December 9, 2013
A tour of my office at home for electronics and other projects
December 8, 2013
With the holiday season upon us, and the availability of 3D printers increasing, we have reached the year that many people will be getting or building a 3D printer and then wondering what they can do.
There are two main ways to get things for your printer to print – you can download them or you can design them.
There are quite a few sites now that host 3D printable models. The first major one is Thingiverse, which is owned by Makerbot (who is owned by Stratasys). Thingiverse had files for 3D priting and for laser cutting. Some models are extremely well made, and print with ease. Other things may not be well designed or could even be impossible to print. A good rule is that if there isn’t a picture of a printed part on the thing’s page, then it’s probably not printable. Also make sure that the printed part fits in your machine. If you have an older printer like mine, some things are just too large.
This page has a listing of more sites with models available.
There are quite a few free tools available that can make STL files for 3D printing. Some are better than others. My current favorite is DesignSpark Mechanical. This a basically a free version of Spaceclaim, with a reduced feature set, but is still very functional. It has the same basic tools as Sketchup, but Sketchup models often have issues with being turned into printable 3D models (Sketchup can’t do small details, and often make parts with some of the faces turned inside out). I specifically recommend against using Sketchup.
Autodesk 123D is pretty good, but the interface can be a little slow on anything but a newer computer.
The other way of designing a part is actually more of a programming language called SCAD. One of the best tools in this category is OpenSCAD. There are many tutorials out on the net, and some things from thingiverse will be in scad format. OpenSCAD compiles a solid model based on parameters you set. This makes customizing a part easy if it was designed well.
Students licences are often available for professional level cad tools as well.
- Autodesk (Inventor) Student
- Solidworks (You can sometimes get this free if you are on a FRC team, or from your school)
What do you want to know about having a 3D printer? Comment below, and I’ll try to answer the questions in a new post.
October 23, 2013
Quick project last night to upgrade a skull with flickering red eyes. Steph had properly themed bouncy balls to go in the eye sockets. I added some red LEDs and an ATTiny13.
I borrowed two different code snippets to make it blink with a nicer look.
Hackaday Link for project 1 (used the LCG formula)
Zenlogic’s PWM code (modified to use only two outputs)
September 17, 2013
I just heard that Designspark, working with Spaceclaim, has just released a free edition of spaceclaim designed to help make enclosures for PCBs designed with Designspark’s other free EDA tools.
This could be a huge advancement for the hobby 3D printing market. Designspark Mechanical can export STL, and being based on spaceclaim means that editing will be quite nice. I have used Spaceclaim Engineer in a previous job, and really was impressed.
Other common tools for 3D hobbiests:
- Autodesk 123D: Painful interface (on older computers), and a medium learning curve, but still quite usable. They recently hid the 3D export option, but it is still there.
- SCAD: Much larger learning curve, but very good (especially paired with DraftSight to make DXFs). Also very nice for the parametric aspects.
- Sketchup: As someone with real CAD experience, making precise things and doing any kind of editing was quite painful. Sometimes has problems with faces flipped the wrong way
- FreeCAD: Nearly usable open source option. The interface is a bit wonky, but it’s not copying all the commercial tools, so that’s understandable.
- Tinkercad: (I have not used this yet)
What other free tools have you used?
August 30, 2013
A video tour of the Metrix Create:Space in Seattle (http://metrixcreatespace.com/). Video taken and edited by NTmedia.
August 24, 2013
A video tour of Jigsaw Renaissance in Seattle (http://www.jigsawrenaissance.org/). Video taken and edited by NTmedia. There was so much material, that we had to edit it down quite a bit. I may do some follow-on videos with the rest of the material.
July 14, 2013
Here is my makerbot electronics as of Friday.
Including the relay board, there are 7 boards involved in running the bot. I finished soldering the proto board to connect my Pro Mega to the Quadstep Friday night.
I got everything torn off and installed my new board stack in place.
Still some work to do for making it look nice, but it’s already a big improvement.
Moving on to the software side, I had a heck of a time getting anything to load from the Arduino environment. After nearly 8 hours of debugging and finally loading the basic blink program via the AVR Isp port (which involved teaching the Arduino environment that my pololu AVR programmer is like an stk500v2), I discovered what was happening. It was toggling the blink Led every 2 seconds instead of 1!
I triple checked the fuse settings against various AVR calculators and they were correct. I eventually broke out the oscilloscope to look at the clock input.
(blurry, but that is 8 Mhz)
To verify, I got a picture through the microscope
That’s an 8 mhz oscillator all right. The only problem is that Sparkfun doesn’t sell a 5V 8 mhz version of this board. They’ll be getting a call tomorrow.
With that knowledge and some munging, I got a 8 mhz bootloader going, and then tried to load marlin reprap firmware. Turns out marlin requires 16 or 20 Mhz.
Next was Sprinter, which I could get loaded, but I wasn’t able to get any functions working. I took a brief detour to write a small sketch for letting me manually toggle all the I/O functions and some rudimentary jogging functions. A few minor edits to the board and I was left to wonder about firmware again.
A bit more digging brought me to Teacup, which is designed to still work even on an Atmega 168 which is pretty impressive. I spent some time tweaking it, and I can now control my makerbot again.
After that I spent some time with Slic3r and pronterface and have a nearly functional system!
July 12, 2013
With the TDS544A up and running, I decided to take a crack at getting data off of it. The scope has a floppy drive (but my laptop doesn’t), a GPIB port, and a printer card with both parallel and serial interfaces. The hardcopy menu has around 18 options for filetypes, and is capable of sending the screenshot to any of the ports or the floppy drive.
Of the options available, I decided to try sending a windows BMP file over the serial port. I used a F-F null modem cable and a USB to Serial converter. On the program side, I started with this autohotkey script which spews data from your serial port into notepad. With a little bit of munging (removing anything to do with sending data, and removing some of the ASCII conversion logic), I was able to get and write BMP files. A full 640×480 color bitmap takes about 90 seconds to transfer (max speed 19200), but the scope provides a compressed BMP (Run Length Encoded) that is quite a bit smaller. These screenshots are from the script, and are of the scope measuring the 1kHz calibration signal from the front panel.
For reference, here is the script (without much cleanup): Serial Image Receive.ahk. It does depend on the RS232 library functions linked to above.
The only issue now is that the scope seems to forget some piece of data on reboot. It may be an NVRAM issue, or just me abusing how the system works, but I need to go to the utility menu and toggle the serial settings to get the scope to transmit.
July 3, 2013
Sparkfun had an awesome deal for people who liked them on Facebook, so I decided to come up with a project. I’ve been looking with envy at the RAMPS board for reprap, and wanted to start getting parts to upgrade my cupcake. A bit of research shows that it’s a stack of an Arduino Mega2560, a connector board, and a couple of Pololu stepper drivers. Ultimachine has a complete kit (solder yourself) for $150. Poking around Sparkfun, I found this collection of goodies for $143 (before the discount):
I’m planning on using the Proto shield to act as a connector board between the Pro and the QuadStepper. I won’t have to add much to it to get the other RAMPS functions, and I probably have most of it in stock.
I may even put in a 24V power supply and I’ll be able to heat the head and build platform in just a few minutes.