yet another downloadable string tension calculator...

[Jim Adwell]

... but this has all the strings listed in the D'Addario string data pdf, including nylon and composition string, stainless steel, brass wound, etc. I'm making it available to anyone who wants it, warts and all.

I needed a way to calculate nylon string tension, and couldn't find an existing solution, so I wrote a program one day in Visual Studio to do just that, and more. This version has data for all the D'Addario strings as mentioned above, will do double and triple string courses up to a total of eighteen strings, shows all values in imperial and metric units (and you can enter values in imperial and metric as well), automatically calculates as you change any input, and can of course save and load results. It comes with a few templates for mandolin, mandola, and various guitars and ukuleles. If that's not enough, I included a down-force calculator - given the break-over angle in degrees, down force is calculated and shown in imperial and metric units.

The calculator is of course free, and can be downloaded from my Google Drive folder here:

https://drive.google.com/file/d/0B85...ew?usp=sharing

There's no malware or spyware of any type in the program, not even Google Analytics.

I've packaged it up in an installer that will install the Visual Studio run-time package needed, if you don't already have it on your computer (you probably do). It should be straighforward to use, except for selecting string values - you select the number of strings and string-per-course from the dropdown lists, or more likely load the appropriate template, and enter or change the scale length, if necessary. The note and octave of each string in the chart can be changed also. Files will be saved under the name entered in the text box at top center - be sure and change it if you don't want to over-write a previous file with the same name.

To change or add a particular diameter and type of string you first click on the string or strings you want to change in the string chart; the selected string(s) will turn yellow. Then you select a string from the lists on the left of the string chart, which will load the value into the chart and un-yellow the string(s) selected. There are a couple of big green buttons on the right - clicking these will raise or lower the pitch of all the strings in the chart by a half-tone (I put that in there for experimental purposes).

Should anyone decide to try the program, any feedback is appreciated, including negative feedback. You can email me through the forum, or post in this thread.

Hopefully someone here will find the program useful.

[Bernie Daniel]

... but this has all the strings listed in the D'Addario string data pdf, including nylon and composition string, stainless steel, brass wound, etc. I'm making it available to anyone who wants it, warts and all.

I needed a way to calculate nylon string tension, and couldn't find an existing solution, so I wrote a program one day in Visual Studio to do just that, and more. This version has data for all the D'Addario strings as mentioned above, will do double and triple string courses up to a total of eighteen strings, shows all values in imperial and metric units (and you can enter values in imperial and metric as well), automatically calculates as you change any input, and can of course save and load results. It comes with a few templates for mandolin, mandola, and various guitars and ukuleles. If that's not enough, I included a down-force calculator - given the break-over angle in degrees, down force is calculated and shown in imperial and metric units.

The calculator is of course free, and can be downloaded from my Google Drive folder here:

https://drive.google.com/file/d/0B85...ew?usp=sharing

There's no malware or spyware of any type in the program, not even Google Analytics.

I've packaged it up in an installer that will install the Visual Studio run-time package needed, if you don't already have it on your computer (you probably do). It should be straighforward to use, except for selecting string values - you select the number of strings and string-per-course from the dropdown lists, or more likely load the appropriate template, and enter or change the scale length, if necessary. The note and octave of each string in the chart can be changed also. Files will be saved under the name entered in the text box at top center - be sure and change it if you don't want to over-write a previous file with the same name.

To change or add a particular diameter and type of string you first click on the string or strings you want to change in the string chart; the selected string(s) will turn yellow. Then you select a string from the lists on the left of the string chart, which will load the value into the chart and un-yellow the string(s) selected. There are a couple of big green buttons on the right - clicking these will raise or lower the pitch of all the strings in the chart by a half-tone (I put that in there for experimental purposes).

Should anyone decide to try the program, any feedback is appreciated, including negative feedback. You can email me through the forum, or post in this thread.

Hopefully someone here will find the program useful.

Nice of you to do Jim! I have not downloaded it yet though I might. I already have several programs including and Excel program that I put together when playing around with guitar to mandocello conversions. But the down force vector computations are really nice touch IMO

I did have a couple of questions for you. Do you use the D'Addario formulae for computing string tensions? Also where did you find all the D'Addario string data in digital format? The only source I know is the .pdf on their web site.

[Jim Adwell]

I did have a couple of questions for you. Do you use the D'Addario formulae for computing string tensions? Also where did you find all the D'Addario string data in digital format? The only source I know is the .pdf on their web site.

The formulae for string tension and down-force come from R M Mottola's website (the same formula as the one in the D'Addario pdf), and the string data is from D'Addario's pdf file. I just removed extraneous characters from the text of the pdf file, organized it for machine reading and put into three text files. The program reads the text files when it starts up. There is also a text file with eight octaves of note frequencies required for the calculations. This sounds more complicated than it was to do.

If other manufacturers ever provide the unit weight of their strings, it would be easy to add them to the program.

[Tavy]

I just spent some time playing with that, and I have to say it works very well, some minor comments:

* The first listed string type in each list is partially hidden by the dropdown box at the top (or vice versa).
* There's no program icon - it displays the default empty icon on the taskbar.
* The installer is un-signed, so Windows 8.1 makes you just through all kinds of hoops to actually install the thing.
* There's no option for variable scale instruments, which is clearly an absolute must

Best, John.

[Tavy]

Here's an interesting one.... I tried to create a pre-set for my prefered FW74 choice, but:

* There's no Chrome .036, and
* The tension for a chrome .026 D doesn't match D'Addario's website.

Any ideas?

[Tavy]

Here's the closest I can get to a J80 OM template:

Octave|Mandolin|Template 22.750 4 2
String1 E 4 LE012 3.19E-05
Drone1 E 4 LE012 3.19E-05
String2 A 3 LE022PB 9.571E-05
Drone2 A 3 LE022PB 9.571E-05
String3 D 3 LE032PB 0.00020573
Drone3 D 3 LE032PB 0.00020573
String4 G 2 LE045PB 0.00041278
Drone4 G 2 LE045PB 0.00041278

Note there's no LE046PB in the database for the G strings.

I also note that the loop and ball end PB strings have slightly differing tensions... weird!

[ddawson2010]

It should also be noted that we have updated our tensions to be a tad more exact. We have a tension calculator as well that reflects these new tensions, which are also reflected on our new packaging - www.stringtensionpro.com.

[morgan]

Don - Some user feedback:

Using stringtensionpro.com, When I try to check mandola string tensions (using "custom instruments"), I get stuck at the string construction page - the continue button doesn't work, and the "get help" instructions say that there is a "get results" button, but there is none.

[Jim Adwell]

I just spent some time playing with that, and I have to say it works very well, some minor comments:

* The first listed string type in each list is partially hidden by the dropdown box at the top (or vice versa).
* There's no program icon - it displays the default empty icon on the taskbar.
* The installer is un-signed, so Windows 8.1 makes you just through all kinds of hoops to actually install the thing.
* There's no option for variable scale instruments, which is clearly an absolute must

Best, John.

Yeah, the scaling could be better. I'll see what I can do about that.

I haven't figured out what an appropriate icon would be. Any ideas?

About signing... I'd have to spend a rather large amount money to buy an installer or upgrade the one I have that Windows 8 won't complain about. Probably not going to happen. I'll look around and see what else I can find, though. I don't have Windows 8 so I can't test for compatibility, unfortunately. The alternative is to provide the executable and support files without an installer and assume the end user has the necessary Visual Studio run-time stuff already or is savvy enough to get it.

Multi-scale instruments... hmmm...


Cheers, Jim

[Jim Adwell]

Here's an interesting one.... I tried to create a pre-set for my prefered FW74 choice, but:

* There's no Chrome .036, and
* The tension for a chrome .026 D doesn't match D'Addario's website.

Any ideas?

The pdf file is incomplete. I've found a few apparent errors in it, too. I can't fix missing or wrong unit weight data (I could make a guess at it, but I'd rather not).

[ddawson2010]

Don - Some user feedback:

Using stringtensionpro.com, When I try to check mandola string tensions (using "custom instruments"), I get stuck at the string construction page - the continue button doesn't work, and the "get help" instructions say that there is a "get results" button, but there is none.

Excellent - we'll share that with our development team.

[Dick Hutchings]

What do you all do with this information?

[Marty Jacobson]

Dick, string tension data is useful for estimating the string gauges for a new instrument with a custom scale length, and for thinking through the structural requirements of the instrument.
It's also useful for figuring out new string gauges for an existing instrument in a new tuning, or to figure out a custom gauged set of strings which is slightly lighter or slightly heavier.

[Dick Hutchings]

Thanks Marty. At this point, I wouldn't know what to do with that information. I just build copies and put standard string on. At least structurally. As you can tell from my avatar, I don't mind making them look a little different cosmetically.

[Tavy]

Data like this comes into it's own when dealing with mandola's, OM's, 'cellos, and citterns, none of which have "standard" scale lengths.

[Pete Braccio]

Hi Jim,

Are you measuring Breakover Angle as degrees off of horizontal? I'm just trying to make sense of the numbers that I'm getting.

Thanks,
Pete

[Jim Adwell]

Hi Jim,

Are you measuring Breakover Angle as degrees off of horizontal? I'm just trying to make sense of the numbers that I'm getting.

Thanks,
Pete

A picture is worth a thousand words, as they say. There is a nice graphic on R.M. Mottola's website that should explain this:

http://www.liutaiomottola.com/formulae/downforce.htm

I used his formula in the program.

[Pete Braccio]

OK. That's why my numbers were all screwy. This guy's equation is completely screwed up.

If we assume that the break angle of the string leaving the bridge toward the neck is zero degrees (which is a good assumption), then the equation for downward force should just be:

F = T sin (y) where T is Tension and y is the angle of off horizontal of the strings going to the bridge.

At y=0° (the strings just touch the top of the bridge, but don't bend over it), F=0

At y=90° (the strings go over the top and then go straight to the top), F=T

[Tavy]

I would tend to agree with Pete's definition - if nothing else, it would be an unusual instrument to have the angle on both sides of the bridge the same?