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  #31   Spotlight this post!  
Unread 06-16-2017, 12:50 PM
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Re: How to bend lexan for a hood?

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Originally Posted by Chris is me View Post
For single ball shooters with a consistent loading path, this will almost always produce more accurate results than a flat back.
Would you say the same is true for non-spherical balls like 2017 and 2009? I'm not disagreeing, just wondering your opinion. I would think that not having a flat back would exacerbate the inconsistency caused by different ball orientations. I haven't done any actual testing on this though, so I'm wondering if anyone can comment on this.
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Unread 06-16-2017, 01:14 PM
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Re: How to bend lexan for a hood?

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Originally Posted by Ari423 View Post
Would you say the same is true for non-spherical balls like 2017 and 2009? I'm not disagreeing, just wondering your opinion. I would think that not having a flat back would exacerbate the inconsistency caused by different ball orientations. I haven't done any actual testing on this though, so I'm wondering if anyone can comment on this.
I am not certain about 2017, since my team did a multiple-ball shooter we really didn't test a no-backing option. The holes in the balls really didn't change the dynamics of the ball shooting that much, though.

In 2009, it probably would have been better to use a flat back, but it also wasn't a good idea to shoot a single ball at a time that year either, so it's sort of a moot point.
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Unread 06-16-2017, 01:25 PM
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Re: How to bend lexan for a hood?

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Originally Posted by Chris is me View Post
I am not certain about 2017, since my team did a multiple-ball shooter we really didn't test a no-backing option. The holes in the balls really didn't change the dynamics of the ball shooting that much, though.

In 2009, it probably would have been better to use a flat back, but it also wasn't a good idea to shoot a single ball at a time that year either, so it's sort of a moot point.
On our limited prototypes, the holes in the balls caused quite a bit of variance on rail shooters.
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Unread 06-16-2017, 03:29 PM
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Re: How to bend lexan for a hood?

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Originally Posted by AdamHeard View Post
On our limited prototypes, the holes in the balls caused quite a bit of variance on rail shooters.
We found the same. A soft backing seemed to help alleviate this provided the ball could be centered left-to-right the same way each time. The ribbed hood we first made had terrible accuracy and the balls would go everywhere. We then tested different hood materials by bouncing a ball on the material and seeing what made the ball bounce the least. Of the materials we had on hand, shelf liner ended up performing the best but I'm sure there was better material out there.

Did anyone have a lot of success with a ribbed hood? If so, what did you have to do to get it working?
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Unread 06-16-2017, 05:43 PM
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Re: How to bend lexan for a hood?

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Originally Posted by Rangel View Post
We found the same. A soft backing seemed to help alleviate this ...
You might want to try corrugated plastic; it already has some give built in. It is also much easier to work with an airgun than polycarbonate. We found out when we used it to prototype gear slides on our robot, and wound up using it because it has such a low CoF with the gear. Caveat - I've never used corrugated for a shooting hood, but I thought it was worth a try.

Also, by "shelf liner", do you mean the contact-paper like stuff, the irregular mesh that many teams use in the drawers of their tool chests, or something else?
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Unread 06-16-2017, 05:48 PM
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Re: How to bend lexan for a hood?

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Originally Posted by GeeTwo View Post
Also, by "shelf liner", do you mean the contact-paper like stuff, the irregular mesh that many teams use in the drawers of their tool chests, or something else?
Yes exactly that material. Our hood was shaped with cnc cut arcs with polycarbonate mounted and bent against the arcs. The shelf liner was then placed on the polycarbonate. I believe we used more layers of shelf liner on the bottom and worked our way up to two layers thick at the end of the hood.
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Unread 06-16-2017, 08:42 PM
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Re: How to bend lexan for a hood?

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Originally Posted by Chris is me View Post
For single ball shooters with a consistent loading path, this will almost always produce more accurate results than a flat back.
What is it about multiball shooters that makes this not the case? I know 2012 also saw a lot of successful hood shooters. Do spines only improve consistency if the flywheel is more consistent as well, ie not being affected by back-to-back balls?
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Last edited by Monochron : 06-16-2017 at 09:09 PM.
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