RC India

Hello, I have setup Towerpro 2409-12T BL out runner motor with 25Amp ESC with 3S 1300Mah 15c lipo in my little cessna.  I have done some flights on it also and it worked fine. Yesterday after putting a new X mount the motor refused to start. only thumping. I tried changing from Tx Rx motor esc but no joy. this morning i tried again and motor is starting up properly but new problem is there. Everything like motor esc & mount is heating up even on idle running. Earlier this motor & esc used to stay cool even after 8-10 min flying. I cant figure out the problem. Kindly help.

I just want to know if it is normal because I didnt notice it before.

Try adding a drop of thin machine oil on the bearings. This happened to me on a new motor, but in my case ESC was not getting hot. I added 1/2 a drop of triflo and the problem solved. Dont add too much of oil, just 1/2 or 1 drop should do.

Adding too much oil will remove all the grease from the bearings and make the bearing more vulnerable (a lesson learnt hard way.).

Thx for the reply. Where to get the machine oil? also I read somewhere BL motors dont need lubing cause there is no friction. I am new to electric so kindly enlighten me.

The bearings still occasionally need oil, for example, scorpion motor manufacturers still recommend using oil once in 10 to 15 flights.

Also see if any magnets have come off or by chance by mistake if you have set the ESC motor timing to High. Timing should be low for most of the small motors. Search this forum, there is a thread for where to get this oil. I got the famous triflo from helidirect. But that good oil may not be necessary for your use.

Dear Vinay Sir, I put on a new motor and the result is same. This motor is new and never been used. So i dont think putting oil will help me. Also what about esc getting hot? I would like to fly this sunday so i cant order oil etc online. I need a solution which will get my plane ready this saturday.

Some of the things that I can think of

1) Try using a different esc.
2) Out runner motors do get hot, does the motor get very hot or its warm ?
3) What prop are you using ? 
4) Try using a different battery.

Hope this helps..Do let us know what happens..

Already tried diff ESCs
I ran motor on 10-30% throttle and it gets considerably hot. Earlier it stayed cool. even the new motor is getting hot.
running it without prop.
i have tried diff batteries.
even the Tx & Rx changed but same result.

No need to call me Sir for God's sake.

Since changing the ESC and motor combination are causing problem, I cant think of anything better as I am also new to this hobby.

Then it means that both the motor and ESC are gone bad, since changing the ESC and motor alternatively are causing problems. The only thing I can think of is the timing set on the ESC. Hope its low.

BTW which ESC?

Try old motor new ESC = see which one is getting hot
Try new motor old ESC = see which one is getting hot
Try new motor new ESC = See even if any of this is getting hot.

Also make sure your new motor for testing is 3S compatible. Else your test results are wrong.

Check the timings on both the ESCs. Keep them low.

Also as I said earlier, my new motor required oil on the first run itself. it was getting so hot on 50% throttle for 1 minute w/o prop that I was barely able to touch it (probably unlubed bearings). But I dont think its required in your case.

When you put the new motor mount, did you by chance cut or chafe any wires ?  If any of the wires are now smaller than what it required to deliver the current needed, things will start getting heated up.  Closely inspect the wires for any knicks and cuts.

he says he tried diff motor and ESC as well, dunno what is going on  :headscratch:

BTW, how does cutting/slimming wires heat up motor? explanation if any?

Another thing I can think of is if the rear end of the motor shaft is rubbing the motor mount. Ususally a hole is required there. Also I have similar motor which heats up moderately when run at 3S 80% throttle for 1 min w/o load.

I think your motor and esc sutaible to 2s\7.4v lipo. You are useing 3s\11.1v lipo so motor and esc get heat.

Nicks and cuts usually affect only the insulation. And any significant reduction of the effective wire diameter (caused by a major cut) would cause the WIRES to heat, due to increased resistance. Would not affect the ESC .and/or motor. Overheating is overload  of some sort. Wattage/current is beyond ratings somewhere.

Every piece has been changed, per various posts.  Other than Vinay's new suggestion of the motor movement being restricted by the new mount, we have to look for reasons where the power rating of the setup is degraded. You are right in that the wires would be the first thing that would get hot, but is that the only effect of a wire being significantly cut or squished ?  I thought the effect would be similar to cold solder joints.

I guess the simple thing is to try running the motor with it being mounted, and see if it gets hot.

Running motors without any load (prop) for long periods is not recommended anyways, so the issue Vinay reported of motor getting hot after 1 minute in no-load condition is not too surprising.

Its true for engines and not for electric motors. RPMs at 80% throttle no load is equivalent to RPMs at load at 100% throttle. Should not be a problem there.

That is not what I have seen in manufacturer instructions.  A quick search lead me to this manual (you can find others) :

http://www.teamnovak.com/download/instructions/pdfs/55-3400-1_r8_motor_10-08.pdf  (see the caution box which says "Never free rev the motor").

Generally, nothing may happen. An engine at no load goes into high speed, due to physically moving part like crank shaft etc may lock up. I see no such issues with motor generally, neither do they consume more current.

The only place where the motor was heating up in my case the 2409(whatever) was at the base of the motor where the bearing is mounted. Another issue with non lubed bearing may be.  :headscratch:  I haven't touched that motor since months now.

Let me find more answers on the net by then  :headscratch:

vinays observation looks very logical to me. Check if the motor after fixing on the mount is giving any extra friction. This can be checked by removing the motor from the mount and checking it by rotating it freely, putting the prop. obesrving, and repaeting the test after mounting the motor on the mount.
Always a watt meter will tell you how much current it is drawing. Check the no load current draw and it will reveal many things.

Towerpro Esc 25Amp. I bought combo with 2409 motor. have tried all possible setups u mentioned. Timing is set low. sorry for late reply.

This plane crashed on last flight because of the mount only. i was using a stick mount and the motor came out of mount in air. my plane was in pieces. i have repaired it and put a new X mount which is more strong and suitable. yes Sir the wires are cut from 2/3 places because of the crash. But i also tried with a new motor and esc as mentioned in earlier posts. sorry for late reply

This motor is made for 2S to 3S lipo. Esc is 25 Amp and i am using 1300 mah 20C 3S lipo.

i tried running it without the mount and its not getting hot upto 30% throttle. also there were some loose solder joints. i will solder them properly and then check it. will reply back tonite when its done. hope this will solve the problem. Thx

I ran the motor without mount and it seems fine now. but to be sure kindly wait till my next post when i am done soldering. As i am new to electric, i will also purchase a watt meter. hope its not a big investment.

If without mount it is running fine, then the mount is the issue... it must be restricting the free rotation of the some part of the motor.  Please check for that first, before trying to do and re-soldering.

See...i have repaired many tower pro motor and i have seen that the winding is done not with a single stand of wire but with two or three parallel running wires.....the word "thumping" what you have used is normally due to faulty winding wire, you will notice a continuous beeping also from the motor when it starts, vibrates and then stop....if you keep on throttle the motor and ESC will heat up.
REASON : if your motor had a crash, there are two possibilities
1. bent shaft
2. broken insulation in the armature (shorting the shaft and the winding in between somewhere) check with continuity tester

in case of tower pro, maximum time, the culprit is bent shaft
NOTE : bent shaft is visible inside the motor and not outside where you mount the prop. open the motor and then see..you will see a slight deviation in the movement once you manage to make the shaft straight your prob will be solved.
Sandeep

I can understand this about the crashed motor but then why the new motor and esc heating up? Also when the motor starts thumping, it stops & restarts like there is a lose connection again and again. As i wrote earlier it seemed fine without the mount. will post some pics so you can see the motor condition closely. i will also re-solder everything and check with/without mount in the evening when i reach home and post results.

It is always a good practice to use an ESC of average value, for example if your motor was designed for a ESC ranging from 25 to 35 amps, it would be good to use a 30A ESC, this because your motor manufacturers mostly test their motors without motor load, (without props)
if you are using a 25A ESC, remember that your ESC is in the limits of the lesser value that your motor was designed for, and if you check the ESC on a Ampmeter you will sometimes notice that they are less then mentioned value eg: 25A ESC will sometimes show less then 25A.(previous experiences)
So it is a best practice to always use a average value ESC.
Also check your cell compatibility while doing so.
Also remember that your towerpro 2409 motor has a RPM of 1600 and your battery is a 3C11.1v
so if we:
1600x11.1V = 17760 is more then the designed RPM of your motor!
try using a 7.4V x 1600 = 11840 combo!
this is lesser then the designed RPM of your motor, so overheating is not possible.
I hope this helps,

Dorwin

however triavial it may appear on the surface, here are few thumb rule that i always embrace, while dealing with marginl problems.
1. Focus  on ways to consistently being able to create the problem, than burying the problem.
2. Extremely important to play with one variable at a time.( for ex as Anwar said, do not do soldering+mount change together)
3. if able to  undo the last change and see if you can recreate the problem, that way we are 100% sure.
4. many times i have felt terms ;Allergy' and 'Loose contact' are synonymous wrt medical and electronics fields. both meaning a lack of enough understanding.


A wattmeter will appox cost USD20.00, link as follows:
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10786&Product_Name=HobbyKing_HK-010_Wattmeter_&_Voltage_Analyzer_

Most propbabaly, (as vinay said,) when the motor is mounted on the mettalic mount supplied,  pushing the motor well inside, the back portion of the motor shaft can touch/ rather press the wooden motor mount. Usually, a 4mm or more  hole is made there to avoid this.. If this is not done then it  can create considerable friction for the free running of the motor.




ashta

Another thing to be taken in high consideration when choosing compatible cell+ESC+motor combos is that the difference in cell voltage reduces or increases the voltage drastically or on a huge amount.
this calculator may be of some help to you in getting the correct values, I haven't used it much but its worth a try!

http://dhrc.rchomepage.com/calc.htm

regards,

Dorwin

I think its the other way round. If you dont know what the motor/prop combo is consuming then its better to have a 35 Amps ESC on the safer side. Coz if a motor manufacturer recommends 35 Amps then its better the ESC be better 35 Amps. Anything less should be chosen only with a watt meter in hand, and doing a static test with a prop on ground at full throttle in the direction of the wind (not against). Also the motor consumes more current if you are closer to sea level. Its always better to have ESC bigger than the motor, typically with a 15 to 25% head room, so that even if there is less air flowing over the ESC, it can survive.

Just my 2 cents.

@CrazyPilot

If your motor is thumping, resolder the wire, other wise the motor may burn. Do not increase throttle when motor is thumping.

BTW how are you Ashtaji, its been so many weeks since we met. Will meet soon once I am free at jakkur.

Thanks for correcting me on this,
well it should be 30A up to 35A.
but, does efficiency decrease with the increase in Amperage?
My answer was based on the above statement, hence "average"

appreciate your point.

Dorwin

No, the efficiency wont decrease as its kinda pulsed supply, also if you use a bigger ESC the heat production is less hence more efficiency. The problem comes with the weight of the bigger ESC.

I get that!

Thanks for the knowledge sharing!

Dorwin

And I switched from Glow to Electric because of all the mess :banghead:. I think I will switch back to Glow engines soon ???. 

Buy a wattmeter and test on the ground.  Way to peace of mind/nirvana in leccies !

I second that Anwar! :)

watt meter is a primary requirement for electrics. Its just like your glow starter  ;)

Ok guys. I am ordering a wattmeter. Will have to wait 3 weeks before i can test further.

Could you guys be so kind to chip in your thoughts on what else should be in my electric caddy? I will order all the things at once so i dont have to wait anymore. Kindly reply soon.

1) Watt meter with voltage analyzer
2) ?
3) ?

2) Extra Lipo.
3) ESC

Sir i dint mean 3 items only. was just illustrating. i need a complete list of items needed for electric flight.  

Add a lipo monitor, spare props, servo tester >:D (not really required.)

ordered these and lot of other useful items. Thx

Dear Crazypilot,

My 2 cents...

a. If you do not have a wattmeter handy, you can always use a digital tong tester (available at any electronic shop for Rs. 250 to350.00). Put the tong tester encasing any one of the wires connecting the ESC to the motor for a brushless DC motor in AC current mode. This will approximately tell you if the current is increasing or decreasing and over a period of use you will know if there are any abnormalities. The values displayed does not exactly tally with the current drawn, but the change in current is significantly understandable. Plus you also have a simple digital multimeter to boot in the field.
b. For charging batteries with standard chargers, one has to either have a battery or a 12vDC source (for 3S LIPOS) with sufficient current ratings (about 5 amps plus). One can use a simple SMPS from a computer to get upto 10amps for 12v. The cost of the SMPS is around Rs.400.00. For field charging if one does not have a 12vDC based charger, one may have to have a "car inverter" which gives you 230v AC. This could become handy if you are also using a laptop computer etc at the field.
c. So a soldering iron and a glue gun would also become handy for quick repairs of planes with crashes. (Foam as well as corroplast based models)
d. What about a foldable chair-cum-table with umbrella... You know the ones one sees in one of the Tata Indigo ads. Cost about Rs. 5500.00 available at
Bangalore. .....Very handy this one... shade from the sun and rain while enjoying flying sitting down.
e. A LIPO checker... very handy in between flights to keep a close watch on the LIPOs.
f. Double sided tape... a must.. especially if you keep changing receivers and ESCs and /or LIPOs
g. Broad Cello tape... a life saver all told at any flying session
h. Squiver Sticks... the kind use in the kitchen... a neat way to strengthen foam/corro in the field.
i. Icecream sticks... needed strength when you want it for repair... not a must
j. A small bag of Rubber bands... can be used as substitute for o-rings if used wisely for a prop-adapter
k. EVOtite... a few tubes of Rs.25.00 each... best cynoacrylate that is available in Chennai for RC
l. .... shhh trying to think

I think thats it. I forgot to welcome you to the Electrics camp... no more wives screaming at screaming, oily, rattling, messy engines.

Happy flying...

Dear mpsaju,

Thx a lot for a detailed reply. I love this site and members who love to help others. now i will go as your list.

a-I already ordered wattmeter. i will also get a digital tong tester.
b-currently i use my B6 balance charger. it connects to my 12v ups battery too. your smps option is great but how will i balance charge the lipos using a smps. also whats the use of laptop on field?
c-i have soldering iron. will get a glue gun in future if budget allows.
d-now that's something to invest my money. although will have to wait long for a 5500Rs. chair.
e-lipo checker in stock
f-double side tape in stock
g-diff size tapes in stock
h & i- i dont know how to use them.
j- rubberbands & o rings in stock
k-where to get evotite?
L- ok

Thx again

 

Crazypilot,
hi,
 i noticed somewhere u mention that the problem was when u put the motor on the mount, Check motor mount bolts, they may be a shade longer than necessay and may be fouling with windings. File the tips a mm or 2 mm off, if she works fine without the mount, nothing wrong with ur motor,
Rameh Tahlan

I second that...
even though i a newbie to this hobby, ur different combination and results clearly indicate there is a problem with the mounting and not the motor/esc!!! Afterall they work fine with your other mount!

The screws are a good point

or u changed from stick mount to X mount, did ur side mount have heat shield? Cooling is less in Xmount. seniors please correct me. On that, one ques from me arent some motors made so that they require air flow thru them for cooling? while some(maybe the same) require some gap at the back for air-flow?

or like Vinay said the new mount is hampering free movement, will making a small depression at the back in the wood(were u mount) help?

IF you do FPV (First Pilot View) as in  you have a camera on the plane alongwith a telemetry transmitter and GPS, you could get the feed from the camera on line via a ground receiver and antenna to your laptop and fly as though you are sitting in it as a pilot would. You could go to very high distances ... as far as  two or three kilometres and still control it very accurately within the range of your transmitters. This is advanced RC modelling for you... like the drones from US

As to Evotite, very similar to super glue but best suited for filed repairs

Saju

Saju ,
I  Like that  ;) but  FPV is not too common a form of flying . 8-) 8-)
I think the fact that  we do it every weekend ( flying a couple of Kms and back  ) seems to have kind of rubbed off in you listing FPV equipment as essential for Electric flying   :giggle: :giggle:.

Crazy Pilot ,
FPV is not essential for flying electric . ;D

We normally get evotite from landmark Oddesey  or similar shops.



Sai

Hellow Anwar Sir, I got my wattmeter and i need some help. Kindly tell me what are the different readings and how are they useful? i was testing a turnigy aerodrive 42-60 sk series motor with 6s 4400 mah (two 3s 2200 in parallel), apc 12X6 E prop and 80 amp besc. the readings are as in pic below. how do i calculate thrust to weight ratio? and what about other readings. thx

(http://img153.imageshack.us/img153/6590/hk0101.th.jpg) (http://img153.imageshack.us/i/hk0101.jpg/)

CP, if you put 2 3S in parallel then your cells will become 3s 4400 mah and not 6s 4400 mah.

Here is what you should see:

Current:
1)Your 2200 batteries 20c in parallel can give you a maximum of 88 amps, but you should not draw more than 70 amps from it. Good for your batteries.
2)Your motor should not consume more than 70 amps with the prop.

Put your watt meter between the motor and batteries and chek to see if the amps are not more, amps indicated by A on your meter. Slowly increase throttle and see readings. Also make sure your ESC is getting good air flow. Check the temperature periodically.

Voltage:
It also shows how much the voltage drops when load increases.

WATTS:
It shows voltage x amps

AH:
It shows how much mah the motor has consumed from your battery since you started the experiment.

Connect watt meter properly. Connecting the battery to watt meter where you are supposed to connect motor will burn it.

Aaal da best!

You would need a spring balance setup etc to calculate thrust to weight ratio. Cant do that with a watt meter. You can see the trust by visiting hobbycity and reading user reviews for respective props.