For the Same weight ball travels different distance

[kjlokesh]

Not sure your teams faces this issue. For the same weight the balls travels different distances, with a difference .5 meters. They they fell short or travel longer. We lubricate all the moving parts before testing.

I have not clue why this is happening. The setup is the same and friction is also minimal. I couldn't able to answer the kids why this is happening and what is causing the variance. sometimes after few run we see a consistency and they it starts again. This is frustrating when you don't know what causing it.

I appreciate if you could share your thoughts. We are using a floating trebuchet, with ball bearing the closed eye loop on a solid rod to guide the counter weight.

[Pebble]

Not sure your teams faces this issue. For the same weight the balls travels different distances, with a difference .5 meters. They they fell short or travel longer. We lubricate all the moving parts before testing.

I have not clue why this is happening. The setup is the same and friction is also minimal. I couldn't able to answer the kids why this is happening and what is causing the variance. sometimes after few run we see a consistency and they it starts again. This is frustrating when you don't know what causing it.

I appreciate if you could share your thoughts. We are using a floating trebuchet, with ball bearing the closed eye loop on a solid rod to guide the counter weight.

I face the same issue, although my trebuchet isn't tuned that well. Perhaps it has something to do with your sling or where you place it each time (I think this is the issue for me). What distances are you getting to? You also might want to take a slow-mo video of your trebuchet to see if there's a difference in where the projectile is released.

[kjlokesh]

We place the sling at the same point. Our setup is fixed, meaning we place the sling at the same point, every run is a tournament run. Kids do a 5 point check before every run. The weight is same, the only variance could be friction caused by the supporting arm where the weights are mounted. We minimized the friction as much as possible by adding lubricants, alignment etc. but still the distance varies for each run.

[knightmoves]

Video your launch from the side in slow motion. Use a camera on a tripod so the view is consistent. Do multiple launches, record how far each one went. Then go through the videos - frame by frame if you have to - and look for differences.