Bouncy Rails Question

[jason]

I'm not a table mechanic, but we have all played on tables that the balls will jump off of the rails when banking. I spoke to a mechanic and they sited a particular reason the rails are jumpy. Without biasing this question by giving the theory, can someone explain the reason or reasons that the balls will jump off of the rails as they do? I believe these are particularly new rails. I just want to know the physics behind what is happening.

Thanks in advance.

 

[garczar]

I'm not a table mechanic, but we have all played on tables that the balls will jump off of the rails when banking. I spoke to a mechanic and they sited a particular reason the rails are jumpy. Without biasing this question by giving the theory, can someone explain the reason or reasons that the balls will jump off of the rails as they do? I believe these are particularly new rails. I just want to know the physics behind what is happening.

Thanks in advance.

cushion nose/point height. if the nose is too low the ball gets airborn. old/hard rubber can do it some but nose height is main culprit.

 

[jason]

cushion nose/point height. if the nose is too low the ball gets airborn. old/hard rubber can do it some but nose height is main culprit.

I was waiting for others to chime in, but he claimed it was because of the humidity and the table close to the door. I wonder if Dr. D has a slow-mo videos of such rails. Also... what makes it bounce back, to which seems to be, faster than the speed going into the rail? Ya' know, bing bing bing...ricochet rabbit style.

 

[rexus31]

I was waiting for others to chime in, but he claimed it was because of the humidity and the table close to the door. I wonder if Dr. D has a slow-mo videos of such rails. Also... what makes it bounce back, to which seems to be, faster than the speed going into the rail? Ya' know, bing bing bing...ricochet rabbit style.

Humidity can and will make the balls bounce off the rails, even on tables with proper nose height.

 

[jason]

Humidity can and will make the balls bounce off the rails, even on tables with proper nose height.

Why is that? I don't understand the physics behind it.

 

[rexus31]

Why is that? I don't understand the physics behind it.

Humidity makes the balls sticky and softens the rubber.

 

[garczar]

I was waiting for others to chime in, but he claimed it was because of the humidity and the table close to the door. I wonder if Dr. D has a slow-mo videos of such rails. Also... what makes it bounce back, to which seems to be, faster than the speed going into the rail? Ya' know, bing bing bing...ricochet rabbit style.

I've played almost all my pool in humid to very humid conditions and i've rarely seen ball hop due to humidity. Low nose height is a different story. Really seen balls hop if rails aren't correct. If humidity can cause hop i haven't personally seen it that i can recall. Some of the worst conditions i've ever faded were in south Texas summers. 90+ temp/humid. is just fkng brutal. The local guys have a big home-court adv on those gaffy tables.

 

[JoeyInCali]

Humidity can and will make the balls bounce off the rails, even on tables with proper nose height.

Huge problem with Mr Sung tables in Asia right now.
They have to turn the ac at full blast to keep from not hopping

 

[jason]

More questions...if it is a low rail, what would be the exact proper height and how does the rail lower/move? Does the humidity warp or expand and contract the wood? These are crappy Valley tables, but I don't ever recall this ever happening on a Diamond. If I get a chance, I will do a slow-mo video of the ball and rail jumping and post it here. I got very used to playing on Diamonds all of the time and now that I have moved, there are none around. Very frustrating to say the least and not even really fun to play on.

 

[boogieman]

More questions...if it is a low rail, what would be the exact proper height and how does the rail lower/move? Does the humidity warp or expand and contract the wood? These are crappy Valley tables, but I don't ever recall this ever happening on a Diamond. If I get a chance, I will do a slow-mo video of the ball and rail jumping and post it here. I got very used to playing on Diamonds all of the time and now that I have moved, there are none around. Very frustrating to say the least and not even really fun to play on.

This would be my guess.

 

[Lawnboy77]

Another reason balls hop is from dirty cushion to ball contact. Just clean the cushion nose in the same manner as the rest of the table. A cap full of Woolite in a bucket of water and a microfiber cloth to wipe those rails down. Happens All the time when you do drills where the CB, or any ball, continues to contact the same point and the rails aren’t cleaned regularly. That one point will develop a ball grab and balls will hop when contacting that point.

Edit: Keeping the balls clean will help prevent this as well, but in a commercial environment I doubt the balls get cleaned when they should.

 

[rexus31]

Another reason balls hop is from dirty cushion to ball contact. Just clean the cushion nose in the same manner as the rest of the table. A cap full of Woolite in a bucket of water and a microfiber cloth to wipe those rails down. Happens All the time when you do drills where the CB, or any ball, continues to contact the same point and the rails aren’t cleaned regularly. That one point will develop a ball grab and balls will hop when contacting that point.

Edit: Keeping the balls clean will help prevent this as well, but in a commercial environment I doubt the balls get cleaned when they should.

You don't want to soak the rail cloth. It's a bad idea to get the rubber wet.

 

[Lawnboy77]

You don't want to soak the rail cloth. It's a bad idea to get the rubber wet.

Yeah you are not soaking it. You ring out the cloth good prior to. If you don’t clean that nose point you will get grime on that point, and it will get hoppy.

 

[realkingcobra]

I've answered this question on Valley tables several times already! The mechanic that did the work caused the ball hopping problems!! If you don't wrap the cloth around the bottom back side of the rail blocks as it's wrapped around the back side at the top, then that lack of cloth wrapped around the bottom back side of the rails makes the nose height of the cushions dip down, because the back side of the top of the rail block is shimmed with the thickness of cloth, spacing out the top of the rail block, but without the rail block being off set the same thickness on the back side of the rails below the rails bolts, there's no way to keep the nose of the cushions at the correct nose height!!!

 

[realkingcobra]

 

[realkingcobra]

 

[jason]

I've answered this question on Valley tables several times already! The mechanic that did the work caused the ball hopping problems!! If you don't wrap the cloth around the bottom back side of the rail blocks as it's wrapped around the back side at the top, then that lack of cloth wrapped around the bottom back side of the rails makes the nose height of the cushions dip down, because the back side of the top of the rail block is shimmed with the thickness of cloth, spacing out the top of the rail block, but without the rail block being off set the same thickness on the back side of the rails below the rails bolts, there's no way to keep the nose of the cushions at the correct nose height!!!

My apology, I should have done a search. I don't spend much time over here but thank you for the answer.

 

[fastone371]

View attachment 776473View attachment 776474

Did that table mechanic chew/gnaw the cloth to trim it? Did he not have a razor, scissors, knife, or an axe?? All would have preformed a superior job to that.

 

[realkingcobra]

Did that table mechanic chew/gnaw the cloth to trim it? Did he not have a razor, scissors, knife, or an axe?? All would have preformed a superior job to that.

Normal bar table work trust me