Standardised Rail Response Test - is there one yet ?

[CreeDo]

Wow - 20MPH is FAST ! :-O

I got the predator break app - I couldnt even clock a speed over 20 MPH !
(Is that laughter I hear ?? :-D) LOL
My average for my fastest & hardest break shots was prolly around the 18 MPH mark.
I then tried the up & down the table tests again at (hopefully) similar speeds (my poor foot rail !) - I was always getting at least 4 rails - usually around 4&1/2 rails - couple of times was 1/2 a diamond off making 5 rails.

This warms my heart... IF a 'firm stroke' as mentioned in the BCA table specs equates to around 18 MPH ?

What do you guys get (how many rails) for the 'up & down test' @ around 18 MPH ?

Note: The predator app sometimes gave me a reading of 10 or 11 MPH when clearly it was nowhere near as slow as that... Hmmm its a handy app, but it doesnt seem even close to 100% reliable ?

Thanx
Cheers.

20 mph is a number I struggled to top, I had come close many times. Passed it only like 2 or 3 times.
I got some good break instruction from Tony Marcino and was able to finally pass it consistently,
though my cb was a little wild. Hardest break was 23.5.

I still don't have the break fully figured out but a few little changes made a real difference.
You'll be able to do it if you get the right instruction and put in a little practice.

The app works with sound and sometimes it gets fooled by other sounds in the room (in a pool hall, other breaks
throw it off). It listens for the click of the tip on the cue ball, and then the cue ball hitting the rack.
When the app comes back with a garbage result, you can click the edit button to see where the soundwaves spike.
If you can drag the sliders to the correct pair of sound spikes, you'll get a more accurate answer instead of some
goofy result like 5 mph or 99 mph.

When there's no sound interference, it's very accurate. Someone compared it to an actual radar gun and I believe
the app's results were within half a mile per hour.

 

[dr_dave]

People might be interested in the following video:

HSV B.15 - straight-on kick shot rebound losses and spin changes for roll, stun, and draw shots

It shows how the cushion and cloth properties affect a rebounding ball. The rail hardware, cushion rubber, and cloth conditions all affect the rebound efficiency, and it also varies with different types of shots.

A good standard measurement (which I did with slow-motion-video analysis, but which could also be done with a speed gun) would be the "rail rebound efficiency" (or effective coefficient of restitution) defined as the ratio of the post-drag outgoing speed to the incoming speed (e = COR = v_out / v_in). Example numbers are given in the video.

For the physics guys out there, here's a technical analysis that shows how the number of table lengths of travel depend on rail rebound efficiency and cloth properties:

TP B.6 - Cue ball table lengths of travel for different speeds, accounting for rail rebound and drag losses

Enjoy,
Dave

 

[realkingcobra]

Dave, all your research would have been even better if your studies could have also been applied to determine at which rail/cushion design produced the best overall results. Such as at what sub-rail thickness, combined with what style/design cushion, with what nose height, gave the best overall performance of the banks/speed and position play of a pool table, instead of just analyzing what already exists on a certain pool table being the test table.

As I've studied over the years, the body of the cushion behind it's nose, is just as important to how the cushions play overall, as the nose height is. So, overall, the body position of the cushion is determined by the sub-rail thickness, which is what determines the bevel is needed to combine the two together to optimize the overall performance of the cushions.

Example: If a sub-rail is 1 3/4" thick, it places the back end of the cushion higher up, while the nose of the cushion is at say 1 7/16"ths of an inch, when compared to a sub-rail that has a thickness of 1 5/8"ths thick, with the same nose height of 1 7/16"ths of an inch. Though the same cushions, and same nose height are repeated, the overall playability of the two different rails are much different. The higher up the back of the cushion, results in a faster responding cushion, while the lower the back of the cushion produces a slower responding cushion if they're set with the same nose height.

The BCA spec's for the nose height of a cushion to cue ball calls for 63 1/2% of the size of the object ball, +/- 1%...but that is really a faults study, as it don't apply to pool tables being built today. Rails on pool tables being built today that are 1 1/2" thick at the sub-rail can not use a 1 7/16" nose height because of the position of the body of the cushion behind the nose. That produces a cushion that pinches the object ball, resulting in cushions playing very slow, and banking very long.

So, in order to make a 1 1/2" thick sub-rail play correctly, with K66 cushions, the nose height has to be dropped to 1 5/16's if a cloth relief is used on the bottom of the rail to staple the cloth to. If no cloth relief is used, then the nose height has to be dropped to 1 1/4" because the thickness of cloth on the bottom of the rail is used to pick the nose height up to 1 5/16"ths.

So, though you can test and figure out what's already been done, it does nothing to determine what is best for a pool table overall to produce the best overall performance of a pool table, as in what rail thickness is the best, what type of cushion is the best...ect...

Glen

 

[realkingcobra]

I look at it this way, if the targeted performance of a pool table is to get the cue ball to travel 5 times back and forth the length of the table, and 9 banks around the table, then you have to design the sub-rails and cushions accordingly, as the two have to work together to achieve the end results

Glen

 

[dr_dave]

Dave, all your research would have been even better if your studies could have also been applied to determine at which rail/cushion design produced the best overall results. Such as at what sub-rail thickness, combined with what style/design cushion, with what nose height, gave the best overall performance of the banks/speed and position play of a pool table, instead of just analyzing what already exists on a certain pool table being the test table.

As I've studied over the years, the body of the cushion behind it's nose, is just as important to how the cushions play overall, as the nose height is. So, overall, the body position of the cushion is determined by the sub-rail thickness, which is what determines the bevel is needed to combine the two together to optimize the overall performance of the cushions.

Example: If a sub-rail is 1 3/4" thick, it places the back end of the cushion higher up, while the nose of the cushion is at say 1 7/16"ths of an inch, when compared to a sub-rail that has a thickness of 1 5/8"ths thick, with the same nose height of 1 7/16"ths of an inch. Though the same cushions, and same nose height are repeated, the overall playability of the two different rails are much different. The higher up the back of the cushion, results in a faster responding cushion, while the lower the back of the cushion produces a slower responding cushion if they're set with the same nose height.

The BCA spec's for the nose height of a cushion to cue ball calls for 63 1/2% of the size of the object ball, +/- 1%...but that is really a faults study, as it don't apply to pool tables being built today. Rails on pool tables being built today that are 1 1/2" thick at the sub-rail can not use a 1 7/16" nose height because of the position of the body of the cushion behind the nose. That produces a cushion that pinches the object ball, resulting in cushions playing very slow, and banking very long.

So, in order to make a 1 1/2" thick sub-rail play correctly, with K66 cushions, the nose height has to be dropped to 1 5/16's if a cloth relief is used on the bottom of the rail to staple the cloth to. If no cloth relief is used, then the nose height has to be dropped to 1 1/4" because the thickness of cloth on the bottom of the rail is used to pick the nose height up to 1 5/16"ths.

So, though you can test and figure out what's already been done, it does nothing to determine what is best for a pool table overall to produce the best overall performance of a pool table, as in what rail thickness is the best, what type of cushion is the best...ect...

Glen,

Thanks for the info. What your suggest would be a good study. If I had a clone, I would ask him to do it, but I don't and I have too many other higher-priority things on my "list." But your ideas are good.

Regards,
Dave

 

[realkingcobra]

If I had a clone, I would ask him to do it, but I don't and I have too many other higher-priority things on my "list."
Regards,
Dave

I can relate:thumbup:

Glen

 

[Fatboy]

I can relate:thumbup:

Glen

no! really! you busy?!?! impossible:grin-square::grin-square:

 

[mamics]

would that mean the cushions are TO lively? A perfect playing table will bank 5 times back and forth length wise, and 9 rails around, with the 9th cushion being the end rail you started from.This test really only applies when the cloth is new, as to many other things decay the flow of the cushions and speed of the cloth when the cloth is aged.

Glen

For sure having rails that are *too lively* would be a problem also.

I guess the up & down test at a known speed is maybe only good for comparison if ur worried about them playing too slow / being a bit dead ?

This 9 rail test sound interesting - is this the ball path to achieve the 9th rail being the one u started from ? (see pic)
Rail angles in pic are rough as guts - order of cushion contact is the main thing I wanted to confirm.
So where do you start & aim for ur 9 rail test ?
start = baulk line, 1 diamond in from side rail ?
aim point = 1.5 diamonds up from foot rail ?
centre ball hit or english of some kind ?
I can only manage 7 rails - maybe with a slightly different start or aim point or english I might be able to squeeze 8. (or more break speed ! :-> ).

I agree that cushion speed (not too fast & not too slow) plus bank angles (not too short & not too long) are a more complete way to measure / rate a table.

Cheers

 

[mamics]

People might be interested in the following video:

For the physics guys out there, here's a technical analysis that shows how the number of table lengths of travel depend on rail rebound efficiency and cloth properties:

Awesome video & love the results graph !

So 15mph to make 4 lengths on the table u got ur data from ? very interesting to know - bewdy !

Cheers

 

[realkingcobra]

For sure having rails that are *too lively* would be a problem also.

I guess the up & down test at a known speed is maybe only good for comparison if ur worried about them playing too slow / being a bit dead ?

This 9 rail test sound interesting - is this the ball path to achieve the 9th rail being the one u started from ? (see pic)
Rail angles in pic are rough as guts - order of cushion contact is the main thing I wanted to confirm.
So where do you start & aim for ur 9 rail test ?
start = baulk line, 1 diamond in from side rail ?
aim point = 1.5 diamonds up from foot rail ?
centre ball hit or english of some kind ?
I can only manage 7 rails - maybe with a slightly different start or aim point or english I might be able to squeeze 8. (or more break speed ! :-> ).

I agree that cushion speed (not too fast & not too slow) plus bank angles (not too short & not too long) are a more complete way to measure / rate a table.

Cheers

I can't diagram the shot but it goes like this. Start where you placed the cue ball, shoot to the right hand head rail about 1 diamond from the corner pocket, this will cause the cue ball to bank off the head rail to below the side pocket on the other side, then continue to the foot rail, then come off there to the side rail, up to the head rail, off there to the head left side rail, then back down to the right side foot rail....that's 8 banks, then lay on the begining end rail...that's 9 rails.

 

[mamics]

I can't diagram the shot but it goes like this. Start where you placed the cue ball, shoot to the right hand head rail about 1 diamond from the corner pocket, this will cause the cue ball to bank off the head rail to below the side pocket on the other side, then continue to the foot rail, then come off there to the side rail, up to the head rail, off there to the head left side rail, then back down to the right side foot rail....that's 8 banks, then lay on the begining end rail...that's 9 rails.

ummm - I dont quite follow - so starting at "X" - shoot towards ??? this will then drive the cueball to ??? etc. etc. (as per this pretty colour diagram with diamond refs.)

Thanx
Cheers.

 

[joelpope]

here's the tool...

This is what you are looking for

 

[mamics]

This is what you are looking for

No its not ! LOL

I found these things a long time ago...

What I am looking for is some kind of standard test for medium to high power shots.

Thanx for ur input in any case - any help / info is good ! :-D

Cheers.

 

[realkingcobra]

ummm - I dont quite follow - so starting at "X" - shoot towards ??? this will then drive the cueball to ??? etc. etc. (as per this pretty colour diagram with diamond refs.)

Thanx
Cheers.

Cue ball travel is as follows. O, M, E, C, R, K, H, T, A.

 

[mamics]

Cue ball travel is as follows. O, M, E, C, R, K, H, T, A.

EXCELLENT - This is exactly what I needed to know - I will try out that line of aim on my table asap.

Cheers.

 

[mamics]

Ahh - what a difference a tried & tested method makes ! (RKC's X to O bank round the table test)

8 rails hitting from X to O (running english) is the most I can get on my table. (cue ball finishes at "S" instead of "T')

Its good that just slamming it hard with centre ball doesnt work - ball jumps off 1st and/or 2nd rail quite a bit.

This looks like an excellent method to test rail bounce at decent speeds.

So - 9 rails is good or bare minimum ?

Who's got a Diamond Pro or Gold Crown V with 860 on it ? how many rails u get with this X to O bank round test ?

Thanx
Cheers.

 

[realkingcobra]

Ahh - what a difference a tried & tested method makes ! (RKC's X to O bank round the table test)

8 rails hitting from X to O (running english) is the most I can get on my table. (cue ball finishes at "S" instead of "T')

Its good that just slamming it hard with centre ball doesnt work - ball jumps off 1st and/or 2nd rail quite a bit.

This looks like an excellent method to test rail bounce at decent speeds.

So - 9 rails is good or bare minimum ?

Who's got a Diamond Pro or Gold Crown V with 860 on it ? how many rails u get with this X to O bank round test ?

Thanx
Cheers.

Actually, 8 is very good

 

[mamics]

Actually, 8 is very good

Crikey - very happy to hear that about my china cheapie table !
So what would my extra $$ for a Diamond Pro or Gold Crown V have gotten for me ?

Looks - agree - my table is kinda ugly.
Stability - agree - I can get slight wiggle on my balls if I give the table a good bump with my thigh. Pretty sure this wouldnt happen with a top of the line table.
Longevity - agree - my table doesnt have all the framework supports of the GC's - so I might get a fraction of sag somewhere over time perhaps ?
Slates - I'm thinking mine prolly aren't honed to the same precision or smoothness as the Diamonds / GC's ?
Rails - mine might loosen up a bit faster / bit more often due to cheaper design of attachment method ?

For what I paid I'm very happy with the playability of the table - especially now knowing that 8 rails is good speedwise !

I'll just have to get used to the "slower than what I was used to" speed in the knowledge that this is par for american tables with 2.25" balls.

Old table used 2 inch balls (snooker rails) - cant compare apples with apples when ball size is different it seems.

Thanx
Cheers.

 

[perfectpocketz]

Ahh - what a difference a tried & tested method makes ! (RKC's X to O bank round the table test)

8 rails hitting from X to O (running english) is the most I can get on my table. (cue ball finishes at "S" instead of "T')

Its good that just slamming it hard with centre ball doesnt work - ball jumps off 1st and/or 2nd rail quite a bit.

This looks like an excellent method to test rail bounce at decent speeds.

So - 9 rails is good or bare minimum ?

Who's got a Diamond Pro or Gold Crown V with 860 on it ? how many rails u get with this X to O bank round test ?

Thanx
Cheers.

The test was a trick shot on and Olhausen table....we're they would place and 100 dollar bill under the 9th rail. You needed to get as close to or on the bill in a sudden death play off.
The best way to play the shot if your shooting the cue ball into the right side long rail first....you would need to help the cue ball get around the table using low left hand English on the cue ball.
The draw shot on the cue ball will allow you to hit the cue ball harder and not make the cue ball jump off the short rail..

This ttest will tell you if the cushions are setting properly on the sub rails.....
The thickness of the sub rails....the bolt system.....brand of cushions.....don't mean your cushions won't get 9 rails.....or track the table properly.

The sub rail where the cushions glue....need to be calibrated according to the brand of cushion your wanting to use on your table.

The sub rail thickness and bevel are different on Diamond....GC...Olhausen....tables and on and on with all tables......that's why not everyone uses the same cushions.

I believe that a table should get 9 rails around.....that shows the tables rails are tracking correctly.....now I don't believe the table should get 5 rails the length of the table.....I believe the table should get 4.5 on the length with a firm hit.

I get 4.5 with Brunswick super speed.......and 5 with Artemis cushions.....with I think play a little fast to me for pool. Both are 55 cushions.
Rarely do I use any other cushions for my rail work.

I'm still trying different things with the Artemis cushion.....I want them to play the same speed as the Brunswick super speed. (5 years and still trying....LMAO)

Mark Gregory

 

[mamics]

I get 4.5 with Brunswick super speed.......and 5 with Artemis cushions.....

I dont suppose you know how fast (in mph) you were hitting the CB for both those scenarios do you ?

Firm hit = ?? MPH ?

Great to read all ur other comments - thanx.
Cheers.