Gian Pablo Villamil

Last time I checked in, I had added the heated build platform and a Paxtruder to the Makerbot. However, things were not quite perfect: things were not sticking to the platform, and I kept getting occasional jams in the nozzle. I could tell things were not quite moving, because I could see the filament “snaking” in the extruder body.

The first problem was solved easily: ordering a roll of 4″ wide thin Kapton tape from here. It just about matches the width of the build platform, adheres easily, and most importantly, hot ABS sticks to it like there’s no tomorrow, with no need to sand it or otherwise prepare it.

For the second issue, I turned to the increasingly vibrant 3rd party Makerbot parts market, and ordered a Makergear plastruder. This is a replacement for the Makerbot nozzle, which makes a number of important changes to the design, including a stronger PEEK insulator instead of the existing teflon, a ceramic heating element instead of wrapped nichrome, and a much heavier nozzle head.

New Kapton and Makergear nozzle

The Makergear nozzle comes with a clever mounting bracket, but unfortunately it doesn’t fit my Paxtruder, so I salvaged the big retainer washer from another nozzle, and mounted it the 0ld-school way. Nice how you can get two upgrades from completely different sources to work together.

These two elements have led to really reliable printing – don’t need a raft, and no filament jams. I printed one half of the Blender monkey, and was pleased with the results. I had been printing slightly hotter than necessary to try to prevent jams, and now I think I can dial the temperature down a bit.

Suzanne the Blender Monkey

I’ll print the other half of the monkey later. I accept it will come out better, less floppy ears…

July 6th, 2010 | Tags: diy, electronics, makerbot | Category: How-To, Technology | Leave a comment

I got around to assembling the heated build platform for my Makerbot. The heated platform is super-useful, as it prevents printed pieces from warping as they cool, and removes (sometimes) the need for a “raft” to help pieces adhere to the platform.

Heated build platform in action, printing an Escher cookie cutter

I’d been put off by the large number of surface mount components involved, but it turned out to be much easier than expected. The 20+ resistors and LEDs are cosmetic, they light up with a red glow when the platform is heated, but I figured I might as well assemble them too. I was able to put the whole thing together in less than an hour, with no special surface mount materials or techniques. Just put solder on a row of pads, pushed the pieces in to place, melted the solder, then went back and soldered the other side of the piece with a tiny drop.

I ended up making a few mods to the platform (this seems to be a recurring theme…)

• First, I inserted a six-pin Molex type connector to make it easy to unplug and remove the platform.
• Second, I encountered the common issue where the MOSFET on the extruder controller shuts down due to excess current, so I set it up such that the heated platform is controlled via a 12V relay (only $7 from Radio Shack). Took about 10 minutes to do, and now the thing works very reliably. The instructions for doing this are on the Makerbot wiki (look for “alternate wiring – relay”) – highly recommended.
• Finally, I used a countersink bit and some M3 countersunk screws to make the surface of the build platform completely level. Gives a bit more usable print area, and avoids problems with the nozzle hitting the bolts.

June 29th, 2010 | Tags: diy, electronics, makerbot | Category: How-To, Technology | Leave a comment

One of the many appealing features of Apple’s iPhone is the ability to make custom ringtones. However, as with most things Apple, there is a an official (and limited) way of doing things, and an unofficial (and much more fun) way of doing things.

Officially, if you want to make a ringtone from a song in your iTunes library, you have to purchase it as a ringtone. This is enforced for DRM’ed purchases from iTunes, and not all songs can be purchased as a ringtone.

However, if your songs are not DRM’ed, either because you ripped them from CDs, bought them without DRM, or they came from another source, then you have a much better option for making ringtones.

Download and install the free, Open Source package Audacity (you will need the latest 1.3.6 version). Audacity is a very flexible program for editing audio files. The latest version includes support for a software package called ffpmeg, which lets you import and save audio files in multiple formats.

Trim out a 30 second segment of your song

Run Audacity, and use it to open the song (or any audio file) you want to turn into a ringtone for the iPhone. Select a 30 second (or less) segment, and use the Trim command to cut out the rest of the song. Use the slide tool (little double-headed arrow in the toolbar) to slide the trimmed segment to the beginning of the project. You can select a short segment at the beginning and end of the song, and apply a Fade In or Fade Out effect. Listen to the song by using the playback controls on the toolbar, until you have something you like.

Export the ringtone as an AAC file

Once you’ve gotten everything the way you want, you can export the song as a ringtone. To do this, go to the File Menu, and select Export… In the resulting dialog, choose AAC as the file type. When you click Save, you will have the option to modify some information about the ringtone. Change the “Name” field to reflect what you want to appear in your iPhone’s Setting menu. After this, Audacity will save your ringtone.

Find the file, and rename it so that its extension is M4R, not M4A. (On a Mac, you may have to use the Get Info dialog in the Finder to do this.) You can now import the file into iTunes, where it will be recognized as a ringtone. Plug your iPhone into your computer, select it in iTunes, and use the Ringtones tab to select the ringtones you want to transfer.

January 22nd, 2009 | Category: How-To, iPhone | Leave a comment

At NYU’s ITP program, the Processing and Arduino programming environments are widely used. Since my main interest in the OLPC is to use it as a controller for projects, and since most of my projects are built using those two tools, I was very interested in getting them running on the OLPC.

In addition, both Processing and Arduino are projects that have a lot in common with the OLPC project: they are focused on education, focus on making computing technology available to groups that previously would have found it difficult, are fully Open Sourced, and rely on a community-based approach to support and development.

Good news: it is strikingly easy (with caveats). The Arduino IDE runs under Sugar (the OLPC’s built-in user interface) and under XFCE (a more conventional Linux window manager). Processing runs fine (albeit slowly) under XFCE. However, it gets confused under Sugar, which doesn’t handle multiple windows well.

Read past the break for instructions!

More »

February 24th, 2008 | Category: How-To, OLPC | Comments (5)