Go Back  RCU Forums > Electric Aircraft Universe > Electric Pattern Aircraft
Reload this Page >

99+ Amps drawn by my Hacker C50-14XL

Notices
Electric Pattern Aircraft Discuss epowered pattern aircraft in this forum

99+ Amps drawn by my Hacker C50-14XL

Old 08-25-2009, 08:47 PM
  #1  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default 99+ Amps drawn by my Hacker C50-14XL

This is really weird, and I'd be grateful if anyone can clue me in as to what's going on.

Yesterday when I was flying I noticed that I was suddenly using about 4000 mah plus per flight instead of the usual 3200 mah per flight. I tried to think what had changed in my setup but I couldn't think of anything. However, today on my first flight my Integral went like a scalded cat for about 3 minutes, and then suddenly the motor wouldn't respond when I advanced the throttle. I landed deadstick, and checked my batteries, and found that in 3 minutes or so of flying I had completely depleted my pack. Which made me very suspicious.

Then I put a watt meter between my pack and my speed control and measured 99 amps at full throttle. So, I figured I either had a problem with the motor, or a problem with the speed control. Fortunately however, I had an extra speed control that I could try, and when I swapped it out I was still drawing 99 amps, so now I know there's something wrong with the motor. I used an ohm meter to measure the winding resistances, and I'm getting a consistent 0.2 ohms.

Does anyone know if this resistance is correct? What could cause a Hacker C50-14XL to go from 60 amps current draw to 99 amps current draw in the space of a day?
Old 08-25-2009, 09:17 PM
  #2  
Chris Moon
My Feedback: (8)
 
Chris Moon's Avatar
 
Join Date: Dec 2002
Location: Leesburg, VA
Posts: 1,366
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Brenner - sounds like a slipped rotor. That was (is) common in those motors. I was under the impression the issue was fixed but maybe not. Dave S. (Chicago) had 2 of them do it a couple of years ago and they jumped from normal up to 100+ amps just like yours.
Old 08-25-2009, 09:52 PM
  #3  
Chris Moon
My Feedback: (8)
 
Chris Moon's Avatar
 
Join Date: Dec 2002
Location: Leesburg, VA
Posts: 1,366
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Remember also that many meters won't read over 99 amps so if it said 99 amps, it was most likely more than that []
Old 08-25-2009, 10:14 PM
  #4  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Thanks for the info. What exactly is a slipped rotor though. I've taken the motor apart and I notice that the rotor appears to have a counterweight on one end. Is this the part that slips?
Old 08-26-2009, 04:13 AM
  #5  
flyf3a
Senior Member
 
Join Date: May 2006
Location: Port Elizabeth, SOUTH AFRICA
Posts: 150
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Hi

What is the temp reading on the controller, if this is high the controller cut-off is coming into effect meaning that your motor is about to go and subsequently fry the controller.

Have seen this happen on 2 Hacker 14 xl motors.

Regards
Burt
Old 08-26-2009, 05:46 AM
  #6  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

I didn't download any parameters from the controller, but everything was very hot to the touch. The motor, the controler, and the batteries. I'd say 60C plus.
Old 08-26-2009, 09:20 AM
  #7  
joenella
Senior Member
 
Join Date: Aug 2005
Location: Odense, DENMARK
Posts: 184
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Have You remembered to change the grease in the gearbox? if running more than 50 flights it might be a problem and You will have a destroyed gearbox suddenly, don't ask why I know
Old 08-26-2009, 12:28 PM
  #8  
67685
 
Join Date: Aug 2004
Location: Nannestad, NORWAY
Posts: 236
Received 1 Like on 1 Post
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Hi,

I have two 14XL, and my oldest needed overhaul after 290 flights. My cooling fan disintegrated, and Hacker,Germany changed 4 bearings ( 2-motor, 2 gearbox ). The planetary gear-bearings was fine and didn`t need replacement. This motor operated normally all time,until i found the broken cooling-fan, probably caused by worn motor-bearings.

I guess frequent inspection/overhaul is an good idea on this motor. Better safe than sorry..

Just my personal experience

Kjell Olav
Old 08-26-2009, 04:42 PM
  #9  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Well, I've ordered a new rotor, new bearings, and a new gearbox. I should get it tomorrow by 10:00 am. I actually can't think of anything else to change. The only thing that I'm not changing is the stator, but the coil resistance seems okay, and there is no evidence of any abrasion, or touching by the rotor.
Old 08-26-2009, 05:06 PM
  #10  
patternflyer1
My Feedback: (11)
 
patternflyer1's Avatar
 
Join Date: Jul 2003
Location: Tracy, CA
Posts: 2,078
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

It's a $250 fix at Hacker. I've had my 14xl in 3 times for this. Make sure you have more than enough cooling to your motor. Don't let it get over 160 degrees no matter what.

Chris
Old 08-27-2009, 08:19 PM
  #11  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Well, I got new a rotor from Hacker Brushless via UPS overnight, and it's fixed! I also replaced all the bearings and the gearbox, so I'm hoping that it's as good as new.
Old 08-27-2009, 08:23 PM
  #12  
patternflyer1
My Feedback: (11)
 
patternflyer1's Avatar
 
Join Date: Jul 2003
Location: Tracy, CA
Posts: 2,078
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Just out of curiosity what did the parts cost.

Thx
Old 08-27-2009, 08:56 PM
  #13  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 763
Likes: 0
Received 3 Likes on 3 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

The prices are as follows:

C50 XL Competition Rotor with Fan $184.99
C50 Competition Bearing $6.50 X 2
Competition Gearbox $179.99

All prices are USD
Old 08-28-2009, 01:20 PM
  #14  
Eggert
 
Join Date: Sep 2004
Location: Slangerup, DENMARK
Posts: 130
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

.....I have had a similar experience ! Apparently, I had been overloading my motor "with too much propeller", 20x15 APC on a 13 windings, and thus causing the magnets to loose magnetism over time. Hence, i drew 100 + amps from the batteries and the controller cut during flights. Actually "toasted" a couple of cells on that account besides the motor.
Old 01-18-2010, 11:21 PM
  #15  
pgvillar
Junior Member
 
Join Date: Jun 2009
Location: Ausitn, TX
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

What's the trick to keeping the 14xl less than 160 degrees? I just started flying E this winter. When summer temps start hitting the 100's here in Texas I am a little bit concerned. I'm flying the Integral, with the air scoops in the front opened per plan. Do I need to do anything more?

Paul
Old 01-19-2010, 12:49 PM
  #16  
67685
 
Join Date: Aug 2004
Location: Nannestad, NORWAY
Posts: 236
Received 1 Like on 1 Post
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Hi,

My solutions in my Hacker/Integral ; 2-chambers stator, works good, engine get barely warm... "Hand-warm" ...

Kjell Olav
Attached Thumbnails Click image for larger version

Name:	Hf98879.jpg
Views:	46
Size:	118.9 KB
ID:	1359573   Click image for larger version

Name:	Xt59795.jpg
Views:	39
Size:	116.1 KB
ID:	1359574  
Old 01-19-2010, 03:15 PM
  #17  
pgvillar
Junior Member
 
Join Date: Jun 2009
Location: Ausitn, TX
Posts: 5
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Kjell,

Wow, interesint engineering there. Thanks for the pictures. What do you for air exit? Do you have exit holes cut into the rear fuselage section somewhere?

Paul
Old 01-20-2010, 01:36 AM
  #18  
67685
 
Join Date: Aug 2004
Location: Nannestad, NORWAY
Posts: 236
Received 1 Like on 1 Post
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Paul,

Here you can see the exit holes ; the two forward for regulator outlet, and the four aft for motor/battery outlet.

...added one more picture of the stator section how it looks from inside when cowling mounted... I did several prototypes with different shape and size, and ended up with this one.

What ever you choose to get the motor cooled, i would recommend to build some kind of a closed duct; from air-intake to partly surrounding the motor.

... Perfect for hot climate as yours

Kjell Olav
Attached Thumbnails Click image for larger version

Name:	Us53705.jpg
Views:	40
Size:	115.8 KB
ID:	1359988   Click image for larger version

Name:	Dy77727.jpg
Views:	38
Size:	111.4 KB
ID:	1359989  
Old 01-20-2010, 02:42 AM
  #19  
67685
 
Join Date: Aug 2004
Location: Nannestad, NORWAY
Posts: 236
Received 1 Like on 1 Post
Default RE: 99+ Amps drawn by my Hacker C50-14XL

... Forgot to mention a thing here...

What seems effective about the stator,except routing the air directly to the motor ; is that the area from the intake increase all the way to the motor. (airspeed / pressure inside the stator chamber).

Kjell Olav
Old 04-26-2010, 07:29 AM
  #20  
hezik
 
Join Date: Aug 2006
Location: VleutenUtrecht, NETHERLANDS
Posts: 613
Likes: 0
Received 0 Likes on 0 Posts
Default RE: 99+ Amps drawn by my Hacker C50-14XL

Magnets de-magnetise when they get too hot. Basically the stronger the magnet, the lower the temperature at which point this will happen. As far as I know, scorpion is the only manufacturer that uses magnets that can withstand high temperatures. Overall any RC electric engine shouldn't get much hotter than the mentioned 160 degrees, wich is already on the hot side. Most used magnets will start to de-magnetise around 185 degrees, and keep in mind that if you measure 160 degrees on the outside, the magnets might be even hotter than that.

You can imagine that if one would replace the default magnets on an engine by magnets that have 'halve the strength', then the current will go up. This is since your ESC will still want to try to spin the prop at the same RPM, so it will just pump more power into it.

Having a good airflow over your engine is pinnacle in this, but it's useless to make all kinds of tunnels if your exhausts aren't functioning or not big enough. Roughly you should have at least 1.5 (preferabely more) the exhaust-opening vs the intake opening.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.