All bar boxes. Valley/Dynamo
How level is "level" for pool tables?
- Thread starter jviss
- Start date
My bad. I did not realize we were talking about bar tables.
We were talking about pool tables. Bar boxes do qualify as such.
Kind of. MaybeWe were talking about pool tables. Bar boxes do qualify as such.
redcordes
New member
It is an excellent concrete slab. As far as the level sensitivity, I am saying a machinist level is way too sensitive. As I said early, as long as the machinist level bubble isn't bottomed out at either end of the vial, it's plenty good enough--which I would say is about 3 or 4 thousandths per 12 inches. My assessment is just passing on what I have learned.
redcordes
New member
..also when you talk about level sensitivity/acurracy, you need 2 numbers, right? Rise vs. run for you construction guys. Pitch, slope, whatever you would like to call it. Saying a level is acurrate to .001 inches for instance is nonsense. Over what length?
What table do you have?
tomatoshooter
Well-known member
Most decent construction levels are accurate to half a thou per inch or .5mm per meter. The problem is that most levels do not have the resolution to be read that accurately. I couldn't find out how accurate or the resolution of a machinist level but I'm sure it offers a higher level of precision.
Starrett 98 Machinist Levels are 0.005" per foot. "Main level vials have graduations that are approximately 80-90 seconds or .005" per foot (0.42mm per meter)". See https://www.starrett.com/metrology/product-detail/98-12 . I believe these are the standard levels for table work. Not sure that any of my "construction levels" approach that precision (I have compared them durectly).
Starrett 199 Master Precision Levels are 10x as precise : "Ground and graduated main vial of 10-second accuracy; one division equals 1/2 thousandth (0.0005) of an inch per foot, or 0.04mm per meter". See https://www.starrett.com/metrology/product-detail/199Z. These things are so sensitive they move if you look at them ... or as Glen says if you walk by the table. I can't imagine anyone remaining sane after using one to level a pool table.
Dave
And again, what pool table do you own?
tomatoshooter
Well-known member
I'm sure your construction levels do not approach that accuracy, it would be impossible to get anything that level on a job site, or even find anything with a flat enough surface that 1/2 thou per foot can realistically be measured.
Obligatory Rick and Morty link anytime folks argue about level.
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You have me confused. In post 209 you say "Most decent construction levels are accurate to half a thou per inch or .5mm per meter. " (bolding for emphasis) .... 0.0005" per inch converts to 0.006" per foot, very close to the accuracy of a MACHINIST level. I know that CONSTRUCTION levels are not anywhere near as precise as machinist level.
Perhaps your post 209 was about MACHINISTs level rather than CONSTRUCTION levels.
Dave <-- has a few Starrett 98's ... and a Starrett 133A
along with other levels.
boogieman
It don't mean a thing if it ain't got that ping.
Imagine my frustration when I'm trying to level a 7' valley after a league night and they won't quit leaning on the table from both sides to get a close look at the level.
I started out with a table with 17 beer coasters and 3 easy slide furniture movers under the feet to make it "level". The legs were all fully extended, one just sitting on the threads (not engaged at all). One leveler bolt bent severely so the foot only touches on one point and is in no way flat to the floor.
I got the table to under one mark (starrette) side to side and 3 marks end to end. I wasn't satisfied but they wouldn't listen, no jack and at this point it's 100X better than it was.
Owner won't buy anything to fix the bent leveler. It's frustrating because if I had 30 minutes by myself and a bottle jack I could have got the table as perfect as possible with a bent leveler bolt but everybody and their brother was suddenly an expert at reading a machinist level while leaning on the table at the same time.
I would have put 3/4" round plywood spacers under the leg levelers so they could have been screwed back up i to the legs far enough to not rish being bent, just sayingImagine my frustration when I'm trying to level a 7' valley after a league night and they won't quit leaning on the table from both sides to get a close look at the level.
I started out with a table with 17 beer coasters and 3 easy slide furniture movers under the feet to make it "level". The legs were all fully extended, one just sitting on the threads (not engaged at all). One leveler bolt bent severely so the foot only touches on one point and is in no way flat to the floor.
I got the table to under one mark (starrette) side to side and 3 marks end to end. I wasn't satisfied but they wouldn't listen, no jack and at this point it's 100X better than it was.
Owner won't buy anything to fix the bent leveler. It's frustrating because if I had 30 minutes by myself and a bottle jack I could have got the table as perfect as possible with a bent leveler bolt but everybody and their brother was suddenly an expert at reading a machinist level while leaning on the table at the same time.
boogieman
It don't mean a thing if it ain't got that ping.
The thing was, the floor wasn't that bad, concrete floor too. The last guy just defaulted to screwing them all the way up. I'd rather find the high spot with them all mostly screwed in (not all the way, but close) and then raise the other to get level. This was like they started them almost fully extended and kept extending them.I would have put 3/4" round plywood spacers under the leg levelers so they could have been screwed back up i to the legs far enough to not rish being bent, just saying
One leveler should be screwed all the way up and not touched at all, then only the other 3 get adjusted.The thing was, the floor wasn't that bad, concrete floor too. The last guy just defaulted to screwing them all the way up. I'd rather find the high spot with them all mostly screwed in (not all the way, but close) and then raise the other to get level. This was like they started them almost fully extended and kept extending them.
tomatoshooter
Well-known member
48" & 24" I-Beam Levels - 2 Pack | Empire Level - Built On Trust
The Empire® 48" & 24" I-Beam Level 2 Pack features .0005"/inch accuracy in all working positions with impact resistant vials.
www.empirelevel.com
".0005"/inch accuracy in all working positions"
Construction levels lack the graduations to be read effectively to that level of precision, at least with mere mortal vision, but it is there. I just checked my 4' level, and a dime under one end (approx .050") is the smallest increment that I would consider visible in good light and a clear viewing angle and a bit optimistic in the field. That's about .001"/inch. That's beyond the level of precision necessary on a typical jobsite. A machinists' level would be at the end of its range until your surface is so close to level that it would be difficult to use, in addition to the surfaces not being flat enough that that level of precision is meaningful. They are both approaching the limits of some juice in a vial.
Empire had a page on their website that discussed accuracy and precision but I can't find it since the redesign. Another way to think about it is if I had a ruler marked in 1/8" increments. The increments could be marked with an accuracy of .0001" but I certainly couldn't actually measure something with that level of precision.
Let me explain something to you, then maybe you'll have a better understanding as to why machinist levels are important when leveling a slate on a pool table. First off, with your long levels you bridge the slate by 4' which means you can't read the levelers on a Diamond table, because you're spanning 4 levelers at a time with that level. An 8" machinist level can read the slate between the levelers, allowing you to adjust, fine tune the level of the slate using the 18 levelers on the frame. And in the event you don't think slate can be flexed to achieve level, you have no business in this conversation!48" & 24" I-Beam Levels - 2 Pack | Empire Level - Built On Trust
The Empire® 48" & 24" I-Beam Level 2 Pack features .0005"/inch accuracy in all working positions with impact resistant vials.
".0005"/inch accuracy in all working positions"
Construction levels lack the graduations to be read effectively to that level of precision, at least with mere mortal vision, but it is there. I just checked my 4' level, and a dime under one end (approx .050") is the smallest increment that I would consider visible in good light and a clear viewing angle and a bit optimistic in the field. That's about .001"/inch. That's beyond the level of precision necessary on a typical jobsite. A machinists' level would be at the end of its range until your surface is so close to level that it would be difficult to use, in addition to the surfaces not being flat enough that that level of precision is meaningful. They are both approaching the limits of some juice in a vial.
Empire had a page on their website that discussed accuracy and precision but I can't find it since the redesign. Another way to think about it is if I had a ruler marked in 1/8" increments. The increments could be marked with an accuracy of .0001" but I certainly couldn't actually measure something with that level of precision.