Looks like you're getting a lot of flex in the track at launch time. Is that by design?
That is not by design, but that is being filmed in slow motion at 420 frames per second. Nearly any k'nex structure under that much force will flex wildly, even if it is not visible to the naked eye.
Makes sense. I think I remember seeing you mention in an earlier post that you were using the K'Nex beams kind of like tent stakes. Does that have a noticeable impact on the rigidity of the structure in either direction?BTW - What are you using to get that kind of video? The couple of times I've looked into high speed cameras they seemed pretty spendy.
Actually, using the rods as tent stakes makes the track amazingly rigid. However, the launch track is not staked down, only the return track. Also, the supports for the loop itself are held in place with piles of bricks.The camera I used is the Casio Exilim EX-FC100. It shoots video at 30, 210, 420 and 1000 frames per second and it costs $200. Keep in mind you wont get the most amazing video quality at the higher frame rate settings (the narrow strip at the very end is shot at 1000 frames per second), but I still love it, it is a lot of fun, and it comes in handy for cases like this!