Accelerometers and rails

Crash

Crash

Pool Hall Owner
Silver Member
Yes, I get bored when I'm on a long weekend in Florida with a family of three teenage girls and a wife ... no Cub, no pool table ... just a new laptop and a neighbor with no secure WiFi. My mind gets to thinking so here goes:

It would be interesting to mount some accelerometers on differents styles of billiard/snooker tables and measure how much force is transferred through the cushion to the rail and beyond.

This could be used to determine if steel block rails are better than wood block; if 4 bolts per rail are more effective than 3; if oak is better than mahogany; if brand A cushions are better than brand B cushions; or if its all BS and it doesn't make any difference.

A lot of myths could be put to rest if a difference could be quantitatively shown between any of the above comparrisons or others not suggested. Maybe this has been done by some manufacturers and they couldn't make any claims based on the results.
 
Crash said:
Yes, I get bored when I'm on a long weekend in Florida with a family of three teenage girls and a wife ... no Cub, no pool table ... just a new laptop and a neighbor with no secure WiFi. My mind gets to thinking so here goes:

It would be interesting to mount some accelerometers on differents styles of billiard/snooker tables and measure how much force is transferred through the cushion to the rail and beyond.

This could be used to determine if steel block rails are better than wood block; if 4 bolts per rail are more effective than 3; if oak is better than mahogany; if brand A cushions are better than brand B cushions; or if its all BS and it doesn't make any difference.

A lot of myths could be put to rest if a difference could be quantitatively shown between any of the above comparrisons or others not suggested. Maybe this has been done by some manufacturers and they couldn't make any claims based on the results.
Click to expand...

You're talking independent lab, controlled environment comparative testing.
Problem is that any technical/quantitative results can be skewed towards whoever commissions the testing.
Also consider that the results will probably be beyond the comprehension of the average person.

Case in point -
See Pg 37 here - http://digital.turn-page.com/issue/4874
(Note that this comparison is a 70/30 cloth vs. a 90/10 cloth so IMO this is meaningless.)

Rather then comparisons, I'd prefer to see manufacturers provide details, features and benefits of their own
products in laymans terms so a consumer could make an educated choice.
 
Last edited:
Speaking for myself, I would like to see some measure of cushion resiliency (boing!).

Then we could find out what the real differences are between Artemis and Superspeeds, and determine if it really matters that Championship cushions don't float.

Bankers and 1-Pocket players would pack durometers, and chide pool hall owners whose tables weren't up to spec into getting new rubber.

On the cue side of things...every cue sold should have weight, balance point, and pivot point specs.
 
Dead Crab said:
Speaking for myself, I would like to see some measure of cushion resiliency (boing!).

Then we could find out what the real differences are between Artemis and Superspeeds, and determine if it really matters that Championship cushions don't float.
Bankers and 1-Pocket players would pack durometers, and chide pool hall owners whose tables weren't up to spec into getting new rubber.
...
Click to expand...

You can have all the specs you want but ultimately it comes down to the guy that
puts the cloth on the rails and sets the table. There lies the biggest variable.
 
Dartman said:
You can have all the specs you want but ultimately it comes down to the guy that
puts the cloth on the rails and sets the table. There lies the biggest variable.
Click to expand...

Now there is an argument for buying cheap cushions.
 
Dead Crab said:
Now there is an argument for buying cheap cushions.
Click to expand...
Not at all. One would reasonably start with a good set of cushions.
The point in case you missed it -
a set of ProAms covered correctly will play better then a set of Artemis covered incorrectly.

What's your definition of "cheap cushions".
 
Last edited:
Do you think it would be possible to catalog the accelerometer results along with player input? It may help to translate confusing results into layman's terms. I,m a player/mechanic and my own experience is the only reference i have when recommending a cushion? Cool idea Crash
 
The Turk said:
Do you think it would be possible to catalog the accelerometer results along with player input?
Click to expand...

Yes it would but the player doesn't matter in this test. I would set up a simple ramp or pendulum for consistent input to the cushion/rail. A ramp would be influenced by the cloth whereas a pendulum would not. The problem to overcome is how to temporarily mount the accelerometer fast to the rail so it can be removed without leaving a mark.
 
Dartman said:
The point in case you missed it -
a set of ProAms covered correctly will play better then a set of Artemis covered incorrectly.
.
Click to expand...

I have made it a point to check out cushion response on as many tables as I can. I also look at the cloth installation. I've done this on a bunch of GC's, a few diamonds and Valleys.

There is, in my opinion, a lot of variation in GC cushions out there. Most of these tables are old, and probably don't have the original rubber. Whoever replaced it may or may not have used Brunswicks. In any case, there is variation in the compliance of cushions as can be determined by touch, as well as by measuring variation in rebound angle.

I really haven't seen any significant cloth installation problems on these commercial tables, except for the Valleys that have been beat up and sat on. Therefore, it is my opinion, that in your average pool hall you will find variations in cushion response that is caused by the type and condition of cushion used.

I may not be a great banker, but I play well enough that I am going to approach a rail with a 10 degree pushback differently than a 7 degree. So, yes, I do think it makes a difference for players.

I think the OP is correct that a cushion spec would be a good thing, not only for original equipment, but also as a standard for existing tables. But, I will include the obligatory disclaimer that I am not an expert.
 
Crash said:
Yes, I get bored when I'm on a long weekend in Florida with a family of three teenage girls and a wife ... no Cub, no pool table ... just a new laptop and a neighbor with no secure WiFi. My mind gets to thinking so here goes:

It would be interesting to mount some accelerometers on differents styles of billiard/snooker tables and measure how much force is transferred through the cushion to the rail and beyond.

This could be used to determine if steel block rails are better than wood block; if 4 bolts per rail are more effective than 3; if oak is better than mahogany; if brand A cushions are better than brand B cushions; or if its all BS and it doesn't make any difference.

A lot of myths could be put to rest if a difference could be quantitatively shown between any of the above comparrisons or others not suggested. Maybe this has been done by some manufacturers and they couldn't make any claims based on the results.
Click to expand...

George - arguments can be made for all those comparisons.
On cushions it's somewhat obvious that manufacturers have more concern about accuracy.

http://www.champbilliards.com/images/flyers/17.jpg

http://www.champbilliards.com/images/flyers/16.jpg

http://www.champbilliards.com/images/flyers/15.jpg

http://www.brunswickbilliards.com/b...s/standard_features/super_speed_cushions.html

http://www.olhausenbilliards.com/ACCUFAST+CUSHION/id/46/

While an accelerometer can give a metric it won't singly answer the question of
whether cushion A is better then cushion B as best would need to be a combination of other factors.

A simpler test - have the same person setup a Bwick (superspeed), a Diamond (artemis) and an
Olhausen (accufast) in the one place for an extended time period.
Use a continuous ramp test to determine accuracy and cushion speed.
The only variable that should remain is which cushion holds up the longest.
 
The Turk said:
Do you think it would be possible to catalog the accelerometer results along with player input? It may help to translate confusing results into layman's terms. I,m a player/mechanic and my own experience is the only reference i have when recommending a cushion? Cool idea Crash
Click to expand...

Player input wouldn't be much more then opinion.
The acc-meter, unless I'm thinking the wrong tool, would only measure force into the cushion.
I'm thinking one would want to measure how much of that force is returned as rebound and
as George suggested, the type of wood/steel in the rail composition would probably have an affect.

Waiting for OTLB to weigh in on this one. :grin:
 
do we all ponder

thank you chase : i feel much better after reading your thread , thought
i was the only one that ponders those things . i read p&b and other mags
from time to time. i think all that knoledge will make a mess in your head.
there are allways pros & cons to every product.when i started playing pool
in the early to mid 70s bought my first two peice cue , the only thing i knew about was weight had to be 19 oz .and cheap my game was ok .
now after p&b . weight,ballance point, tip size,shaft dia.butt dia.
how does it feel ,how is the hit , hard or soft . some 35 or so years later
and 40 or 50 cues in the closet. guess what game still ok.
back to what you was saying most older tables cushions have been changed . i to think go cheap or spend a little more and get better
lets be real . you know what they say , you get what you pay for
but thats not allways true. what is important were they installed correct
the nose of cushion needs to be at proper level to roll right.i am not a table
mechanic but i have helped my friends for years put there tables together
recover and repair . as far as three bolts or four to hold rails on , to me no
big thing,long as there tight as should be. i check nose height before
takeing table apart . most tables nose height is 1 7/16 to 1 1/2
i think 1 7/16 gives a faster roll.to high nose , or loose rail kills roll .
and nose to low will make ball jump.thought for today : think less and play
more pool. have fun john107 : anderson sc
 
Good point.

Drink beer, talk to friends, shoot pool.

Why is there air? Forget it, just breathe.

All the rest is buzz kill.
 
One very good way to do this test is with a pendulum. You would make a pendulum with a cueball as the mass. The ball would at bottom dead center would be about a paper thickness off the bed of the cloth. You would raise the ball to a predetermined height. Then you would release it, into the cushion. It would bounce back. You would record the height it bounces back at. The device would do all the measuring, not the human eye.

This is a very common test in the science world. Its a way to measure how much energy is consumed when testing things by breaking them, with a pendulum.

I've been kicking around the idea of building one of these for a year now, just never had the motivation to actually do it.

This would work very well. I know I might not have described it in a way for everyone to understand, as its late and my eyes are closing...

I'm not a mechanic, but I think devices like this should be used for consistent table installations, and monitoring of existing table conditions.

If a reliable way such as this existed, then people could objectively say this cushion is faster or slower than that cushion. There would be no arguments. And that would lead to a question on why this one is different than that one. Which would hopefully lead to standardizations of manufacture, installation, maintenance, etc.

One common phrase is (paraphrased):

"You can't improve what you can't measure"
 
brain storm

lets leave the technical work of the cushions and table structure to the factory....they have thought of these ideas years and years ago and have spent lots of money investigating how tables play and why......
-

-
Rob.M
 
Very cool idea, I am all about getting empirical data on rail height and rubber compounds and the effect on rebound. One question though, since the height of nose contact is above the equator of the ball and the pendulum would have to swing directly over the front of the nose, how would you account for the upward loading of the cushion once you past BDC as the nose compresses? The ball needs a repeatable velocity residing on plane with the slate so the pinch of the cushion under load is replicated on each scenario. Still worth doing, for comparison between like profile cushions with same height. I would rather have all forces replicated in the experiment so you can quantify actual playing properties. Just my two cents. Again, this is very creative and I appreciate all the positive ideas.
Rob

iusedtoberich said:
One very good way to do this test is with a pendulum. You would make a pendulum with a cueball as the mass. The ball would at bottom dead center would be about a paper thickness off the bed of the cloth. You would raise the ball to a predetermined height. Then you would release it, into the cushion. It would bounce back. You would record the height it bounces back at. The device would do all the measuring, not the human eye.

This is a very common test in the science world. Its a way to measure how much energy is consumed when testing things by breaking them, with a pendulum.

I've been kicking around the idea of building one of these for a year now, just never had the motivation to actually do it.

This would work very well. I know I might not have described it in a way for everyone to understand, as its late and my eyes are closing...

I'm not a mechanic, but I think devices like this should be used for consistent table installations, and monitoring of existing table conditions.

If a reliable way such as this existed, then people could objectively say this cushion is faster or slower than that cushion. There would be no arguments. And that would lead to a question on why this one is different than that one. Which would hopefully lead to standardizations of manufacture, installation, maintenance, etc.

One common phrase is (paraphrased):

"You can't improve what you can't measure"
Click to expand...
 
You must log in or register to reply here.
Back
Top