Monday, May 26, 2014

Adding Servo Motors to the Iron Man Helmet

I decided to spend some time during the Memorial Day weekend to work a bit on my 3D printed Iron Man helmet. I found a handy servo bracket on Thingiverse that somebody else made for motorizing their Iron Man helmet faceplate, and I figured that there was no reason to reinvent the wheel I went ahead and printed them. They ended up with a bit too much slop for my Futaba servos that a friend gave me from his old RC car, but some electrical tape and hot glue took care of the problem. I made some arms up in SolidWorks and printed them instead of trying to find/make metal arms. Right now things are held in place temporarily with hot glue, but when I have everything in its final place I will come up with a more final solution. Next step is to get a microcontroller set up to control the servos and maybe run some LEDs inside the helmet.

Sunday, May 18, 2014

Attempting to Automate Catalyst EX from the Command Line

Since running a 3D printing service at an engineering college has a lot of throughput for random 3d print orders, it was getting very tiring to manually process every incoming stl file and send an email with the part's filament volume used. My boss put together a SQL database with a simple but very useful user interface for managing print jobs that auto-generates the emails and keeps everything organized, but we still had to process each file manually. So I set out to try and find a way to automate the process.

Comparing Catalyst EX to Other Programs by Stratasys
I've noticed that when using the MaracaEX and cmbview applications that there will be an open command line window that isn't present when using Catalyst EX. My hope was that the window was simply hidden for Catalyst and that there would be different command line arguments that could be used for scripting the STL processing.

I wasn't sure how to begin probing into the possible command line arguments that could be used, but as usual the internet had some helpful advice. Following the instructions I used Process Explorer to view the Strings for Catalyst EX, and while it was initially promising I was unable to find any command line arguments to pass. Using /? and /help as arguments also revealed nothing.

Opening STL and CMB files from Command Line
I found some small progress when I remembered that I had set Catalyst EX to be the default program for opening STL files. Using Process Explorer again I was able to see that you simply had to type the following into the command line to have Catalyst open an STL or CMB file (replace testfile.stl with the path to the file if it isn't saved in the same directory as CatalystEX):

C:\Program Files\Dimension\CatalystEX 4.4\nt\CatalystEX.exe testfile.stl
C:\Program Files\Dimension\CatalystEX 4.4\nt\CatalystEX.exe testfile.cmb

Printing CMB File Information to the Command Line
After playing around for a while I experimented with the other .exe files in the same directory and found that running cmbstat.exe with a cmb file for input printed the information out to the command prompt

The output contains the amount of support and model material used, which could be used for scripting, but there is still the problem of having to process the STL file manually.

Catalyst itself appears to use a combination of TCL and DLL files. I will have to do more research before it's clear whether this is possible.

Saturday, May 10, 2014

Poor Man's Google Glass

While browsing Thingiverse I came across an interesting project to make your own heads up display with a Raspberry Pi. The project is originally from Adafruit, and while the video glasses that I fixed up a while ago were too big to use with their case, I was inspired to make my own version with SolidWorks and the (not so) trusty 3D printer. The result came out fairly well, although one of the arms needs to be shortened so the video wires from the screen can reach the main PCB.

The Problems With Using the Wrong Filament in Your 3D Printer

Since hacking the 3D printer there have been a large percentage of prints that have been failing. I set up a webcam to investigate and got the following timelapse footage: Long story short is that the Stratasys printer uses an injection molding grade ABS plastic for it's filament, and the normal stuff that most printers use doesn't fuse with the HIPS support material like it ought to. The parts can curl up and the printer head can dislodge the part like it did in the video. While it's difficult to find the MG94 plastic in filaments, it's very common in bulk pellets, and we are looking into investing in a filament extruder and making our own filament. Until then pausing the print after a few layers and running some superglue around the edges takes care of the problem.

3D Printing an Iron Man Helmet

The first project I've tackled since hacking the 3D printer at school is printing an Iron Man helmet. There are some excellent files available over at the Replica Prop Forum that just need some scaling to fit your head. Since the printer has a 10"x10"x12" build area I did the helmet in three pieces, with the biggest piece taking over 50 hours to print. There were a few hiccups with the new black support material mixing in with the red model material, but nothing that some paint won't hide.

Hacking the School 3D Printer to Save Money

Since taking responsibility for running the 3D printer at school I've been trying to figure out how to cut the costs on the ridiculously expensive filament cartridges that Stratasys sells for $260 a piece, and thanks to the fine work of the people at Have Blue and Gnurds a coworker and I were able to hack the printer cartridges so they could be refilled with generic 1.75mm ABS plastic filament, dropping the cost from $260/Kg to $30/Kg. Now that printing with the 3D printer is affordable there's all sorts of projects that are waiting to happen...