Electrical Musings

Found this post on Craigslist in Twin Falls, ID Old lathe - $50 (Sun valley) Cool old lathe for decoration                                                                       make / manufacturer:  ? Yes, that is a Hardinge Cataract BB57 Bench Lathe such as the one pictured below: Photo from http://www.lathes.co.uk/cataract/ It has a 7" swing, a 36" bed with 17" between centers, and a 5C collet.  The thing weighs a ton and has a massive Jacobs chuck in it.  Yes, I know because I drove down to Ketchum, ID and bought it. I have the tailstock in a electrolysis bath of water and washing soda right now to see if the metal is pitted. If it is usable I will have a nice lathe after some paint. It is missing the bottom portion with the pulleys and speed change mechanism.

I started back into my work on Python CNC as the Bozeman Makerspace has a Shapeoko that my son wants to learn to use. I looked at a bunch of software packages and feel there is a need for a simple SVG based drawing program that has direct g-code output.  Sure you can use a plugin in Inkscape and there is  jscut but I want something that is a little parametric.  I imagine a program with a list of shapes on the right where you can link a milling function to each with a graphical display of the tool paths on the right. This is based on my own process and the tools I used to mill on my Bridgeport CNC.  I started with a CAD drawing and then built code from the drawing with my own Python objects.  Then after outputing the g-code I would import it into NCplot to verify the tool paths.  Then off to EMC2, now known as LinuxCNC, to run in air first and then on a test piece. For the Shapeoko the process is similar: SVG in Inkscape Load it in jscut Output the g-code Load it in GRBL

If you want to use PHP scripts on your web server it is a simple thing to add a script inside a page and save it as a .php file extension. Listing of phpinside.php     <?php        echo "Hello PHP World!"     ?> When this file is browsed if looks like this: Hello PHP World! With the default installation of Apache2 and PHP, however, Apache2 does not know to render an html file as a PHP script. If you name the above file phpinside.html, you will instead see elements of the PHP code when you view the file in a browser. There are thousands of (old) posts for Apache configuration of PHP by editing the httpd.conf file to include HTML as an application/x-http-php type. However, few make note that Apache2 has a new config file structure for Debian (Ubuntu). Refer to the page that I found for a better explanation: Control Escape - Configuring Apache2 on Debian, Ubuntu Now the "AddType application/x-http-php" directive is in the php5.conf file in the &qu

There was a time when CAD and CAM software was simply not available for anyone without paying a substantial sum of money.  The version of AutoCAD 10 (which came on 10 floppies) that I used for a year at MFJ Enterprises to do product documentation cost almost $1000. Even low quality programs cost upwards of $99 or more.  However, in the past few years there have been many new free versions of software available that are high and even professional quality. Sketchup Arguably the first really free CAD software that was good quality was Sketchup . Sketchup was written by a company called  @Last Software which sold the software for $495.  The company wrote a plug-in for Google Earth and soon afterward Google bought the company.  In 2006 at Google Developer Day the developers of Sketchup were there presenting the software and giving away free Sketchup socks.   An important feature of Sketchup is that users can write short snippets of code in Ruby to configure or extend the application

Although PHP is used a lot for SQL scripts, Python is a fine alternative. The commonly used SQL library in Python is MySQLdb.  MySQLdb is an thread-compatible interface to the popular MySQL database server that provides the Python database API. ( from the documentation ) An example showing the guts of a Python MySQL script. import MySQLdb conn = MySQLdb.connect (host = " localhost ", user = " root ", passwd = " admin ", db = " databasename ") db = conn.cursor() db.execute ( " SELECT * FROM table1 ") data = db.fetchall() #do something with the data db.close () conn.commit () conn.close () Looking over the code example : After the import is a connect request to an SQL database.  The database in on the localhost and has the default username and password.  The the actual database name must be specified.  MySQL databases can have multiple databases on one host. Note that on all the code accessing data or running commands on the data

It makes sense sometimes to set up a sandbox for development of CGI.  By sandbox I mean a computer isolated from the web running all the programs needed to develop for CGI.  If you have a Windows machine there are fewer resources available online for setting up Apache, etc than for a Linux box. Note that installing a Apache server does take some resources but I noticed no difference on the 3 GHz Pentium D machine with 1 Gb RAM that I was using. follow these steps in setting up a windows machine: Install Python If you are going to put scripts on a server at an ISP such as 1and1 or GoDaddy you should be aware of the version of Python available to your hosting package.  For 1and1 I installed Python 2.5.  Also be aware that neither 1and1 nor GoDaddy use modpython at this time.   Install Apache Use a standard install of Apache.  It should take only a few minutes to install and configure.  When you are setting up make it "localhost". Add python as a CGI by modifying the foll