HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 09, 2013, 06:25 PM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
Help!
Delayed Motor Start ... ESC Problem?

Hi All,

Problem #1:
I bench tested my hotliner setup today, and noticed that about 3 motor runs out of 4 there is an unexpected/unwanted startup ramp, and this startup ramp varies in duration from about 1/2 second to 1 second before full throttle is reached. This ramping is accompanied by a "electronic/straining" type noise, which may or may not be normal. On the 1 or so occassions out of 4 that there is no ramp, the motor immediately goes to full throttle, which is what I have my ESC (cc125) setup to do ("fast" start is selected via Castle Link). Screen shots of my ESC settings (both advanced and basic) are shown below. The settings I chose are the same as those recommended on Neu's website for F5B using the cc125. I also included some Unilog readings. It can be seen that there is a small hump in current/power/rpm before full throttle is attained (it should be noted that I have seen similar humps with several other setups of mine that don't have this issue, however).

Problem #2:
I noticed that after maybe 1 motor burst out of 5 or 6, the prop windmills a bit, rather than braking hard, which it is programmed to do.

Some other facts:
-The spinner is close to the fuse; however, I do not see or feel any contact between the two.
-The motor is brand new
-The ESC has version 1.23 (from way back) and is allegedly brand new, though I bought it second hand from RCGroups and have not run it with any other motor
-There is no throttle ramp on my Tx that I am aware of, and I used the same model memory to power another glider that does not have this issue
-The battery leads are about 3-4 inches in length. The ESC to battery leads are about 3-4 inches in length. The ESC to motor leads are about 1 inch in length.
-The bullets from the ESC are not the same as those from the battery. The bullets don't quite bottom out in their connections, leaving a gap of about 0.5 mm. Otherwise, the connections seem solid, and the bullets are not cheapies.
-I believe that all solder joints are good.

Setup:
Neu 1506 1D w/ 6.7GB (brand new)
cc125 version 1.23 (allegedly brand new, but bought second hand)
2s 5000 mAh 65C (brand new, with properly balanced cells)
6 mm bullets (pairs don't match perfectly; but, both types of good quality)


Any advice would be greatly appreciated.

AEM
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Last edited by AEMontoya; Feb 10, 2013 at 12:01 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 09, 2013, 07:52 PM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
7,302 Posts
Why the old firmware version?
jackosmeister is online now Find More Posts by jackosmeister
Reply With Quote
Old Feb 10, 2013, 01:38 AM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
Quote:
Originally Posted by jackosmeister View Post
Why the old firmware version?
I bought a RTF plane from way, way back that another RCGroups member built and left sitting around for years. I hear that the older firmwares of these are actually in demand among F5B pilots nowadays; so, I have kept it the same.
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Old Feb 10, 2013, 01:40 AM
Registered User
steveburns's Avatar
Chipping Norton, UK
Joined Jan 2005
749 Posts
Try updating the firmware to 1.56 or 2.11, I've ran 2.11 for the last 2 or 3 years on my CC180's
steveburns is offline Find More Posts by steveburns
Reply With Quote
Old Feb 10, 2013, 01:42 AM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
I just ran the setup some more, doing 24 motor bursts in total. It's almost like the problem is going away. Only 4 of the 24 runs involved the slow startup, and only one of the runs involved the windmilling brake. I have no idea why the problem is so much less frequent than before.

My suspicion about the source of the problem is that it's some sort of timing issue, and that perhaps it exists because of the unusually high kv and wind type of the competition Neu 1506 1D?
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Old Feb 10, 2013, 01:46 AM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
Quote:
Originally Posted by steveburns View Post
Try updating the firmware to 1.56 or 2.11, I've ran 2.11 for the last 2 or 3 years on my CC180's
Thanks, Steve. I noticed that on the data sheet you provided, it says that the data is for the cc180. However, down at the bottom, Phoenix 125 is listed as the device. Do you recommend I try the parameters on that data sheet with my cc125, in addition to upgrading to a newer firmware?
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Old Feb 10, 2013, 06:54 AM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,134 Posts
Hi, there could be a few different things at play here.

First of all, voltage under load is probably around 3.3-3.4V per cell and with 2S that makes only 6.6V or so. This means that on the logic board the voltage goes from 6.6V down to 5V and then back up to 10V through a voltage doubler to provide power for the fet drivers. In this case going from 6.6V down to 5V is easy for the small SO8 chip on the corner. However the voltage doubler still has to provide a solid 10V when it has no overhead to keep this 10V under load. A voltage tripler that provides 15V then drops it down to 12V would have a better chance to maintain 12V due to the 3V extra available when placed under sudden load. Myself, George and others have long since suspected that this voltage doubler is the weak link on the stock P80/P125/P180 logic board.

Unfortionately doing the big mod to this controller would not help you as you need a minimum of 12V under load for this to work. Fine when you run 4S or more but you can not do that with this motor.

I could find an appropriate voltage tripler and modify your logic board but this is not something i would advise you to try your self.

The second thing is, if you where to take it a bit more easy on the controller then the voltage doubler would have a better chance to keep up with things. This unfortionately may not be sufficiently possible with the stock CC firmware as it uses a very hard startup sequence with a low switching frequency. George's firmware is better in that respect.

It would however help if you changed the startup power down to something a bit more sensible like 20%. On your old firmware this means going down to Soft Start (softest) and would also effect the throttle responce as in this old version these two features are still joined together. You would get an initially slow but then harsh exponential power increase as a result. Better would be to upgrade to V1.56 or V2.16 (i am using this one) where you can set the throttle responce seperately (advise between 6 and 8 max) then set the startup power to 20% manually. This may go a long way to ridding you of the problem.

Regarding the brake not working well. This can be down to two reasons. Again it could be due to the voltage doubler flaking out but it could also be due to your settings. You should use 100% brake power but reduce the brake ramp to ''fast''.

Note, you are very close to burning this speed controller as you can clearly see it is not running well. So i would advise against repeated testing if you notice something is still not working well.

Joe
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Feb 10, 2013, 07:08 AM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,134 Posts
Mmmm, having just seen the power graph. I suspect it is the voltage doubler flaking out as the startup pulse is only about 100W. Reducing the startup power to 20% would only reduce this further when it is actually not to bad. Probably due to only running 2S.

We have not tested the budget 200A controller with this motor yet but the amps are within reach and it has a voltage tripler already built in. Could be worth trying this and saving the P125 for another setup, do the big mod on it and then run it on 4S to 6S. Note that George still only uses a P125 for F5B at world championships level so don't waste this one.
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Feb 10, 2013, 11:33 AM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
Thanks for the very informative post, Joe. I will upgrade to a newer firmware today. I wanted to keep the older one, because Castle themselves, about a year or so ago, announced that they recommend v1.23 for F5B setups, and other pilots seconded this. I don't know if the version you mentioned was out yet, though.

The thing that is strange to me is that I thought this combination of motor and ESC was tried and true, having been used successfully by many others in the past. That's one of the reasons I keep suspecting that the ESC is "bad."

Note: I just added the voltage readout in the Unilog reading above. With my untrained eye, it doesn't look like anything is peculiar with the voltage.
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Last edited by AEMontoya; Feb 10, 2013 at 12:02 PM.
Reply With Quote
Old Feb 10, 2013, 12:40 PM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
Okay; I just test the new firmware and recommended settings (see attached data sheet)--no dice.

I gave the motor only 2 bursts, and the problem is just as before, if not worse: slow, jittering/shaky spool up before full power. And, I have to say, when I had it running with a higher degree of success yesterday, it seemed that the "pull" was a lot harder once full power was reached.

I think I am through testing this ESC, at least with this setup, as the last thing I want is a fire in my new plane.
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Old Feb 10, 2013, 12:50 PM
Registered User
sneu's Avatar
United States, CA, San Diego
Joined Dec 1999
7,344 Posts
Quote:
Originally Posted by AEMontoya View Post
I just ran the setup some more, doing 24 motor bursts in total. It's almost like the problem is going away. Only 4 of the 24 runs involved the slow startup, and only one of the runs involved the windmilling brake. I have no idea why the problem is so much less frequent than before.

My suspicion about the source of the problem is that it's some sort of timing issue, and that perhaps it exists because of the unusually high kv and wind type of the competition Neu 1506 1D?

Timing for "D" wind motors should be set to the lowest advance setting available. I would also suggest trying the highest PWM rate available--we have seen it help improve startup issues.

Steve Neu
sneu is offline Find More Posts by sneu
Reply With Quote
Old Feb 10, 2013, 02:20 PM
Registered User
Mark Haigh's Avatar
Barnsley, Great Britain (UK)
Joined Dec 2000
662 Posts
Quote:
Originally Posted by sneu View Post
Timing for "D" wind motors should be set to the lowest advance setting available. I would also suggest trying the highest PWM rate available--we have seen it help improve startup issues.

Steve Neu
Steve,
What timing would you recommend for your 'Y' wind motors.

Cheers,
Mark
Mark Haigh is offline Find More Posts by Mark Haigh
Reply With Quote
Old Feb 10, 2013, 02:24 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,134 Posts
Quote:
Originally Posted by AEMontoya View Post
I think I am through testing this ESC, at least with this setup, as the last thing I want is a fire in my new plane.
I think that is a very wise idea.

Your best bet is to send the controller or just the logic board to me and in the mean time i could send you a budget controller.

Regarding the ''tried and tested'' thing. Electric parts differ as they come off the production line, some parts are better then others and i suspect the voltage doubler. You would have the same problem with more volts and a lower Kv motor on this ESC. The great thing about the big mod is that this voltage doubler is replaced by a much more capable 12V linear regulator.

In the past we have always kind of thought it was the SO8 over heating on higher input voltages as it has to then turn 25V into 5V where 20V becomes heat. Altho there is a lot of truth to this, lately it seems more and more that the actual problem is the weak voltage doubler. In that case you can have a problem running on 2S as much as on 6S.

For those out there who have burnt an ICE controller, ask your self if you have any idea about how the power feed to the fet drivers is done.

jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Old Feb 10, 2013, 02:29 PM
AEM
AEMontoya's Avatar
Bay Area, CA
Joined Sep 2009
988 Posts
More Test Results:

I exchanged the original cc125 with another cc125, and the problem persists. I also used a different RX to no avail. I also tested my TX with the same model memory with another model, and there was no problem. I tested the motor with a multimeter to make sure the resistances between the different motor leads were zero and that there was infinite resistance between each lead and the motor case--all checked out well.

In all, it seems that the problem is either in the brand new motor (direct from Neu Motors), or has to do with ESC settings.

I will try what Steve Neu recommends regarding ESC settings.
AEMontoya is offline Find More Posts by AEMontoya
RCG Plus Member
Old Feb 10, 2013, 03:46 PM
Needs to do 52 legs !!
jjmouris's Avatar
Verenigd Koninkrijk, Fareham
Joined Aug 2008
7,134 Posts
Interresting, it is unlikely for both P125's to show exactly the same behaviour. I would have thought that most of them would be OK with this setup in stock form.

Having said that, the budget controller using George's firmware has a completely different startup routine and you may find this to be much better. Please have a look on my blog and you can also discuss there if you find you need to adjust the software further to suit this motor.

I would save the P125's for use with the big mod and 4S to 6S. Works well with a Neu 1512/1.5D or similar.
jjmouris is offline Find More Posts by jjmouris
RCG Plus Member
Latest blog entry: My F5B saw tooth props
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Quad motor not starting. ESC maybe? Spacenutz Multirotor Talk 10 Jan 27, 2013 07:53 AM
Help! Motor/ESC problem after soldering?? low beeps and motor wont start calle3 Micro Helis 0 Jan 14, 2013 12:58 PM
Discussion Hexa--5 motor starts and one delayed--??? quadman Multirotor Talk 3 Apr 19, 2012 03:45 AM
Discussion Why one of 6 Motor Delayed start??? quadman Multirotor Talk 5 Jan 12, 2012 09:18 PM
Question Align 35A Governor ESC delay at start up thanhTran Mini Helis 2 Jan 02, 2006 01:34 AM