As [Marius Hornberger] was working in his woodshop, a thunderous bang suddenly rocked the space. A brief search revealed the blower for the dust collector had shifted several inches despite being stoutly fastened down. Turns out, the blower had blown itself up when one of the impeller fins came loose. Time to revise and build a bigger, better dust collector!
[Hornberger] is thorough in describing his process, the video series chronicles where he went astray in his original design and how he’s gone about improving on those elements. For instance, the original impeller had six fins which meant fewer points to bear the operating stresses as well as producing an occasionally uncomfortable drone. MDF wasn’t an ideal material choice here either, contributing to the failure of the part.
About a decade ago [Windell Oskay] and [Lenore Edman] spun out of Evil Mad Scientist Laboratories to work on CandyFab, an inexpensive 3D printer that used sugar as its medium. Wondering what happened to CandyFab? It’s been nearly that long since we last wrote about their work and Maker technology has moved on; nowadays 3D printers run the gamut from very inexpensive to production ready. The CandyFab project and nascent company are now shuttered, but there is a epilogue with some interesting lessons.
First of all, the saga of the CandyFab series of printers (above on the same page) is worth a read. Some of what these machines were capable of is still quite impressive by modern standards. Sure your Monoprice Mini Delta may be easy to use, fully assembled, functional when you take it out of the box, and quiet. But what if you need to print something up to 8.5″ x 11″ x 17″? The CandyFab 5000 can do that. Or even a humongous 24″ x 13.5″ x 9″? The CandyFab 4000 can do it, and for a measly $37 (if you printed a solid cube exactly the size of the build volume)! Sugar may have downsides but it’s still a pretty clever medium for some uses.
CandyFab credits the rise of MakerBot coupled with the complexity of iterating from a pile of “surplus junk” (their words) to something kitable. Reading their post-mortem brings to mind familiar problems from today’s hardware world. A spike of fantastic early publicity lead to the need to handle press while rapidly iterating from the aforementioned surplus parts to a reliable and manufacturable design. Then the complexity of balancing a day job and other side projects with the prospect of CandyFab as a business. Ultimately the need for the project in the first place (accessible inexpensive 3D printers) was alleviated by the market and the project came to a graceful close.
Give the post a read, we’re sure you’ll learn something!
[Rory Johnson] writes in to tell us about PlyTop Shell, a Creative Commons licensed design for a laser cut wooden laptop that he’s been working on since 2016. It’s designed to accommodate the Raspberry Pi (or other similarly sized SBCs), and aims to provide the builder with a completely customizable mobile computer. He’s got a limited run of the PlyTop up for sale currently, but if you’ve got the necessary equipment, you can start building yours while you wait for that new Pi 3B+ to arrive.
Originally [Rory] was working on a 3D printed design, but quickly ran into problems. The vast majority of 3D printers don’t have nearly the build volume to print out a laptop case in one shot, so the design needed to be broken up into multiple smaller pieces and then grafted together into the final case. Not only did this take a long time and a lot of material, but the final result had the rather unfortunate appearance of a plastic quilt.
Eventually he got hooked up with a maker collective in Minneapolis that had a laser cutter, and the PlyTop was born. There’s still a 3D printed component in the design that goes in the screen hinge, but the rest of the PlyTop is cut out of a three 2′ x 4′ sheets of 1/8″ Baltic birch plywood. As you might expect, plenty of fasteners are required, but [Rory] has a complete Bill of Materials (complete with purchase links) for everything you’ll need to turn the cut pieces into a fully fledged laptop. He’s considering selling kits in the future, but is still working on the logistics.
In keeping with the idea of complete flexibility, there’s no defined layout for the internals of the PlyTop. Rather, there’s an array of star-shaped openings on the bottom plate that allow the builder to connect hardware components up in whatever way works for them. [Rory] actually suggests just holding everything down with zip ties to allow for ease of tinkering.
He’s also come up with a list of suggested hardware for the keyboard, touchpad, and display; but those are really just suggestions. The design is open enough that it shouldn’t take much work to adapt to whatever gear you’ve got laying around.
To be fair, the rules of the game have changed lately. Time was when a nipper would ask for the impossible, and we dads would never have to deliver. But with CNC routers, 3D-printing, and industrial-grade CAD software you can use for free, the possibility hurdle is getting ever shorter. Still, when his son put in this request, [Alex Lovegrove] really delivered. Everything on this excavator works, from tracks to boom to bucket. There are hundreds of parts, mostly machined from plywood but with a smattering of 3D-printed gears and brackets. The tracks and slew gear are powered by gear motors, while linear actuators stand in for hydraulic rams on the boom. The videos below show the machine under test and the unbearable cuteness of it being loved.
The Maslow CNC project is a CNC mill for sheet woodwork that is designed to be as inexpensive as possible and to be assembled by the end user. They’ve dropped us a line to tell us about a recent project they’ve undertaken as part of a collaboration to produce the PlyPad, a tiny house for Kenton Women’s Village, a project to tackle homelessness among women in part of the City of Portland.
Their write-up is a fascinating look at the issues surrounding the design and construction of a small dwelling using CNC rather than traditional methods. As an example their original design featured an attractive sawtooth roofline with multiple clerestory windows, but sadly a satisfactory solution could not be found to the problem of keeping it waterproof and they were forced to adopt a more conventional look.
The walls of the building are a ply-foam bonded sandwich, and the house is constructed in 4 foot sections to match the width of a sheet of ply. There are several section designs with built-in furniture, for example containing a bed, or storage space.
This house was designed to be part of a community with central washing and sanitary facilities, so it does not incorporate the bathroom you might expect. However it is not impossible to imagine how sections could be designed containing these, and could be added to a full suite of construction choices. We are reminded of its similarity to the WikiHouse project.
Ever wanted to bend plywood but don’t have the equipment or the space to use it? Whatever the issue, dust off those project ideas and take a look at [Ryo Kosaka]’s experimental bending jig.All you need are some boards, a couple of fasteners, and [Ryo]’s 3-D printed connectors.
This is quite the elegant solution for bending in a small space with little noise. The main departure from standard bending methods is that instead of making the bend by clamping the veneers between a pair of positive and negative mold halves, most of the clamping pressure comes from air pumped into a rubber ball. That’s not even the best part: not only is the mold reconfigurable, it’s modular. Want another bend in your thing? Just print another connector and grab another piece of wood.
[Ryo]’s pivoting connectors screw into the end of one board and move freely along the length of a second board. Once the bend angle is dialed up, he locks it in place with a bolt. For the first test, [Ryo] made a lamp base with two bends.The jig worked great except for a small gap that didn’t get enough clamping pressure from the ball. We wonder if rotating the jig during the process would have let gravity address the issue. For the second test, [Ryo] added another piece to make the jig rectangular and made a floating wall shelf. Bend your way past the break for the video version.
Plywood laser-cuts fairly well but has drawbacks when used in serious production runs, as [Marie] explains in a blog post about a quest for the ultimate laser-cutting plywood. One of the things [Nervous System] makes and sells is generative jigsaw puzzles, and they shared their experience with the challenges in producing them. The biggest issue was the wood itself. They ended up getting a custom plywood made to fit their exact needs, a process that turned out neither as complex nor as unusual as it may sound.
Plywood is great because it’s readily available, but there are some drawbacks that cause problems when trying to do serious production of laser-cut plywood pieces. Laser cutting works best when the material being cut is consistent, but there can be areas of inconsistent density in plywood. If the laser encounters an unexpected knot somewhere in the wood, there is no way to slow down or to increase power to compensate. The result is a small area where the laser perhaps doesn’t quite make it through. A picture of an example from my workshop shows what this looks like.
When doing basic project work or prototyping, this kind of issue is inconvenient but usually some trimming and sanding will sort things out. When doing a production run for puzzles like [Nervous System] was doing, the issue is more serious:
A jigsaw puzzle with a large number of cuts in a relatively small area has a higher chance of running into any problem spots in the material. If they exist, the laser will probably encounter them.
Trouble spots in plywood can be on the inside layers, meaning they can’t be detected visually and are only discovered after they cause an incomplete cut.
Increasing laser power for the whole job is an incomplete solution, as excessive laser power tends to make the cuts uglier due to increased scorching and charring.
An inspection process becomes needed to check each puzzle piece for problems, which adds time and effort.
A puzzle that had even one piece that did not cut properly will probably be scrapped because rework is not practical. That material (and any time and money that went into getting the nice artwork onto it) becomes waste.
Plywood is great stuff and can look gorgeous, but [Marie] says they struggled with its issues for a long time and eventually realized they had gone as far as they could with off-the-shelf plywoods, even specialty ones. They knew exactly what they needed, and it was time for something custom-made to serve those specific needs.
Having your own plywood custom-made may sound a little extreme, but [Marie] assures us it’s not particularly difficult or unreasonable. They contacted a small manufacturer who specialized in custom aircraft plywoods and was able to provide their laser-cut plywood holy grail: a 3-ply sheet, with high quality basswood core with birch veneers, and a melamine-based glue. It cuts better than anything else they have used, and [Marie] says that after four years they had certainly tried just about everything.