|Nick Gravagne's Action Geometry Program is once again available with a brand new look and several major upgrades to functionality.
What it does:
Generates Action Ratios of a given piano action and / or any proposed changes you are considering making to the parts or layouts.
Auto-computes two difficult-to-measure action arms (the radial shank input arm and the radial whippen output arm) to greatly simplify things for you and increase accuracy.
Supplies clear, large and colorful drawings for easy reference as to how to layout and measure the action components of key, whippen, and shank.
Supplies you with a much expanded "What If..." page that allows you try out different configurations of the action components such as,
"What would happen if I change the capstan position?"
"What if I change the knuckle distance from 15.5mm to 17mm?"
"I am thinking of getting a new keyboard with a different key ratio."
"What happens if I change the action spread?"
Dimensional changes made or proposed to any action parts will impact and distribute through the system as a whole. The program takes care of these sometimes subtle changes in the background for you.
The Main Form generates "red flag cells" when any parameter is questionable and requires your attention; e.g., you try out a capstan change but the dip required is now 10.8 mm ---------- the dip cell will turn red alerting you to a potential problem.
Yields a Reflected Inertia value.
Tells you how many leads will be required in the key sticks based on the original data entered on the Main Page or per any changes you try out on the "What If..." page.
Relates certain data and computations in Stanwood Balance Weight terms as well as customary Downweight terms.
And much more! Read below and see many screenshots of the program.
Platforms for use
Due to the enormous capability of the MS Excel spreadsheet, the new program requires that you have Excel installed on your computer. Known workable versions include Excel 2003 and later, but may work in earlier versions of Excel. You see, the Excel program runs a multitude of sub routines (called Macros in MS-speak) behind the scenes in order to automate the many interconnected computations across the workbook.
If you are a Mac user, you somehow need to be able to run Excel and all macros. Current users report that the installation and use of Parallels Desktop allows the use of Win XP, 7 and 8 to run on Macs. Also, if you have Mac office 2004 or 2011 the Excel file will run, but Mac office 2008 is problematic and doesn't like to run the background macros. Perhaps obtain a cheap PC Windows running XL OS.
Skip the pricing for now, I want to first read about program functionality
Two versions of the Action Geometry Program (AGP) are available
1) The AGPL, the basic or light version. Though this version does not contain all the worksheets and functionality of the full version it is nonetheless very powerful and does include all pertinent action ratios, key leading per note and inertia values. In addition the program supplies you with a suggested maximum hammer weight column (range from note 1 to 88) which will work with the particular action configuration you are evaluating.
Price for the AGPL is $95 for one computer and $25 for each additional computer.
This light version contains a tab worksheet called UPGRADE. If you would like to upgrade to the full version AGP, and after making payment of an additional $55, instructions will be supplied to you to access and click on the Upgrade button. The full version will then appear.
Note that, although many of the screenshots below relate to the AGPL, some relate only to the full AGP version.
2) The AGP. This full version contains everything the light version has but much more. This version is particularly useful to those technicians who are more comfortable working with protocols such as Balance Weight and Front Weight.
Price for the AGP is $150 for one computer, and $25 more for each additional computer.
Note that if you are a past user of any of our Action Geometry Programs from several years ago (i.e. those old versions did not require the Excel program to run and cost $75) you are allowed a full credit toward the AGP Full program meaning your cost would be $75 for the AGP Full Program.
Price for AGP is $75 for past users of the old program and $25 for each additional computer. Or $45 for the AGPL.
If you wish to purchase the program go to www.gravagne.com where you will find a “BUY NOW” Button. You will also find a dropdown window there listing six purchase options.
AGP Full Program ---- $150
AGPL Basic Program ---- 95
Basic to Full Upgrade* ---- 55
Renner Grad Upgrade** ---- 75
Past User Full Program ---- 75
Past User Basic Program ---- 45
* Upgrade option only available if you are currently running the Basic Program
** Renner Academy grads receive a complimentary AGPL program with Academy attendance, so this option is for RA grads who wish to upgrade to the full program.
At the Gravagne web site, clicking on the Buy button will direct you to the PayPal site where you can pay via PayPal (if you have an account --- signing up is free) or by using your credit card. Look for the credit card link there. When payment has cleared we will either email the program to you or else direct
you to a download link. Should you inadvertently choose the wrong purchase option (e.g. Renner Grad Upgrade when you meant to choose something else) we might catch this at our end or you can notify us and we can work it out together.
You may also call in with a credit card number or send a check to:
5235 N Strawberry Lane
Strawberry, AZ 85544
Trying Out the Program
If you wish to try out the program first, we understand. Send us an email with your request and we will send out the full program which will work for two weeks. After the time period is up the program will ask for an activation code. Should you decide to purchase we will supply you with the code.
Your request for a trial program or an outright purchase will be held in strict confidence. You will not be hounded or contacted in any way unless we are sending out a group email pertaining to any new information we may have that we deem you would likely be interested in relating to the program. If you have purchased the program or simply tried it out and wish to make comments or suggestions, these would be very much appreciated but not expected and we will not follow up on any purchase or trial unless we hear from you.
OK --- on to some of the useful functionality and screenshots.
Note that current versions of the program have been updated and revised, so screenshots below and some of the descriptions herein will have altered a bit when the current program actually runs on your computer.
The Simple AR Calculator Worksheet (aka Main Data Entry Page). It is here where you enter data, i.e. the dimensions you measured on the various action parts.
Requires inputs in the tan boxes only.
A standard color code exists throughout the worksheets. A tan box is for your data entry of the action components layout and measurements of key, whippen and shank or any other input of significance. Green and yellow boxes show computed values; a pinkish box is either a label or else shows that data has been carried from one place to another. A reddish box indicates a “red flag” signifying a computed value that requires your attention.
All functional and computational worksheets within the workbook are locked for your convenience and to protect the integrity of the program.
Again, you can enter data in tan boxes only, which simplifies things for you.
How to layout and measure the action components can be found at the Measure Parts tab at the bottom of the workbook. However, for your convenience a quick view of how to measure parts can be had via the hyperlink text such as Key Out, etc. as seen in the box below.
It is important to note that there are two sets of measurements required. One is named MAR for Mass Action Ratio and the other is DAR for Distance Action Ratio. Be sure to study the Measure Parts and Alt Measure parts tabs. The drawings there are clear and easy to understand.
When first entering data for an action each tan box will be filled in (see below); you can tab left and right and up and down. But after all data is in you can Drag and Select, copy and save to the bottom of the Main Page area and paste for future reference. In this case you would click on the Standard Action heading, drag to the bottom of the tan boxes, copy and then paste to the appropriate cell below in the archive section (more on this later).
When all data is in place (however it gets there) press the blue button to the right where you see text “After entering data, …” in order to run several auto routines in the background.
A summary of calculated values will be automatically created as seen below (data is for a different action). Note the little red triangular flags in the upper right hand corner of several boxes. These are comment flags and are very informative. Rest you mouse cursor over such a box to read the information. For example, the comment found in the first box referenced by label “MAR-SW RO” reads:
“Mass and force develop within and through the action per this ratio (RO) aka the Strikeweight RO. Also, this ratio plays a part in calculating inertia and key lead considerations.”
Once comfortable with the program you will seldom refer to the comments.
Interpretations of the Summary Data are sprinkled throughout the program in the form of comments. For now notice the “Red Flags”, those red cell highlights displaying a too-low 7.71 Strikeweight capability indicating that the action (say, note A52) is only capable of supporting a 6.1 gram hammer. Such a light hammer would be found farther up the scale. Although well-considered, the default of this program reads in one of the many comments:
"For starters we would like to see that the value in the box to the right relates closely with note range C52 plus or minus a few notes in the dropdown list. In this range you will find SWs of aprox 8.6 to 9.0 and a hammer mass of 7 to 7.4 grams. This indicates a strong and healthy action (as long as the regulation dip is in line as well)."
Also notice in screenshot below that a trial Strikeweight (one you entered yourself) of 11.5 (relates to a 9.9 gram hammer) yields a 429 questionable Reflected Inertia along with a too-high Estimated Key Leads Requirement of 4.8 leads. These instant indicators not only tell you what is going on with your action but also prompt you into trying out changes at the “What If” tab to test the limits of what kind of improvement modifications are indicated or possible.
An additional page called the Summary Page is shown below. This catch-all page gathers, summarizes and organizes in readout fashion several useful program parameters.
Action Ratios and key dip
Strikeweights and hammer head weights for three critical notes in the scale
Inertia and estimated required key leads for same three notes
A program-generated maximum hammer weights column for all 88 hammers
Declining inertia values and key leads for all 88 notes
A handy "What Do I Do?" list of Six Basic Steps on how to proceed so as to key you on track
But the Summary Page does much more. Note below that you can enter your own set of prepped hammers (bored, arc-tailed, side tapered and coved) from hammer 1 to 88 and compare these to the max-generated hammer weights program column. Your prepped weights should not exceed those in the max program weights column.
And so let's add a nice visual ---- a graph of the two columns for a handy look-see!
Below note that two drop down boxes are included (only one is showing here) by clicking one or the other appropriate cells. The data in the boxes are a convenient thumb rule for checking the computed SW (in this case 7.71 grams) against the full range of note number and SW and Hammer mass as computed for the action under consideration. Here the drop down box indicates that a 7.71 gram SW relates to a 6.1 gram hammer head.
A similar drop down box is found in the boxes headed “Try Out a S'Weight in Box Below” label where you would be trying out strikeweights of any value weights to ascertain the limit of estimated key leads required.
Additional boxes filled with data found on the Main Page are there for your interest but are not critical to your evaluation of action geometry. Most of your work will take place on the Main Grid as shown above and in the What If. page and the Summary page (or Key Leads page depending on your version).
The Knuckle Trig Box
You do nothing with the Knuckle Trig box. Its purpose is to calculate the Shank Input arm (that red, diagonal line which runs from the hammer flange center pin to the underside of the knuckle). This little arm is critical to all calculations and is virtually impossible to measure accurately, so we let the computer do it.
The Actions Ratios and Dip Box
The Actions Ratio Box reflects much data crunching. But the essential points to notice are these:
The topmost (11 mm) reflects the theoretical dip pertaining to the Action Ratio called DAR (Input DAR / max dip). It will be the highest number of the dips in the column but closely reflects the practical dip that will be required for regulating this action. Still, note the red-cell activated by the dip of 11 mm, which was due to What IF changes proposed for a problematic action, is trending too high requiring a new look at what more realistic changes might be had.
Dip requirements theoretically diminish as the hammer approaches the string, thus the program lists these FYI if not practical consideration. It is important to pay close attention to practical dip requirement circled below when making any proposed changes to an existing action.
The box below shows a good and safe range of dip configurations. This dip of 10 mm is carried upwards to the Summary Box for your convenience.
The Delta Δ Box
Delta (symbol Δ) signifies a changing variable in the world of mathematics. The Delta Box above shows how several functions change as the hammer rises beginning at 2 mm and ending at the string or blow distance. Thus delta functions include a changing Action Ratio, a cosine angle change at the knuckle and repetition lever, a System Inertia change, a Hammer Mass (or Strikeweight) touch sensation of change, a Pure Rotations change (irrespective of dip or hammer rise) and a Hammer Rise to Key Travel ratio.
These data are displayed in graphic form at the Graphs tab at the bottom of the worksheets and included for your interest and as a learning tool. A full grasp of the significance of these data and related graphs is not necessary to evaluate a grand piano action at its most basic level.
The Touchweight Perspective Box
Pianists place their fingers well inside the very ends of the keys. This box accepts three inputs: Grams DW (50 gms is default); Front Key Input (distance from balance pin to the very front edge of the key); and a Touch Distance in from the very front of the key where a pianist might place a finger. The box above taken as a snapshot shows that although the DW is 50 grams, when the pianist activates the key at 55 mm (a bit more than 2”) in from the key end, the touchweight / DW feels like 64 grams rather than 50. This surprising fact should remind us of the remarkable adaptability of the pianist to accept this gross difference in touch as well as to balance and moderate our thinking as to what level of perfection in our work is realistic.
The Save Your Data Boxes
Note that several actions are saved and provided with the program. Many, though not all, represent well setup and functioning actions. Copy and paste them into the Data Entry grid and study as a learning tool as well as a sort of touchstone as to what works and looks good. Try not to alter them so much to the point where you cannot recall the original data, although these actions are also saved in the tab called “Archives”.
The SSBad (or Steinway B bad) data indicates a problematic action. Plug in the data and see what happens. Run through some "What Ifs ..." to see what kind of improvement you might make, but keep an eye on the dip, make sure it doesn't get too high. When red flag-cells turn green you are on the right track! It's fun.
Below is a "What If..." screenshot of testing out a capstan move of 3mm. See small box with text "Move Capstan by + or - “. Instructions and comments can be found on the screen. Press "Ctrl a" or simple click in the large green box to calculate the changes and post all relevant changes to the Main Screen where you can review the impact of your proposed change.
Below is a "What If..." screenshot of testing out a knuckle placement change from a 16.2 mm to a 17 mm knuckle (i.e. the distance from the hammer shank center pin to the center of the knuckle core). The program will make the calculations. Pressing "Ctrl b" or clicking in the box will post all relevant changes to the main screen.
Here we have a "What If..." scenario where a new key ratio is being tried out (e.g. a new keyboard is being considered). Note in the screen that the original key ratio of 1.89 and the front key length of 252 mm have been transferred in from data on the Main Screen for trial here. What is being tried out is a new key ratio of 2.03 along with a relative 258 mm front key length. Clicking in the green box posts the trial data to the Main Screen for recalculation of all relevant data.
There are other "What If..." scenarios to try out and in all cases are easy to use and to auto-post to the Main Screen for recalculation.
The Key Leads worksheet is one of my favorites and the next four screenshots detail some of the functions it carries out. The top of the worksheet includes introductory remarks so you can read them there.
The Key Leads page continues below in the following two screenshots where you can see the hammer and shank along with a whippen. What is being depicted here is a transference of grams-force as it develops downward from the hammer mass (Strikeweight), then through the whippen, and finally through the key resulting in a balancing downweight of 50 grams (+ or -). Follow the red arrow and line. The data working its way from hammer tip to key end is automatic and is generated from the simple data you entered on the Main Page.
Key Leads pages continued.
Note that as interesting as these interconnecting relationships are, grasping their full meaning is not essential in generating useful action analysis on the Main Page.
And we are not done with the Key Leads page. Below is an extensive readout of generated data as it relates to the simple inputs you made at the Main Page. Note the columns headed "Note", “DW Tar." (Downweight target), "BW" (balance weight), "SW" (Strikeweight), "Hammer" (weight in grams), "Inertia", "# of Lds" (number of leads required) for two possible positions in the front key segment. You can set the DW Target yourself, but the program comes with a default of graduated DWs as you see below.
Focusing on the Hammer Column you will find the little read mark indicating the existence of a comment which reads:
Theoretical hammer weight (mass) suggested. Consider these values as a guide to steer you in a consistent direction. Note that the hammer value = the SW less estimated shank SS of 1.6 gms.
As with the Concert Keys WS, this Hammer weights column is based on arbitrary (but well considered) proportions of the frontweight ceiling as proposed by David Stanwood. In any case, consider the values in a relative way in your work.
Understand it this way: if you did not change the action ratio or component configurations in any way, then this range of hammer weight replacements is more or less indicated.
Also, if the action ratio and dip and inertia parameters from the Main Page are acceptable (either as is or due to changes you have made) you may consider the hammer weight scale as a maximum target for your choice of hammer weights, or at least a guide for relative purposes.
For your convenience data generated in these columns is automatically generated with any action data you enter at the Main Page or any changes you are trying out at the "What If..." page.
Now on to the Keystick Inertia page (following two screenshots). Working through this page is more of a learning thing than something absolutely required to workup a decent action on the Main Page. The instructions on the page explain what to do and what is happening here, but in broad strokes you can enter the required data, such as locations of leads in an existing key stick, and the program will generate the inertia of the that key stick.
Key Inertia Page continued showing measurements to the key leads, to the center of the backcheck and to the top of the capstan screw.
I'm a big fan of graphical representations of data, and I bet you are, too; and this is one of the reasons that we chose a spreadsheet format such as Excel to create this new Action Geometry Program. So, I've included several charts and graphs depicting all sorts of data. Below shows one such graph of plotted data of a rising hammer head as it relates to dip and an ever-changing and declining function of Action Ratios.
Below is a screenshot and visual as it relates to the Hammer Bore equation. Use this page to compute the hammer bore by plugging in appropriate numbers in the tan boxes. In the case below we find a string height of 197 mm and hammer flange center height of 147 mm which together yield a hammer bore length of 50 mm.
For those of you who find it convenient and / or necessary to bore the hammers at 91 degrees rather than 90 degrees, this page is for you. Following the plan below will allow the shank to be elevated above the cushion by a few mm while at the same time allow for the hammer crown to strike the string squarely. This configuration is sometimes required or convenient, but is an advanced concept that will demand your full attention. Be sure to measure the angles of the existing hammers, particularly on a factory job, to see how they were hung. A 91 degree rake may be called for in order for things to work out best. In the configuration below we see that a 43.7 mm bore dimension is called out and relates to a 91 degree bore angle.
Screenshot below shows one of the many drawings you will find in the program. This one is of the hammer and shank and details how the various dimensions are to be measured. Note that the small red dotted dimension (the Shank Radial Input Arm) does not require your measurement as it is auto-computed by the program.
Well, that's it for now. As you can see the program is jam packed with useful and educational functionality! Why not try out the program to see if you like it, and would find it useful in your action work.
In any case,
Kind Regards and thanks for viewing the material.