What's this bolt for?

No, really, I want to know. There is a short M3 bolt (that is the right name for the bolts that are all over the Makerbot, right) sitting at the bottom of my build area and... I have no idea where it came from. Everything I can see is still screwed in. Anyone know where this might have come from?

Sorry for the potato quality image. I'm concerned my bot is falling apart.

Iconified Shogi set on Ponoko

Shogi is a cool game that I've always admired. If you capture an opponent piece you can add it to your army on your turn. How cool is that! However the fact that traditional sets are written with Japanese characters make it hard for new players to be willing to climb the learning curve. So I made this set with little icons that describe the movement of the pieces.

A blunt line from the sphere means that piece can move or capture one square in that direction. A pointed line from the sphere means that piece can move in as many unobstructed spaces as are available in that direction. The knight moves similar to it's counterpart in western Chess, except that it can only jump to the two spaces in front of it, and to one to the left and right, not the spaces sideways or backwards.

If you print the set at 80% size it makes a nice little travel set, tho the names of the pieces may become a bit difficult to read.

I decided to put the model for this set for sale on Ponoko. If you'd like to support me you can buy this model and print your own Shogi set and finally play this ancient chess variant.

Bre mentions my TARDIS game in an interview

I knew that Bre Pettis (founder and CEO of Makerbot) got what I was doing with TARDIS Run. He's the only one who commented on it when I finally posted it. But besides him and I it didn't seem like anyone else got it. The Thingiverse PTB didn't see fit to feature it and there's no other comments.

Thanks to Twitter I was alerted to the fact that Bre mentioned it again in his interview with Take Away as an example of the Wacky uses of 3D printing. This isn't the first time Bre used my work as an example of cool things that can be done with 3D printing. Bre mentioned my SD card ring in a CreativeMornings presentation (at 15:38). Hey, I don't mind. I'm kinda getting a reputation as being the quirky designer guy. Yeah, I can run with that.

Watch me model 1

A little while back I did a little experiment, live streaming on Justin.tv a modeling session so you can see me do my thing. . This one was a piece for Just Game. Find out more about them at https://www.facebook.com/justgamecompany or http://justgamehome.com/. I've held off sharing it here until I could offer a time-lapsed version in case you didn't want to listen to me babble for an hour an a half. Making that time-lapse had it's own challenges. But I've finally worked it all out so I can offer you a modeling session and a shorter time-lapse of the same:

At speed:

8 minute time-lapse with music:

Let me know if you like this sort of thing and I'll try to do it more often. I'm willing to make this a regular thing if it has an audience.

If course if you'd like to learn to model like me, I've got a book for that. http://www.packtpub.com/3d-printing-blueprints/book

Finally Printing MetaChess

MetaChess was one of my entries into the Makerbot/Tinkercad Chess challenge that won me my Makerbot and changed my life. Even figured out rules how this chess-on-chess game would play. However until now I've never tried printing it. (Funny thing is I love chess pieces, but I don't play the game very often. Well now I've printed it and... clearly it needs some work.

The biggest problem is one with MakerWare where if two polygons are exactly overlapping the result is a void. This ruined both versions, large and small, of the rooks. Most other slicers do not have this problem. Makerware likes it's models water tight. But beyond MakerWare's problems the models are too small for the chess board I have and the knights could use some work. So I guess it's time to iterate this design. Then, maybe I'll play a game. Maybe.

Finished a video for the book.

New video for 3D Printing Blueprints. I'll have a web site for the book soon and this'll be a major fixture. Apparently the book is also getting some reviews on Amazon and GoodReads. It's been a slow ball to get rolling, but hopefully this'll help.

Doing a video, even a really short one, isn't easy. It's actually a lot of work just gathering the elements and a lot more work editing it. This is why I don't do more videos. Bless Andrew Mazzotta for being willing to do it as much as he does. If I could find a way to get entertaining videos up without the laborious editing process I'd do it more often.

TARDIS Run Complete

TARDIS Run is complete, and what a journey it's been.

It started when I saw MakeALot's foldable TARDIS. I didn't like the way he decorated the outside so I decided to do my own. Only I wanted to do something a little more, and that's when the idea of a board game came to mind. So I determined that I could put a 3x8 board inside the box and I started to play with those limits.

There's a game with a similar sized board. It's this ancient Egyptian game called Senet which, aside from the board and some accessories we don't actually know how it was played. There were 4 paddles used that, best guess, were dropped and used to determine the moves. While I pondered on this I realized that paddles like that create an uneven distribution of moves, so what if instead of rolling, then choosing the piece that were reversed and you chose your piece and hoped that the roll would go in your favor. I'm not sure it's a satisfying mechanic, but it might have some possibility for those who like risk mitigation.

The game itself is somewhat abstract and could just as easily be made without the TARDIS theme that I started out with. But a version without the theme wouldn't get the same attention. On the other hand with the theme I pretty much lose the option of putting it up for sale on Etsy or Ponoko. Oh, it's still on Ponoko, but it's on Thingiverse too and I made a full(er) color version for Staples, tho dat sticker shock.... In fact the price seems to have gone up when I tried to make it more compact and use the space better, so apparently I have no idea what I'm doing when it comes to their full color paper 3D printers.

I would still like to make this available to those who don't have 3D printers, so if you'd like me to print one hit me up on MakeXYZ. Or you could have someone else print it. But if you send me just the TARDISBoard.stl it looks like the price comes to a little under $30 which seems fair to me and I'll make sure everything else gets in there

Troke Update

Hot of the heels of yesterday's announcement, I've taken the Troke game that I uploaded to Thingiverse and added a board that you can buy on Ponoko.

You don't need it to play, but it is super cool and it comes apart for easy storage.

I predict a number of these sorts of project populating Ponoko in the near future. Out of print games made 3D printable.

I've also made this available to print for the staples contest as an experimental thing. Not really sure if the color thing will work, not sure how this sort of thing prints... not sure anything. I really need to try it out, but I don't know how committed I am to the idea, financially.

EDIT: Wow, €161.56 for a color 3D printed version of this game on staples. Not sure anyone is going to pay that much for a board game of this type.

Adventures in Selling Designs part 3, Ponoko and CGTrader

My to-do list is rather long at the moment. I'm making a promotional video and website for the book, I'm going to create a web site for my 3D design work so I can take commissions, I've got some new materials to experiment with, an upgrade for the Makerbot, and a few other things. Lots of good things to look forward to.

In between I have still been hunting for a storefront where I can sell 3D models directly, no streaming, no DRM. Ponoko is still a good option and I'm building a profile there, however Alec at CGTrader has been doing a great job of making it easy for me to build a profile of 3D printables and even promises more help setting up for the Staples store, which isn't exactly what I'm looking for but it has the backing of a major Realtor. We'll where that goes. For now most of the models come from Thingiverse and are for free, but soon there will be more exclusives to these spaces.

Now I just need to fill 'em up with cool stuff.

Testing 3D printed dice fairness - Chi-Square Data

So last time I explored testing if 3D printed dice can be considered balanced and the result was a resounding... oh, there's a proper way of doing this. It's called the Pearson's chi-square test. The basic idea is roll the dice 5 times the number of sides you have, tally up the number of times each side shows up, then subtract 5 (the expected value) from each tally, square the difference and add the squares up. If the number you get is over 55 then your dice is unbalanced. So I printed up a couple of dice, some with 2 shells and 20% infill, some solid, dumped them through the 5 minute dice tower over and over. Then I tallied the results and did some math. Here are the final results in no particular order:

• Dual Extrusion Die - Chi Square = 20
• Customized Die 20% infill - Chi Square = 18
• Customized Die solid - Chi Square = 28
• Cone Holes 20% infill - Chi Square = 12
• Cone Holes solid - Chi Square = 28
• Normal 20% infill - Chi Square = 24
• Normal solid - Chi Square = 40
• "Balanced" Die 20% infill - Chi Square = 22
• "Balanced Die solid - Chi Square = 32
• "Worthless" Die 20% infill - Chi Square = 16
• "Worthless" Die solid - Chi Square = 12

Which means according to the Pearson's chi-square test any of these 3D printed dice are sufficiently balanced to use. And this thing is supposed to have only a 5% failure rate, so there you go. 3D printed dice can be used as dice.

Do I believe it? It seems to me that to get a score of 55 a dice has to be severely imbalanced, so I look at this data as a scale of balance. Which of these dice are most balanced? Well according to my results the list in order, from most balanced to least, is: Cone Holes Infill, Worthless Solid, Worthless Infill, Customized Infill, Dual Extrusion, Balanced Infill, Normal Infill, Cone Holes Solid, Customized Solid, Balanced Solid, Normal Solid.

It pleases me that the so called "Worthless" die ranked so highly regardless of fill. But it bothers me that so many of the solid dice ended up ranked lower because I really like the way they feel. Perhaps the lighter weight allows them to bounce and explore the space better. Which, again, explains why the worthless dice is not so worthless as it has a forced empty center. Many of the highest ranking designs are sharp cornered, but so is the lowest ranked, so rounded or sharp corners don't seem to matter. That speaks well for the chances my hollow die (which I didn't include in this test because I was expecting the rounded corners to be bad). The Customized dice also did fairly well with infill, so that opens up all sorts of options.

Now that these experiments are done I'll be selling them if you're interested in having some.

Conclusion: According to the Pearson's chi-square test a 3D printed dice is sufficiently balanced, but it seems that dice with low infill are more balanced. Who'd have thunk?

3DHacker Round Up 3

In case you're not following me on 3D Hacker:

• I break down how to get something 3D printed
• Andrew unboxes a 3D printer and tries out a Type-A
• I rip on the Makerbot Digitizer for being overpriced
• Andrew visits those changing the world for good in Albania
• There's yet another kickstarter for making things no one needs
• There's a $200 3D scanner that... actually looks good
• I introduce you to YouMagine, Ultimaker's Thingiverse
• Makergeek is running a contest
• Failed prints can be hilarious
• Andrew unboxes and assembles a Printrbot Simple, and wow that box is small
• And 3DBurrito is lost to the dark side

I have also recently been introduced to 3DPrintBoard.com, a forum for many things 3D printing related. You know, in case you don't get enough conversation about the subject here or on Reddit. Ah well, one more place to evangelize.

3D Printing Tidbit - Hairspray, Glass, and HBP

Hairspray on glass with a heated build platform is a brilliant solution to sticking prints to the build platform with surprising effecency if it's done right. Hairspray has some properties that at heat will hold a print on the build platform. I don't remember who on the google groups recommended this procedure but I've been doing it for a while and it works extremely well:

• Get a cheap can of hairspray.
• Prepare your glass plate by coating it with hair spray. I mean soak the print side in the stuff.
• Lay it flat and let it dry. Should take about an hour.
• Spray it again lightly.
• Print ABS with a 100C degree heated build plate and PLA with a 60C degree plate.
• After the print allow the plate to cool completely and the print will remove easily.

If you skip that last step you'll pop the finish from the glass plate and you'll have to respray sooner.

I've been printing for a while on this setup and the best part is I haven't needed to re-spray the plate at all. If I ever do a little water will remove the old hairspray for a re-spray.

Obviously this doesn't work for printers without heated build platforms.

Extending a child rifel

My brother teaches shooting to his local scout troop. The problem is the Remington 514 youth that he uses are too short for anyone but the younger scouts to use. So he proposed I extend the rifle with a 3D printed part.
Nothing much exciting to report, really. Took a stamp of the stock to get the shape and proportions right, same as I've mentioned here and I outline in Chapter 10 of my book. First ones took a little adjustment, then I printed 6 of them. Only got a little delamination on one of them otherwise they worked fine. This is something that I don't know how useful would be to anyone else, but I'll put them up on Thingiverse anyways.

Maybe one day I'll make these modular with a clip on addition, but for now this solution works well. Just a simple block of plastic to solve a problem. Awesome.

Testing 3D printed dice fairness

It's been a question on my mind for a while whether a 3D printed die can be fair and balanced? The reality is that the dice you buy aren't necessarily fair, so making a 3D printed dice fair could actually be an advantage. For a while I wanted to build a clever machine to automatically test dice, but that's been a project I never had time to explore. Finally I decided to print a bunch of dice and just roll away.

At first I printed a 4 dual colored dice, 20% infill and 2 shells. Not knowing there was a proper way to go about this I just stared rolling and recording until I felt a bias turn up. After collecting over 200 data points it seemed to me that there was a bias towards the low numbers for some reason, so I decided that I should try a single color dice.

Next I tried 6 copies of the customizable dice, 20% infill, 2 shells. I wanted this one to work, and the bias seemed somewhat less.

However I theorized that 100% infill would be better. So I printed 5 copies 100% infilled. Only the bias seemed to get worse, 1 hardly ever came up. So I inspected the dice and found discovered there was a seam running up the corner between the 1 and 4 side. Other slicers try to negate this by jittering where they start and end perimeter loops. MakerWare thinks they got rid of the seam so they done, which means when they're wrong you get a zipper up one side. 

I cut off the zipper and tried again. The bias seems to have shifted, but continued to persist. Infact the 20% infill dice still seemed less biased. I worried that the infill wasn't consistent between copies, making each of them mask the biases of the others, which was not the point of multiple copies.

Finally I did some research and discovered that there is a prescribed method for these thing that involves only 30 rolls and does not involve "seems like" analysis. I also discovered that commercial dice aren't always fair and that the rounder dice make imbalance more pronounced. With this in mind I threw away the old data, sought out some flatter dice (for which there aren't many on thingiverse) and started to properly gather data, which I will report on in part 2.

Dual Printing dice

So playing with the new MakerWare dual print option (for a project I'll update on when it's done) I learned a few things.

First of all, the sacrificial walls work great. I mean look at those. Catches tons of drool. Love 'em. However, if you position your objects so that the other nozzle spends a considerable time over part of the object there ain't nothing the drool catchers can do. See how the right dice are a black mess on top? Best to, whenever possible still remember the orientation of your nozzles and keep things away.

Next I learned that my nozzles are misaligned. Gonna have to fix that. The dots on the 4 and 3 side stick out, and the 5 and 2 sides dip in just a few mm. So actually these dice, oversized as they are, are great for testing the alignment of your nozzles.

I'm still in the running for the MyMiniFactory contest. Keep downloading those chess sets to help me run the most awesome contest ever.

New Makerware first impression

Big news, there's a new version of Makerware out. When I decided to adopt Makerware as much as possible I've only found a few little issues. Just last week I found another one, a model that sliced really strange even tho it looked fine in the software. So I've got a lot of tests to run.

The first thing I noticed is that filament diameter is still not editable without editing a text file. No profile editor UI yet either. So that's strike 1 and 2.

But there are some new options concerning dual extruders and support materials. Those will be fun to play with. However, now that I'm using GCode temp override half of that doesn't matter. But the new stuff about generating good paths with the end of sacrificial towers I'm excited to play with.

Then I noticed that opening a new file opens a whole new program window, which is annoying for me because I have 2 monitors and for some reason it wanted to open them on the wrong one my entire session. I got in the habit of using open because I didn't like how the new option used to do this if I wanted to clear the scene to slice another print. So kudos for being consistent, I guess. Too bad they chose the wrong constancy. (Note, I'd rather just clear the current scene than open a new window, if I wasn't being clear.)

Well, at least their fancy new preview mode will allow me to... uh.. where's that fancy new preview mode? There's no button, no menu item. Turns out you have to check the "Preview before printing" button, even if you're exporting to a file, before you hit the Export button in the Make menu. If you fail to do this you do not get the option later without re-slicing the model. But once I found it it was enough to tell me that Makerware is still choking to death on the Guy Fawkes pin, so thanks for saving me that trouble. In fact this preview has helped me find and predit problems in 3 other files in my explorations, so while Makerware still can't slice worth a darn, at least it'll warn you before you print.

Print estimates info is nice, too. I think I'm going to leave this on all the time.

I like the sacrificial walls they've added to dual prints. It would be nice to turn those on whenever I wanted for narrow prints so I could say goodbye to the sacrifical tower.

To sum up:
The good:

• Preview is good, when you can find it.
• Print estimate info.
• New dual print supports.
• New dual print options.
• New dual print sacrificial walls.

The bad:

• Still can't edit filament diameter without making a new profile.
• Still can't make a new profile without editing a text file.
• Still runs into problems with geometry that looks good but slices bad.
• I'd love to have the sacrificial walls on any print I want.
• When exporting to file (at least) I'd love to be able to pull up the preview when the slicing is done. Maybe don't close the status window when the process is done and let me pull that option up myself.

Welp, I'm off to write an e-mail to Makerbot suggestions.