I Agree with USB. Two u shaped pieces fit together would only require the one mold and just a little more glue. Having the edges at 45 degrees would facilitate assembly. Kind of like a universal joint.

I GA you. I think if there's any volume, you would have the advanyage over rotomolding. And a simple two cavity mold would work.

But, there's much we still don't know.

you could make a mold for three sides in a corner configuration which would mate with an identical piece to result in a cube and then use automated ultrasonic or heat welding to mate the two.

Im late to the dance

El... and USB... have it correct

1) you can make a 2 piece mold for a square

2) Blowmold into one corner

3) can be done like a rotomold

This is for high volume production.

One offs can be done by drape molding, or 3d printing.

However a previous contributor is right if doing a small volume, off the shelf plastic stock.

Sppacecannon

Thank you charsley99, Elroy, kramarat, lynlynch, Rorschach, spacecannon, Usbport, for your great ideas and suggestions.

I will be better armed to go into the marketplace now thanks to you all.

Very much appreciated.

What's the Cheapest Way of Mass Producing a Rigid Hollow Cube in Plastic? : get it done in India or China.

This is an amazing thread - never seen so many GA's for so little for so many before. Need to think of something clever to say so I can get one toooooooo.

Good point. You will never get a GA because you are a lowly Guest. It is quite amazing to see all the brown nosing that goes on here at CR4. I think I will register and give you a GA and perhaps you can do the same for me - making the assumption that we are in fact two different persons.

The best way that I can think of is to make a flat shape of a folding cube and then fold and heat weld edges. Given todays manufacturing capabilities this should be able to be accomplished with threes steps, maybe 2.

Size matters.

How big is this thing?

How can anyone dare to attempt an answer to this when they do not know even the most basic answers to "how will it be used"?

How can anyone even attempt to design anything without a basic understanding of how it will be made?

L.J.

Cap, dude, GA for the questions.

but really he's asking for a plastic box, garbage in garbage out.

Thank you BaldSprinter, CAPhelan, charsley99, Elroy, Guests, kramarat, Laughing Jaguar, lynlynch, RoGrrr, Rorschach, spacecannon and Usbport.

The cube shape is part of a kids toy concept, I want to try and sell the concept to toy stockists / wholesalers and they've asked me to price it up before I make a presentation, hence my question as to how to make it as cheap as possible.

It is a toy that hopefully could be passed along, though I accept that may not happen nowadays and they may end up in landfill so I take on board your point about blow-molded resins being capable of recycling.

The cube size will probably be no more that 2" x 2" but it's not critical and accuracy is not super critical either - within reasonable limits.

I hope that's answered al your questions but I want to thank you all again for a very informative response.

Hello Wrench Twirler,

Would you consider gas assisted injection molding. Can you live with a cosmetic blemish on one of the surfaces of the cube?

We use gas assisted molding to produce the Assist Grip for the Toyota Corolla. It is an extremely efficient mold. The part weight is ~1/2- 2/3 of what a solid part would be.

Here is a brief description of the process. We have an 8 cavity mold to produce the handles which are completely hollow.

1.The mold closes and~ 1/3 of the cavity volume is filled with molten plastic. This volume is controlled by valve gating each cavity. A small gas pin sticks into the stream of plastic. When the plastic valve gate closes a shot of high pressure nitrogen (4,000psi,) is forced into the molten core of the shot of plastic. This pushes the plastic to fill the cavity and leaves a void in the part. The product weight from cycle to cycle is very consistent and within a gram of each other for 8 cavities running 24-5.

The valve gate will leave no vestige but you will have a hole of ~ 4mm dia close to the valve gate from the gas pin.

Hope this helps.

Try contacting a molding facility which uses gas-assist injection molding. I have worked with a stretch blow approach for molding hollow items, but you would still have to fasten the last side.

YOu could contact someone in the rotomolding world - I don,t see mass producing in large quantities of these parts w/this proces but they may have developed someting new.

Good luck

I would be interested in your responses for this application - sounds interesting.

Yog