Brushless ESC Timing

[PatMc]

Posted by JayCee on 20/02/2011 18:23:08:

OK

 

Just ran everything up again, reset the throttle that's not the problem ( I would have felt and idiot if it had just been that

 

Readings today Voltage 33.07 Amps42.98 Watts 1344.8

 

JC

Edited By JayCee on 20/02/2011 18:28:20

I can't explain why the power should have varied from your first tests but I'd say the motor has a lower Kv than stated. A bit academic given the ground clearance issue & fact that you've ordered the replacement but you'd probably get the required power with a bigger prop or going to 9 or 10 cells.

IIRC the stated Kv of Turnigy motors is claimed to be within 5% but I think they do vary beyond that & are sometimes incorrectly labelled.

 

PS I know about the throttle range check because I've accidentally re-set mine on a couple of occasions & had brief underpowered flights as a result.

Edited By PatMc on 20/02/2011 18:52:16

[Tim Mackey]

One aspect we haven't explored is the metering - any chance of using a different meter?

If not, perhaps at least connect a regular DVM across the battery in use and compare that to the figure shown on the wattmeter.

I could always send you my wattmeter to use if you want...but I would like it back afterwards.

[John Privett]

Pat - you beat me to it!

 

I was pondering this this morning and wondered about the motor. I've certainly heard of instances where a range of identical-looking motors exists with differing Kv's and at some point in the supply chain a motor gets mis-labelled.

 

JC - have you checked what revs you're getting from the motor? Theoretically a 295Kv motor on 30v would run at 8850rpm, in practice a little lower than that. If yours is running a lot lower then it may indicate a lower Kv motor.

 

(And you didn't need to go to the golf course to get wet today. You could have come up to the Downs and got wet with the rest of us this afternoon... Actually, it wasn't too bad - just a bit chilly.)

[GONZO]

Some more thoughts; the prop size at 17'' is at the lower size rating, what is the pitch?

Have you used a rev counter as well as the wattmeter and checked the revs at full power? Do the revs stay constant during each full power run? Could you have a sliping prop/prop driver?

I'm in suspenders (could be the wrong word) waiting for the answer to this problem.

[JayCee]

I'm confused!

 

Going through the programing sequence, in other words turn on Tx, move throttle to max connect power source, the ESC enters programing mode and goes faultless through the 14 items as listed in the data sheet.

 

However, Normal start up procedure:- Turn on Tx, move throttle to min, connect power source, the data sheets states you will here tone 123....which means the battery supply is OK....yes I do get that, followed by several beeps as it does a cell count...I DONT get that? could this be the issue? is the ESC not counting/finding the eight cells?

 

JC

 

 

[John Privett]

Gonzo - 17X10 is what JC said earlier.

On the question of the ESC gently turning the power down to avoid crossing the LVC, I share Tim's confusion. Well, not confusion exactly... I can quite see that an ESC might do that, but I wasn't aware that any did. Certainly the only ESC where I regularly encounter the LVC (on a little 400 heli) cuts the power off sharply, then reapplies it less than a second later as the battery voltage recovers. But that's just a cheap ESC.

[Tim Mackey]

Posted by JayCee on 20/02/2011 19:09:37:

I'm confused!

 

Going through the programing sequence, in other words turn on Tx, move throttle to max connect power source, the ESC enters programing mode and goes faultless through the 14 items as listed in the data sheet.

 

However, Normal start up procedure:- Turn on Tx, move throttle to min, connect power source, the data sheets states you will here tone 123....which means the battery supply is OK....yes I do get that, followed by several beeps as it does a cell count...I DONT get that? could this be the issue? is the ESC not counting/finding the eight cells?

 

JC

 

 

 

Im pretty sure that the default setting is "auto" cell detect and this does NOT give the beeps - user setting is required to activate cell count beeping - I think

[Tim Mackey]

Posted by Tim Mackey - Administrator on 20/02/2011 17:00:58:
Incidentally, I do believe this model can be user set to "beep" count the number of cells detected at boot up - maybe this should be deployed too JC? It requires a user setting and therefore you ideally need the program card that you have - I believe, ordered.

 

 

AS stated in my earlier post

[Tim Mackey]

Manual

[JayCee]

Just clutching at straws

 

Yes the default is auto!

 

Jc

[JayCee]

Thanks Tim

 

Yes I found my original, seems like a reasonable bit of kit

 

Jc

[JayCee]

JP

 

You might have to come round for coffee and biscuits If I hear any more beep beep, ding dong 1234 I'm going to go mad

 

JC

[JayCee]

Ok Guys

 

Further update to all who have been following this thread.

 

My replacement e-flight 110 motor arrived on Tuesday as did the Hobbywing programming card.

 

Decided to replace the motor first without making any adjustments to the ESC, and sad to say there was no difference in power So all you guys that said it was unlikely to be the motor were correct.

 

So one thing to note here the Turnigy Clone Motor from HK is a bargain at about £35.00 the E-Flite cost me £147.00

 

So on to the ESC, Hobbywing HV Platinum series. The card was very easy to use and to cut a long story short managed to get about another 100 watts by trial and error trying different timing settings.

 

So total Watts in with a 17X10 prop is 1450 watts!

 

I guess the ESC could be faulty but it appears to program fine, again the recommended 85 Amp Phoneix ESC is another expensive bit of kit at about £150.00 money I can't really afford as I now have Two Motors

 

So the only way I'm going to get my magic 1700-1800 watts is to increase the prop size I guess Unfortunately there is a grounding issue so some further modification to the undercarriage will be called for......any ideas what the Watt increase would be if I went to 18X10

 

JC

[Tim Mackey]

I'd expect around 20% increase at least with an extra inch of diameter, less so with extra pitch therefore about 1750 Watts or so?

You may want to try an increase in pitch as well if you can - APC do an 18 x 14 or even higher.  HERE

Edited By Tim Mackey - Administrator on 24/02/2011 08:33:02

[Tim Mackey]

For an idea , here's the difference between a 14 x 7 and 15 x 8 on 6s and a 515kv motor. Approx 35% increase.

Click to see detail.

Incidentally - ignore the ESC temperature reading on the second test - glitch in data

Edited By Tim Mackey - Administrator on 24/02/2011 08:54:47

[JayCee]

Hi Tim

 

Thanks for all the info

 

Was a bit of a disappointment after shelling out on the E-Flite...I should have listened to the voice(s) of experience

 

But look on the bright side I now have a spare motor for another model.

 

Have contacted GC (were I purchased the ESC) as it's the only item left that could be causing problems, unless all the sums were wrong.

 

In the mean time I have ordered an APC 18X12.

 

I live down South, but going up to Newcastle for a long weekend it's my Son's 40th Birthday Party (told you I was old ) Leave tomorrow (Friday) so no PC until Late Sunday.

 

JC

[Tim Mackey]

You're welcome Jaycee - and that's exactly the right attitude - you now have a motor ready for the next project

As suggested earlier, it may well be that the motor wind is not quite on the Kv mark that it says...they can and do vary quite a lot - one of the hazards of the cheaper brands I guess.

I have known some motors to pull way more or less current than specified on a particular prop - and when I complained to a certain "purple" retailer about one such motor - I was told it was probably my measuring equipment - despite me owning three different such items, and also borrowing two further ones from friends, and all readings being within 2% of each other!

Still, there's plenty of other suppliers around to get my frequent custom

Enjoy your weekend - Im off to the slopes right now....25 MPH SSW

[PatMc]

Posted by JayCee on 23/02/2011 23:23:33:
...

So on to the ESC, Hobbywing HV Platinum series. The card was very easy to use and to cut a long story short managed to get about another 100 watts by trial and error trying different timing settings.

 

So total Watts in with a 17X10 prop is 1450 watts!

...

JC

I'd be a bit wary that there's any significant increase in power output. You really need to compare rpm to know if there's any gain. It could well be the case that the motor/esc combo is now at a less efficient setting.

[JayCee]

Hello Everybodies !

 

Back from my Son's 40th Birthday bash in Newcastle........Oh boy do they know how to party it' taken a full 24 hours to start walking straight

 

Just a quick update to anybody that's still interested!

 

The prop selection seems to be the answer to everything. Can't quite remember who posted that the prop I was using was at the low end of recommended props for the motor I was using, but had it in my mind that there were other problems.

 

But after eliminating everything else purchased a 18X12 was using a 17 X 10 and the power has gone through the roof, watts in jumped from about 1400 watts to 2160 watts at 72 amps...way to much, so have now ordered a 17 X 12 and 18 X 10 (getting expensive ) Hopefully will find a combination at about 1850 Watt which would be perfect.

 

Weather permitting will get a flight in within the next week and will post results.

 

JC

 

 

[Tom Wright 2]

JC While your trying props its a good idea to stick to the same brand.as different brands can give different results for the same pitch and diameter,

I did suggest trying a bigger prop way back in the post ,at that stage in the deliberations it would have been a quick and cheap way to establish what was going on,but i matters not we have all been on the lower part of the the leccy learning curve and at least you now have a nice posh motor which will give you the opportunity to compare performance against different price levels.

Glad to hear you are getting the watts you need,but keep in mind those safety margins,sacrificing a bit of ,can sometimes save a lot.

TW2.

[JayCee]

Hi Tom

 

As I said in an earlier post, I now have a spare motor for another project

 

All my props are APC (E) Also purchased a Tachometer so now have the full range of testing and programming equipment, so maybe next time I will be able to make a more informed diagnosis....as you say it's all part of the learning curve.

 

 

JC

[Bruce Austin]

Hi Guys

Merry Christmas, and hope Santa was good to you all!

I have been following this thread, but not for the specific described problem.

A totally different Newbie question. (Mr Moderator please bounce, this if I am raising this on the wrong thread)

I have just bought a HobbyKing ESC and it gives me timing setting options. AUTO, LOW, and HIGH.

There is also an option for frequency selection 16 or 8 kHz

Can somebody please provide an overview of why one setting is better than the other.

The ESC is not creating any problems, that I am aware of, but I have not flown it yet. Just doing all my setting up for a maiden, and would like to be sure. The motor is D2822 14 1450kv 160watts on 3S and 7X4 folding prop.

Go With the Flow

Bruce