Injection moulding

I was very tempted by an injection moulding machine that went for peanuts on ebay at the weekend. It looked small enough to get home without too
much trouble, but I resisted on the grounds that I didn't know enough about them to know what I was getting into.
So, for next time ..
Is it feasible to set up a small moulder at home, turning out objects of no more than a couple of cc ?
Do I need great skill and knowledge, or can I learn as I go ?
Would I just need the machine, or is there lots of support equipment too ?
Can I make moulds with model engineering equipment, or do they need to be something special ?
What sort of materials are reasonable ? Nylon ? Polyethylene ? Polystyrene ? How easily could I get raw materials ?
-adrian
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peanuts
too
enough
objects
too ?

to
Polystyrene ?

Is it feasable: Yes
Do I need great skill or knowledge : No just common sense (you remember that stuff - banned by the EU !!)
Support equipment not needed for small scale work.
ME equip to make moulds?: Yes
I bought a small hand operated (ex school) machine a few years back when the local vandals started burning the buttons on my launderette washing machines - full switch banks only available at 150 each - no buttons. I needed two styles of buttons. I made up a three part mould in my home workshop, saved up plastic milk bottles and their tops in red and green, and also used sliced up blue water service pipe. You need to shred the plastic into fairly small chunks which is a bit tedious. This way I was able to make a full range of buttons in white, red, green and blue and now have a big box of spares. No doubt had I begged at an injection moulding place I could have had more than enough for my needs for the price of a beer, but this was a challenge - my repair engineer was adament that it wouldn't work <G>. Glad to say for the moment the vandals have found other playgrounds.
AWEM
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On Mon, 20 Nov 2006 20:22:39 +0000, Adrian Godwin

Yes, an Austin-Allen or Rabit type moulder will hapily sit in the corner of a workshop and run off 240V and compressed air

Ooooo yes, you must walk the long path to enlightenment. Or you could just ask me<g>

For the ones mentioned above, very little needed. For a standard 'small' industrial moulding machine (ca. 15T -30 Tonnes lock) you will of course need a proper 3-phase supply, a cooling system or chiller for both the hydraulics on the machine, and the mould, and a drying oven for the material.

Yes you can make moulds with this equipment, the biggest hurdle is tool design. Again help is available on here, Kevin Steele does this for a living, I do it when I have to.

Depends on what and how much you want. Small lots I can sell you from stock at my cost price, as I buy my material in at 1000kgs a time, otherwise youwould pay a huge premium for a single 25kg bag of material from the major distributors.

Peter
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Thanks for all the replies. I shall certainly be more keen next time I see one (and I wish I'd bought this one .. ebay 280048015651 )

Huh. It WAS an Austin-Allen.

I might very well do that, especially in the light of your generous offer :

-adrian
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I see

At 12-50 it was an absolute bargain - about the scrap price !
AWEM
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I'm sure he'd have got at least several hundred pounds if he'd put it in the right category. I can't believe how foolish some people are with thier listings.
Regards Kevin
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Adrian Godwin wrote:

You certainly want to order this booklet from Camden Books: <http://search.freefind.com/find.html?id 640675&pageid=r&mode=ALL&n=0&_charset_=UTF-8&bcd=%C3%B7&query=injection> Title: Secrets of Building a Plastic Injection Molding Machine Gingery • £12.90 • (G)

The book says yes.

Thermoplasts. :-)
I bought this book out of curiosity and -albeit being mostly about building such a machine- gives usefull tips for making moulds, what material to use etc.
HTH, Nick
--
Measure twice, cut once.
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I have an Austin Allen Gnat, I am mulling over keeping or moving on.
Joules
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On Tue, 21 Nov 2006 11:24:30 GMT, Joules Beech

Quick blast of DDT should do the trick ;-)
Regards, Tony
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I've just bought some "Morphplast" off eBay - gets pliable enough to mould when heated in hot water but sets like Nylon. May be a cheaper option but less fun (I've considered buying an EDM machine when I don't really need one!!)
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I don't have any urgent moulding needs and my workshop is still recovering from trying to absorb the last bit of (probably unnecessary) machinery, but if you decide to move it on at some point I'd be happy to hear from you.
-adrian
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Adrian Godwin wrote:

Injection moulding has an economy of scale. Parts cost peanuts but machines and tooling costs money. Say you wanted 10 parts and your tooling costs £10,000. Each part now costs £1000 plus material and time (on a machine) so lets add £100. Thats £1010 each! BUT if you wanted 100,000 parts the cost would be £1.01 each. 1,000,000 parts and your down to about 10p each. Moral of the story, unless you want many thousands of parts they will be EXPENSIVE. Make your own tools and you can discount that cost, so yes that makes it MUCH more attractive. With model engineering equipment you could make tools for a small moulding machine.
Pete.
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