Drive Calculator 3.0 is prepared to administer huge amounts of data.
It comes with a SQL database that can hold millions of entries. Even
though we may use no more than a few thousand entries, I thought
that it would make sense to provide a means for filtering the data.
Now that Drive Calculator is no longer limited to spreadsheet
functions, I was able to give the computer more work to do. The new
Drive Calculator has more buttons to play with. This should make it
easier to analyze and compare the data. At first glance, the user
interface may look somewhat complicated, but it isn't.
While the Drive Calculator application is the foundation for this
modeling tool, it is the user-supported database that will make it a
valuable and useful tool. I am providing the application as freeware,
and with help from Gerd Giese of www.elektromodellflug.de and
the users of the former versions, there is some database content
included in the initial release. I cannot spend the rest of my life
measuring drive components and filling up the database. Now, really,
it is your turn: I ask everyone with the knowledge and appropriate
measuring equipment to contribute to the database. With this version
it is easier than ever to contribute and share results, because
data sharing via the Internet is built into the application.
If you feel that you have the skills and tools to contribute useful,
accurate data, activate the sharing option by entering your Internet
access and email account data in the Preferences dialog window.
After that, all of the new data that you have entered will
automatically be passed to a central location (or upon individual
confirmation, if you prefer that). In return you will receive database
updates that are automatically integrated. I promise to keep up the
infrastructure for the online data exchange, look through the
incoming data, and take care of the update files.
Get started - Touch 'n go
For those who have worked with the Drive Calculator 2 Excel sheet,
the transition is easy. When Drive Calculator starts up for the first
time, the Motor radio button and the first two check boxes in the
Motor row and the Propeller row should be checked. Make sure they
are. The Power supply defaults to Constant voltage, which was used
on the Excel sheet. To use the program like the Excel sheet, check
all three "Hold" check boxes. After that, Drive Calculator 3.0 behaves
just like the Excel sheet, except that the measured data, if available,
in contrast to the computed data, will appear at the bottom of the page.
In addition, Drive Calculator 3.0 tries to evaluate the reliability of
the data and displays the results near the bottom, right side of the
application window.
Enter the operating voltage, select a motor, a prop, and possibly a
gear box in the respective popup menus. Drive Calculator will then
determine the motor characteristics and compute the operating point
with the selected prop.
One graph, instead of the two used with the Excel sheet, will display
the characteristic curves of RPM, mechanical power output, and
motor efficiency. My hope is that using one graph is clearer than
having the curves spread over two graphs, as in the former Excel
sheet versions.
The last entry at the bottom of each popup menu list for Power
supply, Motor, Gear box and Propeller is "New ...". Selecting "New ..."
opens a dialog box for the entry of new component data. The new
component dialog windows may also be opened from the Edit menu.
The ESC component dialog box can only be opened from the Edit
menu. For this application, the ESC is considered to be part of the
motor and is selected via the Motor dialog window.
When entering new data, please make sure to use a unique name
for each component. Using a unique name will make the merging of
the data, via the online data exchange, safer and easier. I am also
asking that motor builders adopt the naming convention for custom
made motors that is used in the database. Each motor name starts
with a set of numbers that indicate the most important parameters,
followed by a unique name string, i.e.
242x144 13D630
Quadro
in which
242 is the stator diameter in millimeters x 10
144 is the stator height in millimeters x 10
13 is the number of turns of the winding
D stands for delta termination (Y indicates WYE termination)
630 is the wire diameter in millimeters x 1000 (respective diameter
in case of multiwire windings).
Remember, there is still a Remarks field for individual notes and
comments.
For a description of the functions of the check boxes, buttons, and
additional features, please refer to the manual. The manual opens in
a Web browser. Selecting "Help" in the Drive Calculator application
menu also opens the manual.
Known bugs
Sometimes before a scan run the database engine fails in removing
all data collected in the previous run. As a result you may see a
message like "Select smaller prop" on the selection of one or two
motors even though the scan run is supposed to search for motors
that fit the prop. This is a bug of the database engine I am using, and I
would have to use a time-consuming procedure as a work-around. So
I choose to leave it as it is and hope for a future bugfix of the database
engine. If you encounter this situation, just repeat the scan run.
Modifying a component's name requires you to enter at least two new
characters in the name field. Otherwise the modificaton has no effect.
This bug, only affecting the Windows version, is as well caused by odd
behavior of the development system and will be removed by a future
update.
Please send comments and error reports to
christian@drivecalc.de
Regards
Christian Persson
Hannover, in March 2006