Drew's Robots: GenCon 2014 recap
I went to GenCon 2014 and had a great time. I made the two-day drive out along with my wife and another friend, staying over in wester...| drewsrobots.blogspot.com
Earlier this summer, on a cloudy afternoon with thunderstorms coming, I was out for a quick walk around the neighborhood. The area recently had suffered from some devastating rainstorms with severe flooding, and many homes had flood-damaged furniture and other items piled up on the curbs out front. I gave most of the piles a wide berth, but one such pile immediately caught my eye. | Drew's Robots
Several years ago a friend of mine asked me to make a program for mapping a globe onto a twenty-sided die. I wrote a simple Python script, some basic coordinate remapping and image processing with a simple GUI wrapped around it. The script takes an image that's a flat projected map of a planet, builds a virtual icosahedron around it, projects the image of each part of a globe onto the faces of the icosahedron, and then arranged them on an output image along with fold lines and glue tabs w...| Drew's Robots
I went to GenCon 2014 and had a great time. I made the two-day drive out along with my wife and another friend, staying over in western PA because I'm getting a little too old and weary to drive 13 hours in one day. Next year I might fly instead.| Drew's Robots
I went to GenCon 2014 and had a great time. I made the two-day drive out along with my wife and another friend, staying over in wester...| drewsrobots.blogspot.com
Earlier this summer, on a cloudy afternoon with thunderstorms coming, I was out for a quick walk around the neighborhood. The area rece...| drewsrobots.blogspot.com
After half a year of happily turning out parts, we started having problems with our Makerbot a few weeks ago. Parts were refusing to stick ...| drewsrobots.blogspot.com
Our neighborhood never has a large number of trick-or-treaters, even on a normal year, but I do always make a point of having candy on hand for the dozen or so kids that we get. This year, I wasn't certain we would get any at all, and I wasn't sure I'd feel safe handing out candy face-to-face with them if any did come by. I had for a while been planning to just shut the outside lights off and lock the door, but decided, a few weeks before holiday, that I could hand out candy in a safe, no-con...| Drew's Robots
This year I began an experiment in indoor micro-gardening, which I came to through a comvoluted path that started last year due to my wife's chronic medical issues. My wife is chronically ill, and among other problems has trouble regulating her blood electrolyte levels. Last year, after taking a careful look at her diet, she decided to start eating daily meals of foods high in potassium, especially roasted sweet peppers and mushrooms. This had a notable effect on her energy levels, to the poi...| Drew's Robots
A few months ago, my wife and I binge-watched the first two seasons of The Dragon Prince on Netflix. It’s a cute little cartoon show with some really good writing and well fleshed out characters, and with only 18 episodes so far it doesn’t take long to catch up on the whole thing.| Drew's Robots
After seeing this project on Thingiverse, I decided to build my own portable Retropie gaming console. It looked easy enough to do, there were software builds available ready to install on a SD card, and it would be an excuse for me to gain more experience with Linux and on the Raspberry Pi. Of course, I couldn’t just build the existing design as-is, eventually redesigning the entire case for the features I wanted. I really wanted to improve the ergonomics and packaging efficiency of t...| Drew's Robots
My little walking robot, that this blog was originally created to describe, gradually beat itself to death through performing at conventions and Makerfaires over a period of several years. Broken servos were easy (if expensive) to replace, but eventually welds cracked in the legs and the servo control board developed intermittent faults. Fixes to the structural problems just made it heavier and pushed the already overloaded servos further. About a year ago I gave up and declared it dead.| Drew's Robots
Several years ago when looking for cheap servos to use for my walking robot I purchased a handful of HXT900 micro servos from HobbyKing. They seemed like an incredible deal for less than $3 each, but after brief experimenting I gave up on them. They were very jittery, not terribly strong, and when run at 6V the motor would burn out quickly if the output was stalled. I tossed them in the junk box and forgot about them, writing them off as not usable for my robots.| Drew's Robots
I have updated my scheduling script for GenCon 2014. I had originally not expected to have to make any changes to the code, but GenCon this year moved the location of their event catalog files, and decided to only release the event catalogs in xlsx format instead of csv. While you can still use last year's version of my scheduler by manually downloading and converting the catalog files, I've modified my code to use a converter utility to do the conversion.| Drew's Robots
Decepticons ... Exterminate!| Drew's Robots
Several months ago after slightly reworking the wiring to the J-head, the thermistor slipped slightly loose from its socket in the heater block. The temperature monitoring code in the controller will detect a short or open connection on the thermistor and shut down the heater, but it can't do anything to detect a thermistor that is simply no longer thermally connected to the block, and the heater stayed on long enough to drive the heater block far above its normal operating temperature. I...| Drew's Robots
I designed the original version of this toy as a personal challenge to see if I could - and in the process learned a lot about how to design complex moving parts for 3D printing. The design was vastly more successful and popular than I expected, resulting in a lot of requests for printed copies, but I wasn't really happy with it. The major body joints - hip, knee, waist, elbow - were all too wobbly and weak. In robot form, the toy couldn't stand on its own, and the legs would sometimes ...| Drew's Robots
Since being uploaded to Thingiverse and discovered by the internet, my transforming Tardis toy has attracted a lot more attention than I expected. I designed the toy as a challenge to myself, and as a fun project to keep my mind busy during a week off work with not much else to do. My creation has been covered by cnet, Topless Robot, 3ders, technabob, neatorama, and other places, as well as rising straight to the first page on the Popular Things list on Thingiverse. And they're all usin...| Drew's Robots
I haven't been posting much about my 3D printer lately mostly because I've been busy printing things with it. The printer itself hasn't changed much since my last post - the biggest upgrade I've made was switching to a geared extruder motor to solve some overheating issues, and installing a Raspberry Pi print server so I can print over the wifi and don't need to keep my laptop physically plugged in to the printer.| Drew's Robots
As it is nearly time for the annual hectic GenCon event scheduling frenzy, I have updated my schedule-planning script. The latest version of the script is available here.| Drew's Robots
Now that the printer is mostly functional, I've started working on the secondary structural parts, wiring and circuit boards and such. These parts aren't needed for just printing, but will be needed if I want to be able to pick up and move the printer without parts falling out. | Drew's Robots
First layer adhesion seems to be the key to getting a good print out of this printer. If the first layer sticks evenly and consistently, and stays stuck during the print, the print usually comes out well. If the corners detach, they tend to curl upwards, deforming the part, and in the worst case interfering with the movement of the print head. When a delta printer skips a step, it doesn't just shift the layers above the skipped point sideways as it would in a normal printer. A skipped...| Drew's Robots
With a working extruder, and after MakerFaire a reel of black 1.75mm PLA filament, it's time to try printing. So I drew up a standard 20mm calibration cube in AutoCad, sliced the stl into Gcode with Slic3r, and sent it to the printer in Pronterface.| Drew's Robots
This started out as an Airtripper extruder, but I decided to tweak the design to better fit my printer and the parts I had on hand, and by the time I was finished it was nearly unrecognizable.| Drew's Robots
After blowing up my old PC power supply, I ordered a 360W, 12V industrial supply off Ebay. Two days later it arrived and went right into the printer.| Drew's Robots
For my printer's hot end I chose a Mini J-head Mk II, custom-made by hotends.com. The standard J-head is designed for 3mm filament. I liked the simplicity and light weight of the J-head, but my printer is intended to use 1.75mm filament, so I custom-ordered a mini J-head instead. I had been considering an Arcol.hu hot end at first - liked the idea of an all-steel extruder - or possibly a Budaschnozzle, but the Rostock design really calls for a head that's as lightweigt as practical to m...| Drew's Robots
Several years ago a friend of mine asked me to make a program for mapping a globe onto a twenty-sided die. I wrote a simple Python script, ...| drewsrobots.blogspot.com
