The price of new technology

[dave-in-england]

I had finished my design for a prototype, and had been looking around for someone to actually make the parts for me.

Two identical halves, which fit together at the edge to form an enclosing box, and a smaller base part for them to stand upright on top.

The casings are just 2 mm. thick aluminium, it does not need to be a butch construction.

Each Part size is 160mm high x 160mm wide. 15mm thick.

I had considered having them made at an engineering company who has a cnc milling machine, but there is a lot of metal cutting involved, jigs and fixtures to be made, and probably a lot of expence involved !


Over the last few months I had been watching the rapid proliferation of 3D metal printers featured on You-tube, so I though that this thin wall section would be just perfect for printing in Aluminium.

This printing process is where solid metal is built up from powdered material in layers of 0.002" thick, melted together with a laser beam, until the part is complete.

The advantage of 3D printing is that all edge radiuses and internal threads are actually printed, no extra machining is necessary, no drilling and tapping, no jigs and fixtures required, everything is finished in one go and the part is ready to paint and assemble.


So I contacted a manufacturing company who were showing videos on You-tube, and asked for a quote for the three parts to be made.

They want US$ 6,000 (£ 4000 ) for aluminium or £ 500 for the parts to be made in Nylon. ....

I had been expecting some price around £ 40 !!!

The layer princible gave me the idea of using thin plywood sheets instead of aluminium, so I re-arranged the internal dimensions to suit 3 mm plywood sheet slices.

Luckily I found a new start-up laser cutting company to cut the sheets for me, at a total cost of £27, for 15 parts, so I was very happy with that.

The laser cut width is just about 0.1mm, with clean sharp edges, the oilite bearings were a good tight push fit into the holes, so I was happy with that too.

I have glued all the sheets together and the prototype has turned out really well.

This new metal printing technology is amazing, but only the big money boys like British Aerospace can afford it !

It will be out of reach for us penniless model engineers for a good few years.

Dave

 

[Jonpalt]

Hi,
Interesting post. I have some friends in the US who use rapid Prototyping for all manner of items. Knowing them very well they aren't partial to spending much so will have to see who they use.
Best Regards,.
Jonathan

 

[MuellerNick]

They want US$ 6,000 (£ 4000 ) for aluminium

I could make you 10 castings for that. Plus I'd have a great deal.


Nick

 

[chipenter]

We just had a talk from this guy http://www.modelengineerslaser.co.uk/ send him the C A D file and he will give you a price , takes about ten days to a fortnight , I was impressed with the samples he brought along and how well they fitted together .

 

[dave-in-england]

I had forgotten just how good plywood is for small models.

Maybe the finished item will also be laser plywood, a lot cheaper than having machining done

 

[mu38&Bg#]

Powder metal laser sintering machines are extremely expensive to operate. They are the last resort when subtractive prototyping (machining) is not cost effective. It's just the wrong application of the technology especially if wood is suitable. This is engineering and design, finding the best method to make a suitable product.

 

[Jonpalt]

Hi,
Thanks for reply to my message earlier. Forgot to ask, what is it?
Regards,
Jonathan

 

[LongRat]

I work for a company producing metal sintering machines, and make products with these machines every day. They are great when you have a lot of customised parts to make at once, i.e. 'mass customisation'. Also, for very complex, unmachinable and uncastable shapes. For more simple geometries and large objects that are very much machinable, they offer less of a competitive solution. I must say though, the quote you got is ridiculous and indicates to me that the company did not want your business, probably because of the unit profit they make on the parts they would have made if your item wasn't on the machine.
Also, it's easy to think that the parts just fall out of the machine ready to paint/use/ etc. This is not quite true. The parts are very solidly anchored down (welded) to a solid steel base plate via a complex support structure. The placing of this structure is key to the accuracy of the parts and it needs to be removed prior to using the parts. This can involve a machining step. So you'll see why the technology has it's place, and a very bright future, but it is not for everything.
Plastic rapid prototyping on the other hand, is cheap. You can build your own working machine for less than £500 all-in. Check out the Reprap machines. With the right development, a home engineer can turn out really impressive parts that are now close in quality to industrial machines from a few years ago.

 

[dave-in-england]

I guess that you are right about the company not wanting to waste their time on a tiny one-off prototype.
I just thought that it would be interesting to ask for a quote !

I will look into plastic printing, may be cheaper than machining alloy.

 

[Cogsy]

I just added a Reprap machine to my Christmas wish list . Now I just need to break the news to my wife :hDe: