Pool/Billiards/K-55 or K-66
Hello, I just recently had my rail cushions replaced along with a new simonis 860 cloth. K-66 came of and was put back on. I measured the rail height at 1 1/2" off the bed with a carpenter's square, I guess it could be 1 7/16" depending on how you look at it.
Here's my issue; cushion to cushion measures 49 3/4" by 99 3/4"; I asked my table mechanic about that and he didn't seem to think that was critical. I wonder if my table was suppose to have K-55 on it and my cushions were just replaced with like for like. Based on the measurements and the difference in thickness of the 2 cushion profiles, K-55 should be on my table?
My table is a mid-sixties 9' AMF grand prix. I've heard here and there that AMF basically copied the Gold Crown as a cheaper alternative. Anyway, I ended up with cheap rails as these play considerably slower than my old rails and I'm not happy and am going to replace them with good ones myself. But I want to be sure I'm putting the right ones on. Looking forward to your insight. John
Sorry you're having this problem. I know how much work is involved in putting a table together and how disappointing it is to have one recovered and then not be satisfied with the way it plays. This may be a somewhat lengthy and rambling reply, please read on...
Well, let's see, a nine foot table should measure 50" x 100" from cushion point to cushion point. Your a quarter inch short of that. But K55 is a wider profile than K66 so that would take you in the wrong direction and you'd end up with something like 49 1/2 x 99 1/2. If this is a "wrong cushion" problem it sounds more like the setting strips were cut for K66 and K55 was actually used instead. Did you ever measure the actual length and width "before" you had it recovered? Seems unlikely but it may have been a quarter inch off before. You might check how much "wiggle room" you have when tightening the rail bolts, it could be you can just loosen the rail bolts and move the rails back an eighth of an inch all around. That would be a simple fix.
I have to say I have not worked on an AMF and don't know what cushions they came with originally or if they were all cut for the same cushion profile over the years. Also, unless you bought the table new you really don't know if it has the original setting strips. Or, for that matter, if K66 was actually used under your cloth this time. Several variables here. Just gotta pick 'em apart one at a time starting with the easiest possibilities first.
Although that missing quarter-inch in length and width will make a slight difference in the way 3-rail shots play it wouldn't bother me as much as the cushion height, which affects the way every single ball comes off the rail.
If your cushion point heights are at 1 1/2" the cushions will play a little slow. You should be easily convinced when you measure them, they should clearly be below the 1 1/2" mark, if anything they could lean in the direction of 1 3/8". This is a pretty exact requirement and one that can be easily missed if attaching cushions by hand. It's a bit easier to measure the exact height of the point of the cushion before putting cloth on them and you might check that if you tear it apart.
You probably already know but, raising the point of the cushion allows more of the ball to get underneath the point when it hits the cushion. Higher cushion points slow the balls down by "trapping" them a little under the cushion. That's whey some people like to set the point a little closer to 1 3/8"; less ball trapped under the point means faster rebound. But if you go too far, lowering cushions to increase speed, you'll start having balls hop up as they come off the cushion especially on firm shots. And of course if the point of the cushion was below the center of the object balls everything would just loft off the table.
Try this: put a cue ball on the head spot, aim for the foot spot, and shoot it with a good solid center-ball hit. The cue ball should travel 4 - 4 1/2 lengths of the table. With new cloth, especially Simonis, if you can't get that distance the cushion points are either too high or the cushions are not of good quality, or both.
I always encourage people to buy pure gum rubber cushions. They'll last a lot of years. If you buy cheaper cushions that include clay fillers they can go hard as a rock in half a dozen years, or less. Of course it's easier to recover a table if you don't have to replace the cushions so if you buy rubber that will last for several recoverings it's a great investment.
Final thought for the moment... By World Pool & Billiard Association (WPA) specifications the point of the cushions should be between 62.5% and 64.5% of the diameter of the balls being used. For standard 2 1/4" balls the center of that range, 63.5% works out to 1 7/16" (36.3 mm) but the range between 62.5% and 64.5% is very small (.045"), just a bit over 1 millimeter so it's not an easy height to achieve without specialized equipment or a great eye and extreme care.
Let me know if I can offer any further assistance.