Cost of rapid prototyping vs machined diecast boxes

Call for prices, and then you'll be the expert.

I expect that surface finish, strength, and cost will all be disappointing.

In particular, I would not expect that you can rapid prototype a threaded hole, so if you need to screw anything into the box probably the best you could ever hope for is a hole in a boss that can be tapped

-- and I think the best you could reasonably expect is a boss with a dimple, that still needs drilling and tapping.

Then when you go to tap that hole, you'll find that while the tap needs to exert the same force on sintered material as solid to make threads, the material itself is a lot more crumbly than solid -- and things break. I would expect strength on par with poorly cast iron.

But I could be wrong. After you call for prices, ask them to make a hollow box (or a hollow 5-sided box) the same dimensions as one of the die cast ones. Then show up at their place with a sledge hammer and the afore-mentioned diecast box. Beat each box flat with the hammer, and observe which one bends more before it crumbles -- you want whatever is more ductile.

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Tim Wescott
Wescott Design Services

How does GBP 7 per cubic cm for sintered stainless sound? Dubious surface finish.

Could be. If your market will pay for sexy appearance or it helps differentiate your product.

I could certainly see it being useful, but I doubt it will save much money or result in a very much stronger product. But then die cast pot metal isn't all that strong either.

Complexity of shape probably doesn't matter much, but material volume does.

Cheers! Rich

We use stock extruded boxes

which come in a bunch of sizes, clear anodized or black. Drilling the end plates is easy. Then we attach stickers, which we can make in-house in small lots, or have printed for production.

This isn't very expensive. £100 sounds extreme. Die-cast boxes are hard to machine... nothing is 90 degrees to anything else.

John

I saw that this morning at about the same time I was reading newsgroups. I must be getting old, though -- somehow I just didn't connect the dots, put two and two together, or get the peg in the hole.

(as it were).

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Tim Wescott
Wescott Design Services

I've used

in the US)

they have several different extrusions and a very easy to use design program for front plates one really neat feature is instant pricing at the push of a button, broken down to every little hole, milling, threading, coloring operation so you can tweak it

-Lasse

I haven't had anything made by these folks yet, but they sure have a compelling story. The gallery shows ~ 35,900 designs that have been made by Shapeways customer / vendors.

--Winston

a similarly interesting thing is shown here:

Thanks, Jure Z.

Rapid prototyping is intended to prove concept, not to replace fab techniques....so far. Pricing should be less than disposable tooling, to make sense.

Have you priced 4-axis milling as in optical housing? There was a lot of over-capacity after the telecom implosion. Those machines just didn't go away.......

RL

Are you in the US? If so, I can send you a promising lead I got at a recent AMCON show. For $50, they will make you pretty much anything you want in rapid prototype (within reason). Or, they can send you a sample.

My assessment: End result not rugged enough for production and use. Great for prototyping and sales hype, though.

-mpm

Nemo wrote: : typically cost about £100. I was wondering if anyone here had tried : metal boxes made by any of the rapid prototyping techniques (I gather : laser sintering is the one used for e.g. steel powder) and if the costs : have dropped enough now to be worth considering for small runs? I can

Out of curiosity, I made one item

. I have a nice electric water kettle made of porcelain, but I dropped its lid which broke. With spare parts unobtainable, I had a new lid printed. The procedure through Shapeways was smooth, but actually the printed items still cost quite a lot.

My colleaque got interested about Shapeways before I learned about it, and he had some electronic custom enclosures 3D-printed. His boxes did not use much sintering material (the cost is calculated on the basis of the amount of material used) and ended up at about the same price as non-customized standard boxes from Farnell. I think that for complicated-shaped boxes needing small amount of material and without too delicated details (uch as threaded holes), the process is competitive. Probably not for much else.

Regards, Mikko

You might want to talk to someone local that does sheet metal work. We get metal boxes folded up, welded, PEM nuts added and powder coated for less than that. I'd guess you need quantities in the 50-100 range to make it pay though. Can you make a big order and put the excess on the shelf for a year or two?

George H.