Alessi Lemon Squeezer

[Guest laz]

I’m currently reading IN Des and we have been given an assignment for our prototyping module to investigate the production methods used to manufacture alessi's juicy salif squeezer designed by Philippe Stark.

 

At the moment we've come up with :

For the functional rapid protoyping- lost wax moulding - rapid prototyping a mould from wax then putting it into sand then melting off the wax leaving the shape in sand ready for casting.

 

For batch 50-100 - not to sure what the best method would be on this one, any suggestions would be appreciated!

 

 

For volume - we think the best method would be pressure die casting.

 

 

If anyone can help on the above methods it would be very helpful.

 

regards

 

 

Laz

[Guest newkillerstar]

many faucets are made by sand casting for production (usually brass). these are easy to spot as they are heavier and usually more expensive. not owning a juicy salif, I can't say how heavy it is, but I always assumed it was sand cast, polished and then chrome plated. Should work for small or large batches.

 

For prototyping, I would CNC machine it, or maybe better yet, do a metal SLS (powder metalurgy). Much simpler than the sand cast process if you are going for proof of concept

 

cheers

[Guest superbad]

There is no way in hell you could machine that. You'll be crashing the tool all over the place, and you couldn't get any of the sharp corner details at the bottom. Like you said, investment casting from a SLA blank is probably the best prototype method, because you can make it from the same material as the finished product. SLS (selective laser sintering) might work, but the material can be a little funny sometimes, and it's probably going to be a lot more expensive.

 

Investment casting (lost wax) would be a good choice for smallish volumes. You would create a mold for casting the wax, then use the wax blanks to create the metal parts. Sand casting is an option too, but will require more hand polishing afterwards. You might look at plaster mold casting.

 

I haven't looked at one up close, but I wouldn't be surprised if it's investment cast even at the fairly high volumes it's made in. A die casting or permanent mold tool for that thing would be unusually expensive, because of the difficulty you'd face in machining in the EDM electrode.

[parel 2]

I once saw a video of how golf clubs are manufactured. Instead of sand, they used a ceramic slurry that hardened around the wax blank. The wax could be melted out and then the metal was poured in. I dont remember whether they poured the molten metal directly in though.

[Guest superbad]

That's investment casting. It's cool to see it in person. Any decent sized city will usually have at least one investment casting foundry. Investment casting is used by artists for casting bronze sculptures, so even if you live in a city without a big industrial base, you probably have a foundry nearby. They will usually let you have a look around and watch the process. It's really fascinating.

[Guest newkillerstar]

There is no way in hell you could machine that. You'll be crashing the tool all over the place, and you couldn't get any of the sharp corner details at the bottom. Like you said, investment casting from a SLA blank is probably the best prototype method, because you can make it from the same material as the finished product. SLS (selective laser sintering) might work, but the material can be a little funny sometimes, and it's probably going to be a lot more expensive.

 

there are many ways in hell you can machine that - some that work here on Earth as well. Not every machinist will take it on, but you can machine most anything so long as you are creative about how you do it. Also, it depends upon your vendor, but SLS is not necessarily much more than an SLA. Both will be expensive because of how tall it is.

 

it depends upon the purpose of the prototype

-form study

-proof of concept

-photography / sales

-production preview

 

also - i'd machine it out of ABS

[Guest superbad]

We'll have to agree to disagree that machining that is the best option. Those legs would be singing like crazy, and you'd need a 10" long end mill and a 5 axis machine to get down in there without crashing the head. There *might* be someone out there who can do it, but there is no way it would be cheaper, faster, or better quality than an SLA investment casting. IMO. And machining it from ABS might be (a little) easier, but then you've got a non-functional prototype. The original post specified a functional prototype requirement. SLA casting will give you essentially an exact copy of the finished product, there are lots of shops willing and able to do it, and you can have it in your hands in less than 48 hours. I love machining, but in this case it's a poor choice. Again, IMO.

[Guest newkillerstar]

whatever, dude - never said it was the best option, just an option (would you really machine it as one part? Please)

 

So investment cast the SOB. I'm sure it will be lovely. I think you're dreaming on the 48hr turnaround - you'd be lucky to get an SLA in 48hrs, more like 72 unless you have it inhouse, or some clout with the prototyper. And then you have to get it cast. Now maybe the casting folks are more willing in your area, or have some concept of a deadline, and don't care that you just want one or two and the promise of "later well need thousands". But I've seen that step take weeks, as you get pushed behind the clients paying them real money.

 

Like I said, it depends upon the vendors around you. Its like saying, "every large area has sheetmetal shops, have them make one". Well, yes you may have several in town, but that doesn't mean that they won't rip you off on price (sometimes charging triple or more), and thats assuming they'll take the work. So maybe you've got 8,000 foundries in your area doing bronze sculptures. Great! i'm sure they're hungry for work and will make it in no time for little more than a cookie and a good belly rub.

 

There are exceptions, this may be one, but in many cases, if you want it done, done cheap, and done quick, you're best to stay within the modelmaking/prototyping world. Thus, as stated previously, SLS. The operative word to remember is "rapid"

[Guest Robomod]

That's investment casting. It's cool to see it in person. Any decent sized city will usually have at least one investment casting foundry. Investment casting is used by artists for casting bronze sculptures, so even if you live in a city without a big industrial base, you probably have a foundry nearby. They will usually let you have a look around and watch the process. It's really fascinating.

 

 

I like investmnet casting. My school, San Jose State, has the largest foundry on the west coast of the US. The have a crane systems for investing, and they show you how to make a temporary crucible out of chicken wire and tar-paper. A friend who's in the class said a woman made a six-foot tall hollow aluminum form similar to a stone at stonehenge.

 

About the juicer- It probably sand cast. I saw one in a shop a couple weeks ago, and I did not think to look for any manufacturing marks.

[Guest superbad]

whatever, dude - never said it was the best option

 

For prototyping, I would CNC machine it

 

Whatever, dude.

[Guest superbad]

Another thing: I don't know of any available aluminum SLS materials. Maybe I'm wrong- I'd love to hear about them. I have seen stainless, but it's intended more for creating mold tooling, not finished parts. It's expensive and slow, and support structures for complicated parts like this can be a problem.

 

You don't need any clout with the shop at all- www.quickparts.com will have an SLA part in your hand in 24 hours. That's just one example- there are local shops here that are same day. I do agree that you'd be best using a real RP shop and not some foundry out of the Yellow Pages, but if you live in an actual city there will definitely be a place that can do it all themselves, do it right, and do it when they say they will. We were getting this stuff done in 1997 for god's sake. It's not hard. 48 hours would be an expensive rush job for sure, but not unattainable. And don't forget the need was for a functional prototype.

 

Your machinist would still be laughing to himself 48 hours after you walked out the door. 48 hours after that he'd still be trying to generate valid toolpaths, and 48 hours after that he'd still be making positioning fixtures.

 

And yes, machining it in two halves would be relatively easy- if it had 4 legs instead of 3. If you were thinking of doing the body in two halves and the legs individually, well, have fun with that.

 

 

And to get back to the original post, one other variation on the SLA / casting method is to use a wax deposition machine, which will create an actual wax blank. The wax melts out better than the SLA material so you get better surface finish. The machines aren't nearly as common, but a big shop specializing in this stuff probably has one.

[Guest newkillerstar]

your're an idiot.

 

and nice quoting out of context

For prototyping, I would CNC machine it, or maybe better yet, do a metal SLS

[parel 2]

Calm down guys- its just information. Thank you for the information- but take it easy on each other please.

[Guest laz]

cheers everyone for the replies.

handed in the work in the end and put down for batch-

 

 

 

-firstly SLS of a three piece mould as its the only way to get the squeezer out of the mould

-then wax is put into the mould

-investment cast it

 

Apparently other methods for prototyping were to machine it, with the top cone out of wood, using pieces of MDF stuck together with section cut out drawings stuck onto each of the MDF pieces to allow for the perfect shape to be cut. The legs were the made of steel and welded together and sunk into the mdf sum how? thats what the lecturer said - but not sure how functional the MDF would allow the squeezer to be?maybe after spraying it could be used for some gentle testing???

 

really good debate though, learnt a lot from it!!!

 

next we've got to sort this - Michael Graves Tea Kettle for Alessi

 

Anyone got any ideas for batch 10-50 and volume 5000-100000?

[Guest Travisimo]

Hey LAZ, why don't you just call Alessi... that kind of stuff isn't secret and you might be able to get some dialog going with some interesting designers involved in their projects.

 

I did this recently when I found an interesting softgoods product and wanted to learn how it was made. I talked my way past the sales guys and ended at the production guys, who shared exactly how the designed and produced the product.

 

Can't hurt to try, and pls post what they say if you do it.. Im sure well all like to know after this thread : )