3D Printing Flexible Surfaces Out Of Non-Flexible Material

Here’s some interesting work shared by [Ben Kromhout] and [Lukas Lambrichts] on making flexible 3D prints, but not by using flexible filament. After seeing a project where a sheet of plywood was rendered pliable by cutting a pattern out of it – essentially turning the material into a giant kerf bend – they got interested in whether one could 3D print such a thing directly.

Inspiration for the project was this laser-cut plywood.

The original project used plywood and a laser cutter and went through many iterations before settling on a rectangular spiral pattern. The results were striking, but the details regarding why the chosen pattern was best were unclear. [Ben] and [Lukas] were interested not just in whether a 3D printer could be used to get a similar result, but also wanted to find out what factors separated success from failure when doing so.

After converting the original project’s rectangular spiral pattern into a 3D model, a quick proof-of-concept showed that three things influenced the flexibility of the end result: the scale of the pattern, the size of the open spaces, and the thickness of the print itself. Early results indicated that the size of the open spaces between the solid elements of the pattern was one of the most important factors; the larger the spacing the better the flexibility. A smaller and denser pattern also helps flexibility, but when 3D printing there is a limit to how small features can be made. If the scale of the pattern is reduced too much, open spaces tend to bridge which is counter-productive.

Kerf bending with laser-cut materials gets some clever results, and it’s interesting to see evidence that the method could cross over to 3D printing, at least in concept.

Motorized Turntable Created From TV Stand

[Robin Reiter] had a powered TV stand that only rotates around 20°, because who really needs their TV to rotate fully? He wanted to turn it into a motorized turntable for shooting videos, but first he had to hack it.

After opening it up [Robin] discovered that there was a surprising amount of electronics in the base. In addition to a DC motor, there was a potentiometer attached to a gear to give feedback, but it was set up for partial rotation so it had to be yanked out.

There was also a plastic gear with teeth around just part of the interior. [Robin] took a picture of the gear and dropped it into Fusion360, using the photo as a reference image while he re-created the gear. The new piece had teeth all around the periphery. After printing it out he glued it into the old gearbox, and now he had turned his TV stand into a motorized turntable.

If you’re looking for more along these lines, check out our posts on making parametric models in Fusion360 and turning a turntable into a waveform generator. Continue reading “Motorized Turntable Created From TV Stand”

Using 3D Printing To Speed Up Conventional Manufacturing

3D printers, is there anything they can’t do? Of course, and to many across the world, they’re little more than glorified keychain factories. Despite this, there’s yet another great application for 3D printers – they can be used to add speed and flexibility to traditional manufacturing operations.

A key feature of many manufacturing processes is the use of fixtures and jigs to hold parts during machining and assembly operations. These must be developed before manufacturing begins and must be custom made to suit the given application. Many manufacturers outsource the development of such fixturing, even in large operations – even major automakers will often outsource development of fixtures and new process lines to outside firms. This can have major ramifications when changes need to be made, introducing costly delays. However, 3D printers can be used to rapidly iterate fixturing designs to suit new parts, greatly reducing development time. As stated in the article, Louis Vuitton uses this to great effect – the reduced time of development is incredibly useful when changing manufacturing lines every few months in the fashion industry.

Obviously there are limitations – in a factory producing large steel castings, it’s unlikely a FDM-printed fixture will be much use when it comes to the wear and tear of machining hundreds of castings a day. However, as a development tool, it can prove very useful. What’s more, jigs for light industrial work – think electronics assembly, woodworking glue-ups, or any form of delicate work by hand – need not be as robust. Lightweight, readily produced 3D printed parts may be just the ticket.

Another great benefit of 3D printing is its ability to be used for mockups. You may be designing a product that requires several aluminium parts to fit together, but alas – the parts won’t be ready for weeks. Rather than wait all that time, only to find out something doesn’t fit right, it may be advantageous to print out a plastic version of the parts. Being able to check geometry with actual parts is often very useful, and makes a great tool if you need to present your work to others. It’s much easier to communicate an idea to people if they can hold and touch what you’re talking about!

It’s something worth considering if you’re setting up any sort of small production line – perhaps you’re looking for a way to make populating a run of PCBs faster, or ease the assembly of a series of distributed sensor modules. These techniques may prove particularly useful if you consider yourself a scrappy hacker.

[Hat tip to George!]

Hackaday Prize Entry: DIY DLP

The 3D printing revolution is upon us and the technologies associated with these machines is evolving every day. Stereolithography or SLA printers are becoming the go-to printer for high-resolution prints that just can’t be fabricated on a filament-based machine. ADAM DLP 3D printer project is [adambrx]’s entry into the Hackaday Prize and the first step in his quest for higher quality prints on a DIY budget.

[adambrx]’s current iteration employs a Raspberry Pi 3 and a UV DLP Projector, all enclosed in a custom frame assembly. The logs show the evolution of the printer from an Acer DLP to the current UV DLP Light Engine. The results are quite impressive for a DIY project, and [adambrx] has put up images of 50-micrometer pillars and some nifty other prints which show the amount of work that has been put into the project.

It is safe to say that [adambrax] has outspent the average entry to the Hackaday Prize with over €5000 spent in around 3 years. Can [adambrx] can keep this one true to its DIY roots is yet to be seen, however, it is clear that this project has potential. We would love to see a high-resolution SLA printer that does not cost and arm and a leg.

Printrbot Teases Infinite Build Volume Printer

[Brook Drumm] of Printrbot is teasing a new 3D printer. This is no ordinary 3D printer; this is an infinite build volume 3D printer, the Next Big Thing™ in desktop fabrication.

The world was introduced to the infinite build volume 3D printer last March at the Midwest RepRap Festival with a built by [Bill Steele] from Polar 3D. The design of [Bill]’s printer began as simply a middle finger to MakerBot’s Automated Build Platform patent. This was patent engineering — [Bill] noticed the MakerBot patent didn’t cover build plates that weren’t offset to the plane of the print head, and it just so happened a printer with a tilted bed could also build infinitely long plastic parts.

While [Bill Steele]’s unnamed printer introduced the idea of an infinite build volume printer to the community, a few pieces of prior art popped up in the weeks and months after MRRF. Several years ago, [Andreas Bastian] developed the Lum Printer, an unbounded conveyor belt printer. A month after MRRF, Blackbelt 3D introduced their mega-scale tilted bed printer and later started a Kickstarter that has already reached $100,000 in pledges.

Right now, details are sparse on the Printrbelt, but there are a few educated guesses we can make. The belt of the Printrbelt appears to be Kapton film attached to some sort of substrate. The hotend and extruder are standard Printrbot accouterments, and the conveyor is powered by a geared stepper motor. All in all, pretty much what you would expect.

We do know that [Brook] and [Bill Steele] are working together on this printer, apparently with [Brook] in charge of the hardware and [Bill] taking either his slicing algorithm or firmware modifications (we’re not exactly sure where the ’tilt’ in the Gcode comes from) and getting this printer running.

While the Printrbelt isn’t ready for production quite yet, this is a fantastic advance in the state of consumer, desktop 3D printing. You can check out [Brook]’s teaser videos below.

Continue reading “Printrbot Teases Infinite Build Volume Printer”

Using Nanotubes To Strengthen 3D Prints

3D printing has brought the production of plastic parts to the desktops and workshops of makers the world over, primarily through the use of FDM technology. The problem this method is that when squirting layers of hot plastic out to create a part, the subsequent vertical layers don’t adhere particularly well to each other, leading to poor strength and delamination problems. However, carbon nanotubes may hold some promise in solving this issue.

A useful property of carbon nanotubes is that they can be heated with microwave energy. Taking advantage of this, researchers coated PLA filament in a polymer film containing carbon nanotubes. As the layers of the print are laid down, the nanotubes are primarily located at the interface between the vertical layers. By using microwaves to heat the nanotubes, this allows the print to be locally heated at the interface between layers, essentially welding the layers together. As far as results are concerned, the team reports an impressive 275% improvement in fracture strength over traditionally printed parts.

The research paper is freely available, which we always like to see. There’s other methods to improve your print strength, too – you could always try annealing your printed parts.

[Thanks ????[d] ???? for the tip]

The 3D Printer Packing Problem

Form Labs recently announced the launch of the Fuse 1, a desktop SLS printer that will print all your parts using nylon powder and a laser. This a fundamentally different method of 3D printing as compared to filament-based machines, and the best way to use a Fuse 1 is to fill the entire volume of the machine with 3D printed parts. [Michael Fogelman] decided to investigate the 3D packing problem, and managed to fill this printer with the maximum number of 3D printed tugboats. If you’re wondering, it’s 113, as compared with 82 tiny Benchies using naive bin packing.

The formal definition of this sort of problem is the bin packing problem, or simply calculating the maximum number of items can be packed into a finite volume. There is no general solution to this problem, and it’s probably impossible to create an algorithm that will solve this problem for any collection of 3D models. Nevertheless, it’s possible to create a solution that shows marked improvement over a naive solution.

[Michael]’s solution involves simulated annealing. This algorithm begins by randomly placing tugboats, then mutating the position or rotation of one of the boats for each iteration. The code is less than 1000 lines of Go and is available on GitHub if you already have an SLS printer at your disposal.

It should be noted this type of problem isn’t particularly new to the world of 3D printers. There have been a few tools to solve the bin-packing problem for filament-based printers, but the solutions to these problems are two-dimensional; since filling a bed is a problem that only uses the ‘shadow’ of the Z-axis of each part, it’s a slightly easier problem to solve.

Now that Form Labs’ Fuse 1 SLS printer has been announced, there is a new application for this type of problem in the space of 3D printers. It’s not a perfect solution — and it’s doubtful there will ever be a perfect solution — but if you’re looking for a way to fill the volume of your powder printer with parts, this is the best you’re going to do.