|
|
|
|
|
|
|
|
|
|
Prev | Next | Archive Top Page
It’s long been an assumption in the RP field that there is great elasticity of demand: Lower the price and the sales volume rises by an even greater amount. In recent years, Stratasys and Z Corp. have certainly proven that elasticity holds down to about the $20,000 price level. Indeed, this year Stratasys is poised to sell 2,000 machines or more - a first for any RP company. But what happens if you lower the price to $5,000 to $7,000? Will demand take off like the proverbial bat out of hell? Apparently we’re about to find out.
Desktop Factory, Inc., is planning to introduce a machine in that price range in the next few months. Details and specs are not yet finalized, but from patent publications, the company’s web-site and sales people, the shape of things to come can be seen with some clarity.
The technology can be thought of as a variation on selective laser sintering, and also has some elements in common with photocopying technology. A uniform layer of a metal/plastic composite material is deposited at a temperature near its melting point on an aluminum drum. The powder is subsequently selectively fused or sintered on the drum by a focused, quartz-halogen light source to form a layer of a part with surrounding uncoalesced support material. The heated drum is rotated across the pre-heated top of a build stack and the new layer is transferred to the top of the stack using heat and pressure, resulting in a permanent weld between the layers. The process is repeated until the entire part is constructed. Configurations are described that either use the unbonded powder bed as a support structure or use fabricated supports like stereolithography. The initial product will probably take the latter approach.
One intent of the method is to provide a much lower cost way of making plastic parts having reasonable mechanical properties without the use of a costly high-power laser or laser positioning systems. The technology trades off the use of these generally very expensive components by replacing them with a number of straightforward alternatives: Instead of a laser, an incandescent lamp is used to melt the powder. Instead of galvos for selectively exposing the layer, a stepping motor-driven lead screw mechanism is used. Instead of a heated build chamber, a heated build platform and a heated removable plate for the top of the stack are used to keep the part temperature elevated and to relieve internal stresses. The result is a machine architecture that uses a lot of parts, but most of them would be inexpensive to manufacture in volume. A quite similar tradeoff is what makes laser printers and photocopiers practical.
But it is a tradeoff and it does result in some compromises: Layers are said to be on the order of 0.010 in thick, and the patent mentions controllable spot sizes for the focused light source of from 0.010 to 0.200 in. Stepping motors and lead screws are much slower mechanisms than galvos, although larger light spots can expose wider areas faster. The net result is likely to be that operation will be on the slow side and the parts produced will not be very detailed. The company indicates, however that build speed will be similar to existing, popular 3D printers, and that the first product will be able to build a wall thickness as low as 0.040 in.
Specs of the company’s initial product that are finalized include a build volume of 5 x 5 x 5 in, outside measurements of 25 x 20 x 20 in, and weight of less than 90 lbs. Desktop Factory also says that its material provides superior strength at lower cost than traditional RP consumables. Their patent application mentions the use of plastics such as Nylon, ABS and polystrene, as well.
It would be a mistake to assume that an initial technology introduction is a fixed target. It isn’t - it’s an opening salvo. If this technology gains a toehold with early adopters, there’s probably a lot that can be done to improve it over time. What will be even more interesting to watch is the reaction of competitors to the assault. After all, there’s nothing inherently expensive about several of today’s most popular technologies. That raises the possibility of a new level of competition and a great widening of the market.
For more info Contact:
Desktop Factory, Inc.
130 West Union Street
Pasadena, CA 91103626-229-3190
626-535-2701 FX