound bounces off an object, and the echo is received by another transducer (this one a specially built ultrasonic micro- phone). A circuit them computes the time it took between the transmit pulse and the echo and comes up with distance. Given a speed of 1,130 feet per second (about 344 meters per second), the time it takes for the echo to be received is in microseconds if the object is within a few inches or feet of the robot. Though a few microseconds is a short period of time on the human scale, it’s no problem for modern fast-acting CMOS and TTL ICs. Given a travel time of 13,560 inches per second for sound, it takes 73.7 microseconds (0.0000737 seconds) for sound to travel 1 inch. Or if using centimeters, sound travels 34,442.4 centimeters per second, or 29.03 microseconds per centimeter. In any ultrasonic ranging sys- tem, the total transit time between transmit pulse and echo is divided by two, to compensate for the round-trip travel time between the robot and the object. To calculate in inches, the remaining value is divided by 73.7 (for inches) or 29.03 (for centimeters) to determine the distance. Maximum and Minimum Ranges Sound waves eventually dissipate, so there is a maximum range you can expect from your ultrasonic distance measurement sensor (the range is reduced even more outdoors, where wind disperses sound waves). The maximum distance of the Polaroid ultrasonic transducer is about 35 feet when used indoors, and a little less when used outdoors, especially on windy days. Other ultrasonic sensors have the same, or even less, maxi- mum range. A range of 3 to 6 meters is usually adequate for robotics, where it is not nec- essary to detect objects outside the immediate field of interest. Likewise, ultrasonic systems exhibit minimum working distances. Because the Polaroid ultrasonic transducer is used for both transmitting and receiving, its minimum distance is 6 inches. The reason: The ranging board cannot listen to sound echoes until the transmit phase is complete. The transducer continues to vibrate slightly for a short period after sending a pulse of ultrasonic sound. During this “blanking” period, which is required to eliminate false readings, return echoes are ignored. Ultrasonic sensors that use separate transmit and receive transducers do not require a blanking period, as long as the transducers are microphonically isolated (that is, mechani- cal vibrations from the transmitter are not picked up by the receiver). Minimum working distances can be effectively reduced to about an inch. Ultrasonic sensors use the speed of sound to measure distance. Fascinating Electronics, Inc. 204137 31525 Canaan Rd. Deer Island, OR 97054-9610 USA (503) 397-1222 (503) 397-1191 (800) 683-5487 fascinating@columbia-center.org http://www.columbia-center.org/ fascinating/ Among other interesting products, Fascinating Electronics markets an affordable ultrasonic sensor and backs it up with experimental software. Attach the sen- sor to a motor, as shown on the Web site, to build a scanning “radar” unit. See also their Dual-Wiper Potentiometer and Humidity Sensor. x V Felio Parking Sensor 203023 Lot 5, Jalan Gudang 16/9 Seksyen 16 40200 Shah Alam Selangor Darul Ehsan Malaysia +60 35512 7763 +60 35512 8163 inquiry@feliogroup.com http://www.feliogroup.com.my/ Makers of an ultrasonic parking sensor that is attached to the bumper of a car. Interesting idea that can be applied to robotics. Some sample products available for sale directly from the Web site. x Massa Products Corporation 202473 280 Lincoln St. Hingham, MA 02043 USA sensors-ultrasonic 583 Ultrasonic Sources Acroname http://www.acroname.com/ All Electronics Corp. http://www.allcorp.com/ B.G. Micro http://www.bgmicro.com Hobby-Electronics.com http://www.robot-electronics.com Jameco Electronics http://www.jameco.com/ Hacking Polaroid cameras for their ultrasonic sensors: http://www.robotprojects.com/ http://www.techtoystoday.com/ http://incolor.inetnebr.com/bill_r/robotics.htm Goolge.com search phrases: polaroid ultrasonic hack OR hacking polaroid 6500 ultrasonic robotics Marlin P. Jones & Associates, Inc. http://www.mpja.com/ Polaroid OEM Components Group http://www.polaroid-oem.com Robot Store http://www.robotstore.com/ Robot Store (HK) http://www.robotstorehk.com (781) 749-4800 (781) 740-2045 (800) 962-7543 sales@massa.com http://www.massa.com/ High-end ultrasonic sensors. x Mekatronix, Inc. 202970 316 NW 17th St. Ste. A Gainesville, FL 32603 USA tech@mekatronix.com http://www.mekatronix.com/ From the Web site, “Mekatronix is a manufacturer of autonomous mobile robots, robot kits, microcontroller kits and robot accessories, as well as educational materi- als related to science and robotics. Our robots and microcontrollers provide students with valuable hands- on experience in programming and engineering con- cepts.” Products are available through a few dealers. x sensors-ultrasonic 584 Mekatronix Web page. Migatron 202116 935 Dieckman St. Woodstock, IL 60098 USA (815) 338-5800 (815) 338-5803 (888) 644-2876 info@migatron.com http://www.migatron.com/ Makers of high-end industrial ultrasonic sensors. Web site contains datasheets in HTML and Adobe Acrobat PDF format. x Paul’s Cheap Sonar Range Finder Design 203466 http://www.hamjudo.com/sonar/ How Paul built an inexpensive ultrasonic sonar system using a PIC16F84 microcontroller. Polaroid Ultrasonic Sensors / SensComp, Inc. 202118 P.O. Box 530790 Livonia, MI 48153-0790 USA (734) 953-4783 (734) 953-4518 http://www.senscomp.com/ SensComp, Inc. now wells the Polaroid ultrasonic sen- sors and developer’s kits (“L”, “K” & 9000 Series), along with supporting components. You can order products online or from a reseller, such as Acroname. x sensors ultrasonic 585 Sonar Transducers: Buying New or Hacking Old There are a variety of ways to implement ultrasonic ranging: • Purchase a ready-made non-Polaroid sonar ranging system, such as the SRF08 and SRF04 from Hobby-Electronics.com. The SFR04 requires your robot to calculate transit time of the ultrasonic pulse; the SRF08 handles all calculations for you and returns the result as a digital value. • Purchase a ready-made Polaroid 6500 sonar ranging system. Sources include Acroname.com and RobotStore.com. The 6500 consists of a gold-plated Polaroid ultra- sonic sensor and a driving board, as well as engineering notes and application sheets. • Purchase transducers and build your own ultrasonic distance board. Matched sensors are available from a number of sources, including Jameco, Marlin P. Jones, B.G. Micro, and All Electronics. They are relatively inexpensive (usually under $5 for the pair). You need a circuit to provide 40 kHz to the transmitter, and another to amplify and lock onto the 40-kHz signal from the receiver. • Salvage a sonar ranging system from a used Polaroid camera, such as the Sun 660. These use sensor boards similar, but not identical, to the Polaroid 6500. Using the sources provided in this article, you can hack the ranging board and connect it to any of a number of microcontrollers. The ranging board requires its own 6-volt supply. Acroname—http://www.acroname.com All Electronics—http://www.allcorp.com/ B.G. Micro—http://www.bgmicro.com/ Jameco Electronics—http://www.jameco.com/ Marlin P. Jones—http://www.mpja.com/ Robot Electronics—http://www.robot-electronics.co.uk/ Robot Store—http://www.robotstore.com/ SensComp—http://www.senscomp.com/ Robobix 203706 http://www.geocities.com/robobix/ Circuits include: ultrasonic distance measurement, light-reflection distance measurement, and simple infrared object detection. Senix Corporation 202113 52 Maple St. Bristol, VT 05443 USA (802) 453-5522 (802) 453-2549 (800) 677-3649 http://www.senix.com/ Senix (not the same as semiconductor maker Scenix, which is now Ubicom) is a maker of ultrasonic distance measurement sensors for machinery and industrial automation. x Ultrasonic Imaging (usi) Project 203042 http://www.geocities.com/baja/ravine/ 4301/usi_project/index.htm Or “Fun with Polaroid 6500 modules and a bit of cun- ning,” written by Jim Whiteside. Jim provides notes on using the Polaroid 6500 ultrasonic board and trans- ducer, writing PIC code for Polaroid sonar modules, and more. sensors-ultrasonic 586 ”Supplies Supplies are consumable goods that you use and replace as needed. This section, and the ones that follow, detail consumable supplies commonly used in basic robot construction, including casting and mold-making materials (should you be casting your own parts), chemicals, glues and adhesives, and paints. Refer also to the resources in this section for companies that provide a wide variety of materials and supplies. These might be considered “general stores” for robot building and carry a broad line of industrial compo- nents and consumables. SEE ALSO: Fasteners: To put your robot together Materials (various): Hardware and construc- tion parts Retail-Arts & Crafts: More sources for paints, glues, and adhesives Retail-Hardware & Home Improvement: Local and online retailers for a variety of supplies Enco Manufacturing Co. 203672 400 Nevada Pacific Hwy. Fernley, NV 89498 USA (770) 732-9099 (800) 873-3626 info@use-enco.com http://www.use-enco.com/ See listing under Tools. x d V Grainger (W.W. Grainger) 202928 100 Grainger Pkwy. Lake Forest, IL 60045-5201 USA (847) 535-1000 (847) 535-0878 http://www.grainger.com/ See listing under Materials. x d V Graybar Electric Company, Inc. 203973 34 N. Meramec Ave. Clayton, MO 63105 USA (314) 512-9200 (314) 512-9453 (800) 472-9227 http://www.graybar.com/ See listing under Materials. x V McMaster-Carr Supply Company 202121 P.O. Box 740100 Atlanta, GA 30374-0100 USA (404) 346-7000 (404) 349-9091 atl.sales@mcmaster.com http://www.mcmaster.com/ See listing under Materials. x d $ V WESCO International, Inc. 203974 4 Station Sq. Pittsburgh, PA 15219 USA (412) 454-2200 (412) 454-2505 http://www.wescodist.com See listing under Materials. x V supplies 587 Copyright 2003 by Gordon McComb. Click Here for Terms of Use. ”Supplies-Casting & Mold Making Casting and mold making aren’t skills shared by most robot builders, but they should be. With little training, and only a few dollars in materials, you can produce your own parts for your robo-creations. The process is simple enough: Use plaster or some other material to create a mold from an existing element. One possibility is hubs for wheels. As long as you have one hub for the model, you can make additional ones as needed. The hub can be something you’ve purchased, retrofitted from some other item, or custom made using wood, metal, or plastic. After the mold has dried and cured, you can then cast parts from it. Casting can be made using hard or soft rubber, even certain low-temperature metals. The benefits of casting are twofold: First, you can save money by making your own parts. Buying new sprock- ets, gears, wheel hubs, and other components can get expensive. Once you make a mold, each casting might cost only 25 cents each, depending on the material- obviously, some casting materials are more expensive than others, but overall, it’s pretty inexpensive stuff. Second, you can “mass-produce” unique items, rather than hand-make them one at a time. You need only build one model, then make duplicates with casting. This section lists resources concerned with casting and mold making, including materials and instruction. In addition to the casting arts, this section also includes sources for vacuum forming, which is a process of mak- ing molded shapes with thin plastic sheets. SEE ALSO: Books-Technical: Find books about casting Materials-Plastic: Includes vacuum-formable plastic sheets Retail-Arts & Crafts: Most carry consumer- grade casting and mold-making supplies Abatron, Inc. 203182 5501-95th Ave. Kenosha, WI 53144 USA (262) 653-2000 (262) 653-2019 (800) 445-1754 caporaso@abatron.com Alumilite Corporation 203180 315 E. North St. Kalamazoo, MI 49007 USA (616) 488-4001 (800) 447-9344 world@alumilite.com http://www.alumilite.com/ Alumilite sells casting resins and mold-making materi- als. The company sells supplies in small quantities or bulk (up to 100-gallon drums), as well as Super Casting Kit and Mini Super Casting Kit, both designed for the consumer market. Additional products: • Urethane dyes • Metallic powder • Microballoons • Alumilite 610 foam (expands to 6-10 times the origi- nal liquid volume) supplies-casting & mold making 588 Abatron online. http://www.abatron.com/ Abatron manufactures and distributes adhesives, sealants, coatings, epoxy, polyurethane, and various other resins. Of particular interest to robot builders is their casting and mold-making supplies. Oneinterestingproduct is Woodcast, a two-partlightcast- ing material that is machinable and even stainable. You basically mix up the liquid and pour it into a mold. You can shape and sand the material afterward. If the “natural look” isn’t right for your robot, there’s also Abocast, two- part clear liquid for casting. Abocast is a tooling resin, so you can use it to make complex shapes should you have access to a mill, lathe, or computerized router. x The Web site includes numerous how-tos on mold mak- ing and casting. Product is available through dealers; a dealer locator map is provided at the site. Dealers are located in North America, Australia, Singapore, and the U.K. x V American Art and Clay Co., Inc. (Amaco) 203984 4717 W. 16th St. Indianapolis, IN 46222 USA (317) 244-6871 (317) 248-9300 (800) 374-1600 http://www.amaco.com/ Amaco manufacturers and sells (principally through retailers) a line of arts and crafts products which include WireForm wire mesh (can be sculpted to form a shape), Friendly Plastic (softens in warm water), Easy Metal (thin metal foil), and glow-in-the-dark paints. x Armorcast 202045 P.O. Box 14485 Santa Rosa, CA 95402-6485 USA (707) 576-1619 (707) 576-1619 timdp@armorcast.com http://www.armorcast.com/ Polyurethane resin molds. Much of Armorcast’s prod- uct line is “scenery,” things like miniature trees and rocks for models. Suitable for robot display or for a playing field for your combat bot. x Bare-Metal Foil Co. 203236 P.O. Box 82 Farmington, MI 48332 USA (248) 477-0813 (248) 476-3343 contact@bare-metal.com http://www.bare-metal.com/ Bare-Metal Foil sells bare metal foils, silicone RTV, cast- ing resins, decals, and other products for the model maker. Useful how-to articles. x Barnes Products Pty Ltd. 203174 6 Homedale Road Bankstown, NSW, 2200 Australia +61 2 9793 7555 +61 2 9793 7091 info@barnesproducts.com.au http://www.barnesproducts.com.au/ Barnes is a supplier of silicone rubber, polyurethane, epoxy, polyester resin, foam latex, and other casting and mold-making materials. V Botanical Science 203523 P.O. Box 10909 San Bernardino, CA 92423 USA (909) 382-0175 (909) 382-0179 leanne@botanicalscience.com supplies-casting & mold making 589 Discount Dental Supply http://207.69.159.104/DDS/Home2.html Dental plaster M-PACT Worldwide http://www.mpactmed.com/ Orthopedic medical supplies: fiberglass casting tape, plaster-of-Paris casting New Mexico Clay Inc. http://www.nmclay.com/ Casting plasters, dental plaster http://www.botanicalscience.com/ Makers of 3-D Gel, a nontoxic, very quick setting mold- ing compound. Also clay and plaster products. Sold at arts and crafts stores. x Burman Industries, Inc. 203413 14141 Covello St. Ste. 10-C Van Nuys, CA 91405 USA (818) 782-9833 (818) 782-2863 info@burmanfoam.com http://www.burmanfoam.com/ See listing under Materials-Metal. x V Castcraft 203181 P.O. Box 17000 Memphis, TN 38187-1000 USA (901) 682-0961 http://www.castcraft.com/ Castcraft calls itself “the place for mold making and casting.” Along with metal, plastic, and plaster casting, they offer products, plans, and parts to build a home- made vacuum forming machine. x V Compleat Sculptor, Inc., The 203244 90 Vandam St. New York, NY 10013 USA (212) 243-6074 (212) 243-6374 (800) 972-8578 tcs@sculpt.com http://www.sculpt.com/ Materials, supplies, tools, and service for sculpting, mold making, and casting. x V Composite Store, The 203557 P.O. Box 622 Tehachapi, CA 93581 USA (661) 822-4162 (661) 822-4121 (800) 338-1278 info@cstsales.com http://www.cstsales.com/ See listing under Materials-Fiberglass & Carbon Composites. x V Douglas and Sturgess, Inc. 203178 730 Bryant St. San Francisico, CA 94107-1015 USA (415) 896-6283 (415) 896-6379 Sturgess@ix.netcom.com http://www.artstuf.com/ Casting and mold making for the sculptor: sculpture tools, material, and supplies. Much of it is also useful for most any casting and mold-making project that might involve robots or robot parts. Interesting prod- ucts include: • Atomized metal powders • Coating materials • Latexes and other flexible mold materials supplies-casting & mold making 590 Castcraft Web site. • Foam board materials (such as pink styrene, polyurethane) • Fabricform (plastic laminated between pieces of f- abric) • Altaform (general-use substrate in three different weights) • FormFast (also known as celastic): plastic-impreg- nated fabric softens with acetone; can be shaped and left to reharden x V DRU Industries, Inc. 203245 3800 Midway Pl. NE Unit H Albuquerque, NM 87109 USA (505) 344-0202 (505) 345-2900 (800) 600-6653 magic@drua-1.com http://www.wrldcon.com/dru/ Sellers of Smooth-on, clay products, adhesives, tapes, and mold-making supplies. Eager Plastics, Inc. 203177 3350 W. 48th Pl. Chicago, IL 60632-3000 USA (773) 927-3484 (773) 650-5853 http://www.eagerplastics.com/ Eager Plastics sells materials for plastic casting and mold making. Products include: • Flexible mold-making silicones • Flexible mold-making urethanes • Semirigid and rigid casting urethanes • Epoxy systems • Pigments and dyes • Polyester resins and fiberglassing supplies • Fiberglass fabric • Resin fillers and additives • Release agents For ideas on what you can do with casting and mold making, check out the finished products photos, such as Star Trek VI phasers (made with a smooth casting resin). x V Environmental Technology, Inc. 203532 South Bay Depot Rd. Fields Landing, CA 95537-0365 USA (707) 443-9323 (707) 443-7962 mail@eti-usa.com http://www.eti-usa.com/ Manufacturer of casting and molding supplies: epoxies, adhesives, casting compounds, latex rubber, etc. Avail- able in industrial packaging. Contact the company for more information. The Castin’Craft brand, available in smaller quantities, can be purchased at local craft stores. x eWellness 203491 7750 Zionsville Rd. Ste. 850 Indianapolis, IN 46268-5116 USA (800) 472-0604 info@ewellness.com http://www.ewellness.com/ Medical supplies, including fiberglass casting sup- plies—you use it to make stuff for robot bodies, of course, not to fix broken arms and legs. For con- sumers. x V Far West Materials 203238 405 Woodland Ave. Walla Walla, WA 99362 USA (509) 522-0556 supplies-casting & mold making 591 [...]... USA (61 3) 59 6- 0 350 20 2757 tools 61 5 Nolan Supply Corporation (61 3) 59 6- 6 030 (800) 26 7-8 735 customerservice@leevalley.com http://www.leevalley.com/ Wide assortment of woodworking tools x V Malcom Company, Inc 20 3815 167 6 East Main Rd Portsmouth, RI 028 71 USA (401 ) -6 8 3-3 199 (401 ) -6 8 2- 1 904 (888) 80 7-4 030 http://www.malcom.com/ See listing under Materials-Metal x x 20 2 8 26 75 Maxess Rd Melville, NY 1174 7-3 151... tools, static-control products, test and measurement gear, and hand tools ” Conductive ink pen Photo courtesy of ITW Chemtronics P.O Box 1050 52 464 7 Hugh Howell Rd Tucker, GA 3008 5-5 0 52 USA (770) 24 3-8 800 (770) 24 3-8 899 20 2 62 4 20 2 568 127 78 Brookprinter Pl Poway, CA 920 64 USA (858) 67 9-8 787 (858) 67 9-8 909 (800) 49 2- 7 7 26 sales@wassco.com http://www.wassco.com/ x LPS Laboratories 20 361 4 934 7-1 93rd St Surrey,... Woodworking and Hardware 4 365 Willow Dr Medina, MN 55340 USA ( 763 ) 47 8-8 20 1 ( 763 ) 47 8-8 395 (800) 27 9-4 441 support@rockler.com http://www.rockler.com/ Tools for schools Several catalogs available: general tools, art materials, safety, and industrial machine shop V Screwfix Direct Ltd 20 321 5 20 39 86 20 21 West County Rd C2 Roseville, MN 55113 USA (65 1) 60 4 -6 6 02 (65 1) 60 4 -6 60 6 (800) 32 8-4 64 4 satco@mindspring.com... Products 20 2 62 2 122 00 Thatcher Ct Poway, CA 920 64 USA (858) 48 6- 8 388 (858) 48 6- 8 398 caig 123 @caig.com http://www.caig.com/ Fisher Scientific Electronics-Soldering: Additional chemicals Alfa Aesar Alfa Aesar is manufacturer and supplier of chemicals, metals, and materials for research, development, and production applications 20 25 76 1801 Morgan St Rockford, IL 61 10 2- 2 69 0 USA (815) 96 8-9 66 1 (800) 43 3-7 928 gcw.tech@woodsind.com... Electronic testing tools Applied Industrial Technologies 20 3445 One Applied Plaza Cleveland, OH 4411 5-5 053 USA (21 6) 42 6- 4 189 (21 6) 42 6- 4 820 (877) 27 9 -2 799 products@apz-applied.com http://www.appliedindustrial.com/ x V Home Lumber Company x 400 Nevada Pacific Hwy Fernley, NV 89498 USA 20 27 56 P.O Box 3110 Bellingham, WA 9 822 7-3 110 USA (570) 54 6- 9 66 3 (800) 52 3-4 777 csr@grizzly.com http://www.grizzly.com/ Woodworking... Tool Peddler 20 2459 9907 SE 82nd Ave Portland, OR 9 7 26 6 USA (503) 77 7-8 66 5 20 2759 53 Meadow St Waterbury, CT 067 02 USA (20 3) 57 3-0 750 (20 3) 75 3-9 0 42 (800) 22 2- 6 133 http://www.tools-plus.com/ Tools-Plus is an online tool retailer They have everything: hand tools, power tools, metalworking machines and helpers, accessories, and more Brand names x V (503) 77 7-0 24 6 (800) 34 4-8 469 TP Tools & Equipment tools@toolpeddler.com... Materials Hot-melt glue guns and glues For both hobby and professional use Full-line catalogs are in Adobe Acrobat PDF format IPS Corporation x V HST Materials, Inc 777 Dillon Dr Wood Dale, IL 60 191 USA (63 0) 76 6- 3 333 (63 0) 76 6- 6 335 info@hstmaterials.com 20 2145 20 3803 455 West Victoria St Compton, CA 9 022 0 USA (310) 89 8-3 300 (310) 89 8-3 3 92 (800) 42 1 -2 67 7 http://www.ipscorp.com/ IPS makes the WELD-ON brand... receive don’t meet expectations x V Tucker Electronics 20 2955 1717 Reserve St Garland, TX 750 42 USA (21 4) 34 8-8 800 (21 4) 34 8-0 367 (800) 52 7-4 6 42 http://www.tucker.com/ New and reconditioned test gear A local favorite of Dallas/Fort Worth–area robot builders x V Wacky Willy’s 20 3431 29 00 S.W 21 9th Ave Hillsboro, OR 97 123 USA (503) 64 2- 5 111 (503) 64 2- 9 120 wacky@wackywillys.com http://www.wackywillys.com/... Systems 27 01 Westland Court Unit B Cheyenne, WY 820 01 USA (307) 63 5 -2 26 9 (307) 63 5 -2 29 1 (800) 53 8-1 493 20 2188 Used instruments and parts (scopes, meters, and analyzers) All come with a 90-day warranty for parts and labor; 10-day return-it-if-you-don’t-like-it inspection Does mail order Meter Supplies Your meter will come with a pair of test leads—one black and one red The leads are terminated with needle-like... Micro-Mark See listing under Materials x Kingston Vacuum Works, The 20 4000 P.O Box 3301 Kingston, NY 124 02 USA (845) 33 9-9 375 (25 3) 49 8-5 574 (877) 56 0 -6 398 info@warmplastic.com http://www.warmplastic.com/ x 20 2318 18 Bank St Summit, NJ 07901 USA (908) 27 3-5 401 (908) 27 3-9 25 6 ( 866 ) 27 8 -6 65 3 info@artmolds.com http://www.artmolds.com/ Metal casting kits, supplies, instruction Sells Alumilite, room-temperature . Store, The 20 3557 P.O. Box 62 2 Tehachapi, CA 93581 USA (66 1) 82 2-4 1 62 (66 1) 82 2-4 121 (800) 33 8-1 27 8 info@cstsales.com http://www.cstsales.com/ See listing under Materials-Fiberglass. sheets Retail-Arts & Crafts: Most carry consumer- grade casting and mold-making supplies Abatron, Inc. 20 31 82 550 1-9 5th Ave. Kenosha, WI 53144 USA ( 26 2) 65 3 -2 000 ( 26 2) 65 3 -2 019 (800) 44 5-1 754 . and quick-setting plaster used in mold making. x V Perma-Flex Mold Co., Inc. 20 324 2 1919 East Livingston Ave. Columbus, OH 4 320 9 USA (61 4) 25 2- 8034 (61 4) 25 2- 8 5 72 (800) 73 6- 6 65 3 http://www.perma-flex.com/ Perma-Flex
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