Hooded Shooters.. How much are you compressor your ball?

So obviously some teams don’t want to reveal their design, which makes sense… But I am trying to learn more about ball compression as it leaves the shooter.

My team was finding last night that they were compressing the ball about 2 inches (7 inches -> 5 inches) within the hooded shooter. Generally I think the idea of compressing it is so that you have grip to push the ball forward.

However, just simulating the ball by hand, it takes a lot of pushing to get the ball through the shooter. Not to mention when it leaves the shooter now its less round and can’t fly as smoothly.

It would be my guess that their is a sweet spot of compression vs shooter resistance that gets you your maximum exit velocity. What have teams with this design found that worked for them?

I’d go read through this.

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Here is high-speed video we shot with our shooter (2in compression) clearly showing the power cells are round immediately after exiting the shooter.

Don’t assume that squishing the cells by hand (very slow) will be the same as squishing them through a shooter (fast). I suspect that compression by hand is slow enough to let the air vent out, but compression though a shooter is so fast that the air compresses inside the cell.


Now, do that same test with a well-used PC. Rough it up, put a couple of small rips in the skin… see if it stays round when exiting after making it much easier for air to vent.

Would love to see the range on this though

Here is 35ft range shots:

My team’s youtube channel: https://www.youtube.com/channel/UCRXcfSYmEfn7XpdtmPtiFZA?view_as=subscriber

Link to build thread post with video analysis: FRC 95 The Grasshoppers 2020 Build Thread

Ever consider using the word “please?” It’s not trivial work to do. FWIW some of the cells used in that testing have been shot maybe upwards of a hundred times.



I’m home tonight, but others on my team saw your earlier comment and decided to grab some video. I didn’t edit it, but got the right freeze frames from the two videos.

No apparent difference in either ball immediately after exiting the shooter. Upper has been cut, lower is used and abused, but not stabbed.


So at the end of it, you want the least compression for the best distance you get. Too much compression is not good and too little compression is not good. I would suggest testing multiple compression and record data to compare them after. You will see that some compression will give similar results, and when that is the case you want to use the one with less compression.

Perhaps this is an issue of over-the-web interpretation, but I didn’t read his message as a demand. I read it as a “if you have these different circumstances, I suspect that you will find a different result”.


Several parts of the reply were… off-putting.

  1. The phrase below is pretty aggressive:
  1. The assumption Jon made that we did not test used power cells (we had) is disappointing.
  2. As an FRC leader with many years of experience and a lot of influence I would have expected a more nuanced and constructive response from him. Something along the lines of: “What happens if the power cell is worn or damaged? I think that might affect the outcome.”

But hey, maybe something was lost in translation over the web. I have been wrong before, and I will be wrong again.


There is such a thing as being too sensitive online. I posted the same way I would have to someone on my team that performed such a test and made the rather dubious inference that it was representative of all situations.

But if you really need an apology…

My greatest apologies for not being more clear in my response. I will endeavor to triple check all my posts from now on, and do my best to ensure that nothing I say could possibly be taken the wrong way.


This isn’t an appropriate way to de-escalate a conflict. James explained why his comments made him feel the way he did, and then he gave you an out by acknowledging that it could easily have been a miscommunication or misunderstanding. You don’t need to follow up this by antagonizing him about “being too sensitive”. Let’s try to be more civil than this please.


I tried to de-escalate by simply not replying to the initial request for the word “please” - I didn’t see any benefit to dragging out a conversation about it. This second reply about it just felt like he was trying to further drag this out and call me out personally, and I felt it needed a reply. I’m really not trying to stir the pot here and honestly, I would have much preferred to just leave it at his first post. But I think it’s unreasonable to expect someone not to reply when they are repeatedly called out.

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My comments were not about the fact that you replied, but rather the content of your reply.

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Can this be handled in a separate thread/direct messages, and have this thread return to being about hooded shooters.


Agreed, please keep on topic and PM if you need to.


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