A Machine Shop in A Toolbox: Just Add Time

You don’t need any fancy tools. A CNC machine is nice. A 3D printer can help. Laser cutters are just great. However, when it comes to actually making something, none of this is exactly necessary. With a basic set of hand tools and a few simple power tools, most of which can be picked up for a pittance, many things of surprising complexity, precision, and quality can be made.

Not as pretty, but worked just the same.
Not as pretty, but worked just the same.

A while back I was working on a ring light for my 3D printer. I already had a collection of LEDs, as all hackers are weak for a five-dollar assortment box. So I got on my CAD software of choice and modeled out a ring that I was going to laser cut out of plywood. It would have holes for each of the LEDs. To get a file ready for laser cutting ook around ten minutes. I started to get ready to leave the house and do the ten minute drive to the hackerspace, the ten minutes firing up and using the laser cutter (assuming it wasn’t occupied) and the drive back. It suddenly occurred to me that I was being very silly. I pulled out a sheet of plywood. Drew three circles on it with a compass and subdivided the circle. Under ten minutes of work with basic layout tools, a power drill, and a coping saw and I had the part. This was versus the 40 minutes it would have taken me to fire up the laser cutter.

A lot of the tools we use today were made to win against economies of scale. However, we’re often not doing any of that. We’re building one or two. Often the sheer set-up cost isn’t worth it. Likewise, the skill from being able to do it without the machine will come in handy. There’s an art to using a file properly and getting the expected result. So it’s good to take the time now to practice and develop the manual skills, you never know when you’ll be out trying to do an emergency fit on a part and no one in the area has a single milling machine just sitting around.

So what tools would a hacker need to get the closest to a machine shop without having one or spending too much money? For most needs a person can build a surprising amount of things with nothing more than the following tools.

Basic Metrology: Now if you really want to do precision work you may need more expensive tools, but often we are just spoiled by precision. We can design our parts with a little more wiggle room and just spend the time adjusting them.

  • Calipers – Since they are so cheap now, there is no reason not to own a simple digital or dial caliper. For most work this will be able to measure most things well enough for all practical purposes. Honestly if you’re building something that needs a full metrology suite you’re probably making it hard on yourself. This even goes for production work.
  • Rule – Not a ruler. A steel rule. This will have a ground flat edge and precise graduations. You can use this for layout.

    Chris over at Clickspring is always using the glued paper trick to do some very accurate work.
    Chris over at Clickspring is always using the glued paper trick to do some very accurate work.
  • Square – A carpenter’s combination square can be used for a lot of layout. It’s not as fantastically precise as a real machinists square, but I’ve yet to ever actually need the precision of a real machinist’s square for every day hacking.
  • Compass & Protractor – To be able to layout circles and angles is key. Buy a robust one rather than a nice one. The kind for school children is pretty good.
  • Scribe and Punch- Pencil and Permanent Marker- In lieu of layout fluid a permanent marker is enough to bring out scribed lines on metal. A pencil is great for the rest of the materials. Lastly a punch is essential for drilling holes.
  • Glue stick – With CAD software as amazing and free as it is there’s no reason not to just print out a template and glue it to your part. Contact cement or a simple glue stick is all you need

Working: Next comes working the material itself. Hand working typically happens in two steps. Bulk removal and fine removal. To do the first you need good layout and a bit of experience. To do the second you need even better layout, a godlike amount of patience, a strong back (or a workbench at the right height) and a way to hold the part firmly.

Trust me when I say I've worn out a lot of work gloves and these hold up the longest.
Trust me when I say I’ve worn out a lot of work gloves and these hold up the longest.
  • Stubby Knife (and cut proof gloves) – A knife that lets you get your fingers close to the work, such as an exacto blade or a utility knife. That being said I’m lucky to still have digits with full working ranges. It doesn’t matter how careful you are, it is statistically impossible to not eventually cut yourself with a knife. It then comes down to how damaging that cut will be. Most will hit the flesh of the hand and be relatively harmless, just painful. However, if you hit a tendon say goodbye to full range of motion forever and hello to surgery and picking up an instrument (source: Grew up with an occupational therapist as a parent, that’ll scare the gloves on ya). To that end I highly recommend a good set of kevlar cut-proof gloves. My absolute favorite is the Ansell Blue Nitrile Coated Kevlar HyFlex glove. They’re pricey but they last forever (I would go through five sets of leather gloves in the time it took me to start to see wear on the HyFlex) and give practically normal range of motion and feel for the work.
  • Big File – A coarse bastard file is a must have. If you can only afford one get one with a flat side and a round side. It will be a little difficult not to cut into right angles, but a bit of masking tape or a section of plastic can help with this. Also, the traditional brands like Nicholson can no longer be trusted, do some research before paying more than five bucks for a regular file these days. Only a few brands deliver a long-lasting file. Lastly, watch a few videos on the proper use of a file. If you do it right they’ll cut fast and last a long time.
  • Round File – A round file is useful for a staggering amount of things, but mostly for fitting holes and shaping radii.
  • Little Files – I recommend spending a bit on a nice quality set. One small round, small triangle, and small-D shaped file is a good start. I’d also recommend a small flat file with a safe side for sharpening corners.
  • Japanese Pull Saw – Wood is a great prototyping material and there is no better saw for general woodworking than a Japanese pull saw. If you want to get deeper into the craft then there is a reason for the other saws, but general joints, shaping, etc can be done quickly and precisely with the saw.
  • Hacksaw – A hacksaw can cut through any material as long as you buy the right blade and are willing to sweat. A good hacksaw frame can put a lot of tension on a blade without a lot of added bulk. If it has both a lever action and a thumb screw it is likely to be able to do this. A good hacksaw blade is almost never sold with the frame.

    The metal fabricator's handbook will blow your mind if you've ever wondered how people made armor or hot-rods. It's hard, but technically simple.
    The metal fabricator’s handbook will blow your mind if you’ve ever wondered how people made armor or hot-rods. It’s hard, but technically simple.
  • Coping Saw – Think of a coping saw as a manual laser cutter. There are some nice ones out there, but the blade is the important thing to buy. Weirdly they are getting harder to find these days. I think less people are using them but no shop should be without a coping saw.
  • Plier Set – A set of pliers. Needle Nose, End Cutters, Side Cutters, and Lineman’s is a good place to start.
  • Tongs – I define a tong as any plier that you’re going to heat up. Keep this one separate from your regular pliers. It’s also good for holding something while you beat on it with a hammer. You’ll probably break it eventually.
  • Clamp or Vise – No shop should be without some way of holding a piece firmly. This is one of your most important tools. Really high quality ones usually show up at garage sales or Craigslist; sold by ignorant family members. Look for one that has nice thick jaws and a flat area on the back.
  • Hammer and Scrap Wood – You’d be amazed at the shapes a person can draw out of regular sheet stock with a hammer and scrap wood. This is a must have for the shop. A regular claw hammer and a ball peen are an absolute necessity.

Modern Day Luxuries: There’s no need to stay completely manual though. With Horrible Freight right around the corner or slightly better alternatives for a premium at the home improvement shop there’s no need to to have a few modern luxuries.

A pencil torch and vise come together for a brazing operation.
A pencil torch and vise come together for a brazing operation.
  • Dremel – A cheap rotary tool will make quick work of a lot of shaping tasks. Definitely saves time and there are some things that can’t be done economically without one. Also good for feeding an endless stream of cutting disks into to cut sheet stock without deforming it. Saves time on polishing too if you want to get fancy. Have to be careful not to waste too much time setting-up and forcing this tool to do the work. It’s often considerably underpowered compared to some sweat and hand files.
  • Power Drill and Bits – There is absolutely no reason not to have a decent power drill these days. Get a corded one if you can’t swing the money for a nicer model cordless. This will drill holes, sand, and occasionally act as a shitty lathe. Especially handy if you just want to bring something round into a tolerance for some sort of fit. Get a decent set of drill bits unless you hate yourself. I bought a 30 dollar set with decent coatings and have been replacing the individual bits with their higher quality counterparts as I burn through them. I’m currently on my third 1/8th inch bit.

    Let's be honest. The hobby of 3D printing doesn't really save any time.
    Let’s be honest. The hobby of 3D printing doesn’t really save any time.
  • Pencil Torch – Lastly a good quality torch or pencil torch does wonders. I burned through a few cheaper torches before I finally dropped a hundred dollars on a good quality Portasol. With a torch one can heat treat metals, solder, braze, and more. A person can cut plastics, weld plastics, and shrink heat shrink. It’s an essential tool.

For the rest I wouldn’t go nuts. I’d file them under, “buy as you need”. Of course there are things like screwdrivers etc. but this was intended for shaping operations, not general repair. I would recommend buying, not a tap and die set exactly, but picking a size of fastener (in my case, M3, M6, and M8) and buying the tap, die, and drill set for those.

In the end most prototyping, even today, ends up with a hacker having to still do some 19th century work to get it to fit. However, if you’ve ever seen a real watchmaker at work, you’ll know just how ridiculously far you can get on knowledge of metal backed up by skill with a file.

I know there are a lot of you out there with more and similar experience than I have with this sort of thing. At what point do you resort to modern tools? Any tasks that you found went faster the old-fashioned way? Any tools that I missed? Hand work isn’t a fading skill by any measure, but it’s easy to forget about it with 3D printers as cheap as they are. However, for any technical person it adds instant worth and a far deeper understanding of design and fabrication if you can do it by hand.

Making an Espresso Pot In the Machine Shop

[This Old Tony] was cleaning up his metal shop after his yearly flirtation with woodworking when he found himself hankering for a nice coffee. He was, however, completely without a coffee making apparatus. We imagine there was a hasty round of consulting with his inanimate friends [Optimus Prime] and [Stefan Gotteswinter Brush] before he decided the only logical option was to make his own.

So, he brought out two chunks of aluminum from somewhere in his shop, modeled up his plan in SolidWorks, and got to work.  It was designed to be a moka style espresso pot sized around both the size of stock he had, and three purchased parts: the gasket, funnel, and filter. The base and top were cut on a combination of lathe and mill. He had some good tips on working with deep thin walled parts. He also used his CNC to cut out some parts, like the lid and handle. The spout was interesting, as it was made by building up a glob of metal using a welder and then shaped afterward.

As usual the video is of [This Old Tony]’s exceptional quality. After quite a lot of work he rinsed out most of the metal chips and WD40, packed it with coffee, and put it on the stove. Success! It wasn’t long before the black stuff was bubbling into the top chamber ready for consumption.

Shop Made Squareness Comparator

[Stefan Gotteswinter] has a thing for precision. So it was no surprise when he confessed frustration that he was unable to check the squareness of the things he made in his shop to the degree his heart desired.

He was looking enviously at the squareness comparator that [Tom Lipton] had made when somone on Instagram posted a photo of the comparator they use every day. [Stefan] loved the design and set out to build one of his own. He copied it shamelessly, made a set of drawings, and got to work.

[Stefan]’s videos are always a trove of good machine shop habits and skills. He always shows how being careful, patient, and doing things the right way can result in really astoundingly precise work out of a home machine shop. The workmanship is beautiful and his knack for machining is apparent throughout. We chuckled at one section where he informed the viewer that you could break a tap on the mill when tapping under power if you bottom out. To avoid this he stopped at a distance he felt was safe: 0.5 mm away.

The construction and finishing complete, [Stefan] shows how to use the comparator at the end of the video, viewable after the break.

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Furuta Style Inverted Pendulum Is King of Geek Desk Ornaments

Newton’s Cradle is thought of as the most elegant of executive desk toys. But that 20th-century dinosaur just got run off the road as [Ben Katz]’s Furuta pendulum streaks past in the fast lane, flipping the bird and heralding a new king of desk adornments.

This Furata pendulum has wonderfully smooth movement. You can watch it go through its dance in the video after the break. Obviously you agree that this is the desk objet d’art for the modern titan of industry (geek). Just don’t stop at watching it in action. The best part is the build log that [Ben] put together — this project has a little bit of everything!

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Fail Of The Week: Machining Bismuth

[David Cook]’s summary below the write-up of his experiences working with a bismuth ingot is succinct.

I wasted a weekend learning why elemental bismuth is not commonly used for metal parts.

It’s a fair assessment of his time spent growing unspectacular bismuth crystals, casting a bismuth cylinder that cracked, and machining bismuth only to be left with a very rough finish. But even though he admits the exercise was unsuccessful, he does provide us with a fascinating look at the physical properties of the element.

This is what [David] wanted to make. Alchemist-hp + Richard Bartz with focus stack. (Own work) [CC BY-SA 3.0], via Wikimedia Commons
This is what [David] wanted to make. Alchemist-hp + Richard Bartz with focus stack. (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Bismuth is one of those elements you pass by in your school chemistry lessons, it has applications in machining alloys and as a lead replacement but most of us have never knowingly encountered it in the real world. It’s one of the heavy metals, below antimony and to the right of lead on the Periodic Table. Curious schoolchildren may have heard that like water it expands on solidifying or that it is diamagnetic, and most of us have probably seen spectacular pictures of its crystals coated in colourful iridescent oxides.

It was a Hackaday story about these crystals that attracted [David] to the metal. It has a low enough melting point – 271.5 °C – that it can be liquified on a domestic stove, so mindful of his marital harmony should he destroy any kitchen appliances he bought a cheap electric ring from Amazon to go with his bismuth ingot. and set to work.

His first discovery was that cheap electric rings outdoors aren’t very effective metallurgy furnaces. Relocating to the kitchen and risking spousal wrath, he did eventually melt his bismuth and pick off the top layer once it had resolidified, to reveal some crystals.

These are the bismuth crystals he made.
These are the bismuth crystals he made.

Unfortunately for him, instead of spectacular colors and huge crystals, the sight that greeted him was one of little brilliance. Small grey crystals with no iridescence. It seems the beautiful samples are made by a very slow cooling of the liquid bismuth, followed by a quick pouring off of the remaining molten metal. Future efforts, he assures us, will involve sand-insulated molds and careful temperature monitoring.

Undeterred, he continued with his stock of bismuth and embarked on the creation of a cylinder. Early efforts with a clay mold resulted in cracked cylinders, so in desperation he cast the entirety of the metal in an aluminium baking tray and cut the resulting ingot to a rough piece of stock for turning.

Poor finish on machined bismuth.
Poor finish on machined bismuth.

With the bismuth in the lathe, he then came face to face with what he alluded to in his conclusion above, why machined bismuth parts aren’t something you’ll encounter. His cylinder came out with significantly rough patches on the surface, because bismuth is both crystalline and brittle. He suggests improvements could be made if the metal could be solidified with fewer crystals, but it’s obvious that elemental bismuth on its own is not a winner in the turning stakes.

We suggest you take a look at [David]’s write-up. It may be presented as a Fail of The Week here, but in fact it’s more of a succession of experiments that didn’t work than an unmitigated disaster. The result is an interesting and well-documented read that we’re sure most Hackaday readers will gain something from.

Aside from the bismuth crystals linked to above, we’ve featured bismuth a few times here at Hackaday. A low-temperature soldering process used it in an alloy, and we’ve even featured someone using it in another alloy to print using a RepRap.

Thanks [nebk] for the tip.

Tips For Buying Your First Milling Machine

If you’re interested in making things (and since you’re reading this, we’re going to assume you are), you’ve almost certainly felt a desire to make metal parts. 3D printers are great, but have a lot of drawbacks: limited material options, lack of precision, and long printing times. If you want metal parts that adhere to even moderately tight tolerances, a milling machine is your only practical option. There is, after all, a very good reason that they’re essential to manufacturing.

However, it can be difficult to know where to start for the hobbyist who doesn’t have machining experience. What kind of milling machine should you get? Should you buy new or used? What the heck is 3-phase power, and can you get it? These questions, among many others, can be positively overwhelming to the uninitiated. Luckily, we — your friends at Hackaday — are here to help give you some direction. So, if you’re ready to learn, then read on! Already an expert? Leave some tips of your own in the comments!

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Removing a Broken Tap From Something Really Really Expensive

What happens when you break a tap or a bolt in a component whose price tag sits in the tens of thousands. Just drilling it out and throwing in a nut insert stops being acceptable. Is there a way to remove the tap without damaging the master part at all?

Broken tap stuck in the hole it was threading
Broken tap stuck in the hole it was threading

Well, that’s where [Tom Grafton] of Jerry’s Broken Drill and Tap comes in. He’s here to remove taps and chew bubblegum, and he’s definitely chewing bubble gum loudly the whole time. His primary work horse is a Metal Disintegration Machine.

A MDM is basically half of a typical wire EDM set-up. In EDM you used an electrode to punch a hole through the material. Then you thread a wire through the hole, thread it through a sometimes startling array of pulleys, and get going.

[Tom] used the MDM with an appropriately sized electrode to precisely disintegrate the middle of the tap out. After that it’s some careful work with a specially machined magnetic chisel. A quick chase of the threads with a tap and it’s back to the customer.

As you can see in the video after the break, the end result is a threaded hole that’s so indistinguishable from the rest he has to mark which one it was; presumably so the customer doesn’t forget why they’re paying him.

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