Machine tool

32 Articles

Rolling Out A Slick Rotary Phase Converter

August 6, 2018 by 46 Comments

Home machinists can often find great deals on used industrial equipment, and many a South Bend lathe or Bridgeport milling machine has followed someone home. Then comes the moment to plug it in, and the new owner discovers that the three-phase plug needed to power the new beast is nowhere to be found in the shop. Thus commences the weeping and the gnashing of teeth.

Luckily, [Handmade Extreme] is ahead of the curve in terms of shop power, and built a rotary phase converter to power his machines. Industry generally runs on three-phase AC systems, mainly because three-phase electric motors are so much more efficient and compact than the equivalent single-phase motor. But residential electrical service is either split-phase or, in the UK where [Handmade Extreme] is based, single phase. A rotary phase converter is an electromechanical device that can generate the missing phases – in essence a three-phase motor that can run on one winding and generate the missing phases across the other windings. It needs some supporting control circuitry to do so, such as timers and contactors to switch the winding connections once the motor starts, plus capacitors for motor starting and for balancing the voltage across the phases. The control gear is DIN-rail mounted and neatly wired to a smart-looking control panel. Everything is housed in a sturdy enclosure that’s big enough to serve as a mobile tool cart. It’s a really nice job – watch the whole build in the video below.

If you’re interested in power distribution, we’ve got a primer that covers the basics. And if you’re in the market for machine tools, [Quinn]’s machine tool buyer’s guide will let you decide if a three-phase machine is worth the extra effort.

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CNC Mod Pack Hopes To Make Something Useful From A Cheap Machine Tool

June 21, 2018 by 13 Comments

It is probable that many of us have noticed a variety of very cheap CNC mills in the pages of Chinese tech websites and been sorely tempted. On paper or as pixels on your screen they look great, but certainly with the more inexpensive models there soon emerges a gap between the promise and the reality.

[Brandon Piner] hopes to address this problem, with his CNC Mod Pack, a series of upgrades to a cheap mill designed to make it into a much more useful tool. In particular he’s created a revised 3D-printed tool holder and a set of end stop switches. The tool holder boasts swappable mounts on a dovetail fitting with versions for both a laser diode and a rotary tool, allowing much better tool positioning. Meanwhile the end stops are a necessary addition that protects both tool and machine from mishaps.

The same arguments play out in the world of small CNC mills as do in that of inexpensive 3D printers, namely that the economy of buying the super-cheap machine that is nominally the same as the expensive one starts to take a knock when you consider the level of work and expense needed to make your purchase usable. But with projects like this one the barrier to achieving a quality result from an unpromising start is lowered, and the enticing prospect is raised of a decent CNC machine for not a lot.

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Card Reader Lockout Keeps Unauthorized Tool Users At Bay

May 20, 2018 by 19 Comments

It’s a problem common to every hackerspace, university machine shop, or even the home shops of parents with serious control issues: how do you make sure that only trained personnel are running the machines? There are all kinds of ways to tackle the problem, but why not throw a little tech at it with something like this magnetic card-reader machine lockout?

[OnyxEpoch] does not reveal which of the above categories he falls into, if any, but we’ll go out on a limb and guess that it’s a hackerspace because it would work really well in such an environment. Built into a sturdy steel enclosure, the guts are pretty simple — an Arduino Uno with shields for USB, an SD card, and a data logger, along with an LCD display and various buttons and switches. The heart of the thing is a USB magnetic card reader, mounted to the front of the enclosure.

To unlock the machine, a user swipes his or her card, and if an administrator has previously added them to the list, a relay powers the tool up. There’s a key switch for local override, of course, and an administrative mode for programming at the point of use. Tool use is logged by date, time, and user, which should make it easy to identify mess-makers and other scofflaws.

We find it impressively complete, but imagine having a session timeout in the middle of a machine operation would be annoying at the least, and potentially dangerous at worst. Maybe the solution is a very visible alert as the timeout approaches — a cherry top would do the trick!

There’s more reading if you’re one seeking good ideas for hackerspace. We’ve covered the basics of hackerspace safety before, as well as insurance for hackerspaces.

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Bolt-Together Belt Grinder For The No-Weld Shop

November 21, 2017 by 19 Comments

Belt grinding offers a lot of advantages for the metalworker, and since belt grinders are pretty simple machines, shop-built tools are not an uncommon project. A bolt-together belt grinder makes this tool even more accessible to the home gamer.

With no access to a welder but with a basic milling machine and an ample scrap bin at his disposal,  [IJustLikeMakingThings] had to get creative and modify some of the welding-required belt grinder designs he found online to be bolt-up builds.  The key to a cool running belt grinder is for the belt to be as long as possible, and the 2″x72″ belt seems to be the sweet spot, at least here in the States. Machined drive and idler wheels with the crown needed for proper belt tracking were sourced online, as was the D-bracket for holding the two guide wheels. But the rest of the parts were fabricated with simple tools and bolted together. [IJustLikeMakingThings] provides a lot of detail in his write-up, and it shouldn’t be too hard to build a belt grinder just like this one.

Looking for other belt grinder plans to compare notes? Here’s a grinder with an even simpler design, but with welding required.

A Fix For The Lightweight Machine Tool Shakes

September 16, 2017 by 12 Comments

No matter what material you work with, the general rule is that with machine tools, the heavier, the better. Some people can’t afford or don’t want big tools, though, even with their natural tendency to reduce vibrations. That doesn’t mean something can’t be done to help the little tools, like reducing vibration in a contractor-grade table saw.

This one might seem a little outside the usual confines of the hackosphere, but nobody can doubt [Matthias Wandel]’s hacker chops and he really shows off his problem-solving skills with this one. His well-worn contractor-style table saw has had more than a few special modifications over the years, some of which left it with a shimmy sufficient to vibrate workpieces right off the table. He fashioned a friction damper for the saw’s motor from wood, complete with ball and socket joints to allow full movement of the blade height and angle. That didn’t quite do the trick, but his incremental approach finally found the right combination of factors, and the video below shows a saw now stable enough to balance a nickel.

If the name seems familiar but you just can’t place the hacks, check out [Matthias]’s recent wooden domino extruder, his shortcuts to tapping wood, or of course his classic wood gears layout software.

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Go Go Camera Slider

July 1, 2017 by 5 Comments

Are your arms getting tired from pushing your camera back and forth across your camera slider? That must be the case with [Max Maker], which led him to convert his manual slider into a motorized one.

The electronics are minimal — an Arduino Micro, a few toggle switches, A4988 Stepper Driver, 12V battery pack, and the ever popular NEMA 17 stepper motor. If you’re wondering why we said ‘switches’ instead of ‘switch’, it’s because 4 of the switches are used to select a time frame. The time frame being how long it takes for the slider to move from one end to the other.

Fabrication shown off in the video below will net you a few new tricks. Our favorite is how he makes a template for the NEMA motor using masking tape. After completely covering the face of the motor with tape, he clearly marks the mounting holes and colors in the shape of the motor plate as if he were doing frottage. Then just pull the tape off as one and stick it onto the slider rack.

Not including the cost of the slider itself, the parts list came out to be around $75. Even if you don’t yet own a slider, this a great first adventure into building a CNC machine. It is one degree of freedom and the hard parts have already been taken care of by the manufacturer of the slider. Get used to using belts and programming for stepper motors and you’ll be whipping up your own 3D printer with a fancy belt scheme for the Z-axis.

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Restoring A Strange Milling Machine From Craigslist

June 1, 2017 by 25 Comments

[diyVT] found a real white elephant in this milling machine from Craigslist. It cost him only $200, cheap for a small mill, so it was worth the gamble. We’re not sure what to call this — it’s not exactly a gantry mill, not a horizontal mill, and definitely not a knee mill. The tag says V-Mill, made by either Pierce West or Tree Tool and Die Works, depending on which ID plate you read. The Tree has a three-phase motor, but it came with a phase converter, so it should be good to run on single phase 220 volt household power.

The machine was in good physical shape, at least until the previous owner attempted to move it out of the garage. During the move one of the cast iron chain drive handwheel brackets broke into three pieces. Cast iron is no fun to weld. It has to be pre-heated, welded with nickel rod, and slowly cooled. Some hackers would have given up or built a new part, but [diyVT] accepted the challenge. He put the puzzle pieces back together, grooved them out with an angle grinder, and welded everything. The result wasn’t pretty, but it only has to take the force of the handwheel and the 200 lb gorilla spinning it.

After a bit of work on the motor and head, including a new belt, this tree was ready to cut. [diyVT] snuck out of a family bar-b-que to cut his first chips on the new (to him) machine.

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