Hey everyone.
I’m going to be moving to Cape Town over the next couple months. I start my new job 1st of September, but my house and workshop stuff is only coming down at the end of the year. So thing are probably going to get a bit quite around here till I’ve set-up at a new place.
Chat to you guys soon
The lathe is done! Wow it took long enough. Quick recap (please see part III for the full story)
There were a few parts missing after we finished the rebuild. Parts included a gib strip for the top slide and a spacer for the main spindle. Unfortunately you can’t run the machine without these parts, so another order from myford was needed. At the same time I ordered a dust cover and some other miscellaneous bits.
There was a motor include in the auction, it needed some work, like everything else. But there was no motor controller to be found so we needed to build one.
The controls consist of a Direction switch (forward, reverse) a Start button and a big mushroom Emergency stop. Also there are two 18A 240v contactors for the actual motor switching. Below on the right are the control switches, on the left are the two contactors.
Have a look below at how the motor and controller is wired up to allow you to change the motor direction, but basically you change the polarity on the start wiring to change direction.
Above you can see the finished wired up control box, all that’s still missing is the incoming power cord.
Once the final few parts and motor where installed it was time for some testing. We just found a large steel bolt then tried to round the head and cut a bit of a shaft out of the threaded bit.
We definitely need to get some sharper cutting tools, but the one we had did the job OK. You can see below the final result, not to bad for the first test!
There is lots and lots of tweaking and adjustments left to do. All the slides need to be tightened and aligned, there is also a bit of play in the cross slide lead screw. I’m not sure how much we can fix or if it’s going to need to be replaced. And we definitely need to get some new cutting tools.
So that’s it, all done. We now have a working metal lathe in the workshop. If you want to go back and see how things came together, here’s all the posts.
I’ve got a 1998 HP 200LX palmtop. Wikipedia describes it as:
a personal digital assistant introduced by in 1994. It was often called a palmtop computer, and it was notable that it was, with some minor exceptions, a MS-DOS-compatible computer in a palmtop format, complete with a monochrome graphic display, qwerty keyboard, serial port, and PCMCIA expansion slot.
What I wanted was a single “dongle” that will allow me to connect to the palmtop over USB as well as power/charge it. Unfortunately it require 12V DC to charge or run the plamtop so I’m going to need to use a DC/DC boost converter.
Some links for those that want know more about the HP 200LX
Just to recap from Part 2. After cleaning off the dirt, grime and rust, things where looking good, thats until the paint started giving problems.
The troublesome paint has had 5 months to dry properly, so the respraying went quite smoothly. We finally found the colour that closely matches the original Myford grey. Everything got a good degreasing and sanding before spraying a couple of new coats on. The paint dried with out much hassle, the air was very humid (upwards of 90%) which causes some issues with water droplets but these where fixed with some more sanding and another coat. Read More…
I’ve been looking for a YOURLS url shortener plugin that is compatible with Twitter Tools for a while now. There was one “yourls plugin for twitter tools 2.0” but it’s been unmaintained since August 27th, 2009.
I finally bit the bullet and wrote my own. The plugin is based on Twitter Tools – Bit.ly URLs code and has been tested with WordPress Version 3.0.1. It’s still pretty Beta, for example I don’t check if the Service URL and Signature token is correct or even entered. But it works for me.
Copy the contents of the archive into the wp-content/plugins/ folder then activate the plugin on the “Plugins page”.
yourls-api.php). You can find your Signature token on the tools page of your YOURLS installation.
Here is a packaged version of the plugin yourls-tools.tar (27 August 2010)
I just finished a little project that need a DVM (digital volt meter) panel meter. You can buy these cheapies for R60.00. The one I got was a 3 ½ digit, 7-segment LCD with ±0.5% accuracy.
You get two types, one has a common GND connection, the other needs the supply and measurement GNDs to be isolated. I can’t find the common GND variety in South Africa (well RS has them but they are R300.00). If you connect the GNDs together the meter just displays the “-1″ overload indication. What to do?
Bellow is a simple circuit that will isolated the DVMs power supply and will allow you to use it in your project. Here’s a quick run down of how it works.
Click for PDF
The 555 timer outputs a 70kHz square wave, which is rectified by the two BAT85 Schottky diodes. Capacitors C4, C5 provide the isolation between VCC, GND and the DVM supply. C6 is just a smoothing capacitor.
As you can see it’s very easy to build on a bit of vero-board and could be made much smaller with SMDs.
I bought a Lego Mindstorms kit last month to mess with, I’ve got some ideas for robot localisation that I want to try out. Anyway, the kit comes with a sonar range finder but I wanted a little more accuracy and smaller detection area. I’ve got a bunch of Sharp rangefinders from another project and they would work perfectly for what I wanted. A couple of companies sell after market sensors for the NXT, Mindsensors and HiTechnic but it’s much more fun to design and build your own.
For a little background on how the Sharp sensors work, Acroname Robotics has a good article on them.
I ordered 3 TI MSP430 LaunchPad development kits last month and they finally arrived, there was a huge demand for the boards (they cost $4.30 each) so the delay is understandable. Two are mine and the third is for a friend.
Opening the box there is a Getting started booklet, the Dev board, a second MSP430 microprocessor, some Headers, a 32KHz crystal and a USB cable. I like the little touches on the packaging, like the “Happy Coding, MSP430 MSU Team” message.
I’ve tested it in Arch Linux and everything seems to work fine. By the way, if you are using MSPDebug (version 0.9 or higher) to interface to the LaunchPad you’ll need to use the “rf2500″ driver and it should connect straight away.
mspdebug rf2500
For more information try the following websites:
Now I’ve just got to find something to use them for…
Just to recap from Part 1. My Dad and I bought an old Myford Super 7 Lathe (Serial number SK68133) at an auction. At first glances it looked terrible but after cleaning off the dirt, grime and rust, there was hope.
Below is what we ended up with after completely dismantling everything to parts, cleaning, painting and finally reassembly. But thats not the whole story…
A little bit of a departure from the usual electronics stuff. My Dad and I bought an old Myford Super 7 Lathe (Serial number SK68133) at an auction, we paid R1000 for it, quite a bargain actually.
We got the partially disasembled bed, a box full of the slides and parts, a nice sturdy stand/cabinet, a 3 Jaw self centering chuck and a 4 Jaw adjustable chuck. There was also an assortment of cutting bits and odds and ends. As you can see below the lathe was in bit of a bad shape, I believe it’s been sitting covered, but outside for over 10 years. Not sure about it’s history before that.
Read More…