Smaller radius, larger radius, or don’t worry about it?

irspow

irspow

Member
Whenever I shoot for maximum spin (aiming inside edge of tip to 1/4 cueball) for draw, follow, or english I hit the very edge of tip or ‘shoulder.’ However, I rarely miscue with this offset. Probably because theoretical max spin (offset) occurs at .6 radius and not .5 radius of cueball.

I am wondering if the contact point being on the shoulder or edge of tip is a bad or good thing since I am not miscuing. My questions are:

Would a contact point more inward provide any benefit? (Other than just providing more forgiveness)

If so, would a smaller or bigger tip radius move tip contact point inward? (I think a smaller radius moves it inward)

Finally, since I am not miscuing, should I just not worry about it?
 
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irspow said:
Whenever I shoot for maximum spin (aiming inside edge of tip to 1/4 cueball) for draw, follow, or english I hit the very edge of tip or ‘shoulder.’ However, I rarely miscue with this offset. Probably because theoretical max spin (offset) occurs at .6 radius and not .5 radius of cueball.

I am wondering if the contact point being on the shoulder or edge of tip is a bad or good thing since I am not miscuing. My questions are:

Would a contact point more inward provide any benefit? (Other than just providing more forgiveness)
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It would produce fewer miscues.

irspow said:
If so, would a smaller or bigger tip radius move tip contact point inward? (I think a smaller radius moves it inward)
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Yes, a smaller radius curve hits closer to center.

irspow said:
Finally, since I am not miscuing, should I just not worry about it?
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Don't worry about it, but knowing about it is good.

pj
chgo
 
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Patrick Johnson said:
It would produce fewer miscues.


Yes, a smaller radius curve hits closer to center.


Don't worry about it, but knowing about it is good.

pj
chgo
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Sounds like I have nothing to lose moving to a dime rather than nickel radius then. I mean who couldn’t benefit from more forgiveness? 😃 Oddly, I have a 13mm tip where a nickel should be okay to not be hitting edge of tip near miscue limit.

You might find this interesting (or not). I practice my maximum offset with striped balls. However my stripes are 1.25 inches wide. So I practice aiming my tip edge with edge of stripe. This means my offset relative to cueball radius is 5/9 (.5555) not .5. .5555 is closer to theoretical .6 max offset. So this is why I might be hitting edge of tip with the nickel radius.
 
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irspow said:
Sounds like I have nothing to lose moving to a dime rather than nickel radius then. I mean who couldn’t benefit from more forgiveness? 😃 Oddly, I have a 13mm tip where a nickel should be okay to not be hitting edge of tip near miscue limit.

You might find this interesting (or not). I practice my maximum offset with striped balls. However my stripes are 1.25 inches wide. So I practice aiming my tip edge with edge of stripe. This means my offset relative to cueball radius is 5/9 (.5555) not .5. So this is why I might be hitting edge of tip with the nickel radius.
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The CB's "safe zone" for hitting off center (the space between left and right miscue limits) encompasses an arc of 60°, so to avoid hitting on the tip's edge at the miscue limit, you need an arc on the tip of at least 60°. Here's an illustration of what size coin curve includes 60° of arc on various size tips.

Rule of thumb: a tip's radius should be no bigger than the tip's diameter - i.e., a 12mm tip should have a radius no flatter than a quarter (12.1mm radius).

pj
chgo

60 degree tip.png
 
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(Ramblings of a lunatic 😂)

Those are based using .5R as the miscue limit which requires an angle range of 60 degrees. The theoretical limit is .6R which requires a 73.74 degrees. Let r be radius of tip, D be diameter of shaft, and a be angle range.

r=D/(2 sin a/2). (r here is the radius needed to hit edge of tip at given offset)

Using a 60 degree range, the radius of tip needed will equal the diameter of of the tip.
10mm shaft, 10mm tip about a mm greater than the 8.995 radius of dime
11mm shaft, 11mm tip, which is very close to 10.605 radius of nickel
12mm shaft, 12 mm tip, which is very close to 12.13 radius of quarter

However if we use .6R offset we need a range of 73.74 degrees. So instead of r=D we will get:
r=D/(2 sin 36.87) or r=D/1.2. Now we have:
10mm shaft=8.33mm tip
11mm shaft=9.17mm tip
12mm shaft=10mm tip
13mm shaft=10.83 tip

Notice that the 13mm tip with a .6R offset requires a 10.83 mm tip, very close to a nickel radius 10.605, to contact the very edge of the tip. As I flirt with .555R this is why I contact so close to the edge of the tip whereas at .5R I shouldn’t be close to the edge with even a 12.13 mm quarter radius tip.
 
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irspow said:
(Ramblings of a lunatic 😂)

Those are based using .5R as the miscue limit which requires an angle range of 60 degrees. The theoretical limit is .6R which requires a 73.74 degrees. Let r be radius of tip, D be diameter of shaft, and a be angle range.

r=D/(2 sin a/2). (r here is the radius needed to hit edge of tip at given offset)

Using a 60 degree range, the radius of tip needed will equal the diameter of of the tip.
10mm shaft, 10mm tip about a mm greater than the 8.995 radius of dime
11mm shaft, 11mm tip, which is very close to 10.605 radius of nickel
12mm shaft, 12 mm tip, which is very close to 12.13 radius of quarter

However if we use .6R offset we need a range of 73.74 degrees. So instead of r=D we will get:
r=D/(2 sin 36.87) or r=D/1.2. Now we have:
10mm shaft=8.33mm tip
11mm shaft=9.17mm tip
12mm shaft=10mm tip
13mm shaft=10.83 tip

Notice that the 13mm tip with a .6R offset requires a 10.83 mm tip, very close to a nickel radius 10.605, to contact the very edge of the tip. As I flirt with .555R this is why I contact so close to the edge of the tip whereas at .5R I shouldn’t be close to the edge with even a 12.13 mm quarter radius tip.
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The amount of extra spin going from contact at 0.5R to 0.6R isn’t worth the miscue risk. And best action on power draws happens at 0.4R.

A whole lotta world class players back in the day spun the ball fine with a 13mm tip and nickel radius. Earl’s still at 14mm I believe.
 
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If you want to test this stuff for yourself, start with a quarter radius and gradually go down to a dime. Keep track of practice/playing results.
 
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