At the Boulder Hackerspace we explore art and technology and support each other in developing creative ideas/plans/toys/inventions/madness! Come join us any Tuesday evening at our space where we meet from 7:30 pm - 10 to talk about projects, show & tell, collaborate and get to know more makers in our community!
May 13th, 2015 bitreaper Comments Off on Member Project of the month: the Auto Release Fun Feeder (A.R.F.F.)
Anyone with a bored puppy will tell you, they can be a handful of trouble. Meet Olive, SSD member Jen F’s puppy.
Olive was getting bored in the middle of the day while Jen and her family were out of the home. Olive took to finding ways to entertain herself that was becoming a problem. Miscellaneous household items ended up in the back yard. To keep Olive busy during the day, Jen started hiding treat toys around the house. One of Olive’s favorite is an interactive toy that dispenses food as long as it gets flipped and rolled around.
Check it out here: http://store.petsafe.net/busy-buddy-kibble-nibble This Busy Buddy engages dogs to work for their food, which appeals to their natural hunting instincts. Jen soon discovered that there were a limited number of hiding spots in her house. Olive would find the toys almost immediately after she hid them, defeating the purpose of working up a good boredom.
Being a mechanical engineer, Jen started thinking up ways to delay the release of the ball so that it would provide satisfaction for Olive in the middle of the work day. The solution needed to be simple. Gravity based; so that the release mechanism would only require a single solenoid. Outlet powered; so that batteries wouldn’t be a continual cost. Random timer; so that Olive wouldn’t get used to what time it was released. Quick and easy loading instructions; so that anyone could load and start without a 50 page manual.
The prototype was put together with scrap lumber and eyeballing the gravity ramp. After an evening of mock-ups, Jen had a solid mechanical housing. Jen didn’t have much experience with electronics, however, she knew the hackerspace was a good resource for gurus. She met with John W., who had started working in a T.V. repair shop at the age of 10 in the 1960’s. He drew up a wiring diagram and pointed her in the direction of what she needed to get.
After a week, the only thing she couldn’t find was the timer. At a Solid State Depot Open House, she introduced her project to the group and asked for help. Another SSD member, Mike S., had just received an LCD/Button combo Arduino shield and wanting to put it to work, this seemed like a good project. After a few hours of programming, he had a random countdown timer mounted on a Spark Fun Red Board.
One of the issues that the gurus at Solid State Depot helped her solve was the amount of power that was getting to the solenoid. Because the ball was pushing on the latch, there was a lot of friction. The solenoid needed a larger pulse. This meant more capacitors had to be added.
After a short time of collaborating, Jen had a timer that worked for releasing the ball at random times.
The Auto Release Feeding Frenzy, ARFF, for short has been in use for the last few weeks. Jen has noticed a significant decrease in the number of items ending up in the yard. Jen has had many requests to build more to test on other dogs, but feels she needs more time to evaluate if this solution is going to work long term.
February 1st, 2015 bitreaper Comments Off on Come see us at Boulder Mini-Maker-Faire!
We’re setup in the Boulder County Fair Grounds exhibit building. Come see us and say hello!
As always, the Cyclophone is a popular crowd pleaser. Here member Rob B. demonstrates it to some faire participants.
Our cymatics displays were popular. However, further investigation needs to be done on driving the surface transducer that powers the plate: we burnt it out today. Below is a picture of our cymatics replacement, oobleck. However, we burnt out the speaker in this experiment too. :(. Twice in one day. Ouch!
Here I’m pouring the cornstarch and water mix into the bowl that’s glued to the face of the speaker. Unfortunately, it just didn’t get up and dance like other examples. More experimenting to come!
January 27th, 2015 bitreaper Comments Off on Friction welding with ABS filament
Hack-a-day had an article a short while ago about welding ABS parts together with a short length of ABS filament in the chuck of a dremel tool. The idea is to use the friction from the fast spinning filament to melt the plastic at the junction of the spinning filament and parts. You can find the article here. This reminded me of a toy plastic welding kit that a friend had given my kids. This set uses a battery operated drill-like unit that takes special formed sticks as the sacrificial weld material. You would use it to weld together the plastic parts in the kit to form models.
Styrene welding kit.
I decided to try it out with some scrap flat ABS plastic and a length of ABS filament. I did as the article suggested, snipped off a small length and put it in the chuck of the dremel. As in the article, I used a short length of filament. The curvature of it keeps it from being straight in any length, so shorter is easier to keep from flapping about as it spins. Having experience with the styrene welding kit, I knew that you would need to finesse it and figure out the melting point of both the filament and the plastic being welded. I tried several techniques, but for a flat plate butt joint, the best was having the filament perpendicular to the plates being welded.
Friction welding with a dremel and ABS filament
I was able to produce straight on tack welds with ease. It was working down the seam that was challenging.
Friction welds between two plates
Flexing the two plates after being welded together.
As you can see, the joined pieces can flex a fair bit without breaking the joint. This picture was after quite a bit of welding was done down the seam. Early in the process, I was surprised that I didn’t need that many tack welds on both sides to get the two plates acting as one and not cracking apart with slight flexing.
Stressing the plates until they broke apart revealed the weld depth.
Typically when you’re testing any method of joining materials, you will want to do a tear down test. It took a bit of effort to crack it in half and tear it apart. In the picture above, it can be seen that the weld nuggets tore out, leaving a divot in the plastic where the nugget was. This is a good sign when you’re welding, whether it’s plastic or metal: you always want to see the material tear away from the nugget, rather than the nugget splitting at the seam where it was to join the materials.
My conclusion: if you have a dremel, you can friction weld with filament fairly easily. The welds are strong and can be used to fix broken parts or join prints that couldn’t be printed in one piece. Considering it’s not a huge investment of time to get comfortable with the technique, it’s worth trying out and practising on some failed prints. You’ll get a feel for it, and it will cement it in your head that it’s a viable option other than glue. However, if you’re looking for beautiful welds, this technique won’t produce them!
December 3rd, 2014 jonah eskin Comments Off on Boulder Hackerspace’s first ever video game tournament! (Super Smash Bros)
Last Weekend on November 15th 2014 the Boulder Hackerspace had its very first video game tournament. The games played were Super Smash Bros. Melee, Super Smash Bros. Project M and Super Smash Bros. for 3DS. There were 5 events in total, Melee singles, Melee doubles, Project M singles, Project M doubles and Smash 3DS singles. Here are some pictures of the tournament as it was happening.
One fun thing about this particular series of games is that they are often played on old heavy CRT TVs instead of modern HDTVs. This is because Super Smash Bros Melee is such an old game that HDTVs lag compared to CRT tvs. The lag is only fractions of a second, but is noticeable and distracting when playing a fast-paced fighting game.
November 20th, 2014 bitreaper Comments Off on Project of the week: Estimating distance with SimpleCV
This week’s project-of-the-week comes in the form of a computer vision project by our member Brandon. He’s using SimpleCV on a Raspberry Pi to recognize a circle of a certain color, and then estimate distance to it based on comparing it’s known size to the size it sees with the camera. Brandon has posted some of his code at the bottom of the article, so be sure to look for that.
Pretty awesome Brandon!
[EDIT: it helps if I remember to add the link to his site! ]
October 30th, 2014 bitreaper Comments Off on Project of the week: LED Motion bicycle tail light
This week’s project of the week comes from SSD hacker Rob B. Not satisfied with any old red LED for his bike’s tail light, he decided to break out some addressable LED strip and add some animation to it. The code generates a sine wave function, and varies the duration and the wavelength to achieve the effect in the video. For the LED strip, he’s using the LPD-8806 type. The battery is a standard LiPO pack. The controller he’s using is a StripDriver v1 from one of our other hackers John E. StripDriver has been featured in several hacks around the space, and needs it’s own Project Of the Week, which will come soon.
Rob added that he wants to add a “Party mode” soon, that uses the full capabilities of the RGB LEDs on the strip, but the priority was safety, so red are the only LEDs that light up for the current version.