What angle for rubber cushions ???

[MamboFats]

Goodmorning all,

Regarding the dimensions of pool table cushions I found these graphics online.
The first shows a 20° angle for glueing the cushion, the other graphic of the ARtemis brand I imported in Fusion360 and it measures a ±23°.
The third graphic shows a 45° angle on the bottom side of the cushion (should translate to 15° on the inside rail)

Is there a good/better/best angle ?
Does it depend on manufacturer (Artemis is easily available for me) ?
Can anyone clarify this for me?

thx for your help

Alain

 

[bradsh98]

Goodmorning all,

Regarding the dimensions of pool table cushions I found these graphics online.
The first shows a 20° angle for glueing the cushion, the other graphic of the ARtemis brand I imported in Fusion360 and it measures a ±23°.
The third graphic shows a 45° angle on the bottom side of the cushion (should translate to 15° on the inside rail)

View attachment 614517 View attachment 614518 View attachment 614519

Is there a good/better/best angle ?
Does it depend on manufacturer (Artemis is easily available for me) ?
Can anyone clarify this for me?

thx for your help

Alain

 

[rexus31]

What's ideal? 22.5 degrees?

 

[MamboFats]

If I follow the recommended specifications on wpapool.com,
the height of the point of the cushion should be 63.5% (±1%) of the ball size

62.5% of 2.25" = 1.40625"
63.5% of 2.25" = 1.42875"
64.5% of 2.25" = 1.45125

So according to these 3 graphics, with the given subrail height of 1.688"
21.5° => 1.404" => too low
22.5° => 1.424" => very close to specifications
23.5° => 1.444" => within the tolerance of the specifications

Given the fact that 22.5° is half of 45° or ¼ of 90°, there is a good chance cutting equipment may have a setting for this. I think this is the way to go.

On that WPA page I do not find any size or height for the complete rail itself.
I know there are tables with completely flat rails, others have a small downward bend towards the outside.
Does anyone know of a rule for this, or can I just add the thickness of a stretched cloth (let's say, 1 millimeter, about 0.4" or 3/64")

thx for all your input

I'm really getting excited for the next steps coming close in the next months.
But also knowing, once it gets to be december and january, time will hard to find.
Not worrying, my production schedule focuses on the legs during the winter, the rails in spring, the frame in summer and assembly with the slate maybe this time next year.

Spreading the funding, spreading the fun...

 

[bradsh98]

What's ideal? 22.5 degrees?

It's really a matter of opinion, but it is dictated by the other variables in the design.

The angle used is determined by the height of the sub-rail. Different thickness sub-rails will require different nose heights, in order to play correctly. But, even playing "correctly" is a matter of opinion.

Speaking specifically to this table, with its very rigid design:
If using a 1 11/16" thick sub-rail with Artemis K55 cushions, you will want to have a nose height that is slightly higher than 1 7/16", or around 64.5% of the ball.

When I cut Brunswick rails, I use the same angle, regardless of the cushion. I set the nose height as close as possible to 64% (1.44"). The design of a Gold Crown is nowhere near as rigid as a Diamond, so a slightly lower nose height helps to mimic the response of a Diamond.

 

[realkingcobra]

It's really a matter of opinion, but it is dictated by the other variables in the design.

The angle used is determined by the height of the sub-rail. Different thickness sub-rails will require different nose heights, in order to play correctly. But, even playing "correctly" is a matter of opinion.

Speaking specifically to this table, with its very rigid design:
If using a 1 11/16" thick sub-rail with Artemis K55 cushions, you will want to have a nose height that is slightly higher than 1 7/16", or around 64.5% of the ball.

When I cut Brunswick rails, I use the same angle, regardless of the cushion. I set the nose height as close as possible to 64% (1.44"). The design of a Gold Crown is nowhere near as rigid as a Diamond, so a slightly lower nose height helps to mimic the response of a Diamond.

Seems like you're the only one posting that knows what he's talking about

 

[realkingcobra]

If I follow the recommended specifications on wpapool.com,
the height of the point of the cushion should be 63.5% (±1%) of the ball size

62.5% of 2.25" = 1.40625"
63.5% of 2.25" = 1.42875"
64.5% of 2.25" = 1.45125

So according to these 3 graphics, with the given subrail height of 1.688"
21.5° => 1.404" => too low
22.5° => 1.424" => very close to specifications
23.5° => 1.444" => within the tolerance of the specifications

Given the fact that 22.5° is half of 45° or ¼ of 90°, there is a good chance cutting equipment may have a setting for this. I think this is the way to go.

On that WPA page I do not find any size or height for the complete rail itself.
I know there are tables with completely flat rails, others have a small downward bend towards the outside.
Does anyone know of a rule for this, or can I just add the thickness of a stretched cloth (let's say, 1 millimeter, about 0.4" or 3/64")

thx for all your input

I'm really getting excited for the next steps coming close in the next months.
But also knowing, once it gets to be december and january, time will hard to find.
Not worrying, my production schedule focuses on the legs during the winter, the rails in spring, the frame in summer and assembly with the slate maybe this time next year.

Spreading the funding, spreading the fun...

You can take that 63 1/2% of the ball thickness and throw it out because it only applies to sub rails being 1 11/16" thick. Try that on an Olhausen and see what happens! Don't give advice if you don't know what you're talking about, its better to keep your advice to your own work!

 

[n10spool]

also have take into account the thickness of the rails height wise.how would you adjust 1-1\2" to 2" thick rails? how to adjust for u23,k66 or k55 profile rubber and slight differences for manufacturer mold issues? when would you use cloth and non cloth reinforced rubber and durometer rating of rubber?

This could turn into a good conversation its also a can of worms on how to adjust from brand to brand of table.

 

[MamboFats]

Additional graphics found online:

I am confused by these first 3 pictures: with an angled placement (like the 1st picture) there should be a difference between height of the cushion and the size of that side of the cushion (second picture).
It's pretty clear that the internet provides alternative truths ...

Which one is true?

This Artemis N°66 cushion is supposed to be a K55-profile.
But other dimensions than above.

This is a profile of a Dymondwood rail

 

[MamboFats]

The difficulty in drawing/designing my rails with perfect dimensions is the lack of precise details on the rails.
Plus, they are not a perfect equilateral triangle.

An earlier post of RKC in another topic:
To get the maximum play ability of the K55 cushions, the back height of the cushions must be at 1 11/16", then nose down to 1 7/16". This puts the maximum energy of the cushions behind the nose height like they're designed to be. This fix you did reminds me of another table mechanic that replaced the cushions on several GC3's and ended up with the nose height being to low.

 

[The_JV]

The difficulty in drawing/designing my rails with perfect dimensions is the lack of precise details on the rails.
Plus, they are not a perfect equilateral triangle.

Perhaps you should choose your profile, buy the cushions, and then develop the rails based on real world measurements...?

If I was concerned about building rails correctly. This is the approach I would follow.

 

[realkingcobra]

Perhaps you should choose your profile, buy the cushions, and then develop the rails based on real world measurements...?

If I was concerned about building rails correctly. This is the approach I would follow.

Here's the problem with that, as rail thicknesses vary, so must the cushion nose height, if you want to maintain maximum playability. So now, what is the correct nose height of the cushions on a subrail 1 1/2" thick? Its not 1 7/16"

 

[The_JV]

Here's the problem with that, as rail thicknesses vary, so must the cushion nose height, if you want to maintain maximum playability. So now, what is the correct nose height of the cushions on a subrail 1 1/2" thick? Its not 1 7/16"

...but if you have a piece of cushion and all other variables can be altered to match it's specifics then aren't you in the best position to build rails to suit..?

You cite vary rail thickness screwing with nose height. Well if you start the design from the desired nose height, then you can determine subrail bevel, and then finally thickness... yes/no?

If I couldn't bank on manufacture dimensions to be accurate, then I'd rather reverse engineer from the one most critical point, aka: nose height.

1) Subrail bevel to align nose position relative to cushion back compression characteristics
2) Rail thickness to create nose height based on step 1.

 

[realkingcobra]

...but if you have a piece of cushion and all other variables can be altered to match it's specifics then aren't you in the best position to build rails to suit..?

You cite vary rail thickness screwing with nose height. Well if you start the design from the desired nose height, then you can determine subrail bevel, and then finally thickness... yes/no?

If I couldn't bank on manufacture dimensions to be accurate, then I'd rather reverse engineer from the one most critical point, aka: nose height.

1) Subrail bevel to align nose position relative to cushion back compression characteristics
2) Rail thickness to create nose height based on step 1.

Problem is, no cushion manufacturers can tell you what the maximum playability of their cushions are, unless you first provide them with your rail thickness. On that basis, a set of K66 or K55 cushions can be adapted to fit any thickness of rails, BUT that don't nessasarly mean that the cushions will play at their best, it only means the balls will bounce off the cushions. The question THEY need to answer, is at what thickness of rail, combined with what nose height, and what cloth used, will YOUR cushions play at their BEST?

 

[realkingcobra]

Believe it or not, the cloth on the rails can influence how the rails play and react.

 

[realkingcobra]

The density of the cushions, harder/softer, also influence how they bank, their rebound speed, the whole 9 yards. So keep that in mind when deciding to design your own rails, because table manufacturers don't!

 

[realkingcobra]

How much of the nose of the cushions come into contact with the balls also influence how the rails react. Cushion that come to a sharp point provide less cue ball spin angle off them compared to cushions with a more rounded, blunt nose, because they provide more contact to the cue ball, the cue ball spin angle will increase more wider.

 

[MamboFats]

An earlier post of RKC in another topic:
To get the maximum play ability of the K55 cushions, the back height of the cushions must be at 1 11/16", then nose down to 1 7/16". This puts the maximum energy of the cushions behind the nose height like they're designed to be. This fix you did reminds me of another table mechanic that replaced the cushions on several GC3's and ended up with the nose height being to low.

so, here's a little sketch of these height dimensions
1 7/16 inch = 36.50 mm
1 11/16 inch = 42.90 mm

The thickness of my naked, glued up rail = 46 mm
I plan on routing a little curve just something like the profile in this picture

And like @The_JV says, with these dimensions and upon arrival of the cushions I ordered, I will be able to make all the right cuts to make the rails.

 

[The_JV]

Problem is, no cushion manufacturers can tell you what the maximum playability of their cushions are, unless you first provide them with your rail thickness. On that basis, a set of K66 or K55 cushions can be adapted to fit any thickness of rails, BUT that don't nessasarly mean that the cushions will play at their best, it only means the balls will bounce off the cushions. The question THEY need to answer, is at what thickness of rail, combined with what nose height, and what cloth used, will YOUR cushions play at their BEST?

ah gottcha...

 

[realkingcobra]

so, here's a little sketch of these height dimensions
1 7/16 inch = 36.50 mm
1 11/16 inch = 42.90 mm

View attachment 648124

The thickness of my naked, glued up rail = 46 mm
I plan on routing a little curve just something like the profile in this picture

And like @The_JV says, with these dimensions and upon arrival of the cushions I ordered, I will be able to make all the right cuts to make the rails.

I thought you said you had a GC1, those rails are 1.75 thick from the bottom of the rails, to the top of the formica, right at the edge of the feather strip dado. Yet you're saying your rails are 1 13/16" thick. The only way they could be that this is if you installed another layer of formica on top of the pre-existing formica.