Worried about Significant change in Hacker C-50 AMP draw!  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> Electric Aircraft Universe >> Electric Pattern Aircraft >> Worried about Significant change in Hacker C-50 AMP draw!
Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Worried about Significant change in Hacker C-50 AMP draw! - 7/7/2006 6:40:25 AM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		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


Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize
       Post #: 1

RE: Worried about Significant change in Hacker C-50 AM... - 7/7/2006 7:06:18 AM   
Benoit


 

Posts: 64
Joined: 6/28/2002
From: Cortil-Noirmont, BELGIUM
Status: offline 		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

_____________________________

Just Fly

(in reply to KeithB)
       Post #: 2

RE: Worried about Significant change in Hacker C-50 AM... - 7/7/2006 7:43:49 AM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		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


Attachments
Click to see fullsize image.
Click for fullsize

(in reply to Benoit)
       Post #: 3

RE: Worried about Significant change in Hacker C-50 AM... - 7/7/2006 8:54:37 AM   
rm



Posts: 237
Joined: 11/29/2002
From: ohio, OH, USA
Status: offline 		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.

(in reply to KeithB)
       Post #: 4

RE: Worried about Significant change in Hacker C-50 AM... - 7/7/2006 9:23:56 AM   
Benoit


 

Posts: 64
Joined: 6/28/2002
From: Cortil-Noirmont, BELGIUM
Status: offline 		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



_____________________________

Just Fly

(in reply to KeithB)
       Post #: 5

RE: Worried about Significant change in Hacker C-50 AM... - 7/7/2006 10:15:10 AM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		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



Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize

(in reply to Benoit)
       Post #: 6

RE: Worried about Significant change in Hacker C-50 A... - 7/7/2006 10:30:07 AM   
Pattern_is_Fun


 

Posts: 231
Joined: 9/20/2004
From: San Jose, CA, USA
Status: offline 		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

(in reply to KeithB)
       Post #: 7

RE: Worried about Significant change in Hacker C-50 A... - 7/7/2006 5:32:55 PM   
can773



Posts: 1654
Joined: 1/25/2002
From: Calgary, AB, CANADA
Status: online 		Keith

Which batteries are these?

Thanks,


_____________________________

Chad Northeast

(in reply to Pattern_is_Fun)
       Post #: 8

RE: Worried about Significant change in Hacker C-50 A... - 7/7/2006 6:47:31 PM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		Falcon 5s2p F3A Pro Series. www.falconbatteries.com/custompage.aspx?page=proseries.htm&selection=custom.

Keith

(in reply to can773)
       Post #: 9

RE: Worried about Significant change in Hacker C-50 A... - 7/7/2006 11:41:43 PM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		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.



Attachments
Click to see fullsize image.
Click for fullsize

(in reply to KeithB)
       Post #: 10

RE: Worried about Significant change in Hacker C-50 A... - 7/8/2006 5:05:35 AM   
rm



Posts: 237
Joined: 11/29/2002
From: ohio, OH, USA
Status: offline 		I'm curious if the one your sending in is also a comp motor?

(in reply to KeithB)
       Post #: 11

RE: Worried about Significant change in Hacker C-50 A... - 7/8/2006 5:27:12 AM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		RM, the one I sent back is not the COMP motor. I have one Standard C50 and one Comp C50.

Keith B

(in reply to rm)
       Post #: 12

RE: Worried about Significant change in Hacker C-50 A... - 7/8/2006 5:35:11 AM   
KeithB



Posts: 533
Joined: 1/6/2002
From: Garland, TX, USA
Status: offline 		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

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to KeithB)
       Post #: 13

RE: Worried about Significant change in Hacker C-50 A... - 7/9/2006 2:24:43 AM   
BJM