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FAQ's

 

WHAT DOES A SPIN CASTING SYSTEM CONSIST OF AND HOW MUCH DOES IT COST?

 

You can start Spin Casting your own products with our Basic Equipment & Supplies Package for under $12,000. This is a complete 12 x 4" system and includes the 3 major machine components:

 

 

1) a 3 Post Vulcanizer - for rubber mold vulcanization;

 

 

2) a "Front Loading" Spin Caster - to cast your molds;

 

 

3) a Metal Melting Furnace Assembly -with Digital temperature control to melt your metal casting alloy & maintain casting temperature.

 

 

Also included are our precision ground steel/aluminum Vulcanizing Frames and Aluminum Spacers which are required to vulcanize a mold. (does not include rubber molds or casting alloys).There are no hidden extra charges. Your casting workshop can be set up in a 9'x12' area.

 

 

If requested, we can provide a list containing a recommended assortment of start-up supplies and consumables based on your particular application and requirements.

 

 

1. CAN SPIN-CAST METAL & PLASTIC PARTS TOTALLY REPLACE DIE CASTINGS OR INJECTION MOLDING?

 

Spin-Casting is the fastest, most price effective production casting method from prototype/product development stages; up to low through medium volume production requirements.

 

Rubber mold centrifugal Spin-Casting will not replace conventional die casting or injection molding, when extremely large volumes of parts are required which can amortized the high cost of metal tooling and conventional die cast or plastic injection equipment.

 

The following very simple comparison can be drawn between Spin-Casting & printing:

 

(A) If only a few or several identical copies are required - and office photocopier or laser printer is perfect and economical.

 

(B) If thousands of identical copies are required - a local "fast copy" print shop is perfect and economical.

 

(C) If tens of thousands to hundreds of thousands of identical copies are required - a printing company is perfect and economical.

 

(D) When many hundreds of thousands to millions of identical copies are required - a high speed fully automatic printing plant is perfect and economical.

 

Spin-Casting perfectly fills the (A), (B), and (C) levels of production requirements with the same economics and efficiencies for both plastic and metal parts, just as well as the office photocopier, laser printer, offset print shop, and printing company did for the identical copies.

 

 

2. HOW DOES THE QUALITY & INTEGRITY OF ZINC SPIN-CAST PARTS COMPARE WITH CONVENTIONAL ZINC DIE CASTING?

 

The quality and integrity of Spin-Cast zinc parts are excellent; but a clean very high grade zinc alloy must be used made to correct specifications. The centrifugal force, which distributes metal into the mold cavities, helps to eliminate any entrapped air and fill any shrinkage. Centrifugally Spin-Cast zinc parts have a uniform fine grain structure throughout. If there is any porosity in the castings it is usually visible on the part surface and easily corrected .

 

Zinc pressure die castings, by comparison, have a very fine grain appearance on the surface only. This often hides or masks internal metal shrinkage and porosity. Die castings may have many internal and subsurface defects caused by the high injection pressure of the zinc as it enters the water cooled metal die.

 

 

3. HOW DOES THE STRENGTH OF SPIN-CAST COMPONENTS COMPARE TO CONVENTIONAL ZINC PRESSURE DIE CAST OR PLASTIC INJECTION MOLDED PARTS?

 

ZINC - The zinc Spin-Castings are practically identical in strength to conventional zinc die castings. The special fine grain refined alloying that takes place in Zinc Spin-Cast Alloys is designed to make up for any possible strength difference from the compacting created by the injection pressure of die casting. These special grain refiners and strengtheners can also be introduced into locally purchased ZAMAK (MAZAK) No. 3 or No.5 base metals by the addition of TEKALOY Master Alloy Concentrates.

 

PLASTIC - There is very little strength difference between Spin-Cast plastic and conventional injected parts. The strength properties usually obtained in general purpose injected thermoplastic parts (PVC, PE, PP etc.) can be closely matched by Spin-Casting with the proper choice of a high strength Spin-Castable thermoset plastic.

 

4. WHAT SIZE PARTS CAN BE SPIN-CAST?

 

TEKCAST manufactures Spin-Casting Systems up to 30" in diameter. Our standard units will handle molds up to 4" thick. Special order machines can handle molds up to 12" thick. The maximum recommended individual part sizes for multi-cavity molds are listed in the table below by mold size.

 

Mold DiameterLength Width
9" (228 mm) 3-1/2" (89 mm)2-1/2" (64 mm)
12" (304 mm)5" (127 mm)4-1/2" (102 mm)
15" (381 mm)6 1/2" (165 mm)5" (127 mm)
18" (457 mm)9" (229 mm)6-1/2" (165 mm)
20" (510 mm)10" (250 mm)7-1/2" (190 mm)
24" (610 mm)11-1/2" (292 mm)8" (203 mm)
30" (762 mm)15" (381 mm)11" (279 mm)

 

The above sizes refer to the maximum part size for rectangular shaped components that can be Spin-Cast in 2 to 4 cavity molds. Much larger parts can also be Spin-Cast in center gated single cavity molds, provided the component has approximately a 2" (50mm) square or circle opening in the part, which can be positioned near the center of the mold. For example, large wheels, pulleys, frames, bezels or boxes can easily be Spin-Cast, even if they exceed the above maximum sizes. These larger parts can be positioned within 3/4-1" (19-25.5mm) of the outside diameter of the mold. Parts with total height of up to 3-1/2" (89mm) can be handled on our standard units which accommodate molds up to 4" (102mm) thick.

 

 

5. WHEN SPIN-CASTING PRODUCTION QUANTITIES, DO YOU HAVE TO USE MORE THAN ONE MOLD AT A TIME?

 

Yes. When casting any metal, several molds (usually 3-5) should be cycled together in order to allow each mold to cool down to its proper casting temperatures of 140-185o F (60-85o C) before being cast again. This is important as it prevents both: (a) premature mold breakdown and (b) excessive cavity distortion, which is caused by overheating the molds. With plastic and wax it is best to use 2 molds per Spin-Cast unit because of the longer cycle times required and the more delicate nature of the cast parts when they are being removed from the mold.

 

 

6. IS IT NECESSARY TO HAVE A TOOL ROOM & A HIGHLY SKILLED TOOL & DIE MAKER IN ORDER TO PRODUCE A MOLD?

 

No. Specialized skills are not required to make proper molds. All the instructional information materials and equipment required to make molds are included with each system order. There is no magic to making molds, and TEKCAST manuals completely cover every phase of moldmaking from "A to Z". A person with average mechanical skill can easily follow our step-by-step fully illustrated moldmaking procedures with excellent results. More skill will be required to do very complex molds, but with hands-on experience gained from actual moldmaking, this can also be quickly mastered.

 

TEKCAST holds training seminars and, in addition, also assists its customers when specialized moldmaking skills are required. Our customers can take advantage of our complete moldmaking service when they are unsure on how to prepare very difficult and complex molds. We provide technical support and often make the first molds for them. Once they see how we have done it, it is very easy for them to make the next molds on their own.

 

 

7. WHAT CASTABLE MATERIALS CAN BE SPIN-CAST USING TEKCAST'S SPIN-CASTING EQUIPMENT & CENTRIFUGAL RUBBER MOLD TECHNOLOGY?

 

Spin-Casting machines in conjunction with our TEKSIL silicone rubber molds are being widely used to cast metal alloys that melt below 1000 o F (538o C).

 

Low Melting Metals- melting under 1000o F (538o C) include: Pewter, Tin, Lead and Zinc base alloys. Tin and Lead base Pewter alloys are most commonly used for Decorative and Novelty items or Fishing Lure manufacturing. The fast turnaround capabilities provided by rubber mold spin-casting allows for quicker design and style changes. The lower costs associated with rubber mold casting are a major benefit; making short production runs very cost effective. Organic rubber molds are used for casting alloys that melt below 750 degrees.

 

Commercial Zinc alloys - are especially useful for industrial, engineering and hardware castings because of their high strength and physical properties. In many respects zinc alloys are equal to most of the common cast brass and cast aluminum alloys, as well as class 30 gray iron or low grade steels. In most cases, spin-cast zinc parts can be easily substituted for sand and die castings made in these other alloys, without compromising the part's function or performance.

 

Thermoset Plastics & Wax- Eliminates the need for expensive plastic injection molding. High strength quick setting thermoset Polyurethane and Polyester Resins and pattern waxes can easily be cast utilizing rubber mold spin casting technology.

 

Aluminum alloys, which can cast between 1100 - 1200o F (600 - 650o C) can also be Spin-Cast, but only for very small quantities and for small size components.

 

Copper base alloys such as brass and bronze; ferrous alloys such as iron, steel and precious metals cannot be Spin-Cast. These melt at much higher temperatures which will destroy the TEKSIL molds immediately.

 

 

8. FOR HIGHER PRODUCTION REQUIREMENTS, DOES TEKCAST MANUFACTURE MULTI-STATION TURN-TABLE SPIN-CASTING MACHINES?

 

Several years ago we discontinued manufacturing these very expensive and complex units due to their limited application range. We now manufacture the much more versatile TWINCASTERS and TRIPLECASTERS. With these machines different sizes parts and molds can be cast at exactly the same time. They are much easier to operate and maintain since they consist of our standard combinations of two and three single station "Front Loader" units attached together. These units are 1/4 to 1/3 the price of a multi-station turntable automatic casting units. The TWINCASTER will provide better productivity as a multi-station machine, since it casts two of the same or different size molds simultaneously. The multi-station turntable unit is capable of casting only one mold at a time, and every mold has to be identical in size and type of part and therefore has much less versatility.

 

 

9. CAN MOLD MATERIALS, METAL & PLASTICS BE OBTAINED LOCALLY?

 

Yes and No. The base Spin-Castable metals can be purchased locally. Our TEKSIL silicone rubber mold compounds, which are especially formulated from proprietary materials, are only available from TEKCAST or our distributors. TEKALOY Master Alloy Concentrates are only available from TEKCAST. TEKALOY master alloy concentrates are designed to be mixed (in very small quantities of 5-10%) with high quality ZAMAK (MAZAK) No. 3 or 4 zinc that is available locally on a worldwide basis.

 

As a point of reference, we recommend that new Spin-Cast users purchase a start-up supply of our tried and proven TEKALOY metals and TEK-PLASTIC (that we know work very well), in order to compare the casting quality with similar materials available locally.

 

 

10. WHAT IS (ARE) THE BEST MODEL / PATTERN MATERIAL(S) TO USE WHEN PREPARING TEKSIL MOLDS?

 

The best material to use for models / patterns when making a conventional heat vulcanized TEKSIL mold is definitely metal. Any metal or modeling material can be used as long as it can withstand a temperature of 375o F (190o C) plus up to several thousand pounds of pressure without distorting, melting, breaking or outgassing.

 

 

11. IS ANY SPECIALIZED EQUIPMENT FOR MIXING AND MELTING PLASTICS REQUIRED?

 

No. The high strength fast setting thermoset plastics that are used in Spin-Casting are always supplied in a fully liquid form. They do not have to be heat melted in an oven or furnace like conventional thermoplastics or metals, which are supplied in solid meltable form.

 

Only a simple laboratory type scale and measuring cups are required to accurately weigh out the liquid thermoset plastic resins and catalyst materials before they are hand mixed together. Specialized liquid dispensing, metering or mixing equipment is available for higher production requirements.

 

 

12. CAN WOODEN PATTERNS/MODELS BE USED TO MAKE A VULCANIZED TEKSIL MOLD?

 

Yes & No. Wood cannot take the standard mold vulcanizing temperatures (300 - 335o F/150 - 170o C) and pressures (800 - 1000 psi) required for conventional heat cured rubber mold vulcanization. It would be impossible to form accurate mold cavities from a wooden pattern/model since wood will char, distort and shrivel-up at these temperatures and pressures.

 

On the other hand, it is still possible to make MASTER METAL MODELS from fragile model materials such as wood, plastic, clay, wax and plaster. This can be done by first making a liquid RTV silicone mold. RTV Silicone is a room temperature vulcanizing rubber available from TEKCAST which cures without the need for heat or pressure. It is a very simple procedure and the finished RTV mold can be used to cast multiple exact reproductions in Spin-Cast metal or high temperature thermoset plastic. The castings made from the RTV mold can then be used as models/patterns when making a heat cured vulcanized mold. RTV molds have a much more limited mold life than our conventional TEKSIL heat cured vulcanized molds (approx. 1/10th). They also have little or no shrinkage characteristic, which is also very beneficial.

 

 

13. A LARGE PART OF THE COST OF ANY CASTING IS IN CLEANING & FINISHING THE CAST PART. HOW CAN THIS BE REDUCED?

 

A TEKCAST Spin-Casting system uses very small in-gates (the location where the casting material enters the cavities) which will usually break off the part by hand when it is removed from the mold. Since the in-gate mark is so small, it can usually be left "as is" , without further cleaning or grinding. This completely eliminates cut-off and grinding. The very smooth finish normally obtained on spin-cast parts requires little or no buffing or polishing before use or plating.

 

 

14. IS IT POSSIBLE TO CREATE AN "ANTIQUE" FINISH ON DECORATIVE ZINC & PEWTER CASTINGS?

 

Yes. Mildly acidic concentrates are used for darkening zinc or pewter and tin/lead castings to achieve and "antique" appearance. They may be applied by a swab-on process or immersion of parts. Polish or burnish after dipping to highlight specific areas with our Satin Finish Nylon Buff.

 

 

15. CAN SPIN-CAST ZINC PARTS BE ELECTROPLATED?

 

Yes. All zinc alloys can be easily electroplated. The recommended procedure is to plate first with copper. A layer of nickel is recommended for durability, followed by a finish plate chrome, brass, silver or gold, etc. Electroplating technology is also available for plating plastic castings.

 

 

16. AFTER TEKCAST RECEIVES MY ORDER, HOW LONG WILL IT TAKE TO SHIP A SPIN-CASTING SYSTEM?

 

Our most popular size industrial systems are the TEK 18 x 4 and TEK 20 x 4. The 12 x 4 system is used mainly to manufacture fishing lures or small novelty and jewelry type items. These systems are in constant production and can usually be shipped within 3-4 weeks after receipt of confirmed order. For other size systems, or specially modified units, please contact TEKCAST for lead time required.

 

 

17. WHAT TYPE OF GUARANTEE IS AVAILABLE ON TEKCAST UNITS?

 

All TEKCAST units are fully guaranteed for one year from date of shipment. No charge replacements will be sent for any parts found malfunctioning or defective. TEKCAST's quality control program also includes automatic test stands which fully cycle our units for the same number of times normally required for two weeks of heavy production. All defective parts which may have escaped our pre-assembly inspection are usually detected in this manner before the machines are shipped.

 

 

18. IS IN-HOUSE TRAINING AT OUR OWN FACILITY AVAILABLE FROM TEKCAST?

 

Yes. Our instructors conduct 4-8 day full training programs on a worldwide basis, very similar to the formal SEMINARS. This is done only on a fee paid consulting basis plus per diem expenses (traveling, hotel, meals). The instructor can train up to 6 students at a time.

 

 

19. IS IT ADVISABLE TO FIRST ATTEND THE SEMINARS BEFORE WE START OPERATING THE EQUIPMENT?

 

Yes & No. It would be advisable under the following conditions:
1.) If the equipment has just arrived. 2.) If the equipment is in transit.
3.) If the equipment will be delivered, within 1 month maximum, following the Seminar.

 

The information taught at the Seminar should be fresh in the student's mind and promptly put to use to avoid losing the benefits of the "hands-on" practice and instruction.

 

Our training experience has shown that before attending a Seminar it is much more beneficial for both students and their companies to first have their system set-up and fully operational (using our manuals and videos for reference). The knowledge they gain from actually working with the technology for some time on their own, prior to attending a Seminar, will greatly increase the benefits of our training programs. As a result of this exposure, the students have a better idea of what they have to learn and what specific problems they have to solve. They are then better able to refine their own "Hands-On Techniques" to further improve casting quality and operating efficiency. We actually discourage people who have not worked with the system first from attending the Seminars.

 

 

20. I CAN'T ATTEND A SEMINAR. DO YOU HAVE TRAINING MATERIALS?

 

Yes, TEKCAST has a 5 hour Instructional Training Program to allow you to learn at your own pace. This program is only available to TEKCAST customers. Our exclusive Instructional Training Program is available in both a Standard and Deluxe format in either DVD or Video. We highly recommend the deluxe version, as it comes with an actual tutorial mold and sample parts. They are identical items to the mold made in the training DVD/video for you to use as a guide as you learn how to prepare your own molds and cast a variety of parts. Instructional topics cover proper gating,venting and spincasting techniques for moldmaking and casting decorative, industrial,mechanical and hardware related parts.