warped slate?

akadansmith

akadansmith

AzB Silver Member
Silver Member
i have a 7 foot valley bar box. table is completely level. when i slow roll a ball to the corner pockets they seem to roll away from pocket is this from a slate thats warped or could it be from the felt bunched up under pocket? any help would be greatly appreciated.
 
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maha said:
the table being level is not the same as the slate being level. you level the slate not the table.
if balls roll off the slate isnt level.
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On Valleys it warps cause it so thin. You have to get the box level first. Sometimes you can get the 'twist' out of it, sometimes not. Easy fix if its just too much glue build-up.
 
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CuesDirectly said:
Let's say that you and Rosie O'donnell went on a date, you got back to your house and she jumps on your table. It will FLEX, if she quickly gets off, it will flex right back.

Now let's say that she decides that she loves your balls and starts playing with all 16 of them until she passes out. You find her the next morning, still in the center of the table.

That FLEX would have set in long enough to become permanent, and now you can say it's WARPED.

Same thing with a shaft, bend it and it will bend right back. Keep it in the bent position for a few weeks and you will have a warped shaft.
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If I end up with Rosie ODonell on my table , I will do the right thing and send a 1100 grain 60 cal right thru my deviated septum.
 
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CuesDirectly said:
Let's say that you and Rosie O'donnell went on a date, you got back to your house and she jumps on your table. It will FLEX, if she quickly gets off, it will flex right back.

Now let's say that she decides that she loves your balls and starts playing with all 16 of them until she passes out. You find her the next morning, still in the center of the table.

That FLEX would have set in long enough to become permanent, and now you can say it's WARPED.

Same thing with a shaft, bend it and it will bend right back. Keep it in the bent position for a few weeks and you will have a warped shaft.
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You are describing the phenomenon of 'plastic creep', which is deformation due to long term stresses applied to a material. These stresses are under the yield stress of the material, but due to being applied for long duration can change the shape of a piece.

I don't think stone like slate usually creeps. I would expect that slate on a valley table would sag under it's own weight if simply supported on the edges. Thus, I agree with the plastic deformation you describe, but I expect it isn't the slate, but the supporting wood that has deformed.

In the end, it all adds up to the same. Get a suitable length straight-edge and measure the sag. Shim appropriately on the support structure to flatten (as opposed to leveling) the slate.
 
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I guess I'll get in.

There's many threads in the Mechanics forum on slates moving and how its corrected.

Did you know that glass is a liquid?

Oh Geezzz. Here it comes.

BTW it seems Verhoeven had a similar issue years ago and now have extra steel supporting at each end.
Those slates are 50mm thick.

Its not about how thick the slate is, its about how well supported.
 
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DeeDeeCues said:
You are describing the phenomenon of 'plastic creep', which is deformation due to long term stresses applied to a material. These stresses are under the yield stress of the material, but due to being applied for long duration can change the shape of a piece.

I don't think stone like slate usually creeps. I would expect that slate on a valley table would sag under it's own weight if simply supported on the edges. Thus, I agree with the plastic deformation you describe, but I expect it isn't the slate, but the supporting wood that has deformed.

In the end, it all adds up to the same. Get a suitable length straight-edge and measure the sag. Shim appropriately on the support structure to flatten (as opposed to leveling) the slate.
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Not my table, I own a nine foot Anniversary table.
 
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The table I played on most often for a while was a GC3 at Shoreline Billiards in Mountain View, California. (Table 4, for regulars.) The slates were not doweled. The foot section became hump-backed so both sides would roll towards the cushion. Also, you could see where the seam stuck up in the middle of the table. John Wright, a local table mechanic, drilled through the slate and put a long screw in so he could pull the middle of the slate back down. I have no idea if that was the right way to do it, but it worked.

A small nitty point... The two characteristics you need are "flat" and "level". A flat surface could have a 10-degree slope. Flat means the surface is all in one plane. Level means that the surface is perpendicular to a line drawn to the center of the Earth. A slate that is not flat cannot be level. Parts of it can be level but not the whole slate. In the case of Table 4, two of the slate sections might have been both flat and level but the foot section was neither.
 
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Bob Jewett said:
The table I played on most often for a while was a GC3 at Shoreline Billiards in Mountain View, California. (Table 4, for regulars.) The slates were not doweled. The foot section became hump-backed so both sides would roll towards the cushion. Also, you could see where the seam stuck up in the middle of the table. John Wright, a local table mechanic, drilled through the slate and put a long screw in so he could pull the middle of the slate back down. I have no idea if that was the right way to do it, but it worked.

A small nitty point... The two characteristics you need are "flat" and "level". A flat surface could have a 10-degree slope. Flat means the surface is all in one plane. Level means that the surface is perpendicular to a line drawn to the center of the Earth. A slate that is not flat cannot be level. Parts of it can be level but not the whole slate. In the case of Table 4, two of the slate sections might have been both flat and level but the foot section was neither.
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A nittier point. In engineering, everything has a tolerance. In reality, nothing is truly 'flat', or truly 'level'--you show me something flat or level and I can show you a measuring device that can prove it isn't either. A non-flat surface may indeed be level, based on how it is specified. Level can be 'best fit' based off of a system of measurements, 'three-point', based off of designated points, or other different complex criteria.

Flat will also have specifications. Simply, flat may be +/-. More complicated, flat may be +/-, with a not-to-exceed in any given area.

For instance, I used to work on precision cnc machines that had plates with a flatness tolerance of 0.001", not to exceed 0.0005" in any 6", in a constrained condition. Takes some expensive equipment and good machinists to make. Also takes expensive inspection equipment to verify.

So, what is the criteria for a pool table? Simply that the balls roll true to some specification. For most people, it is enough to say that they visually roll true. Probably some standard somewhere. What does that mean in regards to actually calling out inspection dimensions? I don't know.
 
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DeeDeeCues said:
... So, what is the criteria for a pool table? Simply that the balls roll true to some specification. For most people, it is enough to say that they visually roll true. Probably some standard somewhere. ...
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Here is part of the Equipment specifications from the WPA....

4. SLATES
The thickness must be at least 1 inch [2.54 cm], and the playing surface must be capable, either by its own strength or a combination of its strength and that of the table base frame, of maintaining an overall flatness within + .020 inches [.508 mm] lengthwise and + .010 inches [.254 mm] across the width. Further this surface should have an additional deflection not to exceed .030 inches [.762 mm] when loaded with a concentrated static force of 200 pounds [90.7 kg] at its center. All slate joints must be in the same plane within .005 inch [.127 mm] after leveling and shimming.
 
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Bob Jewett said:
Here is part of the Equipment specifications from the WPA....

4. SLATES
The thickness must be at least 1 inch [2.54 cm], and the playing surface must be capable, either by its own strength or a combination of its strength and that of the table base frame, of maintaining an overall flatness within + .020 inches [.508 mm] lengthwise and + .010 inches [.254 mm] across the width. Further this surface should have an additional deflection not to exceed .030 inches [.762 mm] when loaded with a concentrated static force of 200 pounds [90.7 kg] at its center. All slate joints must be in the same plane within .005 inch [.127 mm] after leveling and shimming.
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Nice, but poorly written. They are calling a 'flatness' and really seem to be defining 'level' when the length deviation is double the width deviation.

It's a realistic, but incomplete and imprecise specification. It works because the manufacturers provide slates that are ground smooth (presumably flat, though, as you described, the flatness can be compensated for, if one gets creative).

It's pedantic, I know.
 
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DeeDeeCues said:
Nice, but poorly written. They are calling a 'flatness' and really seem to be defining 'level' when the length deviation is double the width deviation.

It's a realistic, but incomplete and imprecise specification. It works because the manufacturers provide slates that are ground smooth (presumably flat, though, as you described, the flatness can be compensated for, if one gets creative).

It's pedantic, I know.
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You must be fun at parties. ;)
 
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akadansmith said:
i had a professional company install the felt
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My first table was a Olhausen 3 pc, bought new & installed to perfection. When it needed recovered I got the same people to do it. * Came out perfect again . Needed recovered again & couldn’t get the exact same people anymore. I moved and sold table. Had it 20 years. Now 17 years after that I just acquire a refurbished Valley with 860 HR & new penguin rails. From a “Professional company “
Noticed right off cloth wasn’t stretched evenly. If I wasn’t so desperate for a table I suppose I could have refused delivery. Slow rolls near some pockets and rails are a bit wonky at times . The 860HR is a very heavy cloth and I can believe it definitely a factor if not stretched evenly. The only mechanic I’ve found in my area is not a One pc valley expert. I will pick up a 12” mechanics level at some point but I know will not fix the cloth.
I hope we can both get get our tables up to an acceptable level
Best of luck

* Due to knowing how good a table can play this has probably jaded me for life
 
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akadansmith said:
i have a 7 foot valley bar box. table is completely level. when i slow roll a ball to the corner pockets they seem to roll away from pocket is this from a slate thats warped or could it be from the felt bunched up under pocket? any help would be greatly appreciated.
Click to expand...
Or the frame is twisted. How does he know it is "completely level"?
 
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Bob Jewett said:
The table I played on most often for a while was a GC3 at Shoreline Billiards in Mountain View, California. (Table 4, for regulars.) The slates were not doweled. The foot section became hump-backed so both sides would roll towards the cushion. Also, you could see where the seam stuck up in the middle of the table. John Wright, a local table mechanic, drilled through the slate and put a long screw in so he could pull the middle of the slate back down. I have no idea if that was the right way to do it, but it worked.

A small nitty point... The two characteristics you need are "flat" and "level". A flat surface could have a 10-degree slope. Flat means the surface is all in one plane. Level means that the surface is perpendicular to a line drawn to the center of the Earth. A slate that is not flat cannot be level. Parts of it can be level but not the whole slate. In the case of Table 4, two of the slate sections might have been both flat and level but the foot section was neither.
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Shoreline Billiards in now out of business?
 
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