Catapult issues with boulders

[wilsonmw04]

Data collection is under way...
https://goo.gl/photos/h2Hm3HTgxubcyZep7

[Clayton Summerall]

Have you tried using the exact same ball and shooting it a dozen times? We have a pnumatapult and have 0 issues with ball changes.

[Electronica1]

Originally Posted by Clayton Summerall

Have you tried using the exact same ball and shooting it a dozen times?

Ok, going to need you to explain this one a bit for me. We were relatively solid with getting the high goal from the defenses during our first two events, but then at our third started having this issue. Wouldn't it be better to make sure that we could shoot multiple balls consistently, rather than shooting the same exact ball multiple time which would not establish whether it could handle different ball quality/properties?

[Clayton Summerall]

Originally Posted by Electronica1

Ok, going to need you to explain this one a bit for me. We were relatively solid with getting the high goal from the defenses during our first two events, but then at our third started having this issue. Wouldn't it be better to make sure that we could shoot multiple balls consistently, rather than shooting the same exact ball multiple time which would not establish whether it could handle different ball quality/properties?

It's all about seeing if your mechanim has degraded or changed at all. If it can shoot the same ball to the exact same spot it shows a different issue.

[wilsonmw04]

Originally Posted by Clayton Summerall

It's all about seeing if your mechanim has degraded or changed at all. If it can shoot the same ball to the exact same spot it shows a different issue.

Let me explain the test. We have no issues shooting a single ball. Out of 20 shots, 19 are consistent. Our mechanics have not changed. What you see in our data points is the 30+ shots we took tonight under the watchful eye of a 240 FPS goPro. The yellow tape is the y-axis value of each shot. The paper records the variables of the shot. You can see that as balls wear our shooter gives them a higher trajectory. Why that is is TBA. We haven't looked at the video yet.

We did find out that we have enough adjustment on the pan to get the shot where we want it. The issue was interference with a secondary part. We are going to look at the film, do some analysis and come up with a few more tests.

We will figure this out. More to come. stay tuned.

[Clayton Summerall]

Originally Posted by wilsonmw04

Let me explain the test. We have no issues shooting a single ball. Out of 20 shots, 19 are consistent. Our mechanics have not changed. What you see in our data points is the 30+ shots we took tonight under the watchful eye of a 240 FPS goPro. The yellow tape is the y-axis value of each shot. The paper records the variables of the shot. You can see that as balls wear our shooter gives them a higher trajectory. Why that is is TBA. We haven't looked at the video yet.

We did find out that we have enough adjustment on the pan to get the shot where we want it. The issue was interference with a secondary part. We are going to look at the film, do some analysis and come up with a few more tests.

We will figure this out. More to come. stay tuned.

Do you have a mechanism on the bot that "packs" the ball?

[wilsonmw04]

Originally Posted by Clayton Summerall

Do you have a mechanism on the bot that "packs" the ball?

please explain what you mean by "pack"

[Clayton Summerall]

Originally Posted by wilsonmw04

please explain what you mean by "pack"

We have a device that compacts the ball by about 4" every shot. This seems to have been an integral part of our consistency.

[wilsonmw04]

Originally Posted by Clayton Summerall

We have a device that compacts the ball by about 4" every shot. This seems to have been an integral part of our consistency.

I need to see what you are talking about. what does compression have to do with a shot?

[wilsonmw04]

We have our video from last night. I'm going to do some data analysis on it tonight. If you see anything glaring, give a yell.

https://www.youtube.com/watch?v=OgWG...ature=youtu.be

[wilsonmw04]

Greetings Folks,

Just wanted to give you an update. We found our issues. We found that we were bending our frame with each shot. The anchor to our seat belt was bending towards the shooter and the cylinder mounts were bending the entire frame down significantly. We reinforced the frame with a 1/8" thick patch plate. That worked for a day. Then the shooter went back to it's old habits because that new plate bent as well. We decided to go the route of overkill. We went with a 1/4" Aluminum plate reinforced with 1/8" angle along the long axis of the plate. The shot now makes a satisfying "ting!" when we shoot. Roughly 100 shots and not bending. We have a consistent shot at the outworks now.

he's to hoping we come out of the gate shooting!

[chapman1]

Thanks for sharing the solution. Educational for us all!

[ahartnet]

Originally Posted by wilsonmw04

Greetings Folks,

Just wanted to give you an update. We found our issues. We found that we were bending our frame with each shot. The anchor to our seat belt was bending towards the shooter and the cylinder mounds were bending the entire frame down significantly. We reinforced the frame with a 1/8" thick patch plate. That worked for a day. Then the shooter went back to it's old habits because that new plate bent as well. We decided to go the route of overkill. We went with a 1/4" Aluminum plate reinforced with 1/8" angle along the long axis of the plate. The shot now makes a satisfying "ting!" when we shoot. Roughly 100 shots and not bending. We have a consistent shot at the outworks now.

he's to hoping we come out of the gate shooting!

That's interesting and I'm glad you found a solution. However, I'm not sure how the bending of the frame only impacts new balls and not old balls. Any theories on that?

[wilsonmw04]

Originally Posted by ahartnet

That's interesting and I'm glad you found a solution. However, I'm not sure how the bending of the frame only impacts new balls and not old balls. Any theories on that?

It is odd. What I can tell you is that older balls still have a higher trajectory than new balls. What we noticed is that older balls seem to leave the pan quicker, we assume, getting a slightly longer lever arm from the motion and going higher.

With the changes in the support of the cylinders, all shots have more backspin. We assume that means they are rolling off the pan more. We haven't had time to do slow-mo video after the fix.

Hopefully, we see the same changes on the bagged robot Wednesday.

[PayneTrain]

Originally Posted by wilsonmw04

Greetings Folks,

Just wanted to give you an update. We found our issues. We found that we were bending our frame with each shot. The anchor to our seat belt was bending towards the shooter and the cylinder mounts were bending the entire frame down significantly. We reinforced the frame with a 1/8" thick patch plate. That worked for a day. Then the shooter went back to it's old habits because that new plate bent as well. We decided to go the route of overkill. We went with a 1/4" Aluminum plate reinforced with 1/8" angle along the long axis of the plate. The shot now makes a satisfying "ting!" when we shoot. Roughly 100 shots and not bending. We have a consistent shot at the outworks now.

he's to hoping we come out of the gate shooting!

Good luck! This team will be spooky if the consistency bug goes away.