A small sized, used, injection moulding machine?????

[jplot1]

I am a long retired party who was in the waste removal business for most all of my life. This entailed solving many problems of mechanical, electric, and hydraulic nature.

I now have a patent on a toy like flying machine, and I would like to tinker with the idea of getting a hold of a small plastic injection machine, that would perhaps run on 240 current, to see if I could produce the fairly simple, various parts that I need.

I fully realize that I can get most any plastic company to do this work, but at a cost that is prohibitive. I have always loved the idea of learning new stuff, and this sounds like I could have a ball, and if I fail, so what.

I was thinking there surly is small equipment out there that might sell for one or thousand dollars. Am I wrong? Am I nuts? Perhaps.

I would welcome any help or comments.


jplot1

 

[MacGyverS2000]

If it's a hobby, I would suggest making your own... shouldn't be a big deal for someone who is mechanically/electrically inclined such as yourself.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[seymours2571]

If you were to get a small injection mold machine you would also need the mold tool itself that will form your part. These tools are complex and very expensive themselves.

There is a reason the plastic part prototyping market is so big with so many players. The cost of doing it yourself far exceeds the cost of paying someone else.

 

[jplot1]

Nice to hear from both of you.

This is more then a hobby I think, as I would at the same time be trying to bring to market my invention, and have the means to at least make prototypes, and maybe even mass produce my product.

I realize the mold part is expensive and difficult, but it is possible that I already have some of the tools needed. Metal cutting metal is my first love and I have a 13 inch metal lathe and could adapt a milling attachment to it.

Thanks again. jplot1

 

[MikeHalloran]

Start by using the lathe to make a serious millng machine.



Mike Halloran
Pembroke Pines, FL, USA

 

[ornerynorsk]

Well, everyone seems to be in a cheeky mood and not wanting to answer the original question. Engineering types aren't always the most adventurous. There is always a thousand reasons not to do something. The "gotta try it" attitude is completely alien to most people.

Don't bother building a mill, either, as was suggested. Colossal waste of time. I just picked up a nearly new 9x42 turret mill with digital readout, power feed, and gobs of tooling for $1600.

Yes, you can pick up small injection molders for a song these days. Ebay almost always has some, but your better bet might be to check out some real industrial auctions, where this kind of machinery is usually sold at or slightly above scrap price. An older solid state machine, depending on the size, could go for as little as a couple hundred US.

Good luck in your venture!

 

[Pud]

check out some real industrial auctions, where this kind of machinery is usually sold at or slightly above scrap price.

240V?

Also, when you buy material, you will be paying $$$$ for small quantities unless you have a friendly local moulder.

All the scrap will be yours, too.

If you want to mould hygroscopic materials (e.g. nylons, ABS, Acrylics, Polycarbonate, polyesters, et. al.) you will also need some serious drying equipment!

Ok to make the tools if you can find a moulder who will run them.

I am in the Uk and have a 75 tonne Stubbe which will be free to anyone who can collect it. (I assume as the OP did not state his location he is in the USA). It's 3 phase 415V supply. Four barrel assemblies, two std, one PVC and one thermoset water cooled.) Never raced or rallied!

Cheers

Harry

http://www.tynevalleyplastics.co.uk

 

[Demon3]

I would suggest you try printing your parts using a rapid prototyping machine i.e.

http://www.stratasys.com

You needn't buy the machine but get someone who has one to print your parts.

You can also use a rapid prototyping machine to print a plastic mold that you can then use in place of a metal mold for small runs of parts made by injection molding.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[patprimmer]

Harry

Statistical data would puts the odd of your presumption as being correct as very high. ;-)


Regards
Pat
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[btrueblood]

Along Chris' line of thought, there are companies specializing in quick-turn prototype injection molding. Protomold is a name to google, there may be others. The niche they fit is low-volume (10's to 1000's of parts), i.e. use them after you have had a few runs done with SLA or other rapid prototyping.

Chris, are you serious about a plastic plastic mold? I guess it would work if casting low-temperature, low-pressure resins or thermosets (urethanes, epoxies)...

The name I mentioned has a fairly comprehensive do-it-yourself quote engine, and some fairly good design info. to walk you thru getting a part quoted. At least you could compare costs relative to the do-it-yourself method.

 

[patprimmer]

A spectacle frame manufacture in Australia used only epoxy moulds for their production.

They used wood patterns and a steel bolster to cast the moulds.

They moulded the frames in cellulose propionate.

The moulds lasted about 100 shots give or take about 50 shots.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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[Demon3]

I've seen a mold that was made by Stratasys some years ago. They use their machine to print a mold out of polyphenyl sulfone plastic and then used that to injection mold 100 PP parts or so.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[btrueblood]

Pat, makes sense, but I was thinking of the ABS and PC type plastics that are the "typical" SLA material.

Chris, I didn't know that the higher-temp polymers like PPS could be fabbed, will have to google that brand name to see what's up.

 

[MacGyverS2000]

For the price ProtoMold wanted to charge me for a short run, I could have had many many thousands made in China (and I could keep the mold, for whatever that's worth).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[jplot1]

Looks like I need to keep searching for informaation but the repies here have all been interesting.

That last one about China was great, and I have had my eye on China ever since I started dealing with Harbor Freight years ago. The computer is a wonderful tool, but it still takes a mountain of time to a get anywhere.

I had wanted to post a animation file here, or even just a picture, but I have no idea yet as to how to do it.

jplot

 

[Demon3]

Last time I checked Stratasys had only one machine that could handle the high temperatures of PPS. It was called the Titan.

I worked with them in the past to develop new rapid prototyping plastics. We succeeded in making parts from ASA and MABS.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[jplot1]

I am going to try and put a Youtube animation here of the Base of my project, which is about 2 inches in diameter. The mold would not of course have the leg protrusions as shown, but holes for their insertion. It is bothering me a bit in trying to figure out how one could make a mold for this as all the protrusions are at compound angles and must be quite precise.

http://www.youtube.com/watch?v=ywaVZQMRzzg

Any comments?

jplot

 

[Pud]

jplot1,

Could you not make it in two halves and clip them together?

"Open and shut" tooling.

Harry

http://www.tynevalleyplastics.co.uk

 

[MikeHalloran]

If you're not planning to make huge numbers, you could make the mold of aluminum, clamp it with capscrews, and use manually inserted cores for the legs. You can do stuff like that with a very elemental molding machine, just a step up from the drill press spindle deals.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

From the animation it apears that it is a probably hollow disk for a hub plus 4 round rods inserted into the dsk.

If so it can be fairly easily fabricated from a wood or plastic hub, hollowed out as required for strength and weight and with plastic rods bought from a supplier of semi finished plastics materials. You might even be able to buy hollow tubes suitable size.

If you want to make your own, possibly have an extrusion company produce the profile for the arms. Extrusion dies are a lot cheaper than plastics moulds and make silicon rubber or even wood moulds to cast the hub from thermoset polyester or themoset polyurethane or cast nylon or epoxy.

Regards
Pat
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