Wednesday, January 27, 2016

3D Printing Lego Heads

As an experiment, I tried to make my own 3D printed Lego head using Tinkercad and our Ultimaker 2 3D Printer.

You will need:
Testors Modeling Paint
EZ Digital Caliper (only if you don't use my measurements or want to teach the tool)
Pre-made Lego bodies to test
3D printer
With the digital caliper, I was able to get precise measurements using a pre-made Lego head and body.  You can introduce the students to using a caliper or you can skip this part since the measurements are already done. It wasn't exactly what the caliper measured of course because you have to leave a few .mm as wiggle room.

Here is my project to copy and tinker. The hole inside the orange cylinder is the one that needs to be exact. It is 5.5mm X 5.05mm. All other measurements and shapes can be played with to make huge "Bobble-head" like Lego heads. You can easily delete the hat and ears if you want a standard Lego head or get funkier.

After the meticulousness of painting such a small item as well as the nit-picky measurements, I'd advise middle-high school students for this project. Larger heads might lower the grade level.

The print is made all in one piece with the hat and ears not being removable. I used Testors modeling paint to customize which only required one coat and a sharpie for the facial features.

The print was only 18 minutes, no supports necessary. 

Wednesday, January 13, 2016

Cube 2 3D Printer Review

We have had the Cube 2 3D printers for over a year now and I think it's time to weigh in the pros and cons. For the record, we also have an Ultimaker 2 as my comparison for features. It does come with an extra price tag $ for those features but well worth the staff time I've saved. Most of our 3D printing programs with these Cube machines occur with first time users usually ages 10 and up.  Even if you don't have a Cube it is good to know the limits of any 3D printing machine before purchasing.

Cube Software....
is pretty easy to use. Unlike other printing software (Cura for Ultimaker*) I've used, there are limited options so it doesn't feel daunting to work with.  Is it solid or hollow? Supports yes or no? How large?  Cubify is an easy download off the website and you can download it to as many computers as you want.
Our workflow is we create an object in Tinkercad, save as an .STL file then convert into Cubify. Cubify saves the options from the previous time so be careful. I recommend always putting supports on work especially if it is a patron's first time printing.  Supports also add to the time it takes to print so bear in mind with Cubes the time it says it will finish is not always the case.

*Later editions of Cura, come with a simpler format by switching between expert and quickprint settings.

Due to the lack of advanced features, if a mistake is made in the .STL file there isn't much you can do to fix it within the Cube software. Make sure to save the original .STL to manipulate. Most kids don't have the file level with the work plate which may or may not be resolved with supports added. Cura allows you to separate parts of a print to save time.

Cube Itself...
is plug and play... when it works. We had a print started within 20 minutes of box unveiling. It has a low intimidation factor.  Cube comes with ready to print files on a flash drive. Plug it into the Cube and it will be good to go..mostly.
It's easy to travel with*  so bringing it to community events is nice as long as you have an electrical outlet.  Other printers don't recommend a lot of movement or jarring (plus they can be heavy).

You can get supplies from Staples. Glue is proprietary to prime the work plate and costs $8 each.

*During travel, the filament is going to break between the flimsy connection between the nozzle and the reel during movement.  It's not too bad to clear usually but something you have to check before starting a print.

When the printers started filament jamming, it's not an easy task to get it out.  When I talked to the company they gave us a long Powerpoint presentation (with good pictures) on how to clear a filament jam. It's a learning curve for a librarian without experience taking things apart. You need to get all the screws out, remembering where washers and spacers go, and remove important parts like the fan just to get to the jam. All 3D printers jam at some point, but this one is hard to get unjammed. It took us 1/2 hr every time to clear the jam and sometimes you can't even get to where the filament is jamming due to the way the nozzle is made. This is not ideal to do during a class so usually I'll just promise kids a week to pick up their projects. Videos (not from the company) online recommend unclogging with piano wire while the printer is on so at least it is heated up but the instructions don't mention that.

In direct comparison, the Ultimaker 2 has an easy system that clears clogs. This requires heating and cooling the nozzle using buttons on the Ultimaker. No take apart necessary! This has saves us hours of time devoted to taking apart the Cubes. 

If a print is starting to mess up due to not enough glue on the work plate or you forgot to check if the filament broke in the visible tube between the reel and the nozzle, you can't pause the print, you have to start completely over. This is another example where having a heated plate like in the Ultimaker works to your benefit.

This printer is not a workhorse meant for 10 hrs of printing daily nor does it accomplish fine details especially for very small items. This is what one YouTube reviewer called a "Soccer Mom's 3D Printer" so if people are trying to make prototypes for an invention or a 1 inch T-Rex earring this isn't the printer for them. It was happy to print flat items like key chains, flat earrings, or luggage tags for beginners to get build excitement and confidence with 3D printing.

Don't buy too much filament up front because it does get brittle over time and sometimes the filament breaks inside the reel and you have to take the reel apart to get to it...It's INFURIATING to get the clips off.....

When things did go wrong, I looked to the internet for help but not much luck. It was mostly people complaining about the printer!

Here are some of the variety of things we have printed with both the Cube and Ultimaker 2. I bet you can guess which ones are printed with each machine.  The Cube 2 won't print the new sized iPhone cases which I have heard is a big draw for those with 3D printers.

My advice if you are going with the Cube (especially if you get them for free) is to use it to get people interested and once they wear out, you can push for a better printer.  Keep in mind that they are closing their consumer division. There have been many times that I'm glad we had the Ultimaker as a backup so I could keep printing class items when the Cubes jam and I don't have time to fix them.

Although it may seem daunting at first, I'm really glad that we have 3D printers at our library.  It is an important piece to establishing us as a creative center for the community.