MakerBot Industries

Even Walt thinks the LoBotomy Clinic is a good idea

Do you remember the days of old?  Will you tell your grandchildren of the days when a robot with problems was left to fend for themselves with no chance of improvement feeding on stray bits of plastic, smelling of burnt hair and ABS.   This are things that will be lost in time, like tears in the rain, like the sound of a connecting modem or a hard drive spinning up.  For, our modern times have brought us the LoBotomy Clinic!  No longer will your ‘bots question your awesome makin’ skillz. ¹  Here’s the latest from the LoBotomy Clinicians:

lo·Bot·o·my
noun 1. A series of radical and invasive physical therapies, used to treat ailing robots.

Sad robots make sad humans. If you have a problem, if no one else can help, you could call the A-Team. Or you could check your robot into the LoBotomy Clinic. You can fill out the Intake Form in advance or just show up with your busted bot and we’ll help you diagnose and troubleshoot to get it in tip top shape. Learn the best tips for 3D printing and preventative maintenance, or drop by if you just want to see some finely tuned bots in action. We are looking forward to seeing you at Botacon 0!

Even if your ‘bot doesn’t need any TLC, you have to take a look at that sweet Intake Form.

1. “Can the maker repair what he makes?“ [↩]

First draft on the left, second draft on the right

I’d like to address some comments to the prior two posts.  The first post was essentially about identifying a problem that could be solved with a 3D printer.  In this case, it was the cracked plastic case for my mom’s car key fob.  The second post was about one method for measuring and documenting measurements in a meaningful way.  Basically I trace out the parts on a sheet of paper and draw in arrows indicating the dimensions.

@Mark wanted to know why I was breaking up the posts.

Well, originally I had intended to live-blog the process of identifying, measuring, designing, and printing the solution.  This was not to be for a variety of reasons.  Instead I opted to break what would be a very very long post into discrete sections. ¹²

@Alex Guichet wanted to know when you’d get to see the results and if this was just going to be a teaser.

I’ve broken the entire saga into four posts.  You’ll get to see the finished product at the end.  Promise.

Draft, the First

From the photo above you can see the first attempt on the left.  There were a number of deficiencies in this draft that I didn’t really think about until I was actually holding the part in hand.  In my zeal to measure the electronic-beeper-thingie and the metal key, I had completely forgotten to measure or design the less critical part that allows you to put the darn key on a keyring.  Next, the metal part that is the actual key is quite a bit thinner than the electronic-beeper-thingie.  As such, there needs to be a raised section that is only “key”-width rather than “beeper”-width.  In this first version you can see that there is no such raised section.  I also failed to include a hole for the small screw that holds the key in place and both sections together.  In this draft the two parts do not actually fit together, they are both just flat pieces that do not interconnect in any way.  I also noticed that I made the entire enclosure slightly too big vertically.  Just one more thing to tweak in the next version.

Once it was in my hand, I decided that the next version would allow a portion of one part to fit into a section of the other.  Just looking at the finished product was enough to help me realize all of these deficiencies – that’s why I didn’t even bother to clean the part up. 

Onwards and upwards!

Draft, the Second

From the photo above you can see the second attempt as the two parts on the right.  While these parts were much more suitable than the prior, there were still some issues to work out.  I included a section for the keyring, a hole for the screw to hold the key in place, a lip on one side and a bevel on the other so they would fit together, and I reduced the interior height by 2mm to reduce the extra room.  The parts fit together well – but came apart relatively easily.  I decided the next version would have an even larger lip.  It turns out that a reduction in 2mm was too much, since the electronic beeper just barely kept the parts from fitting properly.  Increase by 1mm.  I decided all of the buttons needed just a little more clearance on each side, so I gave them all 0.4mm more space.  I made created a recessed section for the screw head to disappear flush into the top section once installed.  Lastly, I also widened very slightly the two walls on either side of they key, since it was a very tight fit.

The benefits of drafting

Imagine you had to program by punch card.  Get one punch wrong and that card was toast.  Get one punch card wrong and your whole program was toast.  Sure, you could double, triple, and quadruple check your program by inspecting every punch and the order of every card…  But it’s not a very efficient use of time.  For modern programmers there is little penalty for just taking a chunk of code and firing it up.  The most common worst case scenario is an error code directing you to where the problem might exist.

Now, if software guys can try out a draft of code without any significant penalty, why not hardware guys? ³  I don’t need to get everything exactly right the first time – and I might even find a few improvements along the way.  With an investment of about 20 minutes of unattended printer time and $0.20 of plastic each I got to try out two interim designs – and improve my final design.

Up next:  The final results!

Posts in this series:

• MakerBot Hero:  Car Keys I
• MakerBot Hero:  Car Keys II
• MakerBot Hero:  Car Keys III
• MakerBot Hero:  Car Keys IV
• MakerBot Hero:  Car Keys Epilogue

1. Like Dave Durant long post. [↩]
2. Dave, I kid because I love! [↩]
3. And, for that matter, why not tinkerers, makers, hackers, repair people, and dads? [↩]

Naked pull-less cord

I had a wildly productive Saturday morning this last weekend. ¹  I tore through my honey-do list as if it were made of paper. ²  For those of you unfamiliar with the concept, a honey-do list is a list of things your spouse gives you to fix, take care of, or generally address.

The way our list works is that my wife can add anything she wants to the list and I can ignore it all week long.  Come the weekend, I put forward a good faith effort to resolve as many of the things on the list as I can.  There’s no need to knock them all out, just make a dent.  My wife likes this system because she knows whatever she puts on the list will be taken care of one day.  I like this system because I know there’s a finite number of things, and I can do whichever ones I want whenever I want.  We both like this system because we can see the progress being made on things that need to be done around the house.

One of the things added to my list last week was to get a new pull for our kitchen mini-blinds.  The cheap plastic pull had broken or come off at some point and my wife wanted a new one.  The only requirements were that it “just work” and not be ugly.  No problemo.

I designed a simple cylinder with a hole in the top and knocked it out in clear PLA in 6 minutes flat.  For those of you who don’t print in PLA, it tends to hold its heat and stay malleable longer.  This is a mixed blessing.  On the one hand, the cylinder walls were so thin that they weren’t fully cooled before the next layer was put down, making the next layer up squish the lower layer slightly.  (This can be mitigated with any number of Skeinforge tricks such as the Cool or Orbit settings or using Multiply to create more than one instance at a time.)  The result was a slightly twisty, sculpture-esque tower.  Although the gloppiness of the molten PLA obscured the hole at the top of the cylinder, the part was still so hot that I easily widened the hole with a pair of pliers before it had a chance to cool.  This made for a very easy installation. ³

Printed PLA pull

I was fine with using this as a proof of concept, to make sure I had the basic design down, but my wife liked the twisty nature of the pull and that’s what we have on our kitchen mini-blinds right now.  One of the coolest things about this fix is that I was able to design and fabricate a fix faster than you could yank a part off a shelf, all without leaving my house.⁴

Bonus real conversation:

MakerBlock: Wow, honey.  You were totally right to insist I purchase a MakerBot last year!

Mrs. MakerBlock: <eye roll and grin>  Yes, I’m very glad I insisted you purchase a MakerBot.

1. At least, wildly productive for me. [↩]
2. Which, in fact, it is. [↩]
3. Step one: Untie knot in mini-blind cord.  Step two: Thread new mini-blind pull onto cord.  Step three: Tie knot in mini-blind cord. [↩]
4. A MakerBot might not necessarily be the best fix every home repair.  However, it is the best way to get me to start working on a home repair.     [↩]