pic: Killer Bees Buzz19

[pfreivald]

Originally Posted by Jim Zondag

The catapult has 6 Steel Extension springs. It has a lead screw adjustment on the spring deck which can adjust the spring draw about 5". Total spring force at max draw is about 1000 lbs. Overkill? probably: Awesome? Definitely.
We found that harder was better for shot repeatability.

Would you be willing to share the motor gearing and lead screw type (Multi-start? Single start? Diameter? Etc.) for this setup? I encouraged my team in this direction this year and they abandoned it after what I had deemed not enough prototyping. Alas.

[Jim Zondag]

To adjust the spring tension on our catapult we have a CIM with a 5:1 VersaPlanetary Gearbox. The lead screw is attached to the output of this gearbox with a shaftcoupling. We use a 10TPI single lead Acme Screw. We have a moving carrier block driven by the leadscrew which adjusts a lever arm (green). The carrier has 10" of travel. The upper 4 springs are suspended from a pivot on this lever arm (red). The lower 2 springs have fixed rear mounts and are not dynamically adjustable. We measure the position of the carrier block with a 12" string Potentiometer. THis allows us to adjust the shot from 10' to 50'. This setup has served us very well.

[pfreivald]

Fantastic and elegant, thank you!

[Bryan1625]

You guys were for sure my favorite team to play with/against in quals and elims! Made the match a lot more interesting! Beautiful bot!