Create a Rounded Cube in OpenSCAD

There are two ways to easily make a rounded cube. The first is to use the hull function:

module RoundedCube(size, radius) {
    width = size[0];
    height = size[1];
    depth = size[2];
    
    hull() {
        translate([radius, radius, 0]) cylinder(r = radius, h = depth);
        translate([width - radius, radius, 0]) cylinder(r = radius, h = depth);
        translate([radius, height - radius, 0]) cylinder(r = radius, h = depth);
        translate([width - radius, height - radius, 0]) cylinder(r = radius, h = depth);
    }
}

The second is to use linear_extrude and the offset functions:

module RoundedCube(size, radius) {
    width = size[0];
    height = size[1];
    depth = size[2];

    translate([radius, radius, 0]) linear_extrude(height = depth) offset(r = radius) square([width, height]);
}

Now they aren't exactly identical. They will produce slightly different rounded cubes, but hopefully this helps someone out there use OpenSCAD.

Photographing People

A while back I ran into Joe Edelman YouTube channel. If you want to photograph people and use flash this is a very good channel. Specifically I suggest checking out One Light Portrait Lighting for AWESOME Portraits & Headshots.

Remove Every Other Line in a Text File

Once in a while a while you need to remove every other line in a text file. It's really easy to do with awk from the Terminal:

awk 'NR % 2 == 0' infile > outfile

There are obviously a lot of ways to accomplish this simple task but this is by far the easiest.

Copy a DVD/CD on a Mac

Recently I had to walk a friend over the phone how to make a copy of a DVD, so I wrote down the directions as I went and here they are since the ones I found on the internet were always missing a step. Making a Disk Image of the DVD/CD 1. Run Disk Utility 2. Insert “YourDisk” DVD into DVD drive 3. It’ll show up on the left hand list as: SuperDrive YourDisk 4. Left click on “YourDisk” to select it. 5. Click the “New Image” button at the top in the toolbar. 6. “Save As” will be set to “YourDisk.dmg”. This will change with step 8. 7. On the left hand side choose where you want to save it to. I selected the Desktop. 8. At the bottom “Image Format” is set to “compressed”, change this to “DVD/CD master”. This will change “ YourDisk.dmg” to “YourDisk.cdr”. 9. Make sure “Encryption” is set to “none”. 10. Click Save. 11. This will take a while. 12. Once it’s done, go to the next step. Burning the DVD 13. Eject the “YourDisk” DVD and insert a blank DVD. 14. In Disk Utility, at the bottom of the list on the left hand side you will see “YourDisk.cdr”. Select “YourDisk.cdr” and click the “Burn” button at in the toolbar at the top. Just follow the directions...

Setting Master/Slave on the Canon 580EXII

I always forget how to do this so I'm blogging about it so I know right where to look and so maybe it helps one other person. 1. Press and hold zoom for about 3 seconds to get into the master/slave mode. 2. Rotate the wheel to select between "off", "master on" or "slave on". 3. Press the set button. Don't forget the set button. Happy multiple flash photography!

Lulzbot Taz 5

I got one. I decided to not wait for the Taz 6 for two reasons. It's about 6 months out and a friend has a Taz 5 so we can make tweaks together and support one another. And I have some stuff I wanted to print. Plus Lulzbot, and the community, supports their old printers so well I don't think it'll be out of date any time soon. Some recommendations for first time owners of a 3D printer and specifically a Taz 5. 1. Throw away the knife tool and buy a paint spatula like this: I bought a Liquitex free style. It was about $12 at the local art supply store. The key things you are looking for is the angle holding the spatula part so you can get the spatula flat on the bed without your hand interfering. You also want it to be fairly sharp but strong. This one has variable thicknesses for each protrusion on the spatula. 2. I changed the factory settings on the printer. The factory settings are: Vmax-x: 800 Vmax-y: 800 Vmax-z: 8 Amax-x: 9000 Amax-y: 9000 Amax-e: 10000 Aretract: 3000 I changed these to the following: Configuration->Advanced Vmax-x: 192 Vmax-y: 208 Vmax-z: 3 Amax-x: 2000 Amax-y: 2000 Amax-e: 400 Aretract: 2000 Make sure to store the settings. -> Store Settings 3. The Cura settings change depending on the filament. I've been having great experience with Verbatim 3mm filament using the following settings: Basic: Layer height: .15 Shell thickness: 1 Enable retraction: true Bottom/Top thickness: 1 Fill Density %: 20 Perimeters before Infill: true Print speed: 60 Printing temperature: 0 Bed temperature: 0 Diamter: 2.85 Flow: 100 Advanced: Nozzle size: .5 Speed: 10 Distance: 4 Initial layer thickness: .15 Initial layer line width: 100 Cut off object bottom: 0.0 Travel speed: 100 Bottom layer speed: 30 Infill speed: 75 Top/bottom speed: 40 Outer shell speed: 40 Inner shell speed: 60 Minimal layer time: 5 Enable cooling fan: true The reason I set the temperatures to zero is I turn them on on the printer itself first. This allows gcode to print PLA or ABS. However, the other settings need to match as well. This doesn't work when switching between other brands of filaments that need different settings. For instance IC3D filament is 2.9mm rather than the standard 3mm filament of 2.85 (yeah, that doesn't make sense). However, IC3D filament has been impossible to print with. I had an impossible time on the Type A Machine Series 1 as well. Same problems actually. IC3D filament requires 115 degrees and a slightly hotter bed of 70 degrees, while Verbatim is 105/60. But the IC3D is so chalky if there is any retraction the filament stepper eats through the filament resulting in a failed print. Verbatim is a little more difficult to get though since Amazon won't ship it to me. It's an Amazon bug that we've been going back and forth on for some time. eSun is also good filament. A bit more stringy though.

Bash Script to get Path to Inself

I use bash enough and fumble my way through it that I have little nuggets like this but I never retain them in my brain. So, in contributing to the global bash community and my external brain storage, here is how to get the path that your currently running script lives in.

PATH=$(cd $(dirname $0) ; pwd -P)

And since people typically post scripts like this, even one liners, and don't explain them, I'll explain each piece. 1. The first argument is the full file name to the script: $0 2. Get the directory of the script. You'd think we'd stop there, but we keep going: $(dirname $0) 3. Change directories to the directory containing the script: cd $(dirname $0) 4. Run another bash command: ; 5. Get the current working directory, and -P resolves symlinks: pwd -P 6. Assign the directory containing the script and that is not a symlink so the real path to the PATH variable: PATH=$(cd $(dirname $0) ; pwd -P) There you have it!

External Hard Disk Doesn't Eject On El Capitan

Ever since upgrading to El Capitan all external hard disks won't eject because Spotlight is always running. I have to stop Spotlight with this command before ejecting or risk corrupting the hard disk:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

And then restart Spotlight:

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

Alternative iPhone Music App

The stock iPhone Music app has been getting worse and worse. I finally gave up and searched around for a better music app and have settled (for now) on an app called Ecoute. Ecoute is pretty simple. There isn't much there besides an app to play your music. You can easily create playlists on the fly and it just works where the iPhone Music app really doesn't. If you find the iPhone Music app cumbersome, you don't want to subscribe to Apple Music then give Ecoute a try. Sure it's $1.99 but just works. It's what a music app should be!

CAD Applications for 3D Printing

By far the biggest limiting factor in 3D printing is easy to use CAD software. Here is a list of the best CAD software applications that I've found.

Sketchup - Great for woodworking, but unusable for 3D printing since it only is good down to 1/16 of an inch.

Solidworks - By far the best software package out there. Very expensive out out of the reach of the average person. The student version is $100, the regular version is $4000 with a $1500 yearly license but the one you really want if you want to build assemblies is the $8000 version with a $2000 yearly license. You don't actually own the software and it's more like buying a car than buying software since you have to go through a sales guy that deeply discounts the price at the end of the year, but if you are making money on what you're building then this is the software you want.

AutoDesk - I see people get amazing results from this. I'm not one of them since there are some serious bugs on the Mac. For some reason the model will just disappear in the middle of working with it. I also can't stand the fact that all saved files are in the cloud.

FreeCAD - This is an open source totally free CAD package that is rather good. I doesn't work on the Mac at all. They have a version but don't bother, it's way too old. Lulzbot uses FreeCAD exclusively supporting their open source tradition. If you have Windows or Linux, this is a pretty good package!

OpenSCAD - Like FreeCAD it's open source but it's different than all the other CAD programs out there. At first I was put off by how it works but I now appreciate it. You program everything. This is cumbersome for large models, but actually it works pretty good once you get used to it. My only complaint which has been solved openjscad.org is that you can't anchor an object to a point on another object and have it's world view relative to that point. Rather everything is translated from 0, 0, 0. If they fixed that one problem this would be a much more powerful and competitive product. But I love the parametric functionality and for some things this is what I've been using. Also you can send someone a file in email without an attachment!

ViaCAD - I've settled on ViaCAD. They have some inexpensive options and a lot of features. It makes a lot more sense to me than AutoDesk and I can save files locally and it works on Mac!

3D Printers Part II

A few weeks back I posted about my experience researching 3D Printers and in depth details about my purchase of one specific printer here. Over the Holliday break I had the fortune of bringing home the school's Pegasus printer to calibrate and I have worked with my friend's Taz 5 a lot more and I have changed my mind. I have decided to wait for the Taz 6. It should be out in a few months and it improves a many things over the Taz 5.

The Pegasus overall is an inexpensive printer kit and you get what you pay for. I made a lot of custom parts and modifications. If I get a chance I'll post the STLs of the printed mod parts. The good about the Pegasus is it is inexpensive and a good first step into 3D printing and it will give you a lot of experience. I also really like where the filament roller is. Don't get frustrated though, because it has some down sides that don't happen with all good printers. First, it takes a lot to get it calibrated. Making sure all 3 axis are perpendicular is tough for any printer, but since the parts in the Pegasus are on the lower end to save money there are a few other problems. The stepper motors overheat and when they overheat the print head can end up anywhere. The software must have a firmware update because some things just don't work. I don't like the digital calibrate and the bed screws make it difficult to manually calibrate the bed. Calibrating the X axis is very difficult. The changes I made are to add a bowden tube to prevent any feed problems. I modified the filament holder roller mechanism. I printed out some open beam wire clips. I made a system to level the bed with a class clip and a hand twist nut head. And the Z stepper motor lead screws have a cap on them so you don't accidentally hit them or bend them. That's the short list. There's a few other changes.

The Taz 5 has an X calibration issue that the Taz 6 should fix with a number of other worthwhile changes to an otherwise very solid machine. I like the all-in-one electronics box on the left size. You can see the parts lists, STL files and photos of the TAZ 6 here.

Cookies notification in European Union countries

Apparently there's some law in the European Union that requires me (the blogger) to inform you (the blog reader) if I use cookies and if so what I do with them. I do not use cookies. I only publish little tidbits of information and interesting things I find interesting and useful. But this blog is hosted by Blogger which is owned by Google, and Google does use cookies. Here is what Google does with your cookies. I also have Amazon ads on this blog. However I need to find some time to remove them as I haven't been receiving any money due to something I forgot to read or do. I don't know what their link to using cookies is but I'm sure they do just as much as Google. There's also some map thing on the sidebar that I'm sure uses cookies and sells your information. And in the future I may add other widgets that use cookies. Rest assured if you are viewing this blog with a web browser someone somewhere is using a cookie and storing it in Big Data. If they aren't then your ISP is harvesting your data and tracking what you do. If they aren't then some government somewhere is and they also know what kind of underwear you buy. There is also a small chance that some hacker community out there is storing your data. I like to call these bad hackers Bad Data. So rest assured none of this is happening by me. All I do is look at the pretty graphics that Google provides to see if anyone in the world read this blog.

If you want to know how to delete your cookies click here. If you want to disable cookies in which the entire internet stops working click here. No it really doesn't stop working but they will bug you into turning them back on! So instead, browse in incognito mode by going here.