Rail Height Part 2

thinman

Registered
A few days ago I asked what the rail height should be and and received my answer. I took this information and calculated the average height for 2 1/4" balls which came out to approximately 1.43" (+/- 1 percent). I then converted this figure to millimeters which is 36.3mm. This is of course if my calculating is correct. I then measured rails on the 9 foot table that we play on and it turns out that the rails are anywhere from 2 to 3 mm low. My question is.
What effect will this have on the rebound of the balls? We have noticed since the old rails were replaced with these, it has been a lot more difficult to figure out banks. Would like to hear opinions on this.

thanks,
 
My guess is not much. If your banks are off, I would question whether the rails were aligned properly when put back on.
 
thinman said:
... I then measured rails on the 9 foot table that we play on and it turns out that the rails are anywhere from 2 to 3 mm low. My question is.
What effect will this have on the rebound of the balls? We have noticed since the old rails were replaced with these, it has been a lot more difficult to figure out banks. ...
In my experience, low rails tend to play "shorter" (bounces straighter out from the rail), to play faster (less energy lost in each bounce) and to bounce the cue ball off the table on each contact.

Maybe some mechanic can tell you how to make the cushions the right height -- 3mm shims between the rails and the slate might be a relatively cheap experiment.
 
Bob, you've really hit the nail on the head. Coming up short is exactly what's happening, especially on cross table banks. Not quite as bad on table length banks. Been driving us nuts trying to figure out the angles. We'll have to talk to the people that installed them and mention the shims.

Thanks,

thinman
 
Thanks Dead Crab. Printed the page out from the link you furnished. Will check it out. I'm sure the business that installed the cushions will know the type.
 
I think this is a question for the ask the mechanic section. Kingcobra is a wealth of expert info on this subject.
 
the lower the cussion nose is, the faster the cueball will bounce in the air after contact, and the shorter it will bank.

also take into acount the person that has put the cloth around it. You need to pull the cloth real tight, but if u do it TOO tight, the nose will be pushed downwards. This can easily make a 1 or 2 mm difference.

does this make any sence? :rolleyes: just trying to help
 
I would check that 1. the cushion rubber was installed correctly and 2. the correct profile cushion was used - K66 and K55 have different dimensions. Solartje also made a good point for checking how tight the rail cloth was installed.
 
The quick answer is that the lower rails will "lift" the ball as it is being struck on the underside of the curve, just as too tall of a rail will "trap" the ball. In either case you are losing energy. The measurement I am familiar with is
1 & 11/32" of rail height. Thickness of cloth will be a factor of course. The rail point is supposed to be equivalent to 64% of the ball's diameter. Very few hit that exact #.
 
Rail height

When I was taught to put tables together (late 60's), by an old Brunswick mechanic ...he told me that the nose of the cushion was to be
1 & 13/32 nds. When glueing the cushions, which I have only done a few times, we used a hot glue pot, and then spread the glue on the cushions.
It seemed to work fine.
Boy, am I old!
 
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