cue Dr. Dave's answers to frequently-asked questions
(FAQs),
mostly from the BD
CCB and AZB
discussion forums
maintained for the book: The
Illustrated Principles of Pool and Billiards
and the monthly Billiards
Digest "Illustrated Principles"
instructional articles
How do you clean and maintain a cue?
Wiping with a damp rag and rubbing dry with a dry rag usually does the trick fairly well, especially if done regularly.
from
JoeW:
I have been cleaning cues for many years and have tried many systems
because I like a clean stick. About one year ago someone mentioned trying Mr.
Clean's Magic Eraser. You can buy these in most any grocery store. I have found
there is nothing better to return a cue stick to a like new condition.
Dampen the sponge like Magic Eraser and wipe down the cue including the ferrule. Wipe the excess moisture (there should be very little) and the grime off the cue with a cotton towel.
You can use a dollar bill to burnish the stick if you want to be like the old time pool players.
The best way to slick the cue that I have found is to use an old piece of leather. Could be a piece cut from a belt, the tongue of a shoe or whatever. Soft natural leather is all that is needed.
Wind the leather around the cue and move it as fast as you can up and down the first 18 inches or so. This will heat up and seal the cue. It is almost ready to use.
Wet the edge of the cue tip liberally with saliva and then burnish this with a dollar bill or the back of a piece of emery cloth (that is what I use). This will make the tip look nice but more importantly it will help to harden it and it will be less likely to mushroom.
from Majic:
I smooth the shaft after
using the magic eraser and burnish it. I also use a dry film lubricant afterwards
and this helps seal as well as provide a slick surface. Some people I know use
Rain-X. RZ-50 made by Dupont is a clear product just to mention a couple. If you
decide to experiment with other products just be certain is doesn't dry with a
white film.
From eb_in_nc:
There's a product on the market called
Q-Wiz. It's a double sided pad, the one side for roughing, the other for polishing.
It is a high tech micro abrasive that won't burn through the finish and reduce
the diameter of the cue. I've been using it for one year and love how it works.
I't's also washable and reusable.
"feel," "hit," and "playability"
What is "feel,""hit," and "playability" really mean, and do they affect a shot?
These are qualitative phrases used to describe the shock, vibration, and sound that a player feels and hears during (but mostly after) the cue tip hits the cue ball, especially when the CB is hit off center for English. The feel and sound of a hit are affected by:
There are many physical attributes that contribute to how a cue "plays" and whether or not it is physically comfortable to a player. Here is a partial list:
These things can definitely affect how a cue "plays." Craftmanship and quality are also important attributes of a cue.
The shock and vibration is felt, and the sound is heard, after the CB is already gone, so they have no direct effect on the outcome of a shot; although, some people claim the "feel" is important to getting good "feedback" on the shot, but not all players place importance on this. To many, what the CB does is "feedback" enough.
A cue's flex or vibration can't have much to do with the physics between the tip and CB during the extremely brief (approximately 0.001 second) impact time. Most of the flex and vibration occurs well after the CB is gone. For example, see:
HSV A.25 - Cue deflection and vibration due to firm stroke with English
and
The vibration affects the "feel" of the cue, but it doesn't have much (if any) effect on the physics between the tip and CB.
Regardless of the physics, there
are many "qualitative intangibles" ("feel," "hit,"
"sound," "aesthetics," etc.) that might be psychologically
important to a player even if the characteristics might not have any direct effect
on the outcome of a shot.
What is the purpose for the ferrule?
The main purpose for the ferrule is to protect the wood on the end of the shaft. It allows one to change the tip without damaging the shaft wood, and it might help distribute the impact forces to the shaft during tip impact. The ferrule also affects the look, feel ("hit"), and sound of the cue. A smaller and lighter ferrule results in less squirt (since the ferrule material is typically heavier than wood).
What is different about a
jump cue?
Jump cues are shorter and lighter, with a hard tip (e.g., phenolic). All of these features make it easier to get more rebound height off the table slate with a legal hit.
Can a low-squirt cue help my game?
My December '07 BD article summarizes the results of a poll we had here a while back concerning whether or not a low-squirt cue helps and who it helps. I present and discuss the results in the article.
I also present a logical analysis with a graphical interpretation to try to explain how a low-squirt cue can help. The assumptions of the analysis are similar to what Shepard describes in an example in his Everything you Always Wanted to Know About Cue Ball Squirt, but Were Afraid to Ask article.
BTW, here's the last line of the article: my answer to the question of whether a low-squirt cue can help is: yes, especially if you believe it can help you. The mind is a powerful thing. I use a low-squirt cue and I think I play better with it; therefore, I probably do. I wrote this because the analysis shows only a small expected increase in accuracy with a low-squirt cue for a player with decent squirt knowledge/intuition.
Low-squirt cues might not be good for everybody. Here are what I consider some "down sides" of low-squirt cues:
- A "low-squirt" cue can be expensive.
- If somebody is used to compensating aim with a higher-squirt cue, it might be difficult to adjust to the lower-squirt cue.
- Some people might not like the "feel" or "sound" of a low-squirt cue.
- Some people might not like the taper of some low-squirt cues, especially if a closed bridge is used.
- A low-squirt cue might not be as mechanically sound over long-term use (i.e., the shaft end is not as strong and tough).
- If someone hits lots of low-speed English shots, and he or she is used to a higher squirt helping to cancel some or all of the swerve, then he or she might have trouble adjusting to a low-squirt cue (where more swerve compensation would be required for these shots).
- Low-squirt cues have long "natural pivot lengths," which might not be appropriate for either BHE or FHE. Therefore, there is no simple aim-and-pivot squirt-compensation method ... a "combination" of BHE and FHE will be required. For more info, see my November '07 article.
Does a low-squirt cue allow me to put more spin on the cue ball?
Per my September '07 article, a common low-squirt cue has a squirt angle of about 1.8 degrees at close to maximum tip offset, as compared to 2.5 degrees for a typical regular-squirt cue. So a low-squirt cue offers only about 30% less squirt than a typical regular-squirt cue.
Per Diagram 3 in my December '07 article, if you calculate the effective offsets using the squirt angles above, the percentage change in effective tip offset is less than 0.1%!!! So I think it is safe to say this effect is negligible.
Now, when comparing cues and/or tips, it is important that the actual tip offset is the same for both. If the tip size and shape are different, and one uses "tips of English" as a measure, perceived tip offset can be very different than actual offset, resulting in significant differences in the amount of spin. See my January '08 and July '06 articles for more information (and illustrations).
How do I determine the natural pivot length for my shaft, and why should I?
My November '07 BD article explains and illustrates back-hand English (BHE), front-hand English (FHE), a cue's natural pivot length, and advice for selecting a break cue and bridge distance. The article also presents a simple procedure for measuring the natural pivot length for a cue. None of this information is really new, but I don't think it is widely known and completely understood.
I used the procedure described in the article to experimentally measure the natural pivot lengths for various cues, and here is what I got:
- Predator Z, 19 oz, 11.85 mm tip: 20.2 inches
- Players XIX, 21 oz, 12.75 mm tip: 12.7 inches
- Stinger break/jump cue, 13.5 mm tip: 9.2 inches
As you can see, the natural pivot length can vary quite a lot among different cues.
I also recently posted an analysis that uses physics and math to predict the natural pivot length for a cue. It can be found in TP B.1. The results agree quite closely with my experimental results.
Other conclusions supported by the analysis include:
- Squirt angle varies nearly linearly with tip offset, and tip offset varies nearly linearly with cue pivot angle. This is what makes the BHE and FHE methods effective, provided swerve and throw are also taken into consideration.
- A cue's natural pivot length does vary a little with both tip offset and tip shape (radius), so when comparing different cues with experimental measurements, it is important to use the same tip shape and the same amount of tip offset (English) for each cue.
- Cue pivot lengths reported by Platinum Billiards seem to be too low. They report a range from 8 inches (for a "high-squirt" cue) to 14 inches (for a "low-squirt" cue).
- Expected cue pivot lengths reported in Ron Shepard's 2001 paper "Everything you Always Wanted to Know About Cue Ball Squirt, but Were Afraid to Ask" appear to be too high. He reports a range from 10 inches (for a "high-squirt" cue) to 50 inches (for a "low-squirt" cue).
The last two bullets are the main reason for my posting. My experimental and theoretical values seem to agree quite closely, but values reported by others differ and I don't know why.
Is there a pivot point for a cue that will compensate for throw and/or swerve in addition to squirt?
Unfortunately, the amount of throw varies with cut angle, shot speed, type of English, amount of topspin or bottom-spin, and ball conditions (for more info, see my August '06 through July '07 articles). Also, swerve depends on shot speed, shot distance, cue elevation, amount and type of English/roll, and ball/cloth conditions (for more info, see my March '08 and April '08 articles). Therefore, it is difficult to predict a required cue pivot point to compensate for anything more than squirt. Maybe this could be done for medium speed shots, at medium distances, with a medium amount of English (with a consistent amount of draw or follow); but otherwise, aim-and-pivot aim compensation alone is not adequate to account for all of the subtleties associated with swerve and throw. Having said all of that, aim-and-pivot methods (e.g., BHE and/or FHE) can still be very helpful to many players on many shots.
How much deflection does a cue of given pivot length produce?
from Patrick
Johnson:
The cue ball will be [tip offset] off line for each [pivot length]
it travels.
So if you're using maximum sidespin (say your tip offset = 1/2"), and your pivot length = 12" (for example), then the cue ball will be 1/2" off line for each 12" that it travels.
If you think about it, this also explains why pivoting at the pivot point to apply sidespin compensates for squirt (if there's not much swerve).
"squirt," "deflection," "stiffness"
How is cue deflection related to ball squirt?
These terms can be confusing and misleading. Here's my summary:
"low deflection shaft" =
"low
cue ball deflection shaft" =
"low squirt shaft" =
"low
end-mass" shaft =
flexible (AKA "whippy", compliant, not stiff,
"like a wet noodle") shaft end =
large cue shaft flex (i.e., "high
deflection" of cue tip) with an off-center hit
I also prefer the term "squirt" over "cue ball deflection." I certainly prefer "low squirt cue" over "low deflection cue" (because of the ambiguous meaning of "deflection"). I also prefer "small" instead of "low" because that can also be ambiguous. Although, it's not easy to change the terminology people use when it is so ingrained. As long as people are clear, it really doesn't matter. When I hear "low deflection cue," I just assume the implication is "small squirt shaft."
What is different about the different types of cues and shaft tapers?
Schuler has a good webpage describing the various types of and reasons for typical shaft tapers.
From
Snapshot9:
Cues can up to a 14mm tip, and lots of Break/Jump cues, or Break
cues, or Jump cues have a 14mm tip because a bigger tip is better for Breaking
and/or Jumping. Break cues commonly have a Conical taper (also called European)
for added stiffness.
A Break/Jump cue is one that is used for Breaking and
Jumping with part of butt coming off so that the shorter Jump portion can be used.
Jump cues/portions are commonly
40" long, the minimum length they can
be.
Leather tips are better for control, but Phenolic tips, which are harder, are better for power and/or lift when jumping. I have a J&J Break/Jump cue with a phenolic ferrule/tip combination that I like a lot, and they can be bought for $60/65 dollars. I used to believe in separate Break cue and jump cue, but the J&J Break/jump changed my mind about that, and a Break/jump combo takes up less space in your case. Phenolic tips do some getting used to though, and almost require a center ball hit.
A standard taper started out 8-10"
A pro taper started out 10-13", now is 13-15"
An European taper is like a long cone shape, with no part of the shaft being the same diameter at any 2 points. (constantly tapers down to the tip).
There is also a straight
taper, which a lot of Snooker cues have.
What is the best weight for a cue?
For you main playing cue, use whatever weight feels most comfortable. A heavier cue might be easier for some to keep on line during the stroke, but this is a very individual thing. Now, for the break shot, your optimal weight (for maximum cue ball speed) will depend on your muscle physiology (e.g., fast-twitch vs. slow-twitch muscle fiber dominance). The only way to find out the optimal weight for sure is to experiment.
From pooltchr:
1.
I believe the best weight for any player is the weight that feels most comfortable
for all types of shots.
2. I believe that different weights can produce slightly
different results, but those differences are so slight that most good players
can adapt their stroke to get the desired results regardless of the chosen weight.
3.
While a long draw shot does require more speed than a shorter one (adjusting speed
and or spin is the only way to control draw)we still don't need to use maximum
(break) speed even for maximum draw. For that reason, I think any good player
can get the required speed with any weight cue. Those same players would be able
to adjust their stroke to compensate for the weight differences in various cues.
4.
Since over the course of a game, a player will need to vary speed and spin from
shot to shot, the most comfortable weight to the individual player makes the most
sense to me. It's easier to make slight adjustments to speed and spin with a well
balanced comfortable cue. You can establish a centergistic or reference point
for a stroke speed follow shot, then work from there to know what is needed when
you need to do something else with the cue ball.