Question about the Ring estimator
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Joined: July 11, 2010
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Location: Cave Junction, Oregon, USA

Question about the Ring estimator
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Posted on Wed Aug 11, 2010 8:03 pm
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Ok so i tried to use the ring estimator ( http://mailleartisans.org/articles/articledisplay.cgi?key=10080 ) that is on the site and i cannot seem to figure out how to use it properly. I only used one ring size (ring1) and nothing in the other and it gave me an odd read out. How in the world do you use that darn thing?


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Posted on Wed Aug 11, 2010 9:05 pm
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O.o

Never seen that article before... The explanation is a little... lacking... But let me try and elabourate.

The entire calculation is done with nondescript constants... Thus, you can pick whatever measuring system works for you, but keep it constant.

I chose Inches, since my head works best. And went to work on European 4 in 1 Full Expansion.

'Area to cover' I'm assuming is in Unit^2... Thus, I told it I wanted 20 Square Inches, thus: "20"
Ring Size ID, is the ID of you ring you're using... I decided on 1/4" rings, thus: ".25"

Area per Unit Cell says .125 which I don't understand, but that's fine. It also tells me that each Unit Cell is made of 2 rings... Uh, sure? Let's move on to the numbers we really want...
It says 160 Unit Cells... Well, since it thinks that a Euro 4 unit is made of two rings... The next number should be...
320... Yep...

Okay, so to sum up...
It's telling me that 20 square inches (A patch roughly 4"x5") of European 4 in 1, at full stretch, using 1/4" ID rings, should take roughly 320 rings.
Sounds about right Very Happy


My money's on the nondescript constants being the source of confusion.



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Posted on Thu Aug 12, 2010 3:22 am
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There is no way to use that calculator properly, for e4-1, the math is just plain wrong.

It might give the right results for j4-1 and j6-1 but the formula for e4-1 is junk unless you use an unrealistic aspect ratio.


www.mailletec.com

Y'know, that might just be crazy enough to work!

Joined: July 11, 2010
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Location: Cave Junction, Oregon, USA

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Posted on Fri Aug 13, 2010 3:08 am
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Daemon_Lotos wrote:

I chose Inches, since my head works best. And went to work on European 4 in 1 Full Expansion.

'Area to cover' I'm assuming is in Unit^2... Thus, I told it I wanted 20 Square Inches, thus: "20"
Ring Size ID, is the ID of you ring you're using... I decided on 1/4" rings, thus: ".25"

Area per Unit Cell says .125 which I don't understand, but that's fine. It also tells me that each Unit Cell is made of 2 rings... Uh, sure? Let's move on to the numbers we really want...
It says 160 Unit Cells... Well, since it thinks that a Euro 4 unit is made of two rings... The next number should be...
320... Yep...

Okay, so to sum up...
It's telling me that 20 square inches (A patch roughly 4"x5") of European 4 in 1, at full stretch, using 1/4" ID rings, should take roughly 320 rings.
Sounds about right Very Happy


My money's on the nondescript constants being the source of confusion.


thank again DL......your thought were about the same as mine except you added the step i missed (doubling the ring number).

Lorenzo it wasnt asking for AR it asks for ID....... i misread it first too and put in the AR


we all walk to the same end, no matter what path we follow

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Posted on Fri Aug 13, 2010 4:14 am
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Yes I know, that's not what I meant.

The point is that the calculation doesn't consider aspect ratio at all, it assumes that all rings have the same aspect ratio.

In reality the area covered by 100 18g 3/8" rings is nowhere near the same as the area covered by 100 12g 3/8" rings.


www.mailletec.com

Y'know, that might just be crazy enough to work!

Joined: July 11, 2010
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Location: Cave Junction, Oregon, USA

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Posted on Fri Aug 13, 2010 4:18 am
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ok i understand what you were talking about now, it doesnt take the wire gauge into account so it really is not accurate. because the different wire gauges at the same size ID dont equal the same over-all area covered. Very Happy

At the same time though it is only and estimator... not an exact calculator.


we all walk to the same end, no matter what path we follow

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Posted on Sat Aug 14, 2010 5:47 pm
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The estimation thing is exactly the problem I'm having with it. People want an estimator so they know how many rings to order for a project.

If you plug your numbers into this calculator for a common e4-1 AR(3,4or5) you'll get a number of rings that is significantly LOWER than what you actually need. From what I can tell in some cases it's off by more than 10% so even if you're conservative with your estimate you might still run out of rings.

So pretty much everyone who relies on this "estimate" is going to come up just short on their project and probably need to order more rings, that means extra shipping expenses, making sure that the new rings match the old ones or maybe just another trip to the hardware store.


www.mailletec.com

Y'know, that might just be crazy enough to work!

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