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Old Apr 05, 2012, 09:34 AM
Carbon fiber is our friend
Steve C's Avatar
United States, CA, Lodi
Joined Feb 2001
4,164 Posts
Quote:
Originally Posted by awrightbrother View Post
Has anyone tried this method?
Locating the ESC close to the battery, and extending the motor drive leads.
This is what I've been doing for years and the reason why you probably won't ever see me put the ESC in the fairing behind the motor. I've had really long motor wires and never had a problem. Even twins with one esc in the fuse have been ok. Of course, all bets are off with CC but I quit buying those for my own planes some time ago. If you take away long battery wires and CC controllers, I haven't had any failures that I can think of since. That makes me smile, 'cause I burned up more than my share before those changes!

SC
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Old Apr 05, 2012, 09:53 AM
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Quote:
Originally Posted by erh7771 View Post
KV of the motor changes with longer ESC leads.
I don't think that the KV of the motor changes with longer motor leads to the esc. What determines a motors KV are the amount of turns the wire takes around the stator and the strength of the magnets (if magnets get overheated and lower their magnetic strength, the KV increases).
The only issues I'm aware of is possible radio interference from emf which is easily solved by twisting the leads to null it out.
If the back emf isn't functioning correctly, you should know immediately as he motor won't operate correctly.

Terry
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Old Apr 05, 2012, 11:01 AM
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United States, TX, Grand Prairie
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Originally Posted by Chuchuf View Post
I don't think that the KV of the motor changes with longer motor leads to the esc. What determines a motors KV are the amount of turns the wire takes around the stator and the strength of the magnets (if magnets get overheated and lower their magnetic strength, the KV increases).
The only issues I'm aware of is possible radio interference from emf which is easily solved by twisting the leads to null it out.
If the back emf isn't functioning correctly, you should know immediately as he motor won't operate correctly.

Terry
KV should be RPM in my statement..., the RPM of the motor would drop with longer esc leads to the motor because of resistance...
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Old Apr 05, 2012, 11:15 AM
Pursuit of Happiness
Ron101's Avatar
Brentwood, California
Joined Jul 2007
7,182 Posts
All good stuff guys...
I'm ordering caps this morning and will use the 330 UF on my stuff with shorter y harnesses..... where I don't need so many caps
But on something like my F-18 which needs a 30 inch lead I'll go to the bigger 680 uf's and run five instead of needing 10

I know the extending the motor wires or power lead debate has gone of for sometime... I have used both with good results as I know many others have to with the use of added caps

As for the ESC in the tailcone debate.... I have also done it both ways with good results. I think it's good to be flexable and do what is best for a given project

Take my twin F-18... there is no good place to mount the ESC forward of the fan and get any cooling to them... it will carry two sets of warm 12s 7800 mah packs adding heat to the inside of the fuse. The tailcone on the motors is the best place for the ESC in this case. In my Hawk and Spark... I found good spots forward of the fan to get cooling. So you just have to go with what works....

We know that BVM and Tam have both had great success with the ESC in the tailcone.....many have had thermal issues with no cooling (but that is for another thread ) I've had good luck with either setup as long as you think it out and plan well... naca ducts, added fans, caps, resistors... ect. can all help
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Old Apr 05, 2012, 11:35 AM
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"I asked him about adding caps in the middle of a long wire and he was under the impression that it would create more variables than take away "

I agree with that. First order approximation using a lumped capacitance approach like Castle has done should get you the majority of the benefit in smoothing out the voltage signature.
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Old Apr 05, 2012, 11:47 AM
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United States, TX, Grand Prairie
Joined Nov 2005
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K, ....sigh

Why doesn't caste simply add bigger caps to the ESC to smooth out current flow?

Caps are relative inexpensive and light...and easy to attach....

Cause it's not the caps, it's the FETs are out of tolerance from factory...SUPPO esc's went through a bout of bad FETs on their esc's and they were gimped because of it.

It only takes one to fail or heat up to the point were its properties change and make others fail...

Yaws take?

TIA
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Old Apr 05, 2012, 01:50 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
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just sent my CC collection of ESC's in for the recall ...hope i did it right ....what a pain. it says 6 weeks on there web site .
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Old Apr 05, 2012, 01:57 PM
Pursuit of Happiness
Ron101's Avatar
Brentwood, California
Joined Jul 2007
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Quote:
just sent my CC collection of ESC's in for the recall ...hope i did it right ....what a pain. it says 6 weeks on there web site

it may take longer Roger... it said 6 weeks when I sent mine in early in the recal and it took over 2 months and kept all my best planes grounded.


Oh I missed you question on smaller ESC I won't add caps to my 3s, 4s, 6s, stuff.... it's been working fine. Even my Spark is on 11s with an old CC110hv ...it's got so many flights I'm not worried

Just adding to my new CC 160 HV 2 12s setups
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Old Apr 05, 2012, 03:09 PM
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Originally Posted by AIR SALLY View Post
just sent my CC collection of ESC's in for the recall ...hope i did it right ....what a pain. it says 6 weeks on there web site .
I waited till the rush was over and sent one in last month and had it back in less than 2 weeks.

Terry
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Old Apr 05, 2012, 04:47 PM
Pursuit of Happiness
Ron101's Avatar
Brentwood, California
Joined Jul 2007
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well that's good news!! cool
sounds like they caught up
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Old Apr 05, 2012, 05:45 PM
Aka: Tom Jenkins
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Palm Beach County, Fl.
Joined Aug 2008
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Here's a good question, would caps help on 3s, 4s, 5s when using partial throttle mostly during a flight? After following the links posted here it seems like a good idea regardless of lead length. I half understood the switching more at lower throttle and the inductance thing.
Thanks!
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Old Apr 05, 2012, 05:52 PM
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Joined Feb 2010
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Its a good question. Why is Castle selling a cap pack anyways. Because of under-design? I wouldnt think so since the recent HV2 gave them the opportunity to rev the design entirely if they didnt feel it was sufficient. It could be simply due to form factor alone or form factor together with cost to go with something that works for most end users(staying positive here I know). And for a select few, which may have slightly different requirements they are able to sell them an additional product that must have some decent margin for them. Does the Castle Link data log software have a popup that says "We noticed your data log and hey you need the cap pack - click here to buy now". Now that would be definitive.
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Old Apr 06, 2012, 12:08 AM
3DHOG
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USA, CA, Aromas
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db
Castle sells cap packs because guys want to/need to lengthen their battery wires. if you look at your esc, any esc you will see at least two caps on the end. those are for a 12in wire length, 6in for the esc side and 6in for the battery side. this is how all esc's are designed. so it doesn't matter if its a castle esc or any other esc if you lengthen your battery wires then you should add caps for the additional amount of wire. their is no design flaw or conspiracy
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Old Apr 06, 2012, 08:11 AM
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bri6672's Avatar
San Diego
Joined Jul 2009
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Quote:
Originally Posted by jcdfrd View Post
db
Castle sells cap packs because guys want to/need to lengthen their battery wires. if you look at your esc, any esc you will see at least two caps on the end. those are for a 12in wire length, 6in for the esc side and 6in for the battery side. this is how all esc's are designed. so it doesn't matter if its a castle esc or any other esc if you lengthen your battery wires then you should add caps for the additional amount of wire. their is no design flaw or conspiracy

Exactly! The caps included should be sufficient for most planes but when we start making our wires super long that's the problem.

Seems like some of you are missing the point, before you go running off and buying caps, do the math I shared earlier in the thread and see if you even need them. NOT doing the testing and reviewing the data correctly is why alot of esc's end up as charcoal. And if temps are not correct, well caps are not going to help that. Seems like alot of people never even look at the data, if you are going HV that should be mandatory!
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Old Apr 06, 2012, 08:24 AM
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United States, TX, Grand Prairie
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Quote:
Originally Posted by bri6672 View Post
Exactly! The caps included should be sufficient for most planes but when we start making our wires super long that's the problem...
I've had 2 castle esc pop FETs with less than 1' cables....one with spark resister.

and when I say FETs its the Fets...not a regulator or some resister or the MCU got spiked...the FET cracked almost in half

They replaced the ESCs promptly

Thank goodness they were all on the ground, one guy who's been flying with them for years popped them on hook up of 6s pack 5 months ago.

It's not voltage run time variances, to fix that it's cheap and light and easy...
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