Field Expedient Bandsaw Mill Deals with Leftover Logs

When a questionable tree threatened his house, [John Heisz] did the sensible thing and called in a professional to bring it down. But with a flair for homebrew tools, [John] followed up with a seemingly non-sensible act and built a quick and dirty DIY bandsaw mill to turn the resulting pile of maple logs into usable lumber.

A proper bandsaw mill is an expensive tool. Prices start in the mid-four figures for a stripped down version and can easily head into the multiple tens of thousands for the serious mills. [John] makes it clear that his mill is purpose-built to deal with his leftover logs, and so he made no attempt at essentials like a way to index the blade vertically. His intention was to shim the logs up an inch after each cut, or trim the legs to move the blade down. He also acknowledges that the 2-HP electric motor is too anemic for the hard maple logs – you can clearly see the blade bogging down in the video below. But the important point here is that [John] was able to hack a quick tool together to deal with an issue, and in the process he learned a lot about the limitations of his design and his choice of materials. That’s not to say that wood is never the right choice for tooling – get a load of all the shop-built tools and jigs in his build videos. A wooden vise? We’d like to see the build log on that.

We’ve featured a surprising number of wooden bandsaws before, from benchtop to full size. We’re pretty sure this is the first one purpose built to mill logs that we’ve featured, although there is this chainsaw mill that looks pretty handy too.

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Beautiful Kegerator, Built the Hard Way

[Luke] brews his own beer. And like all beer brewers, he discovered that the worst part of homebrewing is cleaning out all the bottles. Time for a kegging system! And that means, time for a kegerator to keep the brew cold.

Normal kegerators are just a few holes drilled in an appropriate refrigerator. Most fridges have a step in the back where the compressor lives, which makes kegs an awkward fit, so [Luke] decided to build his own refrigerator.

He used beautiful wood and plenty of insulation. He failed, though, because he succumbed to the lure of the Peltier cooler. If there’s one problem with Peltier projects, it’s building first and looking up the specs second. They never have enough cool-juice. To quote [Luke]:

“… a comment I had seen somewhere on the Internet began to sink in: all projects involving peltier devices ultimately end in disappointment.

(Bolding and italics from the original.) But at least he learned about defrosting, and he had a nice wood-paneled fridge-box in the basement.

Rather than give up, he found a suitable donor fridge, ripped out its guts, and transplanted them into his homemade box. A beautiful tap head sitting on top completes the look. And of course, there’s an ESP8266 inside logging the temperature and controlling the compressor, with all the data pushed out over WiFi. Try doing that with your Faraday Cage metal fridge!

We’ve seen kegerator builds before. Some of our favorites include this one that has a motorized retracting tap tower, and one that’s built into the walls of the house.

DIY PCB Fixture Helps You Spread the Paste

(Yeah, we don’t know what that title means either.) But holding your PCBs down in one place and nicely registered while you spread solder paste over them is a problem that needs solving, and [Carsten] did it nicely.

High volume PCB manufacturers have expensive screen printers to do this. The standard hardware hacker solution is to tape some scrap PCBs of the same thickness down to the table to hold the PCBs solidly in place. But if you’re doing a large run, and if you’re already firing up the laser to cut out mylar stencils, you might as well cut out some PCB-holding fixtures to match.

[Carsten]’s blog entry is short on details, but you get the idea just from looking at the picture, right? Adding registration pins to the holder that engage with the stencils could make this a real time-saver as well. As long as you’re lasering the stencil and the holder, there’s nothing stopping you. It’s a simple idea, but a good one, so we thought we’d share. Our only remaining question: what’s a Karate Light?

Precision CNC With Epoxy Granite

Epoxy granite is an overlooked material when it comes to making home CNC builds. As far as time and money goes, when you add in all the equipment it comes out cheaper than an aluminum casting set-up. Epoxy granite has mechanical properties better than cast iron, increased dimensional stability, better vibration damping, and looks awesome when done right. Also, you can cast precision surfaces and threaded holes into your design, which is pretty cool.

In these two videos by [Jørgen Hegner] we get to watch him and a friend make a matching set of precision CNC machines. It’s built in a similar style to other nice builds we’ve featured. This way of making it needs a bigger footprint than a gantry mill and can’t be built as large. However, it solves a lot of mechanical issues and squaring with the gantry design while not being as difficult to get right as a box or knee mill.

After casting they machined the material embedded in the granite to mount the ways. The ways are linear bearings and ball screws. Expensive, but as the footage shows, very accurate.  The rest of the machine is assembled and tuned. Then it gets installed in a home made 80/20 enclosure. We really like the LCD panel that’s incorporated into the front shield of the machine. They really went all out with the CNC control panel. It looks like they can do anything from jog the axis to monitor and control the water cooling for the spindle.

It appears that all the precision work is put to good use as there are some shots at the end of video two of a beautiful clock CNC’d on this machine. Videos after the break.

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Six Years of Work and Rationale In A DIY Book Scanner Documented

[Daniel Reetz] spent six years working as a Disney engineer during the day and on his book scanner, the archivist at night. Some time last year, [Daniel] decided enough is enough, got married, and retired from the book scanner business. There’s a bit more to it than that, but before leaving he decided to dump, not just the design, but the entire rationale behind the design into a twenty-two thousand word document.

One of his big theses in this document, is his perceived failure of the open hardware movement. The licenses aren’t adequate, as they are based on copyright law that only applies to software. This makes it impossible to enforce in practice, which is why he released the entire design as public domain. He also feels that open hardware shares design, but not rationale. In his mind this is useless when encouraging improvement, and we tend to agree. In the end rationale is the useful thing, or the source code, behind a design that truly matters. So, putting his money time where his mouth is, he wrote down the rationale behind his scanner.

The rationale contains a lot of interesting things. At a first glance the book scanner almost seems a simple design, not the culmination of so much work. Though, once we began to read through his document, we began to understand why he made the choices he did. There’s so much to getting a good scan without destroying the book. For example, one needs a light that doesn’t lose any color information. It doesn’t have to be perfect, as the software can correct the white balance. However, it can’t lean too far away from the natural spectrum, it can’t be too bright, and it can’t be uneven, and it can’t be prohibitively expensive. A lot of thought went into the tent light design.

[Daniel]’s book scanners are immensely popular, and are being used all over the world. He’s certainly made an impact, and the community that formed around his project continues to grow without him. He made some interesting points, and if anything wrote a really good build and design log for the rest of us to learn from.

DIY Thermal Imaging Smartphone

We wish we had [Karri Palovuori] for a professor! As an exciting project to get incoming freshmen stoked on electrical engineering, he designed a DIY thermal-imaging smartphone that they can build themselves. It’s all built to fit into a sleek wooden case that gives the project its name: KAPULA is Finnish for “a block of wood”.

It’s just incredible how far one can push easily-available modules these days. [Karri] mounts a FLIR Lepton thermal camera, an LPC1768 Cortex M3 ARM micro, a GSM phone module, and a whole bunch of other cool stuff on a DIY-friendly two-sided board. The design uses 10 mil (0.25mm) trace and space, which is totally achievable with home etching methods. Copper wire bits fill up the vias. Did we mention he’s making the students do all this themselves? How awesome is that?

[Karri] expects that the students will tweak the software side of things. With additional onboard goodies like an accelerometer, microphone, speaker, SIM card, and USB, it’s not likely that they’ll get bored with the platform. He has a stretch hope that someone will take the hardware and modify it. That’s ambitious for sure, but it’s so cool that someone could.

We’ve seen some sophisticated DIY cellphones before, but this one rises above by being easily DIYable and including awesome extra features. Order parts now, and start etching. You could be sending thermal-photo tweets inside of just a few days.

Building a Taller Drillpress

[BF38] bought a mid-range miniature drill-press, and discovered that it was just too short for some of his applications. “No problem,” he thought, “I’ll just measure the column and swap it out for a longer one.” It sounds foolproof on paper.

He discovered, after having bought a new 48.3 mm steel column, that the original was 48 mm exactly in diameter. He’d have to make it fit. But how do you bore out a 48 mm diameter hole, keeping it perfectly round, and only increase the diameter by 0.3 mm? A file is out because you’d never get it round. A lathe is out because [BF38] doesn’t have a lathe.

[BF38] ended up making a DIY honing head, which is a gadget that presses (in this case) two pieces of sandpaper evenly against the sides of the hole to be widened. The head in question is a little bit rough — it was made as a learning project, but it looks like it served the purpose admirably.