Using a lazer to level slates?

Tomster

Registered
I live in Thailand and have seen maybe 100 or so pool table install over the last 10 years.

One of the main install crews here level their slates with a lazer, like this one:

https://www.boschtools.com/us/en/boschtools-ocs/line-lasers-gcl-25-123123-p/

GCL_25_Hero_11.png


They attach a piece of paper to the side of the bondo can, and this has a horizontal line on it. They then move the can around the slates and adjust/add shims it until the line is in the right place everywhere across the slates.

The tables they install always play well, but I have never gone in with a Starrett level and checked how accurate they are. They mostly install Brunswicks, and have been doing so for over 15 years, so they must be doing something right.

But, when I search on this forum, there doesn't seem to be any mention of this, which seems strange. There must be a reason why the mechanics here don't ever use lazers to level slates - what am I missing?

Thanks in advance,

Tom.
 

realkingcobra

Well-known member
Silver Member
I live in Thailand and have seen maybe 100 or so pool table install over the last 10 years.

One of the main install crews here level their slates with a lazer, like this one:

https://www.boschtools.com/us/en/boschtools-ocs/line-lasers-gcl-25-123123-p/

GCL_25_Hero_11.png


They attach a piece of paper to the side of the bondo can, and this has a horizontal line on it. They then move the can around the slates and adjust/add shims it until the line is in the right place everywhere across the slates.

The tables they install always play well, but I have never gone in with a Starrett level and checked how accurate they are. They mostly install Brunswicks, and have been doing so for over 15 years, so they must be doing something right.

But, when I search on this forum, there doesn't seem to be any mention of this, which seems strange. There must be a reason why the mechanics here don't ever use lazers to level slates - what am I missing?

Thanks in advance,

Tom.

All you have to do is check the level of the pool table with a starrett level and you'll have your answer.
 

Tomster

Registered
Would it really be that far off? As long as the cloth is properly stretched the tables they install play perfectly - like really spot on. Most of the big name pool halls here in Thailand use these guys to level their tables (including quite a few Gold Crown V's) and are quite happy with them, not a Starrett to be seen. Which is why I'm so surprised that I can't find any mention of it anywhere eles on the internet, it seems weird.

Anyway, I plan to buy a 8" Starrett (unless there is a better size to get) and a laser to see how they compare, I'll post the results here.:)
 

kid

billiard mechanic
Silver Member
A starrett will show you if you are off the thickness of a dollar bill.. i doubt you can be that precise aligning a 1/8" thick beam of light on a line on a can


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realkingcobra

Well-known member
Silver Member
A starrett will show you if you are off the thickness of a dollar bill.. i doubt you can be that precise aligning a 1/8" thick beam of light on a line on a can


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Not to mention the fact that when trying to level the frame of the table, you're also moving the base in which the level is sitting on therefore changing the level readings.
 
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Renegade_56

AzB Silver Member
Silver Member
A proper tool for everything. A laser shows a line that is uniform with whatever angle the laser is sitting on, while a level shows,,,,,,,, level.
 

bradsh98

Bradshaw Billiard Service
Silver Member
A proper tool for everything. A laser shows a line that is uniform with whatever angle the laser is sitting on, while a level shows,,,,,,,, level.

The type of laser that is referenced is self-leveling, so the line is always horizontal. In other words, the projected laser plane will always be level.
 

mchnhed

I Came, I Shot, I Choked
Silver Member
Most of the big name pool halls here in Thailand use these guys to level their Brunswick tables, including quite a few Gold Crown V's.
Authentic Brunswick Gold Crown V's?
Must be a nice place.
What are the names and locations of these Billiards Rooms?

Maybe you were looking at the New Gold Crown VI's?
 

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realkingcobra

Well-known member
Silver Member
The type of laser that is referenced is self-leveling, so the line is always horizontal. In other words, the projected laser plane will always be level.

What is failed to be recognised is the fact that if that level is sitting in the center of the table, and you're using reference marks for level on a can, and even if you get all 4 corners level, what happens to your refference lines if the table is swayback and the center slate has to be raised up, don't that in fact change all your refference marks ro read different?
 

realkingcobra

Well-known member
Silver Member
Would it really be that far off? As long as the cloth is properly stretched the tables they install play perfectly - like really spot on. Most of the big name pool halls here in Thailand use these guys to level their tables (including quite a few Gold Crown V's) and are quite happy with them, not a Starrett to be seen. Which is why I'm so surprised that I can't find any mention of it anywhere eles on the internet, it seems weird.

Anyway, I plan to buy a 8" Starrett (unless there is a better size to get) and a laser to see how they compare, I'll post the results here.:)

The reason you can't find anything on the enet to read about it, is because it's primitive at best, carpenter levels would be more accurate and faster.
 

bradsh98

Bradshaw Billiard Service
Silver Member
What is failed to be recognised is the fact that if that level is sitting in the center of the table, and you're using reference marks for level on a can, and even if you get all 4 corners level, what happens to your refference lines if the table is swayback and the center slate has to be raised up, don't that in fact change all your refference marks ro read different?

I'm not suggesting that using one of these lasers is ideal for leveling a pool table, though I do have quite a bit of experience using one (for construction projects). If someone were to use one, they would immediately realize that it would have to be placed at one end of the table (on a stationary platform), for the reason that you mentioned, and also because the laser is only visible in one direction.
 

kid

billiard mechanic
Silver Member
For me it goes like this:
Using a laser to level slates is as good as using a hammer to drive in screws


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realkingcobra

Well-known member
Silver Member
I'm not suggesting that using one of these lasers is ideal for leveling a pool table, though I do have quite a bit of experience using one (for construction projects). If someone were to use one, they would immediately realize that it would have to be placed at one end of the table (on a stationary platform), for the reason that you mentioned, and also because the laser is only visible in one direction.

That's my point, building a house using a machinist level would never work either as wood has to many flaws in it to try and maintain any accuracy.
 

Tomster

Registered

Authentic Brunswick Gold Crown V's?
Must be a nice place.
What are the names and locations of these Billiards Rooms?

Maybe you were looking at the New Gold Crown VI's?

That picture is from Players on one of their Metro's, obviously.

The Sportsman has used laser levelled tables since it started in 2009. Many other bars and pool halls do as well, but as I am not directly involved with them it would be inappropiate of me to post names here.

I'm not trying to defend or promote the technique in any way, it's just that it's so common here I wondered why I couldn't find any reference to it anywhere else on the internet. I've even seen a retailer here refer to their tables as being "laser levelled", it's that normal.

In reference to another comment above, the level sits off to the side, not on the slate. They measure multiple points around the slate, I guess they look to get the line in the centre of the 1/8" beam.

Anyway, I am off to buy a Starrett 98-8 later today and will use the method RKC shows in the sticky to level the table on Sunday. I must admit my brain started to melt a bit when I realised that the table I will be installing only has 2 long beams not 3 as in the instructions (and therefore no C value levelling point), but there was enough info in the rest of the document to hopefully get past that.

Thanks,

Tom.
 

tjohnson

AzB Silver Member
Silver Member
The advertised accuracy of laser levels varies according to price (not surprising) but the ~$300 levels claim to have accuracies that are similar to Starrett levels, around 0.005" per foot. So if this accuracy is true, then as others have mentioned it comes down to the beam width. I couldn't find any mention of beam width in the specifications for the few different laser levels that I looked at online. I played around with a cheap $3 laser pointer and the width of the spot was easily 1/8" when I shone it onto a wall that was about 4' away and it got wider with increasing distance. Unless you could confidently place your mark at the top of the beam, this 1/8" width seems like a fatal flaw. I'm curious if anyone has tried measuring the beam width on a real laser level and whether or not one could confidently place a mark at the top of the beam. The spot from my laser pointer had pretty diffuse edges and I would have been hard pressed to confidently (and repeatedly) locate a mark at the same location within the laser spot.
 

fastone371

Certifiable
Silver Member
I have a rather costly laser level that has like a 1/16" dot from a couple feet up to at least 15'-20'. The problem as I see it is that a machinist level is accurate to somewhere around .005, its hard to measure 64ths of an inch with a nice straight edge, what do you use for a target that you can accurately read down to 1/100th of an inch which is not really close to a machinist level?
 

tjohnson

AzB Silver Member
Silver Member
I have a rather costly laser level that has like a 1/16" dot from a couple feet up to at least 15'-20'. The problem as I see it is that a machinist level is accurate to somewhere around .005, its hard to measure 64ths of an inch with a nice straight edge, what do you use for a target that you can accurately read down to 1/100th of an inch which is not really close to a machinist level?

That's a good way to look at it. A machinist level can detect a slope of 0.02 degrees over the length of the level, say 8". Assuming you need a 1/64" elevation difference to be detectable on a laser level (best-case scenario) that elevation change requires a uniform slope of 0.02 degrees for over 3 feet. If each individual slab of a 3-piece slate was perfectly planar, then a laser level might work as well as a machinist level. But they aren't, so it won't.

Machinist levels (in this context) are superior to laser levels because they are amplifiers: They take a small displacement and amplify that displacement through the bubble level so that 0.005" of displacement appears as 1/8" of bubble motion, which is easily discernible. Laser levels do not have the amplification effect - if you need to detect 0.005" of displacement you need to be able to discern 0.005" with your naked eye, as Fastone pointed out.
 
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Tomster

Registered
In the end I bought a Bosch GLL 3-80 - accurate to 0.2mm per meter. So if I place it by the side pocket, the receiver will never be more that 2 metres away from the lazer - max 0.4mm variance, according to the manufacturer specs.

But as mentioned above the thing that the beam shines on is very important as the width of the beam is around 3mm (1/8"). I've tried several different types of receptor material, so far white plastic pipe with a black line around it works ok but suffers from glare. sometimes the black line just dissapears.

I think you need a material that will absorb some of the red light, and make the black line stand out, I also think you need two black lines, one at the top of the beam and one at the bottom to give you better reference. Or possibly something made with projector screen tape that absorbs light, could work.

I undertsand Starrett levels are more accurate, but with the laser if you have multiple receivers you can a quick visual guide to the levelness of the slate that would take a fair bit of figuring out with a Starrett level. So they are useful in a different way, not better.
 

tjohnson

AzB Silver Member
Silver Member
I've tried several different types of receptor material, so far white plastic pipe with a black line around it works ok but suffers from glare. sometimes the black line just dissapears.

Would it be possible to cut a narrow slot into the plastic pipe and use that as the mark instead of a black line? Then when the beam hits it, it just disappears into the pipe and won't reflect.
 
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