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Coroner
05-26-2008, 12:11 AM
I hope I'm doing this right. I'm new to this forum. I would like to ask a pretty simple question. How does the table/ball conditions change the amount of draw on the CB?

At home I have a 8' American Heritage table with 1 1/4" slate, Simonis 860 cloth, and Amamith Pro Cup balls, CB is the Aramith red circle. The pool hall where I play APA league has 8' Brunswick tables, same CB and same cloth. At the pool hall I get about twice as much draw on the same shot than I do at home. I'm sure there's some variability in my draw stroke (I'm not that great a player), but not enough to account for the difference. Anybody have any ideas why there would be such a difference? Thanks in advance for any ideas.

Tony_in_MD
05-26-2008, 05:20 AM
Is your home table in a basement?

Humidity has a big effect on the cloth of a table higher humidity will slow things down a bit. Basements tend to be more humid.

Just one of many explanations.

Rich R.
05-26-2008, 06:29 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tony_in_MD</div><div class="ubbcode-body">Is your home table in a basement?

Humidity has a big effect on the cloth of a table higher humidity will slow things down a bit. Basements tend to be more humid.

Just one of many explanations. </div></div>
In addition to the humidity, I have to ask, what is the condition of your table and balls? Almost all aspects of pool work better if the cloth on your table is clean and the balls are clean.
I can hardly believe that your local pool room would have cleaner tables and balls than you have at home, but it is possible. We do get lazy sometimes. /forums/images/%%GRAEMLIN_URL%%/blush.gif

DeadCrab
05-26-2008, 06:39 AM
It may also depend on how tightly the cloth was stretched when installed. If the cloth on your home table is excessively loose, it may be possible to have it tightened up.

Bambu
05-26-2008, 07:55 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body">I hope I'm doing this right. I'm new to this forum. I would like to ask a pretty simple question. How does the table/ball conditions change the amount of draw on the CB?

At home I have a 8' American Heritage table with 1 1/4" slate, Simonis 860 cloth, and Amamith Pro Cup balls, CB is the Aramith red circle. The pool hall where I play APA league has 8' Brunswick tables, same CB and same cloth. At the pool hall I get about twice as much draw on the same shot than I do at home. I'm sure there's some variability in my draw stroke (I'm not that great a player), but not enough to account for the difference. Anybody have any ideas why there would be such a difference? Thanks in advance for any ideas.

</div></div>

I had the same exact experience, more draw at the pool room. Then I noticed a guy running balls through the ball machine all day long. I figured the reason I got so much more draw was the fresh waxing, and it was. So I was just about to buy the expensive ball cleaning machine, when I returned to the same pool room again. This time the set of balls I got were no different than back home. After thinking it through, I realized that they only clean the balls once a week, on tournament night. Needless to say, I saved 500 bucks!

JJFSTAR
05-26-2008, 01:11 PM
Welcome to the forum Coroner you are about to become a better pool player BTW where are you from?

Coroner
05-26-2008, 07:03 PM
Thank you Tony in MD, Rich R, DeadCrab, and Bambu for your replies.

Yes, my table is in the basement, but it is a 'walk out' basement. That is probably part of the answer. I realized today, after reading above, that if I use the Aramith ball cleaner fluid on the CB before each practice I get more draw. Vacuuming the table seems to help too. I've also figured out that if I keep the temp. higher I get more draw (heater will dry the room out too), the pool hall always seems warm (especially on league night). My cloth seems okay as far as tightness goes, I'll double check next time I'm at the pool hall. So, I think you all have the answer, or atleast part of it. Ideally, I will get my basement just right so I don't have to make much adjustment when in the pool hall.

Hi, JJFSTAR, thanks for the welcome note. I am in Nashville (I just updated my profile). I joined the APA amount 9 months ago and still figuring out how it all works and trying to handle the pressure of competition.

Thanks again for all your replies. All very helpful.

Rich R.
05-26-2008, 07:07 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body">I've also figured out that if I keep the temp. higher I get more draw (heater will dry the room out too), the pool hall always seems warm (especially on league night). </div></div>
Rather than turn the temp up, you may want to get a dehumidifier.

Tony_in_MD
05-26-2008, 09:07 PM
Yep, good advice from Rich I run a dehumidifier in my basement pool room 24/7.

1Time
05-27-2008, 07:34 AM
I find it interesting there is such a noticeable difference despite the OP's attempts to approximate table conditions. The only other relevant variables I can think of are the age and amount of wear of the cloth and the amount of chalk dust on each table.

Coroner, I'm predicting a noticeable decrease in difference over time.

maf
05-27-2008, 11:04 AM
Draw requires friction. Anything that makes the balls or the cloth more slippery will reduce it.

Bob_Jewett
05-27-2008, 03:02 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: maf</div><div class="ubbcode-body">Draw requires friction. Anything that makes the balls or the cloth more slippery will reduce it. </div></div>
While that may seem like a reasonable conclusion, it is not correct. The most important friction when trying to draw the cue ball is the friction between the cue ball and the cloth on the way to the object ball. That friction can wear off some, most or all of the backspin. You will seem to get a lot more draw by waxing the cue ball so that it loses less draw on the way to the object ball.

Once the cue ball contacts the object ball, the friction will allow the draw to take. Less friction just means that it will take longer for the cue ball to come up to full speed, but the final speed of the cue ball drawing back will be nearly the same regardless of the actual value of the friction ball-to-cloth.

One thing that is most noticeable about a slippery cue ball is the remarkable arc you can get when drawing a cut shot. Because the slippery cloth delays the action, you get a much wider arc.

Fran Crimi
05-27-2008, 03:12 PM
My first guess would be dampness but I noticed that no one mentioned age of the cloth. The older the cloth gets the more difficult it is to draw the ball. I'm not entirely sure what the direct cause is because there could be several factors, such as some cloths become looser with age, plus the fibers are burned off, making it a dirty-slick type of surface. Not easy to get the cue ball to spin in any direction when that happens, including back.

Fran

Bob_Jewett
05-27-2008, 03:55 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body"> ... The pool hall where I play APA league has 8' Brunswick tables, same CB and same cloth. At the pool hall I get about twice as much draw on the same shot than I do at home. ... </div></div>
No one here has mentioned something that's a huge factor in many pool halls: the size of the cue ball. The cue ball wears down in play, and if the cue ball is smaller, it is also lighter and much, much easier to draw. For more information on this, see this article from Billiards Digest:

http://www.sfbilliards.com/articles/2005-12.pdf

That article also shows you how to measure the relative size of the cue ball quickly, easily and accurately.

In the case of old cloth, the problem is nearly always that the cloth is sticky, which is to say that there is more ball-cloth friction and the draw wears off faster. Waxing the cue ball in such a situation will often restore new-cloth action for a while until the wax wears off.

Jal
05-27-2008, 04:02 PM
If you have two balls with exactly the same amount of backspin (any spin really), and zero velocity to begin with, the slicker of the two will travel farther before coming to a stop. This may be counter-intuitive, but it's true. (We're assuming that the friction isn't reduced to zero, or so low that air drag becomes significant compared to it.)

And for the reasons Bob J. gave, the slicker ball will usually have more backspin after reaching and colliding with the object ball. So in that respect, it usually starts out with an "advantage" after the collision.

In any of the three phases of a draw shot, before impact, during impact, and after impact, the slicker ball (or cloth) has the edge.

Jim

JoeW
05-27-2008, 04:03 PM
I wash my table periodically with a damp cloth and follow this with a hot iron (no steam). The iron (at wool setting) does seem to speed up the cloth. It also compresses some of the holes or small tears in the cloth.

I learned to iron the cloth from snooker players. I find there are several benefits.

Fran Crimi
05-27-2008, 05:24 PM
Yes, but there has to be friction at some point for the ball to actually roll back. That's where the old cloth with hardly any nap left (and a layer of some kind of oily stuff that can no longer be cleaned off) falls short.

New cloths, on the other hand, are slick, but they have nap which is why the cue ball draws back exceptionally well. (And to those who don't like the word "nap" subtitute 'fibers.')It slides very well all the way to the ob holding the backspin longer and then catches the fibers and rolls back exceptionally well as opposed to a thin cloth with practically no nap left where there's nothing to grab on the way back. Can you draw a ball back on slick ice, particularly one with a thin layer of water so the cue ball is hydroplaning? That's what I think that thin layer of oily stuff on a worn cloth does. It's on new cloth that you'll see effortless table-length draw shots.

Yes, in some cases the reason for not drawing well on old cloth is embedded dirt that causes too much friction on the way to the ob, or if the cloth has become stretched out from use, but I don't think that's the only thing that can happen with old cloths, as I've stated above.

Fran

Fran Crimi
05-27-2008, 05:46 PM
Yes, they used to iron the cloth at PPPA World Championships too. I remember the guys bringing in the irons. The ironic thing (pardon the pun) was that it only helped things for a short while because the increased static electricity from the ironing coupled with the balls rolling on the tables, after awhile caused the tables to slow down considerably, because the cloth fibers were standing straight up from the static. Eventually, that caused them to stop ironing the tables.

Maybe today it's different because the cloths aren't as nappy as they were back then.

Fran

Jal
05-27-2008, 07:08 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fran Crimi</div><div class="ubbcode-body">Yes, but there has to be friction at some point for the ball to actually roll back. That's where the old cloth with hardly any nap left (and a layer of some kind of oily stuff that can no longer be cleaned off) falls short.

New cloths, on the other hand, are slick, but they have nap which is why the cue ball draws back exceptionally well. (And to those who don't like the word "nap" subtitute 'fibers.')It slides very well all the way to the ob holding the backspin longer and then catches the fibers and rolls back exceptionally well as opposed to a thin cloth with practically no nap left where there's nothing to grab on the way back. Can you draw a ball back on slick ice, particularly one with a thin layer of water so the cue ball is hydroplaning? That's what I think that thin layer of oily stuff on a worn cloth does. It's on new cloth that you'll see effortless table-length draw shots.

Yes, in some cases the reason for not drawing well on old cloth is embedded dirt that causes too much friction on the way to the ob, or if the cloth has become stretched out from use, but I don't think that's the only thing that can happen with old cloths, as I've stated above.

Fran </div></div>
I wasn't targeting your post...just tacked mine on the end. But we do have a disagreement.

Ignoring air drag, the least amount of sliding friction, as long as it's not absolutely zero, will result in the longest travel distance. This is because of the longer time it takes for a ball to reach natural roll, and the fact that its average speed during this period is the same as on a high friction surface. (It moves a greater distance because of this extra time.)

The nap, I'm guessing, has little if any effect on the sliding friction, but does, I think, on the cloth's rolling resistance. I would also guess that the higher the nap, the greater the rolling resistance, and therefore the less ball travel distance. But I'm going out on a limb a little here.

Maybe Mac (CushionCrawler), who's accounted for air drag in his tests, can clue us in about it?

Jim

Bambu
05-27-2008, 07:25 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body"> ... The pool hall where I play APA league has 8' Brunswick tables, same CB and same cloth. At the pool hall I get about twice as much draw on the same shot than I do at home. ... </div></div>
No one here has mentioned something that's a huge factor in many pool halls: the size of the cue ball. The cue ball wears down in play, and if the cue ball is smaller, it is also lighter and much, much easier to draw. For more information on this, see this article from Billiards Digest:

http://www.sfbilliards.com/articles/2005-12.pdf

That article also shows you how to measure the relative size of the cue ball quickly, easily and accurately.

In the case of old cloth, the problem is nearly always that the cloth is sticky, which is to say that there is more ball-cloth friction and the draw wears off faster. Waxing the cue ball in such a situation will often restore new-cloth action for a while until the wax wears off.</div></div>

Interesting, Bob. Around how old does a cueball have to be, in order to reap much easier draw? How long before there is a measurable difference in size? And by the time its that old, hasnt the ball pitted in some spots? Or does this happen faster than I had thought? ....Just wondering if it can be an advantage playing with an old cue ball, thanks.

cushioncrawler
05-27-2008, 08:19 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body">...The nap, I'm guessing, has little if any effect on the sliding friction, but does, I think, on the cloth's rolling resistance. I would also guess that the higher the nap, the greater the rolling resistance, and therefore the less ball travel distance. But I'm going out on a limb a little here. Maybe Mac (CushionCrawler), who's accounted for air drag in his tests, can clue us in about it? Jim</div></div>Jim -- Funny thing, with a direktional nap, like we hav on a 12' table, the skidding-friktion varyd with direktion, and woz at a minimum "sidewayz" rather than "with" the nap. Same with rolling rezistance. Havnt time to find my old calcs right now, but air drag (form drag) iz greater than rolling rezistance (say 1 in 100) when v iz over say 4m/s, but skidding rezistance iz say 23 in 100 (alltho it might be less az speed inkreeces).

With a woollen cloth, the friktion iz much less after ironing. I notice this on my home table, if u place too much thrust onto your bridge u find yourself sliding up the table. Koz the scales of the wool open up when cold or "wet". madMac.

Jal
05-27-2008, 10:47 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- Funny thing, with a direktional nap, like we hav on a 12' table, the skidding-friktion varyd with direktion, and woz at a minimum "sidewayz" rather than "with" the nap. Same with rolling rezistance. Havnt time to find my old calcs right now, but air drag (form drag) iz greater than rolling rezistance (say 1 in 100) when v iz over say 4m/s, but skidding rezistance iz say 23 in 100 (alltho it might be less az speed inkreeces).

With a woollen cloth, the friktion iz much less after ironing. I notice this on my home table, if u place too much thrust onto your bridge u find yourself sliding up the table. Koz the scales of the wool open up when cold or "wet". madMac. </div></div>Thanks Mac. I know I probably read it from some of the good stuff you've sent along, but is the drag force proportional to V or V-squared?

Jim

cushioncrawler
05-28-2008, 12:52 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- Funny thing, with a direktional nap, like we hav on a 12' table, the skidding-friktion varyd with direktion, and woz at a minimum "sidewayz" rather than "with" the nap. Same with rolling rezistance. Havnt time to find my old calcs right now, but air drag (form drag) iz greater than rolling rezistance (say 1 in 100) when v iz over say 4m/s, but skidding rezistance iz say 23 in 100 (alltho it might be less az speed inkreeces). With a woollen cloth, the friktion iz much less after ironing. I notice this on my home table, if u place too much thrust onto your bridge u find yourself sliding up the table. Koz the scales of the wool open up when cold or "wet". madMac.</div></div>Thanks Mac. I know I probably read it from some of the good stuff you've sent along, but is the drag force proportional to V or V-squared? Jim</div></div>Jim -- I uzed V^2.0. From my (pendulum) tests Cd for a ball on a surface iz 0.60 (in midair 0.49, but the books say 0.47), plus i allowed an extra 10% for air sqeez in the bedcloth (ie Cd = 0.66), ie in the ball's footprint. Bed-rezistance i took to be 1.40% (from my tests).

I worked out that a ball hit (rolling) at 10.0m/s would reech 186m on an infinite table.
If no air drag(s) the ball would reech 250m (i might hav made a mistake here??).
If we had air drag(s) but no bed-rezistance, the ball would be barely mooving when it got to 1365m.

Jim, when u calculate the rezistances and distances etc, dont forget that air drag and bed-rezistance dont affekt the ball's topspin direktly, and thusly u need to add 2/7ths to something to take into account this bonus bit of energy. But if the bed-friktion iz zero, then u neednt add anthing, u can just sit there and watch the ball sitting there with its original topspin but going nowhere. madMac.

Bob_Jewett
05-28-2008, 11:48 AM
It is important to distinguish between rolling friction and sliding friction. The two affect the cue ball in different ways and they are sometimes misunderstood. Sliding friction relates to the force from the cue ball sliding on the cloth. It causes draw to wear off and it allows draw or follow to take effect after the cue ball hits the object ball. Sliding friction can be reduced by getting new (slippery) cloth and by waxing the cue ball. Waxing is an easy experiment to do, and I recommend it to anyone who hasn't tried it yet.

Rolling friction tells you how quickly the cue ball slows down after it is rolling smoothly on the cloth. With low rolling friction, it takes the cue ball a long time to slow down. If you have one available, check out how long the ball rolls on a heated carom table.

All combinations of high and low values of these two kinds of friction are possible. The most extreme case of low/low I've tried was on a waxed linoleum floor. You can do amazing masse shots under such conditions. New carom cloth is the closest on-table example of this combination.

Low rolling resistance and high surface friction occurs sometimes on thin old cloth that's dirty and compressed. An extreme example would be a very hard rubber surface -- the ball would roll for a long time but there is no way you could keep draw on it.

High rolling resistance and high surface friction is what you often get in bars. Dirty, thick cloth, and dirty, rough cue balls.

High rolling resistance and low surface friction is what you might see with thick, nylon-based cloth in the first week of use.

For an article on frictions on the pool table, see http://www.sfbilliards.com/articles/1995-04.pdf

Included in that article is a simple way to quantify rolling friction. All it takes is a stop watch and a lag shot.

Bob_Jewett
05-28-2008, 11:54 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... Interesting, Bob. Around how old does a cueball have to be, in order to reap much easier draw? How long before there is a measurable difference in size? And by the time its that old, hasnt the ball pitted in some spots? Or does this happen faster than I had thought? ....Just wondering if it can be an advantage playing with an old cue ball, thanks. </div></div>
How clean does the owner keep the cloth? How much use per day does the equipment get? Is the cloth ever vacuumed, or is it allowed to turn into sand paper? Do you hate rhetorical questions as much as I do?

Using the technique in the article cited above, go to your pool hall and measure some cue balls.

In my experience, the wear on the surface of the cue ball is even, barring trips against hard, sharp metal objects, such as tacks in pockets.

Jal
05-28-2008, 08:04 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- I uzed V^2.0. From my (pendulum) tests Cd for a ball on a surface iz 0.60 (in midair 0.49, but the books say 0.47), plus i allowed an extra 10% for air sqeez in the bedcloth (ie Cd = 0.66), ie in the ball's footprint. Bed-rezistance i took to be 1.40% (from my tests).

I worked out that a ball hit (rolling) at 10.0m/s would reech 186m on an infinite table.
If no air drag(s) the ball would reech 250m (i might hav made a mistake here??).
If we had air drag(s) but no bed-rezistance, the ball would be barely mooving when it got to 1365m.</div></div>Mac, I've done the math and would like to compare results. But before doing so, I'd like to know the values of the constants you used, if you will.

Air Density = 1.2 kg/m^3 ???

Did you use the unmodified cross-sectional area in the drag equation, and if so, for what size ball?

For the rolling resistance, you mention 1.40%. I take it then that you used .014g for the deceleration? If so, is the intrinsic bed deceleration or the spin reduced deceleration (as per your comments below). In other words, did you use (5/7)(.014g) for the net deceleration from bed resistance, and similarly apply that 5/7 factor to the raw air drag force (see below).

The number for Cd seems kind of high, but this is what you measured and I'll be happy to go with it. But if you could describe how you got this "surface" figure with your pendulum, I'd be curious to know (not necessary though).

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim, when u calculate the rezistances and distances etc, dont forget that air drag and bed-rezistance dont affekt the ball's topspin direktly, and thusly u need to add 2/7ths to something to take into account this bonus bit of energy. ... </div></div>Good point Mac. A non-torquing force acting to slow down (or speed up) a rolling ball produces 5/7'ths of the effect it would otherwise produce, assuming the ball remains rolling throughout. Thus, my questions about the actual values you used for the drag and bed resistance forces.

Using .014g, unmodified, I got a somewhat larger number than 250m for the pure bed resistance case, but something pretty close to this (about 270m I think - already forgot the exact figure) for a center ball hit (ie, sliding first).

Jim

Fran Crimi
05-29-2008, 07:59 AM
It is important to understand that the best knowledge you can gain as a player is through playing. Nothing is as important as that. So play and learn. But keep playing and don't get overly concerned about not having the exact answer to something. As you can see here, you asked one question and received a bunch of possible answers.

In the end, the best players rely on themselves, and obviously that works; and if you were to ask them how they got to where they are, they would tell you by playing a whole lot and by trusting themselves.

I saw on another message board where Earl was criticized for saying something about how he shoots a certain shot that doesn't agree with the physics experts. Well, hell. It works for Earl.

I just love those critics who say the best players aren't always the best teachers. My take on that is that it takes a certain amount of effort and work to be able to understand the mind of truly great and instinctive player. There is much you can learn from someone like that but not everyone is willing to put in the work to even try to understand.

Fran

Bambu
05-29-2008, 10:22 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob_Jewett</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... Interesting, Bob. Around how old does a cueball have to be, in order to reap much easier draw? How long before there is a measurable difference in size? And by the time its that old, hasnt the ball pitted in some spots? Or does this happen faster than I had thought? ....Just wondering if it can be an advantage playing with an old cue ball, thanks. </div></div>
How clean does the owner keep the cloth? How much use per day does the equipment get? Is the cloth ever vacuumed, or is it allowed to turn into sand paper? Do you hate rhetorical questions as much as I do?

Using the technique in the article cited above, go to your pool hall and measure some cue balls.

In my experience, the wear on the surface of the cue ball is even, barring trips against hard, sharp metal objects, such as tacks in pockets.</div></div>

There is no need to chastise me bob. Your own article refers to a "rough" cue ball.

KellyStick
05-29-2008, 11:03 AM
Cloth tightness can have a big effect as already stated. I covered my own table with simonis and thought I had gotten it tight. I had not. The same cloth at a local table was always very tight and not only draw but ball speed are greatly affected. It's kinda like trying to roll a ball on grass vs pavement.

Bob_Jewett
05-29-2008, 11:28 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bambu</div><div class="ubbcode-body">... There is no need to chastise me bob. Your own article refers to a "rough" cue ball. </div></div>
I apologize for the tone of my response.

As for the roughness I mentioned in the article, I wasn't very clear in the description. It was like the difference between a flat paint and a glossy paint. Both surfaces are smooth on some large scale and there are no bumps or pits even as large as a pinhead, but the friction you have against the surfaces can be very different. The cue ball I mentioned in the article looked as if it had been sanded with 200-grit sand paper -- no shine at all.

Bob_Jewett
05-29-2008, 11:33 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fran Crimi</div><div class="ubbcode-body"> ... I saw on another message board where Earl was criticized for saying something about how he shoots a certain shot that doesn't agree with the physics experts. Well, hell. It works for Earl.... </div></div>
Do you mean the thin cut shot that Peer Landa described on AZB under the title "Earl Strickland & Johnny Archer pool-school review"?

JoeW
05-29-2008, 02:46 PM
All I can do is ask from my state of ignorance.

I installed my own Simonis 860 cloth and later re-installed to get it tighter. I clean the cloth with a damp rag about every two weeks. I noticed that when damp, the Simonis cloth appears to loosen up in the corner pockets. If I push fairly hard on the cloth I can get about 1/2 inch tall wrinkle. Later the cloth tightens up when it is ironed and dry it is not possible to make a wrinkle.

Before anyone asks, I do not soak the cloth but use a terry cloth bar towel that is first soaked and then wrung out as tightly as possible with my hands.

When I checked the speed of the cloth using Bob Jewett's timed lag the table is at competition speed (whatever that number was).

Here are my questions.

1. Would it be worth it to slightly dampen Simonis 860 cloth before installing (or re-installing) to get the tightest possible fit for a fast table?

2. Would this lead to more draw on the CB (all other things being equal)?

Fran I have not noticed any static electricity after ironing the cloth. Perhaps Simonis 860, with less nap, is not as sensitive to this issue. But then I haven't checked. When I next clean I'll try to see if there is any static and will let you know.

Bob could you tell us again how to check table speed. I know it is based on timing the return from the foot rail based on a lag that just makes it to the top rail. But I forget what the numbers are. Was it 7 secs for a 100 speed or competiion nine foot table?

It may be that the OP could then test his table for speed and that would help him better evaluate the cb draw.

Rail Rat
05-29-2008, 03:46 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JoeW</div><div class="ubbcode-body">All I can do is ask from my state of ignorance.

I installed my own Simonis 860 cloth and later re-installed to get it tighter. I clean the cloth with a damp rag about every two weeks. I noticed that when damp, the Simonis cloth appears to loosen up in the corner pockets. If I push fairly hard on the cloth I can get about 1/2 inch tall wrinkle. Later the cloth tightens up when it is ironed and dry it is not possible to make a wrinkle.

Before anyone asks, I do not soak the cloth but use a terry cloth bar towel that is first soaked and then wrung out as tightly as possible with my hands.

When I checked the speed of the cloth using Bob Jewett's timed lag the table is at competition speed (whatever that number was).

Here are my questions.

1. Would it be worth it to slightly dampen Simonis 860 cloth before installing (or re-installing) to get the tightest possible fit for a fast table?

2. Would this lead to more draw on the CB (all other things being equal)?

Fran I have not noticed any static electricity after ironing the cloth. Perhaps Simonis 860, with less nap, is not as sensitive to this issue. But then I haven't checked. When I next clean I'll try to see if there is any static and will let you know.

Bob could you tell us again how to check table speed. I know it is based on timing the return from the foot rail based on a lag that just makes it to the top rail. But I forget what the numbers are. Was it 7 secs for a 100 speed or competiion nine foot table?

It may be that the OP could then test his table for speed and that would help him better evaluate the cb draw.

</div></div>

Joe, I had Tour addtional on my 9' when I first bought it about 2 years ago. One day I left a window open when it was extreamly humid out side. The cloth loosened up so much it was almost unplayable. I tightened up by damp toweling it and letting it dry.
I hated that cloth anyway because it was too fast so I replaced it with Simonis 860. The guy who installed it stretched it very tight and it has'nt loosened up since. He said to use a slightly damp cloth as you mentioned but only rarely.

I can only guess that it is very humid where you live and its not a good idea to leave any windows open.

Simonis is very accurate and reliable so if you have 1" slate the speed should never vary unless its getting worn or it needs brushing. Their website has a lot of good info.

Cheers, Rail Rat

cushioncrawler
05-29-2008, 04:16 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- I uzed V^2.0. From my (pendulum) tests Cd for a ball on a surface iz 0.60 (in midair 0.49, but the books say 0.47), plus i allowed an extra 10% for air sqeez in the bedcloth (ie Cd = 0.66), ie in the ball's footprint. Bed-rezistance i took to be 1.40% (from my tests).
I worked out that a ball hit (rolling) at 10.0m/s would reech 186m on an infinite table.If no air drag(s) the ball would reech 250m (i might hav made a mistake here??).If we had air drag(s) but no bed-rezistance, the ball would be barely mooving when it got to 1365m.</div></div>Mac, I've done the math and would like to compare results. But before doing so, I'd like to know the values of the constants you used, if you will. Air Density = 1.2 kg/m^3 ??? Did you use the unmodified cross-sectional area in the drag equation, and if so, for what size ball? For the rolling resistance, you mention 1.40%. I take it then that you used .014g for the deceleration? If so, is the intrinsic bed deceleration or the spin reduced deceleration (as per your comments below). In other words, did you use (5/7)(.014g) for the net deceleration from bed resistance, and similarly apply that 5/7 factor to the raw air drag force (see below). The number for Cd seems kind of high, but this is what you measured and I'll be happy to go with it. But if you could describe how you got this "surface" figure with your pendulum, I'd be curious to know (not necessary though). <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim, when u calculate the rezistances and distances etc, dont forget that air drag and bed-rezistance dont affekt the ball's topspin direktly, and thusly u need to add 2/7ths to something to take into account this bonus bit of energy....</div></div>Good point Mac. A non-torquing force acting to slow down (or speed up) a rolling ball produces 5/7'ths of the effect it would otherwise produce, assuming the ball remains rolling throughout. Thus, my questions about the actual values you used for the drag and bed resistance forces. Using .014g, unmodified, I got a somewhat larger number than 250m for the pure bed resistance case, but something pretty close to this (about 270m I think - already forgot the exact figure) for a center ball hit (ie, sliding first). Jim</div></div>Jim -- I uzed 1.29. Az u know all of my stuff iz done arithmetikally uzing iteration in excel. Yes, for eech time inkrement, i reduced the retarding force(z) to 5/7ths. Some of the time i assume a 138gm ball, 2-1/16". I assume that the ball iz rolling from the start, whereaz i see that u adopt skidding. I didnt allow for skin-friktion aero-drag (no big deal). I didnt allow for any slippage type losses, ie whilst rolling (inklooding cloth wrinkling etc) -- this kood be severe, in which case it would take heaps off my calculated distancez -- no, wait, this would be automatically inherent in my mezurements for the "grade of the hill", ie 1.4% (sometimes i uzed 1.35% and 1.45%). Aktually, 1.40% iznt the GOTH -- the grade of the real hill facing the ball iz 7/5ths of 1.40%, so i shoodnt call it the GOTH.

My tests. GOTH iz simple -- u raize one end of your pool-hall'z No1 table, higher and higher, untill the ball set in motion duznt slow or fast -- then u mezure the grade -- here u now hav the GOTH for that speed -- then u can repeat this for other speedz -- but it bekumz unworkable for fast speeds (u karnt tell whether the ball iz slowing or fasting).

Airdrag. U swing the ball on a cotton pendulum, and mezure its slowing over time, and write a computer program that tells u Cd, taking into account the drag for the cotton etc etc. I got 0.49 for a ball -- the books say 0.47, but they allwayz uzed big ballz in a wind tunnel. Yes, the 0.49 applyz to the aktual frontal area, non-modyfyd (do they modyfy frontal area nowadayz??).

The 0.60 -- tricky -- i stuck a flat surface under my ball, and repeated the cotton stuff -- then i did it with just the flat surface on its own -- then dedukted one from the other -- presto 0.60. Only it took hours of tests, just to get some good ones with zero wobble etc etc -- just about the most stressfull stuff i hav ever dunn. madMac.

Bob_Jewett
05-29-2008, 07:13 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JoeW</div><div class="ubbcode-body"> ... Bob could you tell us again how to check table speed. I know it is based on timing the return from the foot rail based on a lag that just makes it to the top rail. But I forget what the numbers are. Was it 7 secs for a 100 speed or competiion nine foot table? ... </div></div>
The procedure is described in this article from 1995: http://www.sfbilliards.com/articles/1995-04.pdf

JoeW
05-30-2008, 06:33 AM
Based on Bob's article the OP (original poster) can compare the speeds of the tables in both locations. Check with Bob for the constant to use or the expected times on an eight foot versus a nine foot table.

Bob's article also leads to the suggestion that different brands of chalk may yield different results.

The OP could take his personal cue ball and an object ball to the pool room and use for the different tests eliminating differences between the balls.

Coroner
05-30-2008, 12:16 PM
Thank you everyone for your comments and advice. All of it has been helpful.

So far I've done the following:

1. Wax the CB with Aramith wax about every hour of play.
2. Vacuum the table every couple of days.
3. My cloth is newer than the pool hall and it's pretty tight, so that is probably not it.

This has given me much more draw, much closer to the pool hall. I do live in Nashville and it is humid. I think the last step for me is a de-humidifier (thanks for the suggestion Rich R).

Rich R., my room is about 25 x 20 with 10 ft. ceilings. Any ideas on the size of humidifier I should get and where I should put it? (like under the table?) Any issues with drying out the wood/rails, etc?

Thanks

Bob_Jewett
05-30-2008, 12:21 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body"> ... 1. Wax the CB with Aramith wax about every hour of play. ... </div></div>
One small note: as far as I know, the Aramith ball polish product does not contain anything like wax or silicone. In fact, some sets of rules for carom specifically prohibit any wax or slippery substance on the balls.

If you want to try a separate, temporary experiment, try a paste wax or silicone spray on the cue ball. It will likely produce a dramatic change.

Rich R.
05-30-2008, 05:50 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Coroner</div><div class="ubbcode-body">Rich R., my room is about 25 x 20 with 10 ft. ceilings. Any ideas on the size of humidifier I should get and where I should put it? (like under the table?) Any issues with drying out the wood/rails, etc?</div></div>
Coroner, be sure you get a dehumidifier, not a humidifier, as indicated above. I hope that was just a typo. /forums/images/%%GRAEMLIN_URL%%/blush.gif

There are many brands and sizes of dehumidifiers available. Take your room dimensions with you, when you shop, and read the boxes to get a proper size.

I don't think the location in the room would make much difference. Any corner would do. Most of the dehumidifiers have to be emptied regularly. However, they also come with a hose. If you can place it where you can run the hose into a drain, that would be great and it would save you the chore of emptying the bucket.

Jal
05-30-2008, 06:21 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- I uzed 1.29. Az u know all of my stuff iz done arithmetikally uzing iteration in excel. Yes, for eech time inkrement, i reduced the retarding force(z) to 5/7ths. Some of the time i assume a 138gm ball, 2-1/16". I assume that the ball iz rolling from the start, whereaz i see that u adopt skidding. I didnt allow for skin-friktion aero-drag (no big deal). I didnt allow for any slippage type losses, ie whilst rolling (inklooding cloth wrinkling etc) -- this kood be severe, in which case it would take heaps off my calculated distancez -- no, wait, this would be automatically inherent in my mezurements for the "grade of the hill", ie 1.4% (sometimes i uzed 1.35% and 1.45%). Aktually, 1.40% iznt the GOTH -- the grade of the real hill facing the ball iz 7/5ths of 1.40%, so i shoodnt call it the GOTH.

My tests. GOTH iz simple -- u raize one end of your pool-hall'z No1 table, higher and higher, untill the ball set in motion duznt slow or fast -- then u mezure the grade -- here u now hav the GOTH for that speed -- then u can repeat this for other speedz -- but it bekumz unworkable for fast speeds (u karnt tell whether the ball iz slowing or fasting).

Airdrag. U swing the ball on a cotton pendulum, and mezure its slowing over time, and write a computer program that tells u Cd, taking into account the drag for the cotton etc etc. I got 0.49 for a ball -- the books say 0.47, but they allwayz uzed big ballz in a wind tunnel. Yes, the 0.49 applyz to the aktual frontal area, non-modyfyd (do they modyfy frontal area nowadayz??).

The 0.60 -- tricky -- i stuck a flat surface under my ball, and repeated the cotton stuff -- then i did it with just the flat surface on its own -- then dedukted one from the other -- presto 0.60. Only it took hours of tests, just to get some good ones with zero wobble etc etc -- just about the most stressfull stuff i hav ever dunn. madMac. </div></div>
Thanks again Mac. So on to compare numbers.

With combined drag and bed resistance, I get 157 meters (ball rolling at 10 m/s from the start). This is using the unmodified .014 for the GOTH. As per your comments, I think this is the right one, ignoring any speed dependency. However, if 5/7'ths of it is substituted instead (=.01), it works out to your 186 meters. This is from an analytical integration.

For pure bed resistance (no drag), it comes out to 364 m. This was obtained with two different methods (the same formula used for the above and a simpler standard kinematic relation), so I'm thinking it's okay.

In the case of no bed resistance, I get the ball moving at .00114 m/s at 1365 meters down the road. Sound familiar?

Tell me you didn't measure the bed resistance as described? I mean, I have nothing against it - anyone that corrects for thread drag in his pendulum tests should be given carte blanche - but I'll venture that most proprietors would have an opinion. /forums/images/%%GRAEMLIN_URL%%/smile.gif

I much appreciate you relaying the results of your labors. There is a little bit of a question in my mind as to whether the Cd's are simply additive, as per your method of extracting it from the flat+ball tests, but I can't say I understand the dynamics. Speaking of Cd's, what little reading I did, indicated that sometimes Cd and A (area) come in a matched set, with A modified in some way. But again, I don't know anymore.

Jim

cushioncrawler
05-30-2008, 11:42 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body">...Thanks again Mac. So on to compare numbers.

With combined drag and bed resistance, I get 157 meters (ball rolling at 10 m/s from the start). This is using the unmodified .014 for the GOTH. As per your comments, I think this is the right one, ignoring any speed dependency. However, if 5/7'ths of it is substituted instead (=.01), it works out to your 186 meters. This is from an analytical integration.

For pure bed resistance (no drag), it comes out to 364 m. This was obtained with two different methods (the same formula used for the above and a simpler standard kinematic relation), so I'm thinking it's okay.

In the case of no bed resistance, I get the ball moving at .00114 m/s at 1365 meters down the road. Sound familiar?

Tell me you didn't measure the bed resistance as described? I mean, I have nothing against it - anyone that corrects for thread drag in his pendulum tests should be given carte blanche - but I'll venture that most proprietors would have an opinion. /forums/images/%%GRAEMLIN_URL%%/smile.gif

I much appreciate you relaying the results of your labors. There is a little bit of a question in my mind as to whether the Cd's are simply additive, as per your method of extracting it from the flat+ball tests, but I can't say I understand the dynamics. Speaking of Cd's, what little reading I did, indicated that sometimes Cd and A (area) come in a matched set, with A modified in some way. But again, I don't know anymore. Jim</div></div>Jim -- Yep, i raized one end of my home 6' table. I think that at slow speedz the rolling rezistance woz 1.80%. Uzually the ball rolled faster and faster, or slower and slower, ie rolling rezistance iz less at higher speed -- but i karnt really remember all that well.

Aktually, some of my sliding-friktion tests involved raizing one end of the table to 25% if i remember aright. But my main friktion-sliding tests were done with weights and pulleys.

And, u are korrekt when u add the rolling-rezistance to sliding-friktion, koz rolling rezistance iz allwayz there, 100%, even if the ball iznt rolling (if u see what i mean, which u do). And sliding-friktion iz allwayz there, even if the ball iz rolling -- but here the force iz pushing the ball forward, and the force iznt 100%, it iz just enuff (%) to make the ball's rolling match the ball's speed (if u see what i mean).

Aktually, that damned cotton contributes about 25% (or something) of the total air-drag. madMac.

Jal
05-31-2008, 01:43 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Jim -- Yep, i raized one end of my home 6' table. I think that at slow speedz the rolling rezistance woz 1.80%. Uzually the ball rolled faster and faster, or slower and slower, ie rolling rezistance iz less at higher speed -- but i karnt really remember all that well.</div></div>
That does complicate things. And the variation is probably different for different cloths in different states of wear.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">..And, u are korrekt when u add the rolling-rezistance to sliding-friktion, koz rolling rezistance iz allwayz there, 100%, even if the ball iznt rolling (if u see what i mean, which u do).</div></div>
Mac, sorry, but by "drag", I meant air drag. The numbers are for a ball that's rolling from the start.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">And sliding-friktion iz allwayz there, even if the ball iz rolling -- but here the force iz pushing the ball forward, and the force iznt 100%, it iz just enuff (%) to make the ball's rolling match the ball's speed (if u see what i mean).</div></div>
I think I know what you mean. If you look at any cross-section of the footprint from the side, there are only two points where "true" rolling can be taking place. But is sliding occurring at the other points? Maybe the cloth flexes enough to maintain static friction?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Aktually, that damned cotton contributes about 25% (or something) of the total air-drag. madMac. </div></div>
That's pretty surprising. Why is that?

Jim

Rail Rat
05-31-2008, 11:52 AM
Some other factors might come into play here from a pure scientific analysis on table roll.

The issue date from the factory on some cloth can vary in regards to the quality of sheeps wool of any particular year. New Zealand sheep have a coarser hair fiber than British. but that could change durung a colder (or warmer) year in the highlands.

In different parts of the world gravitational pull from the moon could possibly effect the earths field thus effecting the downward force on the ball.

The natural oil from our hands can possibly effect friction during contact, so the exact state of hand cleanliness if we factor in the type of soap we use (if any.)

Its been noted among veterans that the forward force of a straight cue as opposed to that of a bent cue which applies some slight sideways force in a carefully controlled experiment might show marked decrease in acceleration. But as a layman I can only speculate.

Jal
05-31-2008, 03:12 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rail Rat</div><div class="ubbcode-body">Some other factors might come into play here from a pure scientific analysis on table roll.

The issue date from the factory on some cloth can vary in regards to the quality of sheeps wool of any particular year. New Zealand sheep have a coarser hair fiber than British. but that could change durung a colder (or warmer) year in the highlands.

In different parts of the world gravitational pull from the moon could possibly effect the earths field thus effecting the downward force on the ball.

The natural oil from our hands can possibly effect friction during contact, so the exact state of hand cleanliness if we factor in the type of soap we use (if any.)

Its been noted among veterans that the forward force of a straight cue as opposed to that of a bent cue which applies some slight sideways force in a carefully controlled experiment might show marked decrease in acceleration. But as a layman I can only speculate. </div></div>
I think the moon is definitely having an effect.

Jim

cushioncrawler
05-31-2008, 04:20 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body">...I think I know what you mean. If you look at any cross-section of the footprint from the side, there are only two points where "true" rolling can be taking place. But is sliding occurring at the other points? Maybe the cloth flexes enough to maintain static friction?...</div></div>Jim -- Here when i say "sliding-friktion" i dont mean that there iz ball'on'bed sliding, i shood probably call it static-friktion, even tho (az u point out) the ball contact iznt exaktly static. I woz being lazy with my wordage -- i guess that its similar to me calling it "rolling-rezistance" when this rezistance duznt really need the ball to be rolling at all.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cushioncrawler</div><div class="ubbcode-body">Aktually, that damned cotton contributes about 25% (or something) of the total air-drag. madMac.</div></div><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jal</div><div class="ubbcode-body">That's pretty surprising. Why is that? Jim</div></div>Jim -- Yes, that cotton iz pretty thin, but if u hav a 3m long pendulum of it it sure addz up. If the pendulum iz long enuff the cotton-drag would outweigh the ball-drag.

I guess that one kood point out that the rolling-rezistance tests didnt take into account the air-drag(s), and so would over-estimate the grade of the hill, but at the low test speeds it wouldnt make much difference. Probably about the same (over) difference az the (under) difference due to skin-friktion (which we ignored allso). madMac.

cushioncrawler
05-31-2008, 04:42 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rail Rat</div><div class="ubbcode-body">Some other factors might come into play here from a pure scientific analysis on table roll. The issue date from the factory on some cloth can vary in regards to the quality of sheeps wool of any particular year. New Zealand sheep have a coarser hair fiber than British. but that could change durung a colder (or warmer) year in the highlands.

In different parts of the world gravitational pull from the moon could possibly effect the earths field thus effecting the downward force on the ball.

The natural oil from our hands can possibly effect friction during contact, so the exact state of hand cleanliness if we factor in the type of soap we use (if any.)

Its been noted among veterans that the forward force of a straight cue as opposed to that of a bent cue which applies some slight sideways force in a carefully controlled experiment might show marked decrease in acceleration. But as a layman I can only speculate.</div></div>Rail Rat -- I can see the headlines -- "RailRat collides with CushionCrawler" -- its inevitable.

If u hung a plumb-bob under your table, u wouldnt see much more than an occasional 1 in 500,000 varyation, due mainly to the moon. This would havta be 100 times worse to make any real difference in play. But, interestingly, the moon can make the balls kurve, whereaz a simple change in "G" karnt. A simple change in G will add or subtrakt wt from the ball, without changing its inertial mass -- ie it can make the ball roll further or shorter, but karnt really change its direktion (much). The G force pulling on a billiards player's balls changes between about 9.780 and 9.832 N/kg az she goze from the poles to the equator, a change of 0.532%. This might slow a ball, but it wouldnt kurv its trajektory.

I agree that a bent cue lacks power.

New Zealanders hav the world's record for the buying of gumboots in the summer. madMac.

Rail Rat
05-31-2008, 05:55 PM
Mac, Jim, of course all the deviations mentioned here would be very slight in normal play, however adding all the outside factors we could see an anomaly. We've all experienced a strange roll of the ball in our years of play. I once say a man lose a tournament on a simple little one foot roll to the pocket. Later I saw him sitting out side in the parking lot gazing into the heavens, obviously seeking some explaination..why... why did it roll like that?

He could have hit a bad fiber from a New Zealand ewe!!!

I believe in bent cues.

Moon power too!

-The rat

cushioncrawler
05-31-2008, 08:58 PM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rail Rat</div><div class="ubbcode-body">...We've all experienced a strange roll of the ball in our years of play. I once say a man lose a tournament on a simple little one foot roll to the pocket...</div></div>Yeah -- (1) A grain of sand iz murder. (2) Chalk builds rivers of chalk under the cloth. (3) Then there are dents due to masse & jump shots. (4) On my home table some cement from between the slates came loose, and i had to swish it across inch by inch to under a cushion uzing a safety pin. (5) The latest effort, some of the excess araldite glueing my tip must hav broken off, and then i must hav melted this fragment into the cloth when ironing, and i had a hell of a time picking it out. (6) Plus finger marks on a nappy cloth can do wonders. (7) Misscue divots. madMac.

Rail Rat
06-01-2008, 12:57 PM
I've faced those conditions many times Mac.

But speaking of unusual table conditions, I just returned from a cruise across the ocean to Spain. It was a large ship and actually featured a pool table on board. Now in port it was playable but on the open ocean it was quite a challenge.

The ship would rock enough about every 30 seconds to send the balls to new positions. So we made up a rule: if you have bad position you could only wait 10 seconds then you had to shoot! Of course also you had to time the rocking motion on your stroke or the QBall would roll away on your follow thru. Also you had to become effiencient on wing shots!!

This could be a new game on land!... put a table on hydrualics jacks for motion and now you have Wing Shot Pool... A whole new experience in playing the game!

I could be on to something here.

The Rat

Jager85
06-02-2008, 09:31 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 1Time</div><div class="ubbcode-body">I find it interesting there is such a noticeable difference despite the OP's attempts to approximate table conditions. The only other relevant variables I can think of are the age and amount of wear of the cloth and the amount of chalk dust on each table.

Coroner, I'm predicting a noticeable decrease in difference over time. </div></div>

I definately do agree that humidity has a huge effect on your shots, jot only draw. I had my first experience with this recently. I went out last Sunday night and it was very hot and humid throughout the whole bar. Many of my positions were off, I was scratching where I normally wouldn't, and I had a hard time controlling my draw. A local pro saw I was confused and he came and explained to me that I was scratching alot because of the humidity. He said the rails don't kick as much, nor does the ball roll as fast with the humidity. He said all of the angles off of the rails are narrowed and that a couple of my scratches in the side he told me would have missed by close to an inch in normal conditions.

eb_in_nc
06-02-2008, 09:45 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jager85</div><div class="ubbcode-body">[quote=1Time] A local pro saw I was confused and he came and explained to me that I was scratching alot because of the humidity. He said the rails don't kick as much, nor does the ball roll as fast with the humidity. He said all of the angles off of the rails are narrowed and that a couple of my scratches in the side he told me would have missed by close to an inch in normal conditions. </div></div>

Why would the angles be influenced by the humidity? I can see the speed of the ball being affected but cannot see the connection between humidity and angles being shot off of the cushion?

Rail Rat
06-02-2008, 10:06 AM
If its hot and humid and the pool room has no air conditioning I won't even play there. For me the most aggravating aspect is the slowness of the felt. I'm a touch player and I hate it when you have to constantly power your shots.

Of course it makes your cue sticky and grab your hand. The rails don't react properly and you feel like your playing on a carpet.

I attended a pro match in a local hotel several years ago and the air conditioning was out on a hot humid day. It was brutal. Hardly anybody sustained a run.

Rail Rat
06-02-2008, 10:12 AM
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eb_in_nc</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jager85</div><div class="ubbcode-body">[quote=1Time] A local pro saw I was confused and he came and explained to me that I was scratching alot because of the humidity. He said the rails don't kick as much, nor does the ball roll as fast with the humidity. He said all of the angles off of the rails are narrowed and that a couple of my scratches in the side he told me would have missed by close to an inch in normal conditions. </div></div>

Why would the angles be influenced by the humidity? I can see the speed of the ball being affected but cannot see the connection between humidity and angles being shot off of the cushion? </div></div>

Good point. I think its because the change of the rails surface friction effects the rebound. Also you must hit the ball harder which causes the ball to dig in more and alter its direction.

Whenever I've played in these conditions the rails seem "flat" the've lost some of their bounce.