I have been playing around, and learning as much as I can on my own from a spreadsheet that was credited to Mojo and A. Donaldson. Thanks to both of them for putting this spreadsheet together.

I think I have figured out the basics of it, but my fuzzy 20 year old math skills and zero experience graphing in a spreadsheet is not helping. Also, I am using Neo Office instead of Microsoft Excel. I don't know if this is an issue.

So I generally understand that the elliptical ratio affects the shape of the ellipse. a ratio of 1 means it's a circle fragment.

I believe that when the ratio is over 1, then the curve is more extreme on one axis, and under 1 the curve is more extreme on the other axis. True?

So, is the elliptical ratio on the spreadsheet related to the "+2" marking that Mojo puts on his mouthpieces? If so, how?

My guess is that "+2" means the elliptical ratio is 1.2 and "-1" would mean .9. Am I in the ballpark?

What is the practical range of possibilities for the elliptical ratio on a mouthpiece? Does a given ratio generally feel the same across the board (soprano alto tenor and bari), or are there different comfortable ranges for each instrument?

Also, is it possible to assign general characteristics that go along with a "+1" for example?

As for the spreadsheet, when a solver works properly (which I don't think mine is), I guess it is supposed to take the given data (tip opening, tip rail, elliptical ratio, feeler gage readings) to calculate a curve that fits the data best, and the results should include the actual (.0000 feeler) curve start, other feeler readings, and an elliptical radius.

Is this correct?

I have no idea how to fix the solver on this spreadsheet. Perhaps if I understand the other issues better I can figure out how to get it to work.

Thanks for any much needed help!

Sorry to double post but I realized one mistake I was making with my spreadsheet.
I accidentally deleted the formula in the Elliptical Radius box on some of my files.
It is making more sense now.
But I realize that my theory about the Mojo numbering system must be way off...
Please help...
Thanks!

--- In MouthpieceWork@yahoogroups.com, "Mike" <mike@...> wrote:
>
> I have been playing around, and learning as much as I can on my own from a spreadsheet that was credited to Mojo and A. Donaldson. Thanks to both of them for putting this spreadsheet together.
> 
> I think I have figured out the basics of it, but my fuzzy 20 year old math skills and zero experience graphing in a spreadsheet is not helping. Also, I am using Neo Office instead of Microsoft Excel. I don't know if this is an issue.
> 
> So I generally understand that the elliptical ratio affects the shape of the ellipse. a ratio of 1 means it's a circle fragment.
> 
> I believe that when the ratio is over 1, then the curve is more extreme on one axis, and under 1 the curve is more extreme on the other axis. True?
> 
> So, is the elliptical ratio on the spreadsheet related to the "+2" marking that Mojo puts on his mouthpieces? If so, how?
> 
> My guess is that "+2" means the elliptical ratio is 1.2 and "-1" would mean .9. Am I in the ballpark?
> 
> What is the practical range of possibilities for the elliptical ratio on a mouthpiece? Does a given ratio generally feel the same across the board (soprano alto tenor and bari), or are there different comfortable ranges for each instrument?
> 
> Also, is it possible to assign general characteristics that go along with a "+1" for example?
> 
> As for the spreadsheet, when a solver works properly (which I don't think mine is), I guess it is supposed to take the given data (tip opening, tip rail, elliptical ratio, feeler gage readings) to calculate a curve that fits the data best, and the results should include the actual (.0000 feeler) curve start, other feeler readings, and an elliptical radius.
> 
> Is this correct?
> 
> I have no idea how to fix the solver on this spreadsheet. Perhaps if I understand the other issues better I can figure out how to get it to work.
> 
> Thanks for any much needed help!
>

In my system, I use +4 to indicate an elliptical facing curve with an aspect ratio of a/b = 4.  This is the ratio of the major and minor axis of the ellipse.   It sounds like a lot compared to a circle, but the we are only using a small segment of the ellipse.

I find the +4 is good for medium large tip openings on alto, tenor and bari.  For very large tip openings, a radial +1 curve can make the large tip easier to blow along with a long facing length. Classical facings and sop sax facings work better with more resistance.  Like +8.  I tend to favor using medium long facing lengths and adding resistance with the ellipse shape.  

As you measure a lot of mouthpieces, you will find many variations.  I do not usually force them all the way to my preferences.  I tend to go part the way from where they are at towards what I like.  I steer them in that direction.  I do not want to shock the player too much if they are not looking for a big change.

The built-in solver feature is probably unique to Excel spreadsheets.  Even with Excel it is an add-on option that is installed on request.

I have a Power Point clinic presentation on my site.  If you can view it, it has some good ellipse illustrations and also some illustrations on some table flattening issues.

On Feb 21, 2013, at 4:26 PM, "Mike" <mike@...> wrote:

> Sorry to double post but I realized one mistake I was making with my spreadsheet.
> I accidentally deleted the formula in the Elliptical Radius box on some of my files.
> It is making more sense now.
> But I realize that my theory about the Mojo numbering system must be way off...
> Please help...
> Thanks!
> 
> --- In MouthpieceWork@yahoogroups.com, "Mike" wrote:
> >
> > I have been playing around, and learning as much as I can on my own from a spreadsheet that was credited to Mojo and A. Donaldson. Thanks to both of them for putting this spreadsheet together.
> > 
> > I think I have figured out the basics of it, but my fuzzy 20 year old math skills and zero experience graphing in a spreadsheet is not helping. Also, I am using Neo Office instead of Microsoft Excel. I don't know if this is an issue.
> > 
> > So I generally understand that the elliptical ratio affects the shape of the ellipse. a ratio of 1 means it's a circle fragment.
> > 
> > I believe that when the ratio is over 1, then the curve is more extreme on one axis, and under 1 the curve is more extreme on the other axis. True?
> > 
> > So, is the elliptical ratio on the spreadsheet related to the "+2" marking that Mojo puts on his mouthpieces? If so, how?
> > 
> > My guess is that "+2" means the elliptical ratio is 1.2 and "-1" would mean .9. Am I in the ballpark?
> > 
> > What is the practical range of possibilities for the elliptical ratio on a mouthpiece? Does a given ratio generally feel the same across the board (soprano alto tenor and bari), or are there different comfortable ranges for each instrument?
> > 
> > Also, is it possible to assign general characteristics that go along with a "+1" for example?
> > 
> > As for the spreadsheet, when a solver works properly (which I don't think mine is), I guess it is supposed to take the given data (tip opening, tip rail, elliptical ratio, feeler gage readings) to calculate a curve that fits the data best, and the results should include the actual (.0000 feeler) curve start, other feeler readings, and an elliptical radius.
> > 
> > Is this correct?
> > 
> > I have no idea how to fix the solver on this spreadsheet. Perhaps if I understand the other issues better I can figure out how to get it to work.
> > 
> > Thanks for any much needed help!
> >
> 
>