OMG’s innaugeral FirLumber Rally was a great success, with 17 cars competing. Â Official results will be posted shortly, but in summary, Dave’s electric cheater was the fastest, Eric’s elephant was the most creative, and Nate’s car was the least effort to build. Â Additionally, Dan’s kids’ cars were the fastest among the Squares.
- For Opening New Frontiers – Jay Hannah and Dave Knaack
- For Operational Excellence – Eric Kaplan
As stated at the meeting, the categories for these awards are entirely arbitrary and subject to change in future years; Â Also, we estimate that this prize is roughly 1 million times easier to win than a Nobel Prize, and the cash award has been scaled accordingly.
As for the award for Operational Excellence, this prize is awarded to Eric Kaplan for consistent attention to “things that need done”; He’s involved in everything from staffing booths to designing marketing material and furniture for the space. Furthermore, he successfully facilitated the Makery’s relocation to our new home.
Again, congratulations to all our 2013 winners.
This is your chance to build the best miniature siege engine in Omaha. Â Work by yourself or in a small group to make the best golf-ball*-throwing device you can imagine. Â We will then compete for range and accuracy to crown a champion. The contest will take place at the Makery on September 21st.
Although the competition is called â€œTrebuchet Contest,â€ your device does not need to look like something out of the middle ages. Â You can use any design, any materials, any construction techniques, and in fact anyÂ launchÂ techniques youâ€™d like. Â We want to keep things interesting, so the rules for this contest are very lenient:
The energy used to launch the projectile may come only from the gravitational potential energy of a mass falling no greater than 16 vertical inches.Â Â No explosives, precompressed springs, compressed gasses, batteries, or any otherÂ sourcesÂ of energy. Â Gravity only. Â However, you can use all those things as intermediate steps if youâ€™d like – if you use gravity to compress a spring, or use electronic timing to coordinate the firing, thatâ€™s just good Maker spirit. Â Just be prepared to prove that youâ€™re not contributing any extra energy to the projectile.
Your siege engine requires a remote triggering mechanism.Â Â Mechanical, electronic, whatever. Â You need to be ten feet from the firing position during your shots, and away from the most likely misfire direction (for example, on a standard trebuchet you need to be off to the side, out of the plane of the arm). Â We want to keep things safe.
You cannot aerodynamically assist the projectile in any way.Â Â If you need wadding to seal the projectile in the barrel of your gravity-charged pneumatic cannon, thatâ€™s fine. Â If you want to use a sling which stays attached to the projectile instead of the trebuchet, well, youâ€™re the one who thinks itâ€™ll be competitive to throw more weight than anyone else. Â But whatever you do, the projectile has to take a ballistic trajectory once it leaves your machine.
Weâ€™re trying to keep things interesting and attract the widest range of designs by keeping the rules loose. Â Please donâ€™t abuse this privilegeÂ – nobody wants to read a ten-page rule book covering every possible situation. Â Tech inspection is going to have a â€œspirit of the rulesâ€ philosophy, and you should keep that in mind while working on your design. Â If you have a creative idea or think youâ€™ve found a loophole in the rules,Â please bring it up with Ben as soon as possible. Â Most likely it will be allowed, but if you show up on competition day with something ridiculous, having never discussed it with the organizers, you might find yourself disqualified. Â We promise flexibility and absolute discretion – if we allow your cunning plan, its secret will be safe, and we promise not to steal it for our own designs.
*Golf balls makeÂ idealÂ trebuchet projectiles. Â Unfortunately, theyâ€™re a bit dangerous and bouncy. Â To dramatically increase the chances of scoring each shot by ensuring we can actuallyÂ findÂ each projectile, we wonâ€™t be using golf balls. Â Competition projectiles will be approximately equal in size and exactly equal in mass to a golf ball. Â Projectiles will be supplied for scored shots, although you may test with anything you like.
Competitions and Scoring:
The exact equations used for scoring will be revealed the day of competition, to prevent any rules-lawyering and to allow us more time to perfect them.
You will be scored on your ability toÂ efficientlyÂ throw the projectile as far as you can. Â The mass of your power weight will be taken into account, so if you decide to increase performance with extra weight, make sure youâ€™re getting a proportional gain in range.
You will be scored on your ability to hit a predetermined target at a distance of your choosing. Â The main goal is accuracy, but your chosen range will also affect your score – a 10-foot miss from 100 feet isnâ€™t as impressive as a 10-foot miss at 200 feet.
Mark your calendars, the Omaha Maker Group’s 3rd anniversary (birthday?) get-together is Tuesday, August 20th. As usual, doors open by 6pm. There’ll be food and beverages and even some awards.
Members of OMG recently attended Maker Faire Kansas City. While hopeful that we’d be able to race our latest project “Barbie”–a souped-up power wheel–in the Power Racing Series, several set-backs caused us to withdraw from the event. Team OMGFTW (Omaha Maker Group for the win) may have been knocked out this time around, but we’ve already begun working out Barbie’s kinks, which means one thing–we’re already ahead of the game! Though we didn’t get to race, the Omaha World Herald wrote an article about the trials and tribulations of taking Barbie from a mere girly power wheel toy to a lean mean winning machine. We’re just a group of Racer tech wizards who drive a Barbie, but rely on a cowboy.
Tonight’s meeting was a great success, thanks in large part to Tom’s Balloon Animals presentation/workshop. Â Members and visitors were shown, and then guided through making a variety of plants, animals, and inanimate objects.
Additionally, we had a number of visitors, and worked on projects including a Peltier-cooler proof of concept and a grinder stand. We also dusted off an old Teletype, in preparation for it’s impending Twitterification.
If I hadn’t seen this myself, I don’t know that I’d believe it. Last night, we set out to test this Popsci article, and it seems to hold up.
We had 2 locks donated, a generic U-Lock, and a pretty beefy looking keyed padlock. The U-Lock’s steel turned out to be a bit too soft, and just bent a bunch, but the shackle on the padlock failed relatively quickly.
All said, we used 2 cans of air, but quite a bit of that was spent on the first lock. Both the body of the lock and the shackle sustained quite a bit of damage, though the damage to the body was mostly cosmetic and probably not “breaching”.
If I were to try it again, 2 things: 1. Strike the shackle directly, with a chisel or something, instead of the hammer face. 2. More lighting. Â The high-speed video was too dark to really show anything interesting. Â I keep forgetting how much light that thing takes..
A while back, we decided that we needed a 24v power source for various “testing” applications. This source needed to be durable enough for daily use by a wide variety of people without becoming damaged. It also needed to protect the device being powered, and be easy to maintain.
Given that tall list, Ben suggested a HobbyKing LiPo pack, 6S, 5Ah. With that start, we decided that it should have volt and amp meters for monitoring, as well as a circuit breaker to provideÂ positiveÂ power disconnect, and protect the battery (easily capable of 150A into a dead short).Meters were ordered from Ebay and the breaker was something out of an old UPS.
The blue enclosure is a waterproof storage box from Walmart, modified to pass through various connectors. Â It’s not waterproof at this point, but we’re more after the durability of the polycarbonate than the waterproof aspect anyhow.
Internally, there’s quite a bit going on. Â The battery is packed into a foamed-off area, while the other side contains the electronics, including the circuit breaker,ammeter shunt and all the connectors.
Charging is accomplished via a modified ATX connector (which re-presents the balance plug and main power leads), with a fuse to protect against abuse. The idea is that it’s virtually impossible to charge the battery improperly, or to break a relatively fragile balance connector.
Overall, it was a pretty straight-forward build, and cost around $90, including the battery and all the connectors.