Worried about Significant change in Hacker C-50 AMP draw! (Full Version)

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KeithB -> Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 6:40:25 AM)

After flying today I took a look at the graphs from my data logger and was quite alarmed to find that the amperage draw was about 20% higher than normal, yet the RPMs were not at all higher, if anything slightly lower overall.

Nothing has changed in my setup since my last outing. No controller change, no motor change and no radio change. I’m sure the gears are well greased because I greased them about 15 flights ago. My motor never gets over about 118 degrees during flight, and this is only on days in the high 90’s. Normally it stays in the 95 deg. to 105 deg. range (until after landing at which point it will rise to about 135 deg.).

I’ve included graphs of a flight 6-30-06 and today 7-6-06. No changes, same prop.

After seeing this I preformed a test at the house tonight and used a second AMP meter and sure there wasn’t a problem with the data logger. It confirmed data loggers numbers in the upper 70’s. Normally it peaks out at about 65 amps with the 22x12 prop.

Has anyone experienced this before? I’m worried that I’m about to have a bearing or gear failure, which I can’t afford with NATS in just a week and a half away. I also don’t want to put the extra strain on my batteries. Today the voltage dropped all the way down to about 30.2 volts. Prior to this the lowest I’ve seen is about 32 volts.

If anyone’s seen this behavior before or has a guess of what may be happening please let me know.

Thanks,
Keith B



Benoit -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 7:06:18 AM)

Hi Keith,
I am not a E specialist but if you have less Volt, you need more Amps to get the same power.
65ax32v= 2080w and 70ax30= 2100w
So, it could be a batterie problem which put the voltage down. ( 1 cell could be tired?)
Hope it helps.
Benoit



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 7:43:49 AM)

Benoit,

Thanks for your reply.

Actually, that's the first thing that I thought, that it was a battery problem.

I did two things to rule this theory out. First, I plotted and compared the wattage from the 6-30-06 and 7-6-06 flights and found that there was clearly a higher wattage draw on the 7-6-06 flight. Second, I performed tests with multiple battery packs and found the higher amperage draw in both cases.

See chart below.


Keith B



rm -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 8:54:37 AM)

Probably the rotors slipped if you haven't over heated the motor. Could be demagged if over heated. You should send it to Hacker. The amps will just keep climbing until your esc turns into charcoal one day down the line.



Benoit -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 9:23:56 AM)

Keith,

In case of battery problem and lower Voltage, the input wattage could be higher to get the same RPM (or output power) because motor efficiency should be lower at highest Amps.

But as you got the problem with several batteries, you are right, it should be something else [:o]




KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 10:15:10 AM)

Interesting new info...

I swapped out ESC's and there was some definite difference. The amperage and watts didn't get nearly as high, but the RPM's also didn't get quite as high. I switched to a fresh battery and the RPMs were much closer to the previous ESC, but the Amps and Watts are clearly much lower.

Tomorrow I'll check all the solder joints on the original controller to see if maybe a bad connection is causing the problem.

Attached pics show the difference between the two ESC's. Only thing that concerns me is why the RPM's are also lower on the new ESC.

Keith B




Pattern_is_Fun -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 10:30:07 AM)

I had a similar experience, Hacker C50-14XL, 22x12 prop, all last year I pulled 63-64A, I used the Hacker 77-O ESC. No issues. Early this year my current went to over 70A - do not know the actual current, the AstroFlight Watt-meter I used limited at 70A, but the 77-O controller would current limit and shut the motor down - IN FLIGHT!! Tried many things, sent the motor back to Hacker, and they told me the armature had slipped and was rubbing on something.. they replaced this for free, installing a new armature - I do not have the motor back yet, but 'it's in the mail'.


sc



can773 -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 5:32:55 PM)

Keith

Which batteries are these?

Thanks,



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 6:47:31 PM)

Falcon 5s2p F3A Pro Series. www.falconbatteries.com/custompage.aspx?page=proseries.htm&selection=custom.

Keith



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/7/2006 11:41:43 PM)

Additional new info.

I spoke to Kyle at Hacker and he said based on what I told him and the charts that he thought I may have had a rotor slip. It should be covered under warranty and he's going to try and turn it around quickly before NATS.

I did a test run on both my C50 COMP motor (backup that was going to go in the next plane) and the Current motor in the plane. Both tests were with the same battery and the old ESC. It's very clear that something is wrong with the motor itself.




rm -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/8/2006 5:05:35 AM)

I'm curious if the one your sending in is also a comp motor?



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/8/2006 5:27:12 AM)

RM, the one I sent back is not the COMP motor. I have one Standard C50 and one Comp C50.

Keith B



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/8/2006 5:35:11 AM)

I went and flew the plane with the replaced motor, which is a C50 Competition motor. The one being replaced is a Standard C50. I continued using the Standard Master 90-O controller because Kyle and Hacker felt the problem was not related to the controller, and my static tests looked much better with the new motor.

The data logger verified that the replaced C50 Comp motor significantly reduced the Amp draw, however, I’m disappointed that it didn’t reduce it back to what was the norm prior to things going south. Values are peaking at or slightly above 70 amps, where as I have quite a bit of history with the Standard C50 on the same prop (22x12) where peaks would be at 65 Amps. Looks like I’m still about 8% above where I used to run. Furthermore, my voltage drop is still greater (testing with 3 different flight packs) than when things were working well.

I guess the next test is to replace the ESC, but I have a hard time understanding how the ESC could keep working perfectly well but start drawing more current. I’d think ESC failures would be more binary (working or not working).

The following is a log of the first flight today with the replaced C50 Comp.

Keith B



BJM -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 2:24:43 AM)

What is a rotor slip

Billy



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 3:38:01 AM)

Not sure, something to do with the magnets. I may have the incorrect terminology, but I think that's what he said.

Keith



Pattern_is_Fun -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 4:08:39 AM)

This IS WHAT HAPPENED to my C50 also. They told me it was an armature - which does not make sense to me, but perhaps I misunderstood? As mentioned above, mine pulled in excess of 77A as the 77-O controller started limiting when this happened and the ESC shut down. Mine was replaced under warranty.

sc



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 4:16:24 AM)

Today I flew with the COMP Master 90-O ESC and COMP C50. Unfortunately I’m STILL confused.

Disappointingly the numbers still aren't back to what I’d seen for 100 flights. Today’s AMPS and RPM were both lower than normal.

I’d love to get some feedback from others that are running these combos (both Competition and non-Competition setups) to see if others have also seen these variations. It was my impression that my initial numbers were right in line with what they should be, but I don’t seem to be able to get back where I was.

BTW, the Competition C50 and 90-O are both new. Yesterday was the first time either had been flown.

Thanks,
Keith B






KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 4:40:36 AM)

In anticipation of anyone asking, my ESC setting are:

Brake: 35%
Timing: 3%
Frequency: 8 kHz
Accel: SOFT
Cut Off: SLOW DOWN
Initial Point: Fixed 1.1 ms
End Point: Automatic
Throttle Curve: Linear (Note, I also experimented with Logarithmical with no difference it peaks)
Timing Monitor: ON

I mention this because the charts above appear as though my throttle didn't reach the end point (full throttle). With a an End Point setting of AUTOMATIC, it should adjust to the top stick position it sees. I've been doing this with fairly consistent results for the last 100 flights. Today all four flights had similar upper AMP and RPM values.

If I had a tool to view the RX output in ms I would set a fixed End Point.

Keith B



patternrules -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 4:55:39 AM)

Keith I staring getting higher Amp readings also took the rotor out and same thing the disk was slipping or seperating ( has spaces inbetween each other) in a couple of places and thats the kevlar wrapped rotor.
Do have a question though why is your volts reading at max 20.2 on 10s ???
Steve Maxwell



carmatic1 -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 5:22:07 AM)


quote:

ORIGINAL: patternrules

Do have a question though why is your volts reading at max 20.2 on 10s ???
Steve Maxwell


as per
quote:

ORIGINAL: KeithB

Falcon 5s2p F3A Pro Series. www.falconbatteries.com/custompage.aspx?page=proseries.htm&selection=custom.

Keith


quote:

Pro Series packs are available in a configuration shown to be compatible for F3A competition type aircraft. The actual milliamp rating of each pack will vary slightly. Estimated amperage ratings are in the 5300 – 5400 mAh range. These packs are 5S2P, 18.5V configurations.


they are 5s2p, not 10s



patternrules -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 5:37:03 AM)

Can't fly these models on 5s or everyone would be doing it, has to be 10S, can't get 6000 rpm out of a C50 14xl at 1160 KV X 18.5 volts divided by 6.6 gear= 3251 at prop, I'm running the same motor standard with TP 10s 5300 = 2- 5s4p. Keith is running 2- 5s1p falcon packs. Keith ??? I'm guessing you have the logger on one side of the batteries and not inbetween the motor and controller??
Steve Maxwell
quote:

ORIGINAL: carmatic1


quote:

ORIGINAL: patternrules

Do have a question though why is your volts reading at max 20.2 on 10s ???
Steve Maxwell


as per
quote:

ORIGINAL: KeithB

Falcon 5s2p F3A Pro Series. www.falconbatteries.com/custompage.aspx?page=proseries.htm&selection=custom.

Keith


quote:

Pro Series packs are available in a configuration shown to be compatible for F3A competition type aircraft. The actual milliamp rating of each pack will vary slightly. Estimated amperage ratings are in the 5300 – 5400 mAh range. These packs are 5S2P, 18.5V configurations.


they are 5s2p, not 10s




rm -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 6:14:12 AM)

Steve, that's what he's doing. They log voltage depending on how you attach them, in this case he's hooked to one pack and not in series. Just double the voltage.

I'm no expert by any imagination, only what I've found on my own. The rotor is the part that turns inside the can of the C50. It consists of a shaft that runs from the end of the case out the top and turns the planetary gears in the gear drive, supporting this shaft are two bearings at each end. Inside the can on this shaft is what looks like a bunch of washers attached to the shaft. I assume they're magnets, never really cked. What's happening is these magnets are working they're way loose and moving out of position, causing the problem. I have a C50 now that's got this problem. The end magnet has detached from the rest. This caused me to smoke a 90 acro as I didn't catch it in time. I've had this problem occur several times with different c50's as I have 3 of them now, and they've all had the rotor replaced, two a couple of times now. The one I have a problem with now had its rotor replaced this spring and only has about 90 flights on it. I'm getting the feeling this is an ongoing problem seeing everyone else having the same problem. Looks like we need to monitor the amp drawl of these motors closely. At least that's my view, Hacker doesn't really seem to have a fix for it.

I wonder what the comp c50's will do.



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 11:20:03 AM)

Steve, the voltage is showing 20 volts rather than 40 due to where I have my data logger connected. I don't run a "Y" to my ESC, rather I run a loop so the data logger is only seeing the voltage of one pack. It does however read the correct AMPS as the current flows through the data logger.

It seems flaky, but it's not a big deal. I did the wiring as I did to save the weight of the extra wire and extra Dean's connector. The motor is seeing 40 volts for sure [:)].

Keith B



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/9/2006 11:23:42 AM)

Steve, FYI, the Falcon packs are 5s2p, two in series.

Keith



KeithB -> RE: Worried about Significant change in Hacker C-50 AMP draw! (7/10/2006 6:46:50 AM)

Today’s post is to compare the difference in AMP draw and RPM between:

a) The Competition C50 / Competition Master 90-O combo, vs.
b) The Competition C50 / Standard Master 90-O combo.

Neither yields the results I’m used to seeing.

I could buy the thought that the Standard 90-O has gone haywire, but why in the world would the new COMP combo be so off ?

So what’s up? Clearly there’s some major calibration difference between the two Master 90 ESCs.

Prop was a APC 22x12E.

Perplexed,
Keith B



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