Lukas Hoppe is taking on the big boys with this project. The18-year-old is about to finish school in Bremen, Germany, and he’s launched an Indiegogo project aimed at funding his build of a Selective Laser Sintering printer–cheap–that he says includes all the key elements of industrial machines all wrapped up in an open source package which includes a heated build chamber.
He calls it You-SLS, and if building one alone isn’t enough, Hoppe wants his printer to be the cheapest SLS printer you can get your hands on. While there are a number of projects underway to build prosumer-level SLS systems, he expects that his will be very, very inexpensive.
So why an SLS system? Laser sintering allows objects to be built with a much smaller set of design restrictions and doesn’t require support structures as the powder itself provides supports. The process offers a number of advantages over FDM and SLA machines as professional-grade nylon sintering powders can create much stronger objects than parts built with current FDM or SLA machines.
In case you’re not familiar with the process, SLS works by scanning a laser across the surface of a thin layer of powder to fuse material wherever the laser strikes the powder bed. Thin layers of powder are deposited across the build surface, and the process repeats until the model is complete. This is a very simplified explanation of the process, but crucial details and information are available at the exceptionally complete OpenSLS Wiki led by Andreas Bastian.
Hoppe says he faced a number of challenges in designing his DIY SLS printer.
Sintered layers of powder are subject to warping as they’re built, and to counteract that tendency, designs for SLS printers require a build chamber capable of maintaining a constant temperature of just 10 degrees Celsius lower than the melting-point of the powder material being sintered. Hoppe says his system will employ a three-way heating system: each of two pistons will be equipped with two 300W heating cartridges and the build chamber will be heated by two optical heaters which will feature independent temperature feedback controls.
To cool the various lasers, stepper motors, and electronics, Hoppe says his design moves the two watt lasers outside the hot environment by creating two sections: a lower segment, which contains the two pistons and a recoater, and the upper segment that holds the XY-stage and the laser diode. This segmented design means the hot and the cold parts of the machine are separated.
Hoppe says the build volume of his You-SLS will be approximately 20 x 15 x 10 centimeters to allow large parts to be printed diagonally and without using too much powder to fill the bed.
At this stage, Hoppe says he’s comfortable that the critical design work is nearly done and that the most difficult problems have been addressed. He expects only slight, and cosmetic, variations will pop up in the final design. But it wasn’t easy getting there.
“To create and verify the design, I went through countless experiments and tested many subsystems, such as the powder distributor,” Hoppe says. “The experiments included the sintering of sugar, with my modified RepRap FDM printer.”
He says that the money raised by his campaign will be used to purchase the laser cut aluminum and acrylic parts and the electronics he still needs. Hoppe says he expects the total cost of the device to fall within the $1950 to $2200 range, and he adds that he’s already laid out the lion’s share of that money to purchase and test various parts.
“Even if I don’t reach my funding goal, I will continue to work on You-SLS,” Hoppe says. “Every dollar makes my life easier.”
Do you think Lukas Hoppe can pull off his goal of creating a working, inexpensive SLS 3D printer? Do you plan to support his IndieGoGo project? Let us know in the SLS Printer for $2000 forum thread on 3DPB.com. Check out Hoppe’s Indiegogo campaign video below, as well as more photos of the You-SLS 3D printer.