Technology advances

It was around nearly 20 years ago, if not so common.  The first SLA parts for engines I remember were in about 1995, although these were only for mock-up and visualization then as mechanical properties were not so good.  A few years later ('99?) I first made use of an SLA machine which printed sand moulds and cores to cast accurate, working, prototype cylinder heads.

Also in 1999 we used a SLA plastic piece for the casing of a working hand-held computer which was subsequently cast in polycarbonate.

Simon

Doh, don't you just wish this stuff had been around twenty years ago..

My mind boggles at the opportunities for invention this kind of technology affords.

Couldn't post from work (not allowed to post on forums from work) but my group operates four additive layer manufacturing machines. I find it interesting that there is suddenly so much press around these devices as we have been using them for almost 15yrs. We operate three plastics SLA machines (stereolithography) which use a liquid resin. A laser fires into the resin and cures a 0.1mm layer and bit by bit the platform descends into the resin and the part is made. Current build volumes are 650x750x550mm but we are able to stick the stuff together with Plexus to produce bigger parts. There a loads of different materials out there which all have their pros and cons. These systems are not however cheap, costing around £350k!!!!!
We also have a DMLS (Direct Metal Laser Sintering) Machine which uses powdered metal although the rest of the process is largely the same. Build volumes are approx. 250x250x215mm so significantly smaller, but you can produce some fantastic shapes that just aren't achievable with conventional machining. Officially materials are totally homogenous but thats not strictly the case. Again loads of materials are available from hi-tech aluminium alloys and titanium alloys, and many standard steels are available. The biggest hurdle other than material properties is learning to support the parts correctly and for the metal parts how to manage the thermal stresses.

Ultimately the technology will creep more and more into the mainstream but the only real benefit is being able to create shapes or features you cant conventionally machine, and this requires a revolution in design practices as you have to design from the inside out.

There are loads of other ALM (additive layer manufacturing) techniques such as weld layer deposition which allow you to effectively create a near net shape billet of material which then only needs a final machining cut, thus saving you all the wastage you get from machining a conventional rectangular billet or bar.

In terms of boat usage, I have used the tech to produce foil moulds for a foiling cat which we made in a couple of days and required minimal hand-finishing. I have made prototype models of an American Suicide class dinghy that I designed which would use the rig from a 29er (I posted the pics of this in SA about 5yrs ago), the publicity model for the C-class Invictus and I know that the Invictus C-class guys got a titanium mast foot grown for them.

we have just got a 3D printer at college, and a mate at uni has 3D printed a complete jib car system, it all moves, even the ball bearings inside!

brainfart... any news on the LiteSkiff?