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Geometry: How could a Diamond bank differently than a Brunswick?
- Thread starter lawlist
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I play on a Blue Label every day. My thinking has always been, Diamonds "bank short?" Oooook, have you tried hitting it softer? Cause it don't look like they bank short at the DCC. From my experience you can't just manipulate the angle on a Diamond like you can a GC simply by slamming it into the rail. It is different (and better) than a GC, just like every other aspect of a Diamond is better than a GC.
In the end you have to learn to make allowances for what you do to the ball and each table will play a little different.
Yes, try passing a physics course without understanding geometry
Sent from the future.
The Blues play great. The Reds banked short. Diamonds are different from GC's but i wouldn't say they're any better. I do like the fact they're built in the U.S. and not farmed out.
It is more than that. Geometry says the angle of incidence equals the angle of reflection. But physics is what says no it isn't, depending on the physical characteristics of friction, speed, temperature and a host of other physical factors. Let alone the effects of spin.
Yes, but physical effects don't negate the geometry; it's still the underlying "map" that shows how physical effects change things.
Being familiar with the map helps you learn to cope with and control the changes.
pj
chgo
lawlist
Registered
From a layman's point of view, my initial thought is that the table/rail designers should have gone out of their way to make the rails in such a way so that most shots (without left/right spin) obey -- as close as possible -- the standard angle of incidents / angle of reflection, including, but not limited to soft banks, medium force banks, and very forceful banks. I certainly am not qualified to flag a "design flaw" in popular brands, but perhaps the table/rail designers did not do all of their homework before mass production was commenced ...
Well, no, geometry says nothing directly about the reflection angle of anything. Geometry does say that if the two angles are equal then a whole bunch of other things are also true, such as some diamond systems.
Geometry is also initially silent about the collisions of pool balls, but if physics tells geometry that the object ball will be driven straight away from the contact point when the cue ball hits it, then geometry is willing to tell you about the inch-and-an-eighth aiming system, and the "center-of-the-lens-of-overlap" system, and Mosconi's "aligned-stripes" system, and "the-frozen-ball-and-the-cushion-at-the-same-time-system" and a bunch of other stuff, most of which is wrong because the object ball is not usually driven straight away from the contact point.
Careless physicists make sloppy statements which lead poor Geometry to lie to people.
As for the OP, the most important statement about physics/geometry above is by Andrew Manning who pointed out that the cue ball loses 50% of its speed (and 75% of its energy) in some cushion contacts. The sloppy physicist thinks no significant energy is lost, maybe because he sees the angles are close to the same. And maybe he doesn't notice the spin on the ball that just got cushion-induced side spin.
It takes a special cushion design to make the speed losses in the two directions -- along the cushion and into the cushion -- nearly in the same proportion which is what makes the two angles close to the same. I think we have Phelan to thank for that.
For those interested, a complete summary and demonstration of all effects that changes kick and bank angles on a pool table can be found here:
things that affect rebound angle on kick and bank shots
Enjoy,
Dave
StraightIn
Registered
Many moons ago all of the banking effects listed on your website were learned by many hours of play and the help of more experienced bankers (not the money type). Thanks for the excellent writeup and explanation of the different effects. The fact that object ball speed changes the final angle complicates a given bank shot along with your consistency.
The table issues can vary a lot from table to table of a given brand. How tight and evenly the cloth is installed on the rail cushions changes the bank angles also. Uneven tension on the rail cloth will make a given table bank very inconsistent. How tightly and evenly the rails are tightened to the table also play a part in how well a given table banks consistently.
The Brunswick SuperSpeed cushions were developed about the same time that the Gold Crowns were designed (1958-1961). They added cloth to the rail cushion that was vulcanized in the final product. This design was used because through testing it would result in the most consistent bounce. So for around 40 years the Gold Crowns used in tournaments had very similar bounce from table to table. The newer versions still use these cushions.
Since then numerous companies have built pool tables and all of them typically came up with their own cushions and used them as selling points. Most of these companies tout their new cushions to have superior speed. Increased cushion speed doesn't necessarily make the rails have more consistent bounce angles but they will be different than the standard used before the turn of the century.
Diamond info...............
I emailed them about the Red/Blue deal. They said that the subrail angle was changed 1/2deg. Also said that they've used Artemis Int'l. No.66(K55 profile) cushions on the 9ft's for over 15 years. BTW, they responded very quickly imo. Some outfits you message and get crickets.
I emailed them about the Red/Blue deal. They said that the subrail angle was changed 1/2deg. Also said that they've used Artemis Int'l. No.66(K55 profile) cushions on the 9ft's for over 15 years. BTW, they responded very quickly imo. Some outfits you message and get crickets.
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I had Artemis installed on my GCI because that was the "in"cushion at the time and Superspeeds were looked down upon. Also had all the popular stuff done, tightened pockets, pocket angles "fixed", and sub-rail modified for current cushions, this was a Monarch cushioned table. Anyhoo, my GCI plays as similar to a 9' Blue Label Pro-Am as I can shoot, I have compared the diamond system on each several times. Im just not sure what cushion a 9' Blue Label Pro-Am comes with.
All Diamond 9ft's use Artemis Intercontinental No.66 cushions.
WinterArcher
Registered
A number of factors play into how a table banks. Even two tables that are "identical" will have differences. Here are some of them:
1. Different shape to the "nose" of the rubber
2. Tightness of the cloth over the rubber
3. Nose height
4. Newness of the cloth
5. Humidity in the room (always changing)
6. Consistency of the diameter of the balls in use
1. Different shape to the "nose" of the rubber
2. Tightness of the cloth over the rubber
3. Nose height
4. Newness of the cloth
5. Humidity in the room (always changing)
6. Consistency of the diameter of the balls in use
Why would you not play with standard 2 1/4 balls?
OneArmBandit
Registered
Grew up in the Southeast, Play a tournament in a large room, ask where the air condition is...lol. Tables nearest the air condition/air exchange will be dryer and play much faster! Tables nearest the door, much slower, where air is exchanged with the normally humid air outside.
OneArmBandit
Registered
Balls particularly cue balls get worn and shrink! Played in an old pool room in Carrboro, NC. The cue ball was so much shorter it was amazing. You could hardly get it to follow a few feet, but you could draw it 4 rails with little effort.
As mentioned above, they wear down.
Like the room OAB mentioned, I used to play every day in a rec room where the cue balls were about 2mm small. That's about 4%. That means they are about 12% light because they are small in all three directions.
During that time, my position game changed to nearly all draw. I was not aware of the ball size or my game change until I tried to play in another room with balls that were more matched.
Later I played in a room that kept the same sets of balls for maybe a decade. Maybe two. Those OBs were also small by maybe 2mm. A new cue ball didn't draw so well from them.:wink: