CONTACT POINT ON CUE TIP
I found AzBilliards after reading Dr. Dave's page
Cue Tip Size and Shape Effects. Dave quoted some posts from this forum.
I'm buying a new cue and choosing between either 11.9 or 12.5mm diameter and either a dime or a nickel radiused tip.
I looked at the geometry and
chose a 12.5mm diameter and a dime radius.
Different people will weigh the factors differently, but the reason I chose this combination was to move the contact point on the cue tip further from the edge of the tip. All of the other factors I considered were about a wash, but the location of the contact point on the cue tip varied significantly, from 0.8mm to 2.2mm.
My goal here is not to convince anyone of anything. You are probably all better pool players than me. I just thought the drawings I made were interesting and maybe someone would want to see them.
Figure 1.
Figure 2.
These were my goals in choosing between the four options:
1. Minimize spin sensitivity to cue offset. This means I want 1 mm of cue offset to spin the cue ball as little as possible -WHILE STILL being able to attain maximum spin, which is achieved at a 30 degree contact angle on the cue ball. My goal is to reduce
unwanted spin due to stroke errors.
==>
I found that spin sensitivity is a function of tip radius only, and it doesn't make much difference. A dime tip radius requires 18.8 mm cue offset for maximum spin, and a nickel tip radius requires 19.6 mm; which is about the same.
2. Understand how spin varies with cue offset. Avoid non-linear relationships.
==> I graphed six evenly spread out cue offsets, and their resulting spin angles, for both nickel and dime tip radius. See graph below.
I found that both functions were very linear.
3. Make sure the contact point on the cue tip is not too close to the edge. The tip will compress and the contact will expand to maybe 3mm in diameter, -I don't know. But it does seem better if this spot is not on the edge. Maybe it doesn't matter, but it seems better not to be on the edge.
==>
I found that this contact point DOES vary significantly with cue diameter and tip radius, from 0.8mm with a 11.9 nickel to 2.2mm with a 12.5 dime. See dimensions below in the second drawing.
4. Additional factors:
- Tip clearance above the table -> more is better, but they were all about the same.
- Cue tip mass -> less is better, but the difference looked insignificant.
- Cue feel through my bridge -> I like 12.5 better, and it's more robust.
So given that I'm an intermediate player, and it would not be easy for me to try a lot of cues before I buy one; I'm just going to base my decision on tip contact point and buy the cue, and then I'll get used to it. -It actually arrived 30 minutes ago
I hope my drawings and analysis were interesting. I'm curious what people think of my reasoning, and if I missed anything obvious.
Cheers,
P.S. I also posted a
Pool-Shot Physics Demo Robot I helped with at our local high school.
