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Forum Index : EV's : Foxcon Electric
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Trev Guru  Joined: 15/07/2006 Location: AustraliaPosts: 640 |
Swapped motors in the EV Hilux and with the motor out of the EV Hilux, we have done some initial testing for suitability &/or feasability for use in small aircraft. While the test was exciting, it also was dissapointing. The motor could only reach 1500rpm, 2000 needed. The motor could only draw 220A. The rpm too low to allow more amp flow. Batteries were at 150v. This test used the standard propellar normally used on the aircraft. The pulling force only reached 92kg, just over half of the Subaru EA81 engine with a 2.5:1 reduction drive. This motor would be good if we used a reduction drive, but we were hoping that we could do it direct drive. We changed the pitch of the propellar with some increase in pulling power. The next test will be with a shorter prop, smaller diameter.  
 
Trev @ drivebynature.com |
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oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Obviously having too much fun. Looks like the reverse problem of the windmill, now you have to match the blades to the power plant. If less pitch gave higher pull, then it sounds like lack of torque at the rpm you had been running. Seems like the battery was under done. If you have to resort to smaller prop at higher rpm, then one suspects just not enough grunt (motor or battery impedance) What was the terminal voltage at full prop power? Maybe the batteries are the limiting factor with their current capacity. May need higher battery voltages to get around the current deficiency of the battery design. ...........oztules Village idiot...or... just another hack out of his depth |
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| Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 640 |
oztules, lots of fun. Problem appears to be not enough torque at the RPM. But when the RPM is increased by decreasing pitch, then the motor can accept more current, which results in greater output power. We tested some other props, all varied in diameter, but smaller diameter than the original test. The results were just as much dissapointing. There was slightly more gain in thrust with the smaller props taking more amps at higher rpm, but nothing to get excited about. I have no problem (in the right gear/speed) getting 500 amps at 150v to the motor in the Hilux, but could not get that amount of amps with any of the props. Voltage was no problem - 150v The batteries cannot be the limiting factor, volts or available current. These Powersonic AGM are capable of delivering some 2000? amps. Motor, not enough grunt. It has a peak of 75kw. We could not get that much. The next test was done some time later by Foxcon. I was not there. 6 cheapy lead acids were connected (72v) direct to the motor and the thrust was similar to what we had acheived through the speed controller. Then 12 of these cheapy lead acids were connected (144v) direct to the motor. The thrust pulled the scales to the end of the slide (200kg of force), and nearly blew the fellow over that was standing at the back to read the scales. He tryed to push the scales back but it was hard up against the end, it was not going to budge. I wish I was there. That would have been so good to see. So........ this proves that it is not the motor. Could it be the speed controller ?????  
Trev @ drivebynature.com |
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| Robb Senior Member  Joined: 01/08/2007 Location: AustraliaPosts: 221 |
Do these motors have adjustable brush timeing. More current draw at higher RPM sounds like this is not your average dc motor as far as timeing goes. |
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electricman Newbie  Joined: 15/06/2009 Location: CanadaPosts: 1 |
How about a Re-Drive from a Rotax Ultralight or one from Eggenfellner Aircraft or Powersport Aviation? The one from powersport might be the nicest - since it was bult for a Rotary Engine - just might need different gears! www.myelectricfly.com/ and http://nogas96volts.blogspot.com/ for routine news |
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| Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 640 |
A little history check.... I really believe the speed controller was the biggest issue with the tests done posted above. I have worked with other controllers since which are much better. About the suggestion of Re-drive (previous post). As said above we were hoping for direct drive. As for sourcing.... no problem.... I make the Re-drive, cast and machine, see http://www.foxcon.com/Reduction-Drive.html  OK....now for an update In Sept we tested a QS motor, 12kW rated vehicle hub motor. Rated to max 1480rpm and said to be higher than 350Nm of torque. While the rpm is lower than we wanted, thought it would be a good motor to run a test anyway. Using the standard propeller on different pitch angles. Battery voltage of 155v. 28 degrees 1340rpm max 213A pull force of 84-85kg 23 degrees 1378rpm max 180A pull force of 84-87kg 18 degrees 1440rpm max 140A pull force of 78kg            Trev @ drivebynature.com |
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| Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 640 |
Today was testing a Golden Motor 10kW With factory settings in the speed controller..... Battery pack at rest 53v and under full load 46v. Standard propeller. Pitch angle 12 degrees 219A 1950pm pull force of 96kg Pitch angle 15 degrees not as good as 12 degrees. This so far has the highest pull force and the least draw of power. Seems too good to be true, but that's what we measured.     Trev @ drivebynature.com |
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