Pscale 360 - Help File

Introduction: (Please read at least once - Jump to Table of Contents)

Why 360? 2014 heralds in the 25th year since the inception of Pscale. Starting as a MS-DOS program in 1989, it was ported to Windows 3.1 around 1996. During 2009, it became apparent that Windows 7 would finally kill Pscale because it would no longer support Windows 16 bit program code. At this time, we developed a work around using the Open Source DosBox platform resulting in the PscaleX Cross Platform solution. We believe that the PscaleX platform will continue to run in all future versions of Windows. However, the irony here is that Pscale for Win under PscaleX requires running a version of Windows 3.1, under DosBox. So, here we are, running Pscale for Win on Windows 3.1 (1995) under DosBox within a 2012 Windows 7 Operating System. This, in itself is coming around in a full circle.

It turned out that PscaleX also runs on all Apple computers with Intel chipsets. However, PscaleX still required shipping a "Demo" version of Pscale for Win that included Windows 3.1 ."Ahhh, I'm sorry Judge, but my 400+ registered users were orphaned by Windows 64 bit. What was I to do? I could not, in good faith, just leave them stranded".

The prevailing thoughts have been that we were NOT going to rewrite Pscale for 2014 and forward Operating Systems. However, in the the words of LaRoy Edwards "Sometimes we do things just because we can". To that end, we have, in fact, rewritten Pscale for today, and future Operating Systems,

Pscale 360 is written in Javascript and html and will run in any modern Internet Browser. With, or without, an internet connection. This means: Desktops, Tablets, Smartphones, under any Operating System, and anything else that will come likely come down the pipeline.

Unfortunately, we have had to pay $1200.00 in Graphics Library License fees in order to be able to distribute Pscale 360 to everyone in the manner that is most functional all around, so we hope you will continue with your support for this new version.

Finally, this help file will attempt to mitigate between long time Pscale users and new users. Please bear with any redundancy provided for the newcomers.


The author, Tremaine Parsons, and Sierra Software Services, has taken due care in the preparation of this document and the associated programs. In no event will Tremaine Parsons, or Sierra Software Services, be liable for damages of any kind, incidental or consequential, in regard to or arising out of the use, performance, or form of this material presented herein and in the programs accompanying this document. No representation is made regarding the suitability of this product for any particular purpose.

Pscale 360 License:

The price paid Pscale360 entitles you to use the program on any computer or computer device that you own, but at no time are you allowed to make multiple copies available for others to use unless they are within your employ and agree to discontinue use after employment ends. Pscale360 is written in Javascript and Sierra Software and Tremaine Parsons request that you not decompile, or reverse engineer, the Pscale 360 portion of the Pscale Javascript code.

Furthermore, Pscale 360 includes a Javascript Graphing Library written by Antanas Marcelionis of Lithuania and released as "amCharts" from which Sierra Software Services and Tremaine Parsons purchased a distribution license that allows us to redistribute the library to purchasers of Pscale 360.  We ask that you honor our Pscale360 license, as well as the amCharts which includes, but is not limited to, wording as follows:

5. PROPRIETARY RIGHTS: All intellectual property rights in the Software are owned by amCharts or its suppliers, as applicable, and are protected by law, including but not limited to Lithuanian copyright, trade secret, and trademark law, as well as other applicable laws and international treaty provisions. The structure, organization and code of the Software are valuable trade secrets and confidential information of amCharts and its suppliers. You shall not remove any product identification, copyright notices or proprietary restrictions from the Software.


You agree that you may not and shall not and that if applicable, the Employer may not and shall not (a) modify or create derivative works based upon the Software; (b) decompile, disassemble, or reverse engineer the Software in whole or in part; (c) defeat, disable, or circumvent any protection mechanism related to the Software; (d) use the Software or any parts of it to develop a product directly competing with the Software.

The entire amCharts distribution license is located at:

Interesting Note: I can't find the story, but Antanas Marcelionis of amCharts started around +-2002 by figuring out how to make a Pie Chart in Javascript. As of 2013, amCharts customers have included Microsoft, Cisco, NASA, Motorola, Proctor and Gamble, Bank of America, NBC Universal, Morningstar, and many more. Again, please respect our software licenses.

Table Of Contents:

Which Browser Should I Use
Program Installation
Getting Started with Pscale 360
Pscale 360 - You'll now be working in a memory space - Save to File Often
Loading and Saving Pscale 360 Graphs/Files
Data Entry
Data Entry Fields - Top Menu
The Other Buttons and Fields - Mid Menu
Interpreting the Graphs
Running Pscale360 Without an Internet Connection
Scale Measurements
Bass String Rubbings or Tape Measurements
A Simpler Pscale360 and How Close is Close Enough
Practical Scaling Cause and Effects - What if's
Low Tenor/High Bass Bridge Considerations

Which Browser should be used:

Pscale360 was developed mostly using the Firefox Browser Version 24 and then tested on various versions of IE, Chrome, Safari, and Opera on Macs and Win XP,  7 and 8.  The main computer used for development was a 10 old CPU with Windows XP Service Pack 3.  The following Minimum Versions work fine on desktop computers: Internet Explorer 9 and up (8 is painfully slow and 10 is recommended), Safari 3.04 and up, Firefox 5 and up, and Google Chrome (lowest versions tested was 1/4/14 version 31.0). Our personal preference is Firefox or Chrome.

Tablets and Smartphones: Android devices should have Android version 4.0 or higher though I did manage to get Pscale360 running on a Galaxy Tab2 version 2.2 with the Opera Light Browser. Iphones or Ipads should have IOS 4 or above. We have not tested older IOS versions.

Program Installation:

Pscale 360 can be run from the internet but we encourage all users to download the distributions and burn them to a CD for backup. It is also recommended that you install Pscale "locally" on your desktop or laptop computer. Pscale is comprised of one folder named pscale360 which contains html, jpg, .js, and .txt files. If you work locally on your computer you can save your scale.txt files in the same folder. You can also just copy this folder to a USB drive or CD to move to a different computer. The default  install folder name is pscale360

If you have a username and password you can access everything from the following link:


You can run Pscale 360 from here but more importantly access the program distributions for Windows or Mac Systems. Once Pscale 360 is installed on your desktop of laptop, you can transfer the folder to tablet devices.

Getting Started with Pscale 360:

It is best to familiarize yourself with Pscale 360 using your desktop computer for the following reasons: Almost all Column Headings and Table Buttons have browser "Tool Tips". When you hover your mouse over a label or button, the tool tip gives an explanation of the heading or the function of the particular button. It will be easier to get comfortable with the new interface and basic functions using a desktop computer before you move to a tablet or smartphone. Also, many Desktop Browsers allow allow for "Save as" and "Open"  which makes file handling easier (see below).

You can move to any desired note by clicking any of the plotted graph dots.

Pscale 360 - You'll now be working in a memory space - Save to File Often:

Unlike Legacy Pscale, the nature of Javascript running in Browsers is not conducive to concurrent file read and write operations. This is, by design, a Security feature built into Browsers. Therefore, it is necessary to keep Pscale 360 work sessions in memory. This is a drawback in that if your power goes out, or you inadvertently close your browser, you will loose your work session data. Therefore, it is most important that you learn to save your data on a regular basis. This is a trade-off in that: we wanted Pscale 360 to be usable without an internet connection. We included this, primarily, for all devices outside of a WiFi / Internet connection. Another, less expensive, alternative would have been to code Pscale 360 in PHP but this would always require an internet connection and we do not think a program tool should require an internet connection.

Loading and Saving Pscale 360 Graphs/Files:

Note: Some Desktop Systems can use the new HTML5 File Handling API (explained below)

Note: Pscale 360 does not yet completely support Bichord Plain Wire Pianos

To get around javascripts file read/write security restrictions, Pscale 360 is designed to Load Scale Data using the Select All, Copy, and Paste functions common to all computers and devices. Ctrl A (select All), Ctrl C (Copy), and Ctrl V (Paste) (or Cmd A, Cmd C, and Cmd V key on Macs).

Pscale 360 files are saved as plain text files and loaded from plain text files. But, they have to be copied and pasted to load a previously saved file.

Both Windows and Mac Browsers allow the user to open local files using the File, File Open option. St start Pscale 360 one would locate and open 360.html You can open a scale.txt data file the same way for copying and pasting to load the file.

Most Windows Desktop Browsers allow one to "File, Save as" type .txt files as well as "File, Open" to open a scale file.

Mac Users will need to know how to access their text editors and save .txt files. It would be helpful to make a copy of the icon (in the applications folder) and move it to the desktop to have it handy. The TextEdit app may default to saving to files of type RTF with and HTML option. You can save your scale files as type html or go into Text Edit Preferences and set it up to handle text files by default. As you are saving files to be copied and pasted back into Pscale 360, the files can likely be saved in any format.

On Tablets and Smartphones, if you paste scale data into an email or memo and then you can re-fetch the data with your Tablet or Smart phone

Saving on Desktop Computers: The fastest way to Select All, Copy, and Paste is to use Ctrl A, Ctrl C, and Ctrl V key combinations respectively. On the Mac keyboard you would use Cmd A, Cmd C, and Cmd V key combinations. You can also pull down the Edit Menu and use the Select All, Copy and Paste options. On many Browsers you can also pull down File and use Save As and change the file to type .txt

Saving on Tablets and Smartphones: Select All, Copy, and Paste functions on these devices are a little device specific but generally, you touch and hold the text and the options pop up for your selection.

Note: Apple Ipads and Iphones are rather restrictive regarding their file systems so you will have to paste into an email and send to yourself or paste into a "Notes/Memo" file. One can also use an App like iFile.

Note: When loading a different scale file, it is necessary to Select All and Delete the data currently in the Paste Scale Data input box before pasting in the new scale data.

The Libray Button

The Library Button loads a page listing all the sample scale files that come with Pscale 360. Any scale file that you save will not appear on this list. As there are many files, users might find it helpful to name their files starting with an _ (underscore) . An example would be: _myfile.txt

If you name your scale files this way, they will always appear at the top of the list when using your browsers File, Open command.

Some Desktop Systems can use the new HTML5 File Handling API

Note: Pscale 360 Version 1.0 anomaly: If you can use the Browse Button to select different scale.txt files you cannot then use the Library Button and Copy and Paste a new scale file into the Paste Scale Data field. You must reload (refresh) the page before you can use the Library button with Copy and Paste. If you want to review the Library sample scales that have descriptions it is best to just use the Copy and Paste method.

Also, new HTML5 File Handling API only applies to files that you load and save from your "local" computer. If working Pscale 360 online, this feature will only access files on the users "local" computer.

The new HTML 5 Specification contains some File Handling which makes it easier to load and save Pscale 360 scale files. While partially supported on tablets, Pscale 360 limits its use to Desktop browsers (non mobile devices). This has been tested and verified to work using recent versions of Firefox and Chrome browsers on both Windows and Apple desktop systems. Safari seems to load files, but not save files.

If the users desktop browser supports HTML 5, there will be an additional line of options at the top of the main page "Middle Menu".
The left portion of the top line allows the user to select a .txt scale file. This will preload the Paste File Data Box. At this point, the user clicks the Load button and the file will load. No Copy and Paste required. (next image)

When ready to save a work session, the user clicks the left side Save button (as per the copy and paste method) and this will preload the File Name and Data boxes on the top right side. The user can modify the filename and click the Save5 button to save the file.

By default, Windows systems place the saved (downloaded) file in My Documents/Downloads and Apple systems place the saved (downloaded) file in Documents. However, Firefox, Tools, Options, General allows the user to select "Ask me where to save downloaded files". Chrome, Settings, Advanced Settings allows for the same option.

Finally, it should be mentioned that Browsers and HTML 5 consider a saved file to be "downloaded" but it is actually data saved from memory space on the users computer. Likewise, Browsers and HTML 5 consider loading a file from the computer as "uploading" when in fact the Pscale user will be opening a text file from the users computer. If the user was running Pscale 360 from an internet URL then they would be uploading and downloading. However, our preference is to run Pscale 360 directly from our hard drive or USB drive and thus not need an internet connection.

Note: This File API has not been tested with Internet Explorer but we believe it will require at least Version 10.

Data Entry:

For the most part, Data Entry is fairly self explanatory. However, in Pscale360, there are two basic methods for data Entry: Note by Note or Grid Entry. On Desktop Computers, "hovering" over any column label will provide a description of the label.

With Note by Note, one just selects the data entry values via the 2nd to top row data fields with "Pull Down", Select, and Choose Menus. Or, enter data in a blank data input field if no "Pull Down" option is available. The user just works their way downward note by note. In this case, the graph should auto-update with each data selection or entry change. (The Calc Button is there as a fail safe  to Force Calc)

With Grid Entry, one can just shoot down the necessary columns entering appropriate data as you go.  (see caveat below) Note: it is faster to use the [..] batch entry command on Note TYPE, and ENDS fields of the top Menu Bar (explained in Data Entry Fields  below). The DIAM Field in the Top Menu also has a [...] batch entry option but the Grid/Spreadsheet form has an even better batch entry command for DIAM (explained below).

Then do the rest of the data entry in Grid/Spreadsheet mode.

The Top Menu and Grid/Spreadsheet Entry methods are linked so that any entry from the top Menu is updated in realtime to the Grid/Spreadsheet data entry table. Likewise, the Grid/Spreadsheet data entry table is linked to the scale data internal data in memory and updated in real time with the exception of the following caveat:

Caveat: When entering data in Grid/Spreadsheet mode, the scale data data is updated in memory but we decided not to dedicate processor time for graph redraws while entering data in Grid/Spreadsheet mode because we will just be stepping down through the scale data entering numbers as fast as we can reliably can.

For this reason, it is necessary to click the "ReCalc" Button to update the graph after any Grid/Spreadsheet changes.

The Grid Entry tool is also an excellent way to view of your scale data for error checking.

As a general rule, users will enter a new scale data from measurements recorded using Grid Entry as it is faster. Once the data is entered, we would click the ReCalc Button to refresh the graph. We would then "Autoscale" the Bass. Finally, we would step note to note using the "Top Menu" to "tweak" and refine our scale using the + and - Buttons to a finished state.

Data Entry Fields:

The Top Menu Data Entry fields are as follows:
(In a regular Desktop Browser you can "Hover" the mouse  over column headings for "Tool Tips")

Note # is obvious and you step down or up using the - or + buttons, "Pull Down" to Jump to Note #

Type is Note Type: TP (TriChord Plain),  BS (Bichord Singlewound), US (UniChord Singlewound), UD (UniChord Doublewound), TS (TriChord Singlewound),  and [..] (Global Batch to set them all in one step). [..] allows one to set TYPE for all notes of the scale in one step.

SPLM is Speaking Length in mm. It is an input box in case you want to go to resolution of .5 mm. The - and + buttons will automatically step the value down or up in 1 mm. increments.

DIAM is the plain or core wire diameter (currently limited to American Decimal). The - and + buttons will automatically step the value down or up by increments of .001" Note: starting at .051, American piano wire jumps in increments of .002". (.051 .053 .055...)  The [..] option allows one to set DIAM down for # of notes in one step.

ODWRAP is  the Outside Diameter of a wrapped Bass String (currently limited to American Decimal). The - and + buttons will automatically step the value down or up by increments of .002".

ENDS is the Exposed core at each end of a wound Bass String. For simplicity here, we are only tracking one value as these values should be the same at each end of a balanced string. [Even if we had 10mm on one end and 20mm on the other, the Inharmonicity would calculate the same as if we had 15mm at each end. Therefore, we only need to track one value. The [..] option allows one to set all ENDS for a range of notes in one step.

ATSD is the length of the Agraffe to Strike Distance in mm. This is used to calculate Hammer Contact Time as explained in "The Calculating Technician" by Dave Roberts.

The Grid/Spreadsheet Data Entry form:

Entering data in this form always requires that one uses the Tab key to advance to the next field, or pressing the Enter key, to make sure that any entered value is saved.

The Grid/Spreadsheet DIAM batch command: The DIAM column of the Grid form has a batch fill command that is even faster than the Top Menu DIAM [..] option.

Starting in the top DIAM field (Note 88) of the Grid form, one can simply enter  31/4  in the field and it will autofill a value of: .031 down for 4 notes and leave the cursor in the next empty field (Note 84). With this command, one can just enter something like the following for a very rapid filling of this column: 31/4 Tab key  32/4 Tab key  33/6 Tab key. This autofills 4 notes @ .031, 4 notes @ .032, and 6 notes @ .033  and so on down the column.

The Grid/Spreadsheet data entry form has the following additional fields/columns.

This information is needed if one is NOT sending a quality String Rubbing to the String Maker. On Desktop systems, one can "hover" for explanations but a brief explanation follows:

BPHP1 Speaking Bridge Pin to back of Hitchpin in mm. for UniChords, Left String of Bichords, Left String of TriChords. Ref point: Standing at keyboard looking at strings.

BPHP2 Speaking Bridge Pin to back of Hitchpin in mm. Right String of Bichords, Center String of TriChords. Ref point: Standing at keyboard looking at strings.

BPHP3 Speaking Bridge Pin to back of Hitchpin in mm. Right String of TriChords. Ref point : Standing at keyboard looking at strings.

LSPLM Longer Speaking Length in mm. for straight bridges with un-notched Bichords.

AWSM Length of Overwinding Step on UniChord Doublewound in mm.

WRAP Wrap Constant for specific notes if different than default value. Blank for Copper, I for Iron, A for Aluminum. Note you can also use the Specific Gravity divided by 10 of the wrapping material so you could use something like .79 for steel or 1.9 for Bass String wrapped in pure gold.

The Other Buttons and Fields:
The Mid Menu

Underneath the main Graph(s) there are a number of Buttons and Input fields. Most are self explanatory. On Desktop Computers you can "hover" your mouse over any of these and get an additional explanation of their functions. It is always recommended to start using Pscale 360 on a desktop system to get to know the various functions using the "hover" tool tips.

A few items on the Mid Menu require special mention:

The Wrap Constant input field: (Holds true for Wrap Values in the Grid as well - See  Wrap above)

This input field will usually be empty, contain a C, or a value of .89 if the Bass String wrapping material is Copper.

If the Bass String wrapping material is is Iron or Steel, the values can be I (Capital i) or .79

If the Bass String wrapping material is is Aluminum, the values can be A or .29

Setting the value of this input box sets all bass string notes to this constant (global).

Dbl.Wrap Step Length mm. input field:

The Dbl.Wrap Step Length is the length that the outer wrap extends beyond the the inner wrap on a double wound bass string. Looking at a double wound string the outside diameter "steps" down for a length of anywhere between 13mm and 21mm. A longer step length will result in higher Inharmonicity and a shorter step length lower Inharmonicity. Most 4' 11" to 5' 4" grands will probably want a 13mm. step length. Most String Makers will accommodate a request for a 13mm. step length. Setting the step length in this input box will set all the doublewound strings.

Note: Autoscale sets all step length values to 13mm.

The Pitch Input field:

The Pitch input field is only included to display Pitch to alert the user if an imported Pscale file was previously pitch altered.

Error Check Button: This is an important final check that will alert the user to possible Bass String Scaling issues. It is not a 100% perfect check (heck, what is). It checks for the following:

Error Check - Wrap to Core Ratio:
It has been posited that, if possible, Double Wound Bass Strings should not exceed an Outside Diameter (ODWRAP) to Core (DIAM) ratio of 5:1. That is, ODWRAP/DIAM <= 5. In theory, overloading the string with wrap can diminish flexibility. Pscale has always considered this limit to be 5.5:1.

It has also been posited that, if possible, Single Wound Bass Strings should not exceed an Outside Diameter (ODWRAP) to Core (DIAM) ratio of 3:1. That is, ODWRAP/DIAM <= 3. In theory, overloading the string with wrap can diminish flexibility. Pscale has always considered this limit to be 3.5:1.

On short string scales you may have to push the limit to 5.5:1 (Dbl) or 3.5:1 (Single). We can also state, as fact, that there are many vintage "Name Brand" pianos with single wrapped bass strings having a wrap to core ratio as high a 4:1.

Error Check - Break %:
This alerts the user to notes that have exceeded a Break % of 66.

Error Check - DIAM-Up-Dn-Up:
We are normally used to seeing core wire and outside wrap diameters increase as we move downward through a bass string scale. The Autoscale feature will sometimes place a higher core diameter on a higher note in the bass scale. This is not to say that this cannot be done but we feel that it is best not to allow this as it may raise questions or confusion with string makers. So, Error Check attempts to flag when Autoscale does this.

The one exception here is that when moving from TriChords to Bichords, it is fine to jump down core wire sizes. This is also true when moving from Bichords to UniChords.

The Hidden Button: This Button gives the user extra info. In particular, Wrap to Core ratios, Dual Speaking Lengths in un-notched BiChord bass notes, and addl. information.

The Typogram Button: The Typogram output is  provided if one wants to experiment with the five types of steel piano wire manufactured and marketed by Stephen Paulello. He believes that "hybrid" scaling with varied hardnesses of piano wire can get all of your strings to a more optimum point of uniform stress or "elasticity". You can manually copy and paste each Pscale360 Typogram column into his spreadsheet and then manipulate his wire type for more uniform stress rates. We find this interesting, educational, and worthy of consideration. More at:

The 9' and <=7' Buttons: These two Buttons change the Inharmonicity Guidelines between <=7' (default) and 9' Concert Grand.

The Ham/Str Contact Button: If the user is tracking Hammer/String Contact Time, this Button will calculate Hammer/String Contact Time. Of additional importance: This window also displays Uni, Bi, and Tri Combined Tensions so the user can evaluate combined tension jumps.

The Compare Button: This is the connection to the Pscale File Compare option. It is recommended that one saves any current work session data before moving to File Compare. File Compare is most useful in demonstrating "before" and "after" scenarios on a particular rescale. However, it is also very useful if one re-caps bridges and wishes to "tweak" speaking lengths as the Text Out option will give one a printout of the  + or - speaking length adjustments. Finally, the File Compare tool is interesting to compare speaking lengths of similar pianos made by different manufacturers.

The Graph:

The "hockey stick" black lines are Inharmonicity guidelines for pianos up to 7 feet in length and Inharmonicity values are plotted using Blue Dots. It is preferred to keep inharmonicity below, or at,  the upper inharmonicity guideline but it is quite acceptable for fall below the lower guideline. Relative smoothness of inharmonicity is desired. Concert Grand inharmonicity curves can be set by clicking the 9' Button.

The three sets of horizontal black dots represent Tension guidelines for pianos up to 7 feet in length and Tension values are plotted using Red Dots. These upper and lower guidelines represent three ranges, left to right, as Unichords, Bichords, and Trichords. The guidelines will change to the extent that the initial graph is based on 12 Unichords and 18 bichords and your piano for evaluation may be different. As the graph is Logarithmic, the tensions are plotted at Tension/100 to look Ok on the Log graph. It should be noted that concert grand pianos often have Unichord tensions of up to 350 or more lbs. per string.

It should also be noted that the calculated tension (red dots) displayed on the graph is per string tension. This is why the Uni, Bi, And Tri guidelines step down. Actually the black tension guidelines step down in a ratio of 10:1, 8:1, and 7:1 ( 200/20 = 10, 160/20 = 8, 140/20 = 7 )

Break Point %:
The Break% is plotted on the graph as Purple Dots. Generally Breaking Point % should not exceed 66% but it is currently debated that modern wire (Mapes Gold) is good for up to 70%. It is generally held that we do not want to exceed these values as wire will lose "elasticity" when stretched beyond these values.

Loudness/Sustain: (often also referred to as Impedance or Z)

Positioned to the right of the main Pscale graph is the Loudness /Sustain graph. The height of this graph auto adjusts to the number of notes that contain data so it is not fully representational until looking at a complete scale. Dave Roberts, author of The Calculating Technician",  includes this factor as worthy of consideration. In fact, he states to following calculations in order of importance:
1] Inharmonicity (Smoothness of)
2]Unison Loudness/Sustaining Factor (Smoothness of)

3] Hammer.String Contact Time (Smoothness of)

Note: It is curious that smoothness of Tension is not mentioned in the above order of importance and we are sure that certain current scale designers place smoothness of tension as more important than Loudness/Sustaining Factor as presented in "The Calculating Technician".

As for defining Loudness/Sustain Factor, we shall take the liberty of including the following quote from "The Calculating Technician":

"The physical significance of this factor is that the larger it is (everything else being equal), the more quickly the vibratory energy in the unison is transferred to the soundboard, thus producing a louder but less sustaining tone."

The actual numeric value of each data point in this graph is not of much significance. It is the smoothness and/or large jumps in values that should be considered. There is one exception where the specific values may be considered. This is covered in Low Tenor/High Bass Bridge Considerations

By default, this graph updates in realtime after any calculation. If you are calculating note by note, you can uncheck the Realtime? checkbox if using a 10 year old computer (say XP Service Pack 3) and save .63 seconds per calculation.

Note: The original Roberts "Calculating Technician" Loudness/Sustain formula yields rather large numbers with jumps in numbers like 1620 moving to 1438. Having consulted with other "calculating technicians" it has been found that taking the Roberts Loudness/Sustain number and dividing by 20 yields more meaningful and recognizable number. This will yield a corresponding jump of between 81 and 72. The graph looks the same but the numbers are easier to grasp. Pscale 360 uses the Roberts Loudness/Sustain calculation divided by 20.

The SPLM Error Graph:

This graph  is the absolute best way to check if you have entered a Speaking Length Error. An error will either stick out like a sore thumb or, if not,  probably will make little difference in the end scaling result.

The Check BPHP Error Graph:

This graph is the best way to check if your have measurement errors in the bass string "Tail Data" that you send to your string winder if you do not use string rubbings.

This graph will not be to scale but will give you an approximate layout of the hitch pins. in relationship to the speaking bridge pin on the bridge for each note. The key here is to print this graph and then compare it with the "stagger pattern" of your hitch pins and make sure that you did NOT reverse a BPHP1-BPHP 3 data entry.


Note: It is most important that you save your input scale data to a file. I usually  append the letter o (for original) to the end of a file name. Once saved, you can continue with AutoScale or reload the original scale if you want to start a new AutoScale.

The AutoScale function in Pscale 360 is nearly identical to Legacy Pscale. However, the various Options have been reduced to a Tension Drop Down Menu and a single line Target Start,End Tensions input box.

The AutoScale function will do most of your bass rescaling work but you will have to manually review and "touch up" or "tweak" the AutoScale results. You will want to click the Error Check button to view possible problems. You will also want to step downwards through each bass note from top bass note to bottom bass note to make sure that DIAM sizes and ODWRAP sizes gradually increase in size, The exception here is that when moving down from the lowest Bichord to the top Unichord, there can be a drop in core wire size. This is also not to say that a smaller core wire diameter could not exist on a lower note within a Bi or Uni section because I have seen it done by prominent Scale Designers. However, you may not want ro risk confusing your String Winder. As a "Rule of Thumb", DIAM and ODWRAP sizes increase as you step downwards from top Bass Note to Bottom Bass Note.

Also, defining a AutoScale range (notes # through #) may not be implemented in the initial release of Pscale360 so it is preferred that you decide, and change, any plain wires that you are going to convert to BiChord wound notes before AutoScale.  No biggie if you don't , but you will have to manually edit / tweak any plain wire notes that are converted to BiChords after an AutoScale.

Multiple Autoscales on the same loaded file are not recommended. It is better to reload your saved original file to try different AutoScale Target Tension options.

The Autoscale Tension Drop Down menu defaults to the 10:1 8:1 7:1 Ratios. The 10:1 8:1 7:1 Target Tension option sets a straight line of tension taking the average plain wire tension (7:1) and setting the BiChords in a relationship of 8:1 and the Unichords 10:1. The yields fairly large combined tension jumps between Uni and Bi bass string sections. The tension guidelines are actually determined using the 10:1, 8:1, 7:1 ratios relationships. This method will yield a Uni and Bi Tension Graph similar to:
Figure 1(except top 2 bichords - low tenor bichord changeover)

To better understand the 10:1, 8:1, 7:1 ratios concept as developed by the late Dr Albert Sanderson of Inventronics, let us look at the lower tension guidelines of 200 lbs. (Uni), 160 lbs. (Bi), and 140 lbs. (Tri): 200/20=10, 160/20=8, and 140/20=7. 10:1, 8:1, 7:1 ratios 

The Most Even Tension option: This is the method that we had come to favor in recent years as it provides the smoothest  combined tension jumps moving from UniChord to Bichord to TriChord notes. However, we are currently re-evaluating this as a favored method.

Remember, the graph points represent tension of only one string when there might be two or three. So, a Uni, Bi, Tri spread that looks like:
 Figure 2
will actually yield transitions of only a few lbs moving from Uni to Bi to Tri. Logic might dictate that this method makes the most sense. However, having looked at hundreds of original scales, this practice has not been seen with any regularity.

The 3rd Average menu option just splits the difference between the high and low tension guidelines and produces a Tension Graph similar to Figure 1.

Note: Over the past few decades, different schools of thought seem to have developed. One may favor uniform tension per Figure 2 which will give larger Loudness/Sustain jumps between Uni Bi and Tri sections.

An other may seem to pay more attention to the Loudness/Sustain factor at the expense of larger tension jumps between Uni, Bi, and Tri sections.

Interestingly, a Figure 1 tension scenario will yield a much smoother Loudness/Sustain graph.

Having reviewed "The Calculating Technician" recently, we are somewhat undecided pending further testing. Actually, we currently believe that either autoscale method will likely produce an improved string scale over the original.

Running Pscale360 Without an Internet Connection:

This feature is very important to us! We should not pay for software that requires an internet connection to do our work. Pscale 360 on Desktops (on any Operating System), or Tablets running Android should not present any problems once saving the necessary files to the computer or device is determined.

However, Apple Tablet (and phone) devices are very restrictive with regard to saving files from outside sources to the respective device being used. Therefore, we are very pleased that an inexpensive app named Offline Pages will allow you to run Pscale 360 on your Ipad tablet or phone without a signal/connection. The Standard version is $4.99 and the Pro version is $9.99 but the standard version should work just fine and you can upgrade to Pro if necessary..

The fact that we have written Pscale 360 in "Browser Javascript" also allows us to not have to play the "Apple Developer Dance" @ 100.00 +++ per month and all kinds or restrictions much worse than if you lived in a "Gated Community".

Author comment on Smartphones and Tablets:

Pscale360 on smartphones and tablets is a definite benefit however we can't imagine doing an entire scale on a smartphone unless desperate. A 7 to 10 inch tablet is completely manageable. We see the primary benefit here to be reviewing scales or perhaps showing results to clients and colleagues. A desktop computer will be absolutely the easiest working environment for Pscale360.


All Legacy Pscale Documentation is available as .RTF files at:
However, if you "hover" over each column description using your desktop browser, it will tell you most of what you need to know about measurements.
It is recommended that you try and read the Legacy Pscale Documentation with the caveat that many of the step by step procedures will not apply to Pscale360. But, the document contains a worthy amount of useful information on the subject at hand.

Bass String Rubbings or Tape Measurements:

This is currently a bit controversial. For the past several years we have favored a good quality Bass String Rubbing because a good rubbing will not make a measurement error where as it is fairly easy to make a measuring tape read error or data input error.

Some String winders prefer measurements while others prefer rubbings. Most will accept either.

With a rubbing, one merely has to provide a wire diameters data sheet and mark on the rubbing where you want your wrap windings to terminate. However, it is also a good idea to check that the offsets from the top of the hitch pins to the bass of the hitchpins is uniform throughout the bass notes and to note on the rubbing the actual hitchpin offset. On some pianos, this can change throughout different sections of the Bass Hitchpins.

If providing tape measurements it is critical that you double or triple check your measurements. Also keep in mind that un-notched bass bridges with BiChords contain two different speaking lengths.

A Simpler Pscale360 and How Close is Close Enough:

We have tried to simplify Pscale 360 to contain all of the features of legacy Pscale while at the same time, make it easier to use and understand without numerous separate windows and nuances.

Tension and Break % are rounded and no longer calculate to 3 decimal points. Rounded is really close enough.

Pscale 360 is currently limited to decimal diameters. Hopefully, a dedicated metric version will follow.
The difference in size between American and Metric Steel Piano Wire is about .0005. In plain wire notes this difference might vary the per string tension +- 1 to 3 lbs. In a wrapped bass string, the difference is usually less than 1 lb. In both string types, Inharmonicity will vary a little as well. However, our overall goal is to smooth Inharmonicity and Tension and deal with any specific scaling anomalies.

Calc All Wraps has been removed.
Legacy Pscale has a routine that takes Bass String outside diameters (DIWO) and calculates which gages of American Copper will produce a result closest to the desired Outside Diameter.

Many String Winders are likely to use either American or Metric copper and core wire. More importantly, a good string winder is going to know which sizes of their copper (American or Metric) are going to produce a target outside wrap diameter.  Therefore, Calc All Wraps is not really necessary.

Good string winding will usually produce strings within +- .001 of the target Outside Diameter. Occasionally, due to available copper sizes, the result might be +-.002. As a consequence, what you get is not going to match exactly the results of your Pscale graph. But, again, our overall goal is to smooth Inharmonicity and Tension and deal with any specific scaling anomalies.

For those compelled towards more accurate numbers, Pscale 360 files can be exported and then imported into Legacy Pscale(X) which calcs Tension and Break% to 3 decimal places and also plain/core to 4 decimal places. You can also load a scale, Autoscale, and then Calc all wraps if you wish to experiment and see how this affects your graph.

Finally, we doubt anyone could ever hear or perceive any difference in +- .002 in a bass string or .0005 in a plain/core wire.

The Pscale 360 Print Bass routine no longer subtracts an "elongation" factor. What is printed in the Print Bass String Winding report is lengths as measured in the piano. Any qualified String Winder is going to know how to deal with "elongation" under tension. They have to know this in order to make strings from rubbings.

Practical Scaling Cause and Effects - What if's

As a general rule, the following behaviors occur: (All else staying the same)

Plain Wire

If we decrease diameter, Tension and Inharmonicity go down. Break % stays the same.

If we increase diameter, Tension and Inharmonicity go up. Break % stays the same.

If we decrease speaking length, Tension goes down, Inharmonicity goes up, and Break % goes down.

If we increase speaking length, Tension goes up, Inharmonicity grows down, and Break % goes up.

Bass Strings

If we decrease core diameter, Inharmonicity goes down. Break % goes up, Tension stays the same.

If we increase core diameter, Inharmonicity goes up. Break % goes down, Tension stays the same.

If we decrease outside diameter, Inharmonicity goes up. Break % goes down, Tension goes down.

If we increase outside diameter, Inharmonicity goes down. Break % goes up, Tension goes up.

If we decrease speaking length, Tension goes down, Inharmonicity goes up, and Break % goes down.

If we increase speaking length, Tension goes up, Inharmonicity goes down, and Break % goes up.

Low Tenor/High Bass Bridge Considerations

The Low Tenor to High Bass changeover is most often an area of a piano where scale anomalies exist. Most of these can be corrected or improved by manipulating tension and inharmonicity.

There is an additional factor than some "calculating technicians" take into consideration.  The lowest tenor bridge speaking length is usually significantly longer than the highest bass bridge note.

If the lowest tenor speaking length is, say, 20% longer than the highest bass bridge note, then one might seek a Loudness/Sustain (impedance or Z) value for the top bass bridge note that is 20% higher than the Loudness/Sustain (impedance or Z) value of the bottom tenor bridge note.

The sample1087.txt rescaled Chickering 4' 11" is a good example of this:

The lowest tenor bridge note is 29 with a speaking length of 946 mm and a Loudness/Sustain (impedance or Z) value of 58

The highest bass bridge note is 28 with a speaking length of 792 mm and a Loudness/Sustain (impedance or Z) value of 69

So, we get something like x/y = y/x  or 946/792 = n/58

946/792 = 1.1944444

1.1944444 * 58 = 69.277775 which is close enough to 946/792 = 69/58

This result yields an inverse relationship between speaking length jump and Loudness/Sustain (impedance or Z) jump.