Author: Maker Block

I tried to print Bre’s Darth Vader head but there was either a problem with the STL or my gcode.  When arhimed uploaded a smaller cleaner version of Darth Vader’s head I just had to print it up.  (Just updated to add another picture of this piece).

Sweet, no?  Again, this is a pretty extreme close-up.  While there are very minor striations created by a super small Z axis wobble, the model is smooth – nearly silky in texture.

I’d really like to see a robust printable open source interconnecting building block system for the MakerBot.  Something than can build large (or small and intricate) rigid structures with moving parts.  So far there’s:

1. The lazzor-cutable metabrick from metalabs.
2. Lego compatible laser cut blocks by clothbot
3. The printable metabrick by wizard23

Of the one printable variety, it doesn’t really lend itself to rigid structures as it uses a round clamp to attach to a round pole.  Don’t get me wrong, it is a very cool piece and I’m really glad someone designed it – it just isn’t what I’m looking for.

I’m wondering if a slot/groove system might work – similar to the system used in Zaggo’s prinstruder or the modular boxes by Domonoky.

As a kid I preferred Construx to Legos.  Construx allowed me to build large objects with moving parts in three dimensions.  Whereas Legos main point was that it came in better colors.

I’ve designed a few Construx pieces I’m looking forward to building.  The only problem is that at least one of them may be too large for me to print with my current set up without significant warping.

Update 5/26/2011: MakerBots, DIY 3D printing, and the science of calibration has come a long long way in the year since this post.  I’ve been distracted with other projects, but I’m pretty confident that I could print some very reasonable lego-compatible bricks.

Having printed a few legos, I haven’t printed any more.  I’d certainly like to – but the print resolution isn’t quite there yet.  The pieces don’t stick to each other very well and stick to real legos even less well.  Official legos are engineered to ridiculously exacting standards, so they always fit together.  I mean, have you ever seen a lego piece that didn’t fit other legos?  I’ve never even heard of such a thing.

My latest batch of MakerBot tweaking may have brought me closer to the dream.  I printed up a new Vader head, which turned out beautifully.  I had lowered the one particularly warped Z axis rod below the top toothed pulley edge by about 1mm – which has nearly eliminated the Z axis wobble.

With printing from an SD chip, eliminating wobble, reducing slack on the X and Y belts…  I think I’m ready to take another run at printing up a lego piece.

By the way, as fun as it was to print up four 2×2 lego blocks using the Skeinforge multiply feature, I don’t recommend it.  There’s a lot of cleanup between pieces that just makes it not worth it.

MakerBot posted Bre’s interview with Shapeways the other day.  There were some things that really resonated with me:

1. Starting a business, surviving on Ramen, forgoing sleep, and rushing a prototype to market. I started my own business three years on a shoe-string budget by working on my idea during my off hours.  Doing something I love and earning money doing it is an incredibly rewarding experience.  I highly recommend it.
2. Most MakerBot owners are not just engineers and architects, but people who are just excited about personal manufacturing. I’m not an engineer, architect, or any kind of sciency-techy kinda guy by trade or training.  One thing I try to remind people is – if I can build and get a MakerBot up and running, so can you.  In any case, I may not  be someone sick of waiting on a jet pack, but I’m totally psyched about having a robot that can build anything I can dream up.
3. If you’re bored, you’re not living life. Find something you love and believe in and do it every single day, whether or not you get paid to do it.  Start doing it right now, because you don’t have a moment to lose.
4. Crowdsourcing. I have a batch 9 MakerBot which came with printed pulleys.  However, by the time batch 9 rolled around there was no longer a need for printed pulleys.  Bre hints that the crowdsourcing program is going to come back later this year.  I suppose in the meantime I could put together a big pile of Mendel parts – but I’m going to wait until I’m printing ABS on a heated build platform or finally got the nerve to try out some PLA.

I suppose it was inevitable.  Azimov’s immutable Three Laws of Robotics are:

1. A robot may not injure a human being or, through inaction, allow a human being to come to harm.
2. A robot must obey any orders given to it by human beings, except where such orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

My bot has injured a human, me.  The other day I leaned in too close to observe a build and the ‘bot’s Z axis pulley/belt yanked out a hair from my head.

My bot has refused to obey the orders of a human.  Refusing to obey my orders is kinda the default mode for my ‘bot.

My bot has harmed itself despite my numerous verbal commands to the contrary.  When aborting a build my ‘bot has occasionally tried to carry out additional orders – by pushing the Y or X carriage so far that either the pulley, belt, or both are shoved out of whack, thus damaging it’s own alignment.

There are at least four thermistor tables out there to choose from.  Zach 1, Zach 2, Jet, and Tim.  The first time I updated my extruder board’s firmware with a new temperature table I used Jet’s and the second time I used Zach 1.  (The second time was because the extruder spark incident and almost certainly unrelated to Jet’s table).

My understanding is that Tim’s table has a higher “resolution,” meaning there’s a lot more resistance / temperature pairs.  However, I’ve been using Zach 1 without a problem so there’s no reason for me to switch.

After finishing my printstruder (you can never have too many spare parts) I lowered the one warped Z axis threaded rod.  I probably lowered it about 1mm farther than it was before I had raised it to install the Z axis crank.

I guess sometimes that kind of thing makes a difference.  I’m watching my little ‘bot print up something right now… and it’s looking fantastic.  So far there’s no hint of the former regular but slight shift that you can see on the TARDIS and Dalek.  Mind, the TARDIS and Dalek are some of my best prints.  Anyhow, this is truly encouraging – with a nigh elimination of this warp, I am that much closer to printing precision parts.

One of the members on the MakerBot Operators group has posted his process for calibrating his ‘bot and adjusting Skeinforge settings.  It appears ridiculously thorough and I’m looking forward to trying it out.

You can see how badly the cooling ABS warped on the base plate, especially on the left.  All of the parts, except perhaps the insulating retainer ring at the bottom, have a slight warp to them.  I expect most of my ABS prints will suffer from this to one degree or another until I install a heated build platform.  But, that’s a project for another day.

In these pictures you can also see the more pronounced effect of the warped Z axis threaded rod, again more prominent on the base plate.  The shifted layers occur approximately every 1mm or so.  As I’m less concerned with the cosmetic effect on a purely functional piece such as this, I didn’t bother adjusting this Z axis threaded rod until after I finished the prinstruder.

My little bot is just crank out parts today.  :)

I’ve finished the Idler Bracket v3, Motor Bracket v3, Base Plate v3, and Insulating Retainer.  After a little cleanup the parts fit together very well.  I think one of the most interesting parts about printing pieces designed by others is seeing some aspect of the 3D model that doesn’t really quite make sense – but once it’s printed out and fit together you understand the design decision.

Take, for instance, a little divot in the Motor Bracket v3. I didn’t get why it was there… until I fit the parts together.  I can now see that it’s purpose is to act as a cone to funnel and guide the plastic filament.  This is the sort of wonderful little nuance that can be produced as part of a 3D printed object that would probably be difficult, if not impossible, to recreate in a lasercut layer system such as the plastruder.