RunRyder RC
WATCH
 1 page 819 views Post Reply
Home✈️Aircraft🚁Helicoptere-AlignT-REX 500 › 500 stock motor losing power
08-23-2008 01:09 PM  12 years ago
Topic Vote0Post 1
mmc205

rrElite Veteran

PA - USA

MyPosts All Forum Topic
500 stock motor losing power
HI all, i'm on my 26-30th flight, stock motor, stock esc, 425 blades, 6s 3000 max amps pack (only about 10 cycles) 12t pinion and it seems like i'm losing motor power. This heli had way more power when i first got it. I pulled the motor and it feels like the bottom bearing may be shot, but i'm not totally sure. I've heard some others say that their 500 motor would lose power after about 25 flights, perhaps due to head and increased resistance. I measured across each phase with my multimeter and got .8 ohms, which seems pretty high, could someone else repeat this on a stock motor which seems to be in good shape, or even on a scorpion 1600kv? I know the resistance is published, but i'm not sure its measured in the same way that i am measuring it. Any ideas, suggestings, similar happenings? could i possibly send this back to align? I wouldn't mind getting a scorpion but my skills don't require a hotter motor just yet. Anyone know an align rep on runryder?

Also, wanted to add the mesh was set properly all around the main gear, so i dont' think that is adding any extra resistance or force on the bearing.
***Logo 600 vbar***Henseleit TDR vbar***
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-23-2008 03:08 PM  12 years ago
BrunoBL

rrKey Veteran

Pomerode, SC, Brazil -26.71, -49.17

MyPosts All Forum Topic
Are you comparing .8 Ohms against published a figure (is the resistance knowingly too high)?

Also, what reading do you get when shorting the test probes? My VOM will read zero Ohms when I short out its test probes, but repeating the test with cheaper probes I get .4 Ohms. If you read a nonzero value, you may subtract that from the .8 Ohms you got from the motor windings.

...Bruno.
Spectra G on Avgas 100LL, Jewel generator
T-Rex450SE V2
DX7
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-23-2008 06:57 PM  12 years ago
mmc205

rrElite Veteran

PA - USA

MyPosts All Forum Topic
Are you comparing .8 Ohms against published a figure (is the resistance knowingly too high)?
I dont know what the stock align motor should be phase to phase, but for comparison the published specs on the scorpion 1600 kv is about 0.016 ohms, but i think this is probably measured differently than i measure it.

as for my multimeter, it zeros with the leads crossed. mostly, i'm hoping someone can put a multimeter in resistance mode across any two of the three leads to the stock 500l motor (one that is in good shape) and tell me what they get.
***Logo 600 vbar***Henseleit TDR vbar***
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-23-2008 08:15 PM  12 years ago
BrunoBL

rrKey Veteran

Pomerode, SC, Brazil -26.71, -49.17

MyPosts All Forum Topic
Let's see if someone chimes in with specific measurement on that motor. But wow, at 0.016 Ohms the Scorpion has 1/50th the resistance of your motor, that is a wild difference!

Did you get the same results in all 3 windings? It would not be likely (I think) to have the same problem, if there is a problem, in all 3 windings at the same time, with the same 0.8 Ohm reading at that.

...Bruno.
Spectra G on Avgas 100LL, Jewel generator
T-Rex450SE V2
DX7
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-23-2008 09:24 PM  12 years ago
manic flyer

rrNovice

East sussex, UK

MyPosts All Forum Topic
Just measured a stock trex 500 motor with 5 flights on it and it was .0 Ohms, my multimeter only goes down do .1 Ohms.

Matt
Raptor 50, Raptor 30, hummingbird 3D pro
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
08-24-2008 01:55 AM  12 years ago
mmc205

rrElite Veteran

PA - USA

MyPosts All Forum Topic
thanks manic flyer. I'm not sure what it should be but it seems yours is somewhere between close to zero and .1 ohms. Mine certainly seems rather high at 0.8 ohms. Oh, and to answer your question brunobl, i did measure it across between all three phases and got 0.8ohms on all counts. I'm still not sure how exactly reistance is measured as its stated in specs. I'll look around a bit.***Logo 600 vbar***Henseleit TDR vbar***
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-24-2008 02:45 AM  12 years ago
BrunoBL

rrKey Veteran

Pomerode, SC, Brazil -26.71, -49.17

MyPosts All Forum Topic
You know, this reminds me of a problem that I had with a brushless motor that I use as a generator in my gasser heli. It failed (but did so altogether, different from you symptom) and since I had ordered a new one, I decided to take that one apart. I found a very cold solder joint where one wire was a common connection to all 3 phases. I managed to re-solder it and the motor is still running today, but I never had the guts to put it into use in anything that flies!

I understand that some motors don't use solder anywhere in the windings (the individual insulated windings make it all the way to the bullet connector solder where they are finally joined, so by looking at the wire type you may be able rule out this possibility (bad solder in the motor) without too much trouble.
I'm still not sure how exactly reistance is measured as its stated in specs.
True, but anyway, Manic flyer's reading is nearly an order of magnitude lower than your motor and seems to be consistent with the 0.016 Ohm speck that you quoted.

EDIT: Of course Manic flyer's reading is 0, but we are assuming it must be between 0 and 0.1 (his lowest possible reading), that's where I derived the order of magnitude comparison from.

Please keep us posted of your progress.

...Bruno.
Spectra G on Avgas 100LL, Jewel generator
T-Rex450SE V2
DX7
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
08-24-2008 08:09 AM  12 years ago
leftyatm

rrVeteran

Elkton, MD, USA

MyPosts All Forum Topic
Could be a bad batch of motors. Speak with Align maybe it's still under waranty and they will make good on it. That would be nice if they did. Especially with such few flights. It could also be in your set-up. Maybe there is excessive drag somewhere and the motor got too hot one time.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 819 views Post Reply
Home✈️Aircraft🚁Helicoptere-AlignT-REX 500 › 500 stock motor losing power
Print TOPIC

 1  Topic Subscribe

Sunday, September 27 - 1:44 pm - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online