Hackaday Links: March 6, 2016

There’s the R2 Builders Club, hundreds of people are building BB-8, but there are a few robots that don’t get enough love from the amateur propsmiths. [Kenneth] just finished up his build of Crow from MST3K. He built Tom Servo a year or so ago and K-9 from Doctor Who. The beautiful thing about building MST3K robots and Doctor Who props is that you’re probably working with a larger budget than the prop department had.

Heathkit’s new website is up. The two products we know about so far – an AM radio kit and a slim jim antenna – can only be described as, ‘meh.’ Still, there are a few upgrades for old kits available and the requisite amount of nostalgia.

On today’s issue of, ‘should not be attempted by anyone, ever, under any circumstance’ here’s how to build a table saw at home. Yes, it’s a table saw built from a piece of aluminum, styrofoam, hot glue, and a shoe box. The guy really botched it by not going for the zero clearance insert here, but at least the fence is only a few dozen degrees off parallel with the blade.

[Mathieu] is working on a Mooltipass Mini. It’s tiny and the scroll wheel thingy makes things fun.

March 18th through March 20th is the Midwest RepRap Festival in Goshen, Indiana. This is, by far, the best conference, meetup, or festival we go to year after year. We’ll have a few members of the Hackaday crew at the event, and rumor has it the Internet has made it to Indiana this year.

Adafruit got a writeup in the New Yorker. The article is technically about the art of PCB design, but as with most general interest pieces on electronics it is awash in non sequiturs and simply defining the terminology.

[Oscar] built a miniature replica of a blinkenlight computer last year for the Hackaday Prize. This was the PiDP-8/I. While it looks awesome, the PDP-8/I is inherently limited. [Oscar] has his design methodology down, and now he’s working on a miniature replica of the king of the PDPs. It’s the PiDP-11/27. It’s just a prototype and render now, but the finished project will have custom switches, a handsome bezel, and will be much more capable.

MAME is now FOSS. That’s great news, but think about the amount of work that went into making this happen. MAME is 19 years old, and  that means everyone who has contributed to the project over the years needed to sign off on this initiative.

Circular saw + Innovative Fence = Unique DIY Table saw

A table saw is often the first machine the aspiring woodworker wants for the shop. But even a lightweight contractor’s saw is not cheap, and a really good cabinet saw is both expensive and incredibly heavy. And any table saw is an intimidating machine that can liberate your fingers from your hand in a trice. Looking for a solution to all of these problems, [Seumas] has come up with a unique table saw conversion for a circular saw that improves safety and lowers the barrier to table saw ownership.

Flipping a low-cost circular saw upside down and attaching it to a table is old hat – we’ve seen plenty of examples of that before, including this recent post. Where [Seumas]’s idea shines is in the integration of the fence and the table. A typical fence needs to stay perfectly parallel to the blade while being dead square to the table, but still needs to be moved to adjust the width of cut. In [Seumas]’s design, the fence is fixed to the table, and the whole table slides left and right on high-pressure laminate rails. In theory, the fence will never go out of true, and the width of cut can be a lot wider than the typical table saw – an impressive 3 feet to the right of the blade.

As for safety, [Seumas] shows off quite a selection of DIY attachments in the video after the break. He builds his own Lexan blade guard, anti-kickback pawls, and stock hold-downs. Add in the little touches like shop-made clamps for locking the table, extending outfeed support, and built-in dust collection, and you can make yourself a pretty capable machine at the fraction of the cost of buying.

Continue reading “Circular saw + Innovative Fence = Unique DIY Table saw”

Making A Wooden Bowl Without A Lathe

Typically, when creating a wooden bowl a crafts person would do so on a lathe. A chunk of wood would be bolted to the head stock and the bottom of the bowl turned to an appropriate shape. Then the half-bowl-shaped wood is flipped around on the lathe so that the material on the inside of the bowl can be removed. This traditional method of bowl turning requires a lathe, turning tools, and the serious technique and skill required for the task.

The master maker of weird wood working tools, [Izzy], decided to make a wooden bowl without the use of a lathe. He created a unique fixture to cut the shape of the bowl on a table saw, a piece of equipment that is a bit more common for the average DIYer to have. The fixture itself is made of wood and supports a standard hand drill in a vertical position. The soon-to-be bowl is bolted to the drill and hovers just above the table saw blade. The table saw is turned on and the fixture allows the work piece to rock back and forth creating the bowls outside shape. The drill rotates the piece so that the contours are consistent around the bowl.

The bowl is then flipped over and re-attached to the drill. This time to cut the inside of the bowl, the fixture is locked in the vertical position and the wood is dropped straight down on the spinning blade while being rotated. The saw blade cuts a perfectly hemispherical cavity in the wood. The final bowl looks great after a little sanding and an application of oil. Check out the video after the break.

This isn’t the first time [Izzy’s] projects have been here on Hackaday, check out his DIY Band Saw and Wooden Sphere Cutter.

Continue reading “Making A Wooden Bowl Without A Lathe”

Homemade Table Saw Starts With Circular Saw

How often do us tinkerers go out into our basement/garage shop and don’t have the correct tool for the job? Most would say it happens more often than they would prefer. One option would be to buy the tool, but it is always more fun to build what you need! [kadambi] was in need of a table saw and decided to build his own.

He’s using a circular saw as his starting point but this isn’t just any old circular saw. This one has a riving knife that prevents work piece kickback and human contact with the back of the spinning blade. The saw is mounted upside-down to a wooden table that is supported by a wooden box frame. The boxy frame has another function, it acts as a dust collector. A vacuum is ported into the box frame creating a low pressure condition and most of the sawdust is sucked into (and settles on) the bottom of the box. Only a small amount of dust makes its way into the vacuum, preventing otherwise inevitable filter clogs. Out front is an industrial on/off switch as well as a separate e-stop switch.

[kadambi] has done some test cuts and is happy with his saw’s performance. If you’re interested in more DIY table saws, check out this mini saw or feature-filled one.

An Improved Table Saw Fence With Threaded Rod

Back in the bad old days, table saw fences were terrible. You would have to measure the top and bottom of the fence before each cut, just to make sure the fence was square to the blade. In the 1970s, [Bill Biesemeyer] invented a better table saw fence, one that was always square, and included a measuring tape, right on the table saw.

[Jer] wanted an upgrade for his table saw and came up with what might be the next evolution of the table saw fence. It will always produce a square cut, but unlike the 1970s version, this fence has repeatability. If you rip a board to 1″, move the fence, come back to it after a month, and try to rip another board to 1″, those two boards will be exactly the same width.

The secret to this repeatability is a threaded rod. On the front of the fence is a big, beefy piece of threaded rod with 16 threads per inch. On the fence itself is two nuts, cut in half, welded to the guide, with a lever and cam to lock them in place.

When the lever is up and the nuts are disengaged from the threaded rod, the fence easily moves from one side of the table to the other. When the fence is locked down, it locks to the nearest 16th of an inch, and only the nearest 16th of an inch. While that may seem a little large for a relatively expensive tool, this is wood we’re talking about here. There’s not much reason to make the resolution of this fence any smaller; wait until the humidity changes and you’ll have a piece of wood that’s the desired dimension.

Continue reading “An Improved Table Saw Fence With Threaded Rod”

Modern Tools From Old Table Saws

Somehow or another, the modern hackerspace isn’t centered around table saws, drill presses, band saws, lathes, or mills. The 3D printer and laser cutter are the tools of the future. No one has yet figured out how to build a 3D printer or laser cutter out of several hundred pounds of cast iron, so until then [Chad] will lead the charge modifying old table saws into these modern machine tools.

The build logs for the laser engraver and 3D printer are pic heavy and text lean, but there’s enough detail to make a few educated guesses. Both of these machines use Craftsman table saws from the early to mid 1950s for the chassis. Inside each chassis, the rails, belts, and shafts that make up a Cartesian bot are installed, and the electronics are tucked gently inside.

There’s a lot of creativity in this build; the electronics for the 3D printer are tucked away in the shell of the old motor. For the laser cutter, the focus adjustment is the same knob that used to lock the blade at an angle.

While this may look like a waste of two beautiful tools, keep in mind these are equivalent to contractor saws you can pick up at Home Depot for $500 today. They’re not professional cabinet saws, they just look really pretty. They’re still a solid piece of metal, though, and refurbishing the frames into useful tools is probably the best thing you could do with them.

Thanks [Frankie] for the tip.

Automated Table Saw Cuts Photovoltaic Solar Cells

[sudarshan] is a solar hobbyist and needed a way to cut solar cells for his projects. He had previously created a rotary tool saw but manually feeding them through was sketchy at best. With just a slight wrong movement of his hand or flex in the work surface would cause the cell to break. These cells are extremely brittle and break easily. He needed a method of cutting these cells that was free from jitters and would cut in a straight line. He looked around his junk bin and found an odd solution… a scanner. Yes, the type you would scan photos in your computer with. The scanner had two critically important features, a flat surface and a carriage mechanism that moves perfectly parallel with that flat surface.

[sudarshan] made a solar cell cutting mini table saw with that scanner and made the cutting happen automatically. He mounted a motor with a diamond saw disk to the carriage, that is responsible for the cutting. The blade was positioned just high enough to poke through the plexiglass that replaced the original glass bed. A power switch turns on the cutting disk motor and an Arduino was used to move the carriage, including the cutting blade, back and forth. Two of the stock scanner buttons were reused and wired to the Arduino to keep the saw looking good.

The first few passes of the saw were done to cut a slot in the plexiglass. In order to cut a solar cell, the cell is taped to the bed with the desired cut location aligned with the slot in the plexiglass bed. Once everything is set, hit the ‘go’ button and the saw blade is slowly pushed through the cell, leaving a straight, clean cut.

Continue reading “Automated Table Saw Cuts Photovoltaic Solar Cells”