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Author Topic: An old Roto Grip Gold Grenade is giving me problems...  (Read 2466 times)

JessN16

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An old Roto Grip Gold Grenade is giving me problems...
« on: February 11, 2009, 06:19:41 AM »
For those that remember the Roto Grip Gold Grenade, I was able to find one on eBay for $20 a few weeks back, in good condition. This is a pearl urethane ball with a core that is basically a lightbulb.

When I got the ball, it had already been drilled. I would guess you'd call it a label drill. The label is dead center in the palm and rightside-up (i.e., the word "Roto" is just under the bridge). The "star" is right below the words and if that little mark inside the "star" is the CG, it's dead center.

The span was very close to mine, so I just plugged and redrilled the thumbhole. I did not change the fingers.

Unless the pin was drilled out by one of the finger holes, there is no visible pin on this ball. There's something that looks like it MIGHT be a pin, but it is on the bottom of the ball 180 degrees around from the label.

The problem it's giving me is that it's trying to track right over the thumbhole. In fact, it's almost tracking like a full roller. My PAP is 4 over 3/8 up and the only time I hit any of my gripping holes is on my Girard-drilled Columbia Reaction Roll, which has the pin under the thumb, and I might only clip the thumbhole once. I don't even hear it.

But on this Gold Grenade, it's hitting the hole six or seven times, loudly, before it flares away (and we're talking about a ball with a max 1-2 inches of flare, so it's not going very far). In order not to hit the holes, I have to tilt the ball way over, and that's not why I bought this -- I bought it to play straight up the track when the track was dried out.

What can I do to fix this?

Jess

 

tenpinspro

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Re: An old Roto Grip Gold Grenade is giving me problems...
« Reply #1 on: February 11, 2009, 04:42:38 PM »
quote:
Unless the pin was drilled out by one of the finger holes, there is no visible pin on this ball. There's something that looks like it MIGHT be a pin, but it is on the bottom of the ball 180 degrees around from the label.


Hey Jess,

This was and is for some the standard method to hold pancakes in place (target zones, white dots..etc).  The pin was 180 degrees away from the label.  If you look at the first run Col blue dots from Kentucky, the blue dot is now on the other side of the ball 180 away, I saw them in production on one of my trips.

If this is true, then I'm "guessing" the core may also be centered to cg/label as all original urethanes were produced (Angles, Hammers etc..) so you have a pin in palm layout right now.  I don't know how dynamic the cores were then but I guess a flare increasing weight hole couldn't hurt but don't know how much it'll help either.  

Fwiw, we were taught to drill 9 inches away back in the 90's until the cores became more dynamic that they started to flare over the hole so it was reduced to 6 3/4.  Maybe positioning of the core changed as well, not sure.
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Rick Leong - Ten Pins Pro Shop
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Edited on 2/11/2009 6:01 PM
Rick Leong - Ten Pins Pro Shop
Co-Founder - Tag Team Coaching
"El" Presidente of the Legion

JessN16

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Re: An old Roto Grip Gold Grenade is giving me problems...
« Reply #2 on: February 11, 2009, 05:44:52 PM »
quote:
quote:
Unless the pin was drilled out by one of the finger holes, there is no visible pin on this ball. There's something that looks like it MIGHT be a pin, but it is on the bottom of the ball 180 degrees around from the label.


Hey Jess,

This was and is for some the standard method to hold pancakes in place (target zones, white dots..etc).  The pin was 180 degrees away from the label.  If you look at the first run Col blue dots from Kentucky, the blue dot is now on the other side of the ball 180 away, I saw them in production on one of my trips.

If this is true, then I'm "guessing" the core may also be centered to cg/label as all original urethanes were produced (Angles, Hammers etc..) so you have a pin in palm layout right now.  I don't know how dynamic the cores were then but I guess a flare increasing weight hole couldn't hurt but don't know how much it'll help either.  

Fwiw, we were taught to drill 9 inches away back in the 90's until the cores became more dynamic that they started to flare over the hole so it was reduced to 6 3/4.  Maybe positioning of the core changed as well, not sure.
--------------------
Rick Leong - Ten Pins Pro Shop
Tag Team Coaching - Co-Founder
"El" Presidente of the Legion



Edited on 2/11/2009 6:01 PM


Rick,

Thanks. I don't know if it makes a difference or not, but the core in this ball isn't a pancake block -- it's a lightbulb-style core that actually looks a little like a grenade (probably marketing related to the name) or maybe Brunswick's Rocket core out of the Sidewinder. I think it's oriented "sideways," however, instead of standing up like it is in the Sidewinder. It should be a pretty low-RG ball.

Regardless, let's say I'm going to drill a weight hole to get it to get off the holes -- where do I put it? If I do have a virtual pin-in-the-palm ball here, then it's also pin-on-top-of-CG, as the CG is grip center. Thus, I have no secondary mark to go through exiting the pin (i.e., pin through the CG 6 3/4 away).

I would assume the weight hole is going to go in the thumb-positive quadrant, but should it go inside the VAL, on it or past it? And how close to my PAP? And how big a hole should I use?

Jess

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Re: An old Roto Grip Gold Grenade is giving me problems...
« Reply #3 on: February 11, 2009, 08:58:09 PM »
My apologies for my earlier post about my friend's Roto Grip Grenade ball being confiscated at the airport.
His was the grenade spare ball, not the Gold Grenade.





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tenpinspro

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Re: An old Roto Grip Gold Grenade is giving me problems...
« Reply #4 on: February 13, 2009, 01:10:25 PM »

 
quote:
Rick,

Thanks. I don't know if it makes a difference or not, but the core in this ball isn't a pancake block -- it's a lightbulb-style core that actually looks a little like a grenade (probably marketing related to the name)


Hey Jess, yes I understand but I was just trying to explain that all original urethanes were produced to be dead center on cg/label.  At the time, (maybe because it was new technology to insert cores) the pins were located right on top of cg. We were also taught at the time that you wanted true roll out of the ball and "no flare" which makes sense to have it created as pin in palm.  From my understanding, it wasn't until Faball made what they thought was a blem when one of their cores shifted during curing and created a pin out. They tested it and realized flare was good and that it out performed the pin in palm creations so it went from there.

I have a friend who was in the business during the Grenade series (and Tanks I think) so I'll get some feedback from him as well.  I'll pm you with the details bud, thanks.



 I still have my Ultra Angle which came off the truck when Lichstein and Hall were there (Hall was still a kid then)
--------------------
Rick Leong - Ten Pins Pro Shop
Tag Team Coaching - Co-Founder
"El" Presidente of the Legion

Rick Leong - Ten Pins Pro Shop
Co-Founder - Tag Team Coaching
"El" Presidente of the Legion

JessN16

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Re: An old Roto Grip Gold Grenade is giving me problems...
« Reply #5 on: February 13, 2009, 02:11:18 PM »
Rick,

Thanks a bunch, I can always count on you for help.

I'm beginning to think this ball is mismarked in some way. I *NEVER* hit holes unless I go beyond 6" on the pin and/or induce reverse flare. I have two other pin-in-palm balls (Rico-drilled Storm Thunderstruck series balls) and the track is very far away from the thumb. Those balls even cause my PAP to appear to shift from up to down (still at 4 over, however). This ball seems to have retained the upwards vertical component to the PAP but the track itself is killing me. I'm covering the same large circumference of the ball, it's just in the wrong place. (g)

Jess