ArmedZagi

My Feedback: (1)

Hi,

I've got a problem with the motor on my glider. After it runs about 30 seconds it just shuts off... The whole 30 seconds the RPMs are steadily decreasing.

This is the motor I'm using [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBYM9&P=0]GP S-600R[/link]

This is the ESC [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKBF6&P=0]GP C-55[/link]

The gearbox [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXSL79&P=ML]GD-600[/link]

Prop [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXZ996&P=7]MAS 12x8 Folding[/link]

Here's the packs I'm using [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLVG2&P=ML]DTX3800[/link]

Any ideas whats causing this? I'm lost...I broke in the motor, used the capacitors, and I'm Deffinatly Not exceeding the amps on the ESC. What now?

Thanks for any help.

jzrf6c

I've had the same problem with My Ultra stick. I us the GP ss-45 and have found that I MUST charge my Lipos right before I fly (within 24 hours usually). If I don't the controller senses low voltage and start reducing power to 30% as I recall.

Hope this is helpful.

pilotpete2

Sounds like a battery/charging issue.
What charger are you using, and did you do a 16 hr. forming charge at 380MAh?? If you have a voltmeter try checking the battery voltage under load, better yet get a Watt meter so that you will know how many amp you are drawing.
Pete

ArmedZagi

My Feedback: (1)

My charger only has 2 options.. Slow Charge and Peak Charge. And a dial to set the charge rate.

In plain writting on the batteries it says "DO NOT TRICKLE CHARGE" So I use peak charge at 2amps.

This is what I'm using... [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXUF43]Intellipeak pulse charger[/link] I've had it for 6 years.

EDIT: The charger has worked fine on similar packs through the years and I used it on my Zagi 3 times just today. I dont think the charger is to blame.

The charger is also on the Recomended list in the battery info.

ArmedZagi

My Feedback: (1)

Ok, after some more bench tests I've found...

1. The Battery stays cool

2. The Conector where the battery attaches to the ESC gets Very hot.

3. The ESC stays pretty cool

4. The motor gets BLAZING hot... I mean hot enough to blister my finger tip the second I touched it... [:@]

Anyone who can make sense of this?

packyj

You may want to check out your motor. I had a small 180 motor completely fall apart on me once and had those same symptoms. Took a peek inside the can and found two of the magnets had come loose... a bunch of gummy gooey black powder and eventually a reason to replace it with a 250

ArmedZagi

My Feedback: (1)

It seems to be in good shape still.... Its brand new.

pilotpete2

Item #4 It sounds as if you are overpropped for that motor at that gear ratio. You need to know how many Amps you are drawing with that setup. You need to get hold of a Watt meter to know what is going on.

Item #2 If your battery pack still has the Tamiya style connector, it needs to be change out. With the amount of current you are drawing anything less than Deans Ultra or Anderson Power Pole connectors will be a problem.
Good luck,
Pete

ArmedZagi

My Feedback: (1)

It was suggested that I put on deans plugs several weeks ago but I never got a second opinion and just forgot about it...

Any suggestions on prop size? Its a 3:1 gear ratio and Im currently using a 12x8 folding prop.

Here's a few I'm looking at now....

12x6.5

11x7

11x6

Here's the website.... [link=http://www.hobby-lobby.com/freuden.htm]Props[/link]

Edit: Can I just buy the blades or will I need the yoke, spinner and prop adapter as well? If yes, what size prop adapter will I need (if any).

EDIT 2: Im going to start taking a 1/4" at a time off the prop I have now and see what that does.

ArmedZagi

My Feedback: (1)

Ok I took off a 1/4" at a time until it was down to an 11x8. That let it run about 2-3 minutes but it finally died. This time the Battery got hot also. The motor wasnt Nearly as hot this time so we must be on the right track. Strangley enough even though the battery was hot, the connector was still cool.

I'm topping off the battery again and I'll take off another 1/2" and see what that does. That will make it 10.5x8...so it will be the equivilent of the 12x6.5 I was thinking about.

ArmedZagi

My Feedback: (1)

I got the same run-time with the 10.5 as I did with the 11x8 ...How small a prop is this going to need?

pilotpete2

Hi ArmedZagi,
I'm a bit stumped here, looking at the setup you have I would think it would be OK with the 12-8 prop and gearing down 3:1 and only running a 7.2V pack. The Tower website does not give any real specs on that motor and I don't have a program like MotoCalc to crunch the numbers.
To use the Props that you linked to from Hobby Lobby, you would almost certainly have to buy the complete yoke/spinner deal to use Graupner or Aeronaut props (these are the "better" folders for gliders, I use both)
One other thing I wanted to clarify on charging Nimh cells, they should not be left on a "trickle" as the lable states, but a "slow" charge is not a trickle.
A trickle charge is usually a rate of 1/50th of the battery capacity, in this case only 76 Ma, this is used to maintain the charge on Nicd batteries after they are fully charged, but will cause problems with if done "long term" on Nimh batteries.
A slow sharge, or overnight charge is done at C/10 or 1/10th the rating of the cells, in this case 380Ma for 14 to 16 Hrs, this is always prefered for charging when time is not a issue and for "forming" a new pack, this slow "overcharge" of the pack allows all the cells to equalize slowly and come up to full capacity, see if you can set your charger on slow charge and a rate as close to 380Ma as you can.
I wish I could be of more help on the motor issue, after the Holiday why not give Tower a call, their techs may be able to give you some more help on prop choices.
Good luck, and Happy New Year,
pete