Tuesday, June 12, 2012

A New Home For The Raspberry Pi

I received my shipment from Adafruit Industries today. Amongst the things I ordered was their Raspberry Pi enclosure.

The "Pi" in its new home
I must say I really like this enclosure. It was a breeze to put together and keeping all the components visible (and safe from grubby hands) helps with the geek factor as well.

As of writing it's out of stock at Adafruit, but it seems they restock more often than it says on the web page so be sure to check regularly if you want one for yourself.

Now I have no excuse not to start messing around with the "Pi" - should be fun!

SUMPOD Bed Leveling

I now have the final bed leveling mechanism assembled. This version is a lot easier to fine-tune than my first try. Another advantage is that it is pretty heat resistant so I can add a heated bed if and when I decide to.

Spring loaded action...
A big thanks to Mark Hindess for sending the parts needed!

Sunday, June 3, 2012

SUMPOD Printing

This weekend I finally got to do a proper test-run on the SUMPOD (total printing time around 7-8 hours). After using most of last week to trouble shoot and figure out usable settings I stumbled upon Airtrippers excelled Skeinforge settings. Since he already has his SUMPOD up and running and having excellent results, from what I can see, at least I knew these were going to work.

After browsing Thingiverse a bit I ended up on the "Mustache Ring" for my first, proper, test. It has some nice detail and doesn't take too long to print so one can experiment a bit.

First proper test object. Mustache Ring.
If you look closely you can see that there are gaps and that the layers don't fill properly.

So far I haven't had any big issues getting the plastic to stick to the printer bed, but changing the filament and using the new Skeinforge settings apparently made a huge difference. All of a sudden it wouldn't stick at all. At first I though I needed to up the temperature in the print head, but that only made it worse. I also played around with the height of the nozzle over the print bed. Supposedly you should have the nozzle touch, or even press a bit into, the blue masking tape, but that just made the PLA bunch up around the print head. Reducing the temperature back to 185 degrees C in addition to increasing the distance a bit  did the trick - although now it almost stick too well and I have to rip the masking tape off of the bed on larger objects. I doubt that is right.

I soon realized I was going to need something to help unwind the filament from the spool since I can't go over and unwind a chunk every 15-20 minutes on multi-hour prints. Yet again Aitripper saved the day with his design for the Pocket Reel Roller. He also lists his settings for printing this, but I needed to change those around quite a bit before I had something passable.

Mainly I had to change "Speed -> Object First Layer" (all to 0.2) and "Fill -> Infill Solidity" (to 0.9). Print time was around 2.5 hours.

Third print of this part. 
With roller bearing installed.
Not exactly pretty, but I think it will do the job. The last part actually came out worse, but I think that's because the belts have gotten a bit of slack. I'll tighten them up a bit and hopefully that'll do the trick.

All installed - turns pretty easily as well.
I still has some way to go to get the quality up to the level I like, but playing around with the parameters in Skeinforge has a lot of potential - I only have to learn what causes what and that's not something that's done over night with the amount of parameters you have access to.

Inventor Fusion

Since I tend to stay in OS X on my iMac the only real reason i boot into bootcamp and Windows 7 is when I need to do something in Alibre Design. Unfortunately Alibre is Windows only and from what I gather (please correct me if I'm wrong) they have no plans to port it to other platforms. Not that I blame them - it's generally a huge task to convert a program from Direct-X to OpenGL. Especially when you have tons of legacy code.

So today I got my fill of jumping back and forth between OS'es so I thought it was time to check out Inventor Fusion for Mac by Autodesk. Luckily they have a free technology preview of this software which I installed it a while ago - just never got around to test.

First impression of the user interface was good, although a bit more simplistic than Alibre, followed by the obligatory; "how do I do this and that in this software". After a couple of quick-run-through videos on YouTube courtesy of Autodesk I had a rudimentary understanding of the software.

Upper part of outrunner motor bracket designed in Inventor Fusion.
Although some operations are a bit tricky I think it's more about figuring out "the correct procedure" to get stuff done so by playing around with it a bit more I think the overall experience is going to get better.

Since this still is a technology preview it crashed on several occasions, which is to be expected I guess, even though the operations I did were on simple objects. It even corrupting my scene file, but yet again my (paranoid?) habit of saving new versions paid off so no big loss.

Over all it is much faster to fire up Inventor than booting to Windows so I think I'll stick with it, at least for simple objects, for now.