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View Full Version : Need to make plastic injection molded parts.



Clevelander
05-26-2012, 08:45 PM
I need to make some small plastic parts in a plastic similar to delrin but their size makes machining them seems impractical. Here's the thing....right now I'd be making the part on spec so I don't want to put a lot of money into it. The best way to describe the part is to think of a golf tee that is about 0.90" in dia and about .250 long with a small tit on top to keep a spring aligned.

Anyone interested in giving it a go to make the part? It's part of a small product I'm trying to make that should sell a few thousand pieces per year if I can product the product.

KIMFAB
05-27-2012, 01:31 AM
Here is a possible solution if you have the time.

http://www.kimfab.com/pictures/forum/plasticpress%20011a.jpg

Made from a military surplus aircraft landing gear, a pipe wrapped with nichrome wire with a sensor and a power steering pump for pressure.

I can do about 6 cc of PVC or ABS with it.

You can throw one together for next to nothing but you will still need the mold.

DFMiller
05-27-2012, 01:34 AM
Have you looked at some of the manual injection machines out there? They are modest in price and the molds are rather cheap. If your part volume is small enough they would work. A google search should turn up several options. The raw materials for a mold for a production machine adds up really fast.

Have you looked at any of the cast options?

Let us know what you find.

Dave

Jaakko Fagerlund
05-28-2012, 06:06 AM
Yup, I would suggest a premade or DIY version of a small injection machine and making the mold yourself.

If doing a standard mold to a commercial machine, the usual small sized mold components cost about 1000 EUR.

Grind Hard
05-28-2012, 08:45 PM
http://www.techkits.com/pim/index.htm


http://www.techkits.com/pim/images/in_drillpress.jpg


I built something similar awhile back for a batch of plastic "things" that we used at work. Shipping spacers to prevent a hole from collapsing during transit.

Easy enough to make if you have a lathe.

kd4gij
05-28-2012, 10:32 PM
Look into 3D printer kits.

http://www.cnczone.com/forums/3d_printers/

MinnesotaHSM
05-29-2012, 01:56 PM
Draw your part in CAD and send to http://www.redeyeondemand.com/

HWooldridge
05-29-2012, 05:54 PM
Why can't they be machined? That size range is not microscopic by any means and within the range of a good lathe.

jdunmyer
05-29-2012, 07:58 PM
The Projects Five book from Village Press has plans for a small injection molding machine that they claim could be built for maybe $50.00.

Toolguy
05-29-2012, 08:48 PM
Check into ProtoMold if you don't want to do them yourself. They can make the mold and mold the parts pretty quick and cheap.

kd4gij
05-30-2012, 01:55 AM
delrin is fun to machine you could make that part on a wood lathe. A nice sharp tool and have at it. I love working with it even on my old craftsman lathe I can take cuts the full tool width. Get a piece of 1" round stock and have at it