Slingfest 2017 Announcement

Just wanted to let everyone know that Tommy Falgout of TheLab.ms, AKA the Slingfest organizer has announced that this years event will be held on October 29th.

We need to start planning repairs for “The Pegasus”. After our maxed-out firing last year we caused numerous damages.

If anyone is willing to inspect Pegasus and collect a list of repairs, we can better plan ahead.

Lets win again this year!

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Last year, they were making noises about limiting the size of teams to something like eight people. Any word about that?

What is a slingfest?

From memory:

  • New throwing arm
  • Replace throwing arm strongback
  • Repair V track for casters
  • Replace cracked caster

Probably a number of improvements we could make:

  • Symmetric release mechanism
  • Improved/reinforced arm
  • Steel counterweights
  • Improved trigger mechanism
  • Improved raising gantry
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I think I have my answer now. Catapult fun and chicanery I presume.

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Is there a DMS Catapult subcommittee or SIG? I would like to get in on the chicanery. If I can learn some new skills along the way, all the better!

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I’d be interested in this type of chicanery. Do we have a meeting setup soon?

Okay, I Googled ‘slingfest’ and got the scoop. Is Pegasus a Trebuchet or other type of catapult?

It’s a floating-arm trebuchet, a contemporary design. It has a more pronounced snap to the payload acceleration relative to the more conventional counterweight trebuchet.

How much chicanery does it have? :wink:

Surprisingly little since it needs some rebuilding and redesign before it’s likely to be ready to fire. We’ll also be wanting a truck with a liftgate in order to move it.

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I have a truck, trailer and winch that we can use to move it. I would assume counterweight is removable. I realize it will still be pretty heavy without weights.

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Last year I made three sling pouches for it. We only used one and as far as I can recall, it survived. I assume we do not need a replacement? (Do we know where the “old” ones are?

1000lbs of custom-formed concrete weights. Steel would be vastly preferable, however at a going rate of ~$0.50 / lb for freeweights on Craigslist, that’s a lot of budget. Perhaps some scrap heavy sheet/light plate steel cut on the plasmacam this go-round.

As far as I know it’s all still in the offsite locker sans perhaps the li-po cells we used to run the lift and a few other odds-and-ends (such as the guidance chute that was dismantled immediately afterwards).

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What form factor would be preferable for the steel? I might have a way to get steel plate pretty cheap.

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I have virtually no specialized skills that could be brought to bear, but I’m game and willing to help out.

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The question really becomes, what skills can be brought to bear. Can you lift heavy objects? If not, that’s ok, can you help lift a pony keg? If not that’s ok too, you can man the keg pump and nozzle =) Bonus points if you assist with consuming beverages springing forth from said keg. It’s not required, they’re only bonus points.

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Agreed and I’m also happy to bring some ‘deep cuts’ from my wine collection.

In all seriousness, I would like to better understand the engineering principles being implemented, and I can twist a wrench with the best of them.

Just let me know when and where, and I will come help.

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Ideally something approximating Olympic free weights. Otherwise, anything that can be cut to a reasonable size that’s compatible with the crossbar. Because steel is much more dense than concrete and our clearances are designed around those concrete weights, dimensions aren’t likely to be so critical. Round is ideal for safety and balance.

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Could getting steel plate, maybe 1/2" or so and cutting the rounds on the plasma CNC in multiples, then weld those together, create a good alternative? Would that be less costly?