HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Apr 08, 2008, 04:00 AM
.
Joined Nov 2006
732 Posts
edited
prinz is offline Find More Posts by prinz
Last edited by prinz; Nov 10, 2008 at 04:03 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 08, 2008, 08:49 AM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Quote:
Originally Posted by prinz
louis,


a little suggestion:
you should beginn to differencing data for the older "G1" and the newer "G2" if the special motortype was/is built with both statorshapes.
the difference in kv and stiffness for the same winding is significant.

some users try to use the scorpion calc data for the older G1 to find a good dimensioning for their models and are wondering, if the real data abberate from the precalculation!

second question:
how do you meassure your R i?
I have in all my motors about 130-150% copperfilling of the manufacturer winding - but I calculate a bit more ohmical resistance for the winding compared to your data for the manufacturer winding.
for my guess is your tool much to optimistic!
have a look of the attached comparison made from the same data!
ralph
www.powercroco.de
Hi Ralph
Next release I have to add "G1" suffix on all G1 motors
I suppose Georges sent to me G1 versions
For the six 40xx I don't know what I received

For Rm I measure at 20C, directly on the connectors
My software makes a Rm evaluation regarding temperature.
But my Kth (C/W) is measured on the flange
So maybe there is a temp. gradient between copper and flange
It depends also of running time (0.5 minutes maybe doesn't corresponds to your test)
Also my freeware takes into account an ESC internal resistance (including ESC wire lengths, and connectors) that is evaluated.
It is possible that my freeware is slightly optimistic, but my goal was to give an order of magnitude.
Sure, as Drive-Calc is based on a dynamical Rm averaged for several real world tests, with the exact ESC, it could be better.
But if you change ESC or voltage, maybe the accuracy is less
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old Apr 08, 2008, 09:17 AM
.
Joined Nov 2006
732 Posts
edited
prinz is offline Find More Posts by prinz
Last edited by prinz; Nov 10, 2008 at 04:04 PM.
Reply With Quote
Old Apr 08, 2008, 11:24 AM
Registered User
Carl Petersen's Avatar
United States, AZ, Quartzsite
Joined Mar 2002
1,630 Posts
Quote:
Originally Posted by Fourdan
Hi
In the library, I can put myself if I know two coefficients, got after measurements. So I am interested when vendors send me props I have not.

If you have results for any Scorpion motor + any prop
Voltage at ESC input (not the pack config, that is too much uncertain)
DC Current at ESC input
rpm
thrust if possible
I can do, if I am confident

Another solution is to use "generic" with default coeff Kpower=Kthust=1
Scorpion Calculator is compiled with the prop library

Louis
Thanks for the reply. Thrust is going to be difficult to get but I'll supply what numbers I can get for these new props.
Carl Petersen is offline Find More Posts by Carl Petersen
Reply With Quote
Old Apr 30, 2008, 04:01 PM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Scorpion Calc v3.06

Hi
Scorpion Calc is up-dated
v3.06 for Metric or Imperial (preferences are saved)
Go to post#1 in this thread
Please destroy older versions (but first ... test the new)
Recently tested S4025-10, S4025-12 and S4025-16
New prop APC 18x10E (#228 n100W = 2997 rpm)
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old May 01, 2008, 12:34 AM
.
Joined Nov 2006
732 Posts
edited
prinz is offline Find More Posts by prinz
Last edited by prinz; Nov 10, 2008 at 04:22 PM.
Reply With Quote
Old May 01, 2008, 04:00 AM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Quote:
Originally Posted by prinz
and the G1 / G2 distinction ?

ralph

www.powercroco.de
Hi Ralph

For now I have no precise info-advice from Georges or Lucien to place a suffix and to complete the list as a function of versions, as I told them. They are very busy .. sure.

But you are right ... it would be a good improvement.

I think that Georges & Lucien are listening about that.

Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old May 14, 2008, 12:47 PM
Registered User
Joined Feb 2002
63 Posts
Louis,

Excellent work. I have been using my own excel spreadsheets for years to get better results than commercially available software. However, your version gives the most accurate results I have seen.

I actually measure the Kv, Io, and Rm of each of my motors. If I plug these values into your application, I get extremely accurate predictions on both current draw and prop rpm. This is based on recording data from an eagletree logger both on the ground and in-flight.

I do have one minor issue. It seems that the pitch speed calculation is off if you use a gearbox. For example, if I put the gearbox ratio at 4, the motor speed and prop speed are correct but the pitch speed is low by the multiple of the gearbox. I can just multiply by the gearbox ratio to get the correct value, but I thought you might want to fix it.

Thanks,

Steve
stevemangum is offline Find More Posts by stevemangum
Reply With Quote
Old May 14, 2008, 07:53 PM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Quote:
Originally Posted by stevemangum
Louis,

Excellent work. I have been using my own excel spreadsheets for years to get better results than commercially available software. However, your version gives the most accurate results I have seen.

I actually measure the Kv, Io, and Rm of each of my motors. If I plug these values into your application, I get extremely accurate predictions on both current draw and prop rpm. This is based on recording data from an eagletree logger both on the ground and in-flight.

I do have one minor issue. It seems that the pitch speed calculation is off if you use a gearbox. For example, if I put the gearbox ratio at 4, the motor speed and prop speed are correct but the pitch speed is low by the multiple of the gearbox. I can just multiply by the gearbox ratio to get the correct value, but I thought you might want to fix it.

Thanks,

Steve
Hi Steve
Thanks for your flowers.
Regarding the pitch speed I have to check ASAP.
It will be fast then to fix the error.
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old May 15, 2008, 12:10 PM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Scorpion Calc v3.07

Hi
Scorpion Calc is up-dated
v3.07 for Metric or Imperial (preferences are saved)
Go to post#1 in this thread
Please destroy older versions (but first ... test the new)
Two bugs fixed
a) Gear Box & pitch speed
b) unit for altitude (m or feet)
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old May 15, 2008, 03:38 PM
Registered User
Carl Petersen's Avatar
United States, AZ, Quartzsite
Joined Mar 2002
1,630 Posts
Sorry to intrude but (on 3.07) if I save a file say test.mmc and attempt to reload it I get a data file corrupted message. Worked for me in a prior version.

Clue: Fails if using a custom entry for the motor. Does not fail for Scorpion motors.
Carl Petersen is offline Find More Posts by Carl Petersen
Reply With Quote
Old Jun 11, 2008, 05:35 AM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Scorpion Calc v3.08

Hi
Scorpion Calc is up-dated
v3.08 for Metric or Imperial (preferences are saved in .ini file)
Go to post#1 in this thread for download new release
Please destroy older versions (but first ... test the new)
Save/open bug seems fixed (to be confirmed)
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Old Jun 11, 2008, 07:18 AM
Registered User
Carl Petersen's Avatar
United States, AZ, Quartzsite
Joined Mar 2002
1,630 Posts
Save/open works for me here. Thank you Louis!

Next time you have the hood open on the program could the Propeller->Filter entry, in Preferences, be saved as well.

Thanks again...
Carl Petersen is offline Find More Posts by Carl Petersen
Reply With Quote
Old Jun 25, 2008, 05:17 AM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Scorpion Calc v3.09

Hi
Scorpion Calc is up-dated
v3.09 for Metric or Imperial (preferences are saved in .ini file)
Go to post#1 in this thread for download new release
Please destroy older versions (but first ... test the new)
New HK 3026 and HK 4035 Scorpion outrunners
Louis
Fourdan is offline Find More Posts by Fourdan
Last edited by Fourdan; Jul 01, 2008 at 05:43 PM.
Reply With Quote
Old Jul 01, 2008, 05:43 PM
Registered User
Fourdan's Avatar
Antony (France)
Joined Sep 2003
3,019 Posts
Scorpion Calc v3.10

Hi
Scorpion Calc is up-dated
v3.10 for Metric or Imperial (preferences are saved in .ini file)
Go to post#1 in this thread for download new release
Please destroy older versions (but first ... test the new)
Filter for props (preferences) is now saved
Louis
Fourdan is offline Find More Posts by Fourdan
Reply With Quote
Reply


Thread Tools