Cheapest Prototype Model Materials

Ruler, paper and pencil and much brain.

+ Child's wooden Building blocks.Many types-afew boxes each type.

Visit Gift shops soon after Christmas Gifts Buying is over!

Nier Design Owner:

Modeling CADD programs. No materials required.

Mark

You are right, as long as you have it in your CPU, if no, but cheap it is the pencil and the paper.

Cost.

Depends on how you value your time

We make prototype forms for our boats and consoles etc - see www.explorermarine.co.uk.

We used to use plywood formers with pine strip coverings, but now we find it is much cheaper to use polyurethane foam and shape that to the desired shape and then skin it with GRP before final shaping and creation of a good surface finish. Then we polish before we take the moulds off that shape.

In the absence of any replies from people who have expertise in this area: I'd have though epoxy was a good starting point.

Maybe try:

Texas Cement Products, Inc.
4000 Pinemont Dr.
Houston, TX 77018
Phone: 713-682-8411

Hi

I have built a lot of molds. The easyest it foam.

Hope this helps

James

The reply depends on how much functionality you need from your model. If it's just to look at for style etc then foam, card & paper as suggested are ok, we use a slightly denser form of polystyrene which can be machined. If you need to check fit & function you need to be approximating the properties of the finished parts.

The CAD suggestion is a good one & there are free CAD programmes available.

FOR "CERRO ALLOYS" CHECK THESE WEBSITES.
http://www.hitechalloys.com/hitechalloys_009.htm http://www.hitechalloys.com/hitechalloys_002.htm http://www.alloyinnovations.com/standard-cerro-alloys.html http://www.alloyinnovations.com/
CERROLOW 117 alloy is used in jigging or fixturing delicate parts for machining, dental molds, prosthetic development work, proof casting (internal measurements), fusible element in safety devices, radiopaque contrast medium in X-ray, low temperature solder and many craft applications such as castings. Cerrolow 117 is a eutectic alloy with a melting temperature of 117º F. It can be melted in a double boiler. Intitial expansion then shrinks to .0000" per inch in 30 minutes. CERROSAFE alloy was originally made for toy soldier castings. One of its most popular uses today is casting to check gun chambers. Cerrosafe shrinks during the first 30 minutes and at the end of one hour is EXACTLY the chamber size. Some other uses are casting cavities such as threads, dies, molds, blind holes, duplicate patterns in foundry matchplate making, support work pieces while machining; spray coating wooden patterns, dental lab techniques, masks for electroplating. Cerrosafe is a non-eutectic alloy with a yield temperature of 162.5º F. GOOD LUCK HAVE FUN

<Cerrolow 117 is a eutectic alloy with a melting temperature of 117º F. It can be melted in a double boiler>

WOW -that low?

Can we leave the main questioner and learn some more on this alloy which will melt inside a feverish man's mouth?

And what is a double boiler?

"<Cerrolow 117 is a eutectic alloy with a melting temperature of 117º F. It can be melted in a double boiler>" "Wood's" metal is similar.

Cerrolow 117 or one of its cousins is used in bending tubing to prevent collapse and ill formed bends. It is easily removed by immersing the finished bent shape in very hot water and draining the alloy.

A double boiler is a common, (at least in the US,) cooking utensil consisting of a lower pan or pot, partially filled with water, and a second pan or pot which fits in the top of the first. The combination is set on the stove and steam heats the bottom and sides of the upper pot so as to avoid hot spots and overheating of the food being prepared in the top pot. QED?

"What's the best and cheapest type of modeling compound for small scale custom mechanical parts development and production?"

As usual there is no "One Fits All" solution to your inquiry. Exactly how or what functionality must the parts have? Just for visual observation, or for assembly to check relationships between parts, interferences, etc.?

"The designer bent across the board, wonderful things in his mind were stored, he said as he rubbed his throbbing bean, 'How can I make this part tough to machine? I know, I'll put the part that holds the cap way down here where its hard to tap. ,,,,,,,,,,,,,,,,,,He cried 'At last. It can't even be cast!"

Almost anything can be modeled using index or bristol card stock, balsa wood, aliphatic resin carpenter's glue, and similar materials from hobby and craft stores. "Paper Engineering" is an art form all of its own. See <flying-pig.co.uk> for examples.

The ultimate in small parts modeling, is not cheap, but can produce spectacular results, is a system of "desk top publishing" which lays down tiny amounts of a plastic compound in a manner much like an inkjet printer, layer by layer to build up a 3-D model of whatever you can draw with a compatible 3-D drawing program. High end machines cost on the order of $50K and a low end, price wise, on the order of $3K. "The Whizzit," for example produces excellent output at a more that competitive price.

"The Designer"

I found the full piece. It is being posted for all to enjoy.

THE DESIGNER

The designer bent across the board, Wonderful things in his mind were stored.

And he said as he rubbed his throbbing bean, How can I make this thing tought to machine?

If this part were only straight, I'm sure the thing would work first rate.

But 'twould be so easy to turn and bore, It never would make the machinist sore.

I'd better put in a right angle there, Then watch those babies tear their hair.

Now I'll put the holes that hold the cap, Way down here where they're hard to tap.

Now this pierce won't work, I'll bet a buck, For it can't be held in a shoe or a chuck.

It can't be drilled and it can't be ground, In fact the design is exceedingly sound.

He looked again and cried "Ar Last!" Success is mine, "It can't be cast!"

From an anonymous source circa 1942

Durhams Rock Hard Water Putty, cheap, fast, machinable, readily available.