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Old Sep 10, 2012, 11:19 AM
Lee Liddle
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But if you are talking about two motors on one shaft, that will change everything because the rpm will be much higher for the fan to hit 12lkw, but each motor will only carry 1/2 the load so the 880kv may be great on 14s when run in pairs. It would hit around 40k rpm. 33k takes about 6kw. If the motors will sync it might be awesome.
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Old Sep 10, 2012, 11:22 AM
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The twin idea is another project

This is just for the setup that was started on this thread but it seems the stock motor will pull too much current.

I think I might try the twin though it since the KV seems to be close. Perhaps a tungsten shaft?
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Last edited by Air Head; Sep 10, 2012 at 11:48 AM.
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Old Sep 11, 2012, 06:55 PM
Lee Liddle
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The YEP 120 can easily do 140a on 12s as long as it has good airflow.
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Old Sep 12, 2012, 02:49 AM
speedin n da weeds :)
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That car place has a esc that is 300 amps 2 150 amp esc that use the same pwm so both esc get the same synchronized spin per motor.
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Old Sep 12, 2012, 11:42 AM
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6 phase motor

Have you seen this?
Turnigy C8085 BLDC 6-Phase Dual Controller Rewind (4 min 29 sec)
Why use 2 motors when you can package all in one?
I do not think any motors are made to match. So you will have to measure winding resistance. If they do not match then you will have to rewind so you can have a matched pair.
Also see http://www.rcgroups.com/forums/showthread.php?t=746922
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Old Sep 12, 2012, 05:12 PM
speedin n da weeds :)
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I don't think it has to 100% even to work..... One motor may pull a few more amps... but within reason.... the power both motors make would be crazy! I think losing sync on one motor would over load the other one is what needs to be looked at..
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Old Sep 12, 2012, 05:42 PM
Lee Liddle
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Wow, what a cool idea! I`ve got to play with this for sure. Another advantage for a high rpm edf motor is that not only would the amps be 1/2 for each esc, but the pwm rate would only need to be 1/2 also. PWM can be an issue with high pole count motors. Very, very interesting.
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Old Sep 12, 2012, 08:25 PM
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Quote:
Originally Posted by sikky View Post
I don't think it has to 100% even to work..... One motor may pull a few more amps... but within reason.... the power both motors make would be crazy! I think losing sync on one motor would over load the other one is what needs to be looked at..
This guy knows allot about motors-- http://www.rcgroups.com/forums/showp...53&postcount=4
He says there maybe problems on start because of sync problems. But once they start the esc will sync themselves to the motors.
This would be the same if using two motors tied together. If the motors are matched then there should be no timing issues other than start.
More reading - http://www.rcgroups.com/forums/showthread.php?t=1665401 read first post. "Operation at start-up and low rpm is a bit rough yet it starts to sing above 1500 rpm or so. " He also said that he did not know the timing of the esc
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Old Sep 12, 2012, 08:48 PM
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Christian Lucas on rc groups has experimented with this for years. Look him up for information on 6 phase.
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Old Sep 12, 2012, 10:22 PM
Lee Liddle
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That makes sence because a motor running with a prop or rotor is constantly adjusting to different load conditions. The esc works to keep the motor running a a constant rpm based on the position of the throttle. So slight diff in the motors should be treated by the esc like any other load condition.
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Old Sep 14, 2012, 05:40 PM
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YEP 120 settings?

Hi Lee

Would you know what settings I should use?

What do you think about adding a heat sink?

Thanks

Rick
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Old Sep 15, 2012, 07:25 PM
Lee Liddle
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I`ve never used the YEP with the Turnigy 4030-880 motor but it should work fine.

You need fast start which is set up in the initial programing part. Then I use auto detect for cell count. I`m using high PWM and try both 15 and 30 degree tomming.

As long as you have some cool airflow over the esc, it should be good for 5kw without an added heat sink. I`d recommend cutting the heat shrink and the label off of the existing flat heat sink for better cooling. Also I see no reason that you couldn`t leave the existing flat plate in place and then glue an aux heat sink directly to it with something like JB Weld.
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Old Sep 23, 2012, 09:40 AM
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Rotor Trim

I am about to cut down the rotors and dont know how much clearance I need.

How much gap should there be?

Thanks for the help

Rick
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Old Sep 23, 2012, 10:01 AM
Lee Liddle
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I shoot for 1/16". A little more doesn't seem to affect performance much.
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Old Oct 11, 2012, 03:57 PM
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Change Sun 4 blade and T600 880kv motor

Has anyone used one of these fans? It seems that the flat on the motor is causing the shaft adapter to have about 0.60" runnout.
Looks like the shaft needs to be changed.
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