I believe that it was Michael Phelan -- whose company turned into Brunswick -- who standardized both the diamonds and the profile of the (newly vulcanized) rubber on American tables around 1850. I think it is entirely possible that the shape and height of the rubber was figured out by experiment to match the diamonds for a 2:1 rolling ball bank/kick. If the nose height is low, a ball banks short and if it is high, the ball banks long. Maybe Phelan adjusted the height to make the simple geometry work for where he wanted to install the diamonds on his width of rails.
Here is one more group of pictures I just made. This is much more realistic. This is the corner 5 system, shooting through the 3rd diamond, which is supposed to take you to the corner on a heated 10' carom table. (thru the second diamond instead for a 9' GC pool table). I got the rough track from Dr Dave's site. It does not matter if I'm off a bit on the "true track" for the purpose of this discussion. Clearly this track is way more realistic than the one in post 44. Anyway, the first picture is a 100x50 table and I used the corner 5 system and made the lines follow the diamonds. Each line has its angle measured, and underlined in blue. But those angles are not "driving" the lines, the 3rd diamonds on the two longs rail are (which I got from Dr Daves site). The second picture is a 80x40 table. On this one, I kept the same angle dimensions, but did not align to the diamonds. The angles are driving the lines, not the diamonds. You can see when the ball got to the 4th rail (the end corner) it has a .81" difference in position between the 9' table and the 7' table. The balls don't know where the diamonds are. The balls will react off the cushions the same way across different tables. So keeping the angles underlined in blue the same across both tables is more real world IMO than aligning to the diamonds. I also know the balls arc after contacting the rails. Of course that's not shown here. But again, all those affects are cumulative, and I would still expect a difference between table sizes.
First of all when you use the corner 5 system
when you aim at The 3rd diamond
the ball goes to the nose across from the 2nd diamond on the 3rd rail
not toward the 3rd diamond
First of all when you use the corner 5 system
when you aim at The 3rd diamond
the ball goes to the nose across from the 2nd diamond on the 3rd rail
not toward the 3rd diamond
I'm back home where my Winning One Pocket book lives. I found the page I had read 25 years ago and have it below. Apologies for the copyright violation, I hope one page is ok.
It seems Mr Eddie Robin, the author of maybe the best pool book written, also thought the tables should be made 2:1 on the gutter line. Interesting in the text he also writes early tables were 2:1 from the middle of the cushion or where the cushion meets the wood.
I corrected my prior corner 5 diagram in post 59. I had the track slightly wrong, I had the 3rd rail thru diamond 3 instead of thru diamond 2. This one is correct and Dr's Daves picture is below it for comparison (although flipped). It made no difference, the end position of the ball was still .8 inches different when comparing the 7' table with the 9' table.
I was drawing a table for fun in CAD and came across a couple interesting things. The dimensions of the cushions and the diamonds came from the WPA site, which is a copy of the old BCA specs, complete with typos. The picture shows a bank/kick from the corner to the side. On the right half of the table, I'm using the gutter line, which is how the ball moves in real life (disregarding rail compression). On the left side of the picture I'm using the nose of the cushion. Both are perfect mirrors. The angles are different. On the right picture, which I believe is correct, the aim point is not even perfectly across the diamond.
I believe I saw something similar to this in Wining One Pocket where they had an accurate table diagram with the diamonds. I haven't read it in 25 years though, and don't have the book handy right now. I vaguely recall the author of the book was suggesting the rail diamonds should actually be on the cloth gutter line to be accurate, rather than on the wood rail.
I think this all stems from the actual playing area that the center of the ball can "touch" is not really 2:1. This would be the gutter line. The gutter line is not 2:1.
I don't really have a point here, I just found this interesting. Maybe the question would be if tables were invented today, should they have been made with the gutter line being 2:1, rather than the cushion nose?
Here is the CAD link. You can spin it around and zoom in/out if on a computer using the mouse or keyboard arrows. It won't work as well if you open the link on mobile:
I have drawn several Pool Tables on AutoCAD & Sketchup, I always use the gutter line as 1.125, half the diameter of the object ball, where it meets up with the cushion nose. You might want to add a skosch to that, because the ball does penetrate the Cushion Nose line... on harder shots.
Check out my stimpmeter thread from today. I have a slow motion video of the ball contacting the cushion multiple times. (It’s higher than normal, however).
I corrected my prior corner 5 diagram in post 59. I had the track slightly wrong, I had the 3rd rail thru diamond 3 instead of thru diamond 2. This one is correct and Dr's Daves picture is below it for comparison (although flipped). It made no difference, the end position of the ball was still .8 inches different when comparing the 7' table with the 9' table.
First of all when you use the corner 5 system
when you aim at The 3rd diamond
the ball goes to the nose across from the 2nd diamond on the 3rd rail
not toward the 3rd diamond
And I implied it was completely not relevant to the fact that a different table size has different angles based on solely the table size. I only re-did the drawing to appease you It still showed the exact same thing.
And I implied it was completely not relevant to the fact that a different table size has different angles based on solely the table size. I only re-did the drawing to appease you It still showed the exact same thing.
Its enough to miss the side of the ball you are going at on a 3 rail kick, lets say efren playing a one pocket safe to hit the edge of the ball and put the CB behind the stack.
But I agree, it's not a big deal in the grand scheme of things. The whole point of the thread was more "this tiny detail is interesting".
It's true though, the pictures all prove it, even the ones with the non-optimal track lines. Mr Eddie Robbin wrote about it, and he's no banger like I am
Yes, Mr Robbin. I'll be back at the book next week and can review it.
I didn't mean to redo the rails today. I more meant: "if pool/carom tables were invented today, yet we magically knew everything about them, would it have been better to make the gutter line a true 2:1, and/or to move the sights on the cloth or somewhere else"?
Depends on the approach angle whether you aim to the diamond or opposite. So now we would need 2 sets of sights.
IMO pool tables play short anyway. maybe the 2:1 kick comes out close, but as Eddies says, better to get a feel for the table.
Its enough to miss the side of the ball you are going at on a 3 rail kick, lets say efren playing a one pocket safe to hit the edge of the ball and put the CB behind the stack.
But I agree, it's not a big deal in the grand scheme of things. The whole point of the thread was more "this tiny detail is interesting".
It's true though, the pictures all prove it, even the ones with the non-optimal track lines. Mr Eddie Robbin wrote about it, and he's no banger like I am
Just because you put up a picture doesnt mean its true
You also stated your lines do not take into account the running english off the rails
Last
every billiard book on the corner 5 shows the cue ball hitting the nose of the rail in front of the diamond on the 3rd rail
Based on this and your other thread
You gave way too much free time !
Another last
Do you really think efren is not going to hit the side of the ball he wants to when kicking at it?
Just because you put up a picture doesnt mean its true
You also stated your lines do not take into account the running english off the rails
Last
every billiard book on the corner 5 shows the cue ball hitting the nose of the rail in front of the diamond on the 3rd rail
Based on this and your other thread
You gave way too much free time !
Another last
Do you really think efren is not going to hit the side of the ball he wants to when kicking at it?
It's very true. Dr Dave and Bob are in this thread. They would have disagreed. Instead they said its not a big deal.
You can draw it yourself on a piece of paper and a 30 60 90 plastic right triangle. Then repeat it with a different sized paper. The end ball position will be different.
It's very logical. The center of the ball is not following a 2:1 rectangle. So when the size of the table changes, its proportion changes.
You can take it to an extreme, for example make the table cushion nose to cushion nose 200x400 inches for the "big table", and 20x40 inches for the "small table". When you take it to those extremes, the difference becomes huge. Taking things to extremes is a good way to test a theory.
I agree I gave away a lot of free time It sounds like you did also
It still showed the exact same thing.
