# Hood angle range and speed

Hi, I want to design an adjustable hood to make during the off-season and I wanted to ask what is the range of angles you used to shoot and what was the speed of your hood?
We are planning to shoot from the entire field, from the terminal to the fender.

That is really dependent on a large number of variables. Will you have two rollers? What size are your bottom rollers? What size might your top rollers be?

Generally speaking you can get a rough range of required launch angles from newtonian physics and get a first level approximation from that (hood angle 90 degrees from launch angle).

For every team, this answer is very different. The best option here is to do the math (well not actually, we used the ARIMB calculator for that)
The range of release angles changes depending on the release height, desired release speed and path you want the ball to take (how high do you want the apex of your parabola)etcâ€¦ I think that designing a variable hood is a great challange that should be done in full which means also doing the math yourself based on your own teams design constraintsâ€¦

Regarding hood speed, I dont remember what we landed on, we just wanted our motor to run on low voltage and the hood to reach its range of angles in about .5 seconds .

Yep it will use 2 rollers, probably 4 inch for the bottom and 2 inch for the top.

Regarding hood speed, I dont remember what we landed on, we just wanted our motor to run on low voltage and the hood to reach its range of angles in about .5 seconds .

Thanks, sounds reasonable, I will do the math on that.

In that case, you can assume fairly low rotational energy initially and newtonian calculations will be close. There are a number of online calculators that will include air resistance, which should not be ignored when doing your initial calculations.

A good rule of thumb is to gear your motors to run at half motor speed while generating enough surface velocity for your most common shot.

Our team had a setup similar to what it seems you want, we had our hood set up to have ~60 - 65 degrees of travel from shooting vertical, and we could shoot full field if our limelight could detect it. During prototyping we could shoot balls about 40 - 50 feet with 1.5" of compression before the top roller and 2" of compression at the top roller. Max throttle we would use was about half. The extra compression helps reduce ball slip on the flywheel leading to more exit velocity. We didnâ€™t see many issues with ball inconsistency until ball psi was about half of its normal pressure. As for the hood actuation itself, we had a neo running a 1:48 planetary gearbox with a gear meshed on the end to one bolted directly to the side of the hood plate. It took a minute to get it tuned well, but after that it hasnâ€™t had issues to date.

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If found too often the shooter you build does not shoot balls parallel with the tangent line you drew in cad. Make sure you add a decent margin to your desired travel. My best advise is simply prototype it!

I was less reffering to tangent lines in CAD, more so to ballistic calculators ( IIRC the one we used was using air resistance to a certain extent) from my experience (in both 2020 and 2022) our calculations gave us exactly what we needed. I would still add a bit of wiggle room like you said for safety but i think that getting a ballpark estimation from some calculations is a good idea, and also seeing the graphs and visualizing the trajectory is something you should do, especially before prototyping a shooter that shoots the ball and hits the ceiling (unfortantly Iâ€™ve witnessed it happen a couple of times)

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