Making Plastic Prototypes

Contact "Silhouete" or "Arque Silhouete" for quotes and such. They used to specialise in small production runs using multiple technologies and provided EXCELLENT support. If you have a solid model aready, they can probably make a tool and get you parts within a week.

We used to send them CAD models and they would have to create the "positive" and then the tool and we could get parts within days.

They were located in Melbourne, so should be handy for you in Adelaide.

Hello There,

Have you a cad model of the end fitting. Is there a left and right part needed. For such a small quantity you could get away with an aluminium mold eventhough it is glass filled nylon but P-20 type tool steel is better.

The cost of the mold depends on the intricacy of the shape and the tolerance demands. What percentage of glass filling is also important. If there is a molding company near you, you can either bring in a finished tool and get them to produce your parts or have them build a cheapie tool to prove out your concept.

If you are cnc'ing the part in steel then you can do 80% of the cavity work and get some guidance from a good moldmaker to complete the rest.

There are Master Base molds bases into which you can fit an insert with your cavity. The blanks can be purchased or made cheaply and your detail cavity work can be done quickly and more economically using such a system.

I can estimate cost and delivery here in the US and in China for your own mold or just for finished parts. Your local moldmaker or a knowledgeable machinist may be your best bet and it keeps the work local. If you need some guidance on the design etc I would be glad to help.

Thank you both for your input, I've contacted the Melbourne company and will email them a solid model, when I'm further down the development track.

The end fitting will be in two or three sections and able to be assembled both left and right handed, I hope!

The percentage filling I am unsure about and gather that the higher percentage is more difficult to mould. I will get advice on that.

Thank you for your offer on design guidance, 2tinker, it is appreciated, what format are you able to view? It would be very handy to talk to someone with a feel for the process.

Tony

Hello Tonymech,

I can read the following formats, DWG, Iges, Step, anything produced with Catia, Pro-E, Solidworks, SolidEdge,

There is a way to email your files to me privately. I can take a quick look and do a DFM check to look at draft, possible undercuts etc and give you an idea of pricing and timing if you answer the questions below.

If you just have conceptual sketches I can probably save you a lot of CAD time by giving you the basic design guidelines of general wall section, draft necessary, coring out, radii, surface callout, gating options and material suggestions.

If you spend a little time to answer the questions below, you will be able to figure out whether you can make a profit on your part before spending countless hours in design and development.

1. You need to begin with your yearly projected volume of parts. (We can figure out the most economical number of cavities.)

2. With a part volume and weight I can tell you the approx shot size and material cost, molding cost based on cavitation in the tool etc.

3. Tell me the projected area of the part and we can figure what tonnage machine you need to run in.(molding cost)

4. Suggest your preffered material and and I may be able to suggest alternatives.

5. Consider your packaging from the molder to your business, dunnage can get expensive. Is the part stackable etc. All these things should be considered to give you the best shot at a successful launch.

Hope this helps.

Why not do an SLA prototype to confirm the fit and verify the design? This type of prototyping is getting pretty cheap. Then you can make a mold from the SLA model.

http://www.protocam.com/html/slapro.html

Thanks Usbport

I can check the fit with the aluminium prototype we are using to develop the idea and would think making enough parts for a test screen would be prohibitive with this method. I will check it out though.

Wow Doorman. I want one. No, I need one. It would be quiet a learning curve but the outcome would be saving time and money in the end. Good to see the young dudes have a go and be so enthusiastic about it.

Maybe it will not help OP Tony (lead time) but it would be the perfect tool to have. I only had a quick look but will delve in a bit deeper when I find the time. Great link, Ky.

I think that is a pretty cool machine too. I spent some time yesterday designing an oddball shaped bracket which I will initially make out of .062 aluminum. It requires some odd cutting and hole drilling which will be a pain to do by hand. It would be so much easier to tell the machine to crank out 100 of these and go do other things. Using ABS, I would probably have to make them thicker using ABS, but that is no big deal.

Bill

http://www.shapeways.com/

Tony, Saw your post & thought I'd pass on some information to you. We're a powder coating company out of North Salt Lake, Utah, USA specializing in fluoropolymer material. If you're in a position to need a your prototype to be powder coated. We'd be more than happy to help. Please feel free to call me or email me @ 1.801.979.9919 / swenhoward@fisherutah.com. Thanks, Swen.

Swen,

Why would you powder coat GF nylon?