Car inrunner motor problem

[prateek13]

Hi

My nexx 8's motor is not working properly and when i opened to check i found a loose and broken magnet on the shaft...
what should i do?
please help

[iamahuman]

The rotor has de-bonded. Did you give it full throttle in the air?

Did you overheat the motor? They're the 2 main reasons for de-bonding a rotor.

The heat kills the glue or the centrifugal reaction from over revving the motor rips the magnets apart.

If you didn't overheat it and the magnet is structurally sound, you can try re-gluing it but I wouldn't take the chance as you might have cooked the windings if you overheated the motor.

I'd suggest getting a new motor and ESC.

[roopeshkrishna]

Prateek, if you are buying a new one, please give me the old motor.. 

[prateek13]

Thanks for the clarification....

so i will need to buy a motor .....
can you recommend some .....

my main two areas for getting a motor is its price(<4.5K) and availability(<2weeks)

[aviator]

Would u like to take this :

Sensor Motor Brushless motor 3.5T 9150KV for 1:10 car

Bullistorm Motor   B540 -    3.5T(450S)   
MaxWatts (W/60S)        450   
KV (rpm/v)                        9150   
Motor Size   52.5 x 36(mm)  52.5 x 36(mm)   
Motor Weight                162 g   
Magnetic MaterialOperat-ing Temp   392°F (200°C)   
Compatible Bullistorm Speed Controls   Bullistorm120A   
Recommended Use                          Off/On-Road High Traction   

[iamahuman]

That thing will burn up in a Nexx8 in a minute or two.

That is a 3650 motor. You'll need a 4068 or 4074 motor. And that Kv rating is only suitable for a very large on road track geared very low.

Try this. Not sure if it can reach India in under 2 weeks.

This one is a friggin' beast. If you can, get this. But you'll need good batteries to go along with it.

What are you planning to do with your car? I might be able to source a 1/8 system for you from Bangalore....

[prateek13]

thanks guyz
@iamahuman if you can do so you are welcome

[pravesh736]

That motor is a 10th scale motor.  Nexx8 is eight scale .. would be useless to put that .. contact murli of joy rising hobby heshould have an extra stock motor of the nexx8 .. as he upgraded his system

[pravesh736]

Sry forgot to read imhumans reply ..

[J R H]

http://www.hobbypartz.com/96m801-4074-2000kv.htm

This above motor wont fit in the nexx8.. The motor length should be not more than 70 or 71mm max.. The above motor is 73.8.. I have the Tenshock 2400 Kv but in stock..

[iamahuman]

Oops, forgot that the Nexx8 has clearance problems with longer motors...

[prateek13]

is there any other available option?

[roopeshkrishna]

Prateek.. i am here in a corner for your damaged motor.. 

[J R H]

Hobbywing is the best upgrade you can go for. Electric buggy need to have minimum of 1900kv and max of 2400 kv..

[iamahuman]

... Electric buggy need to have minimum of 1900kv and max of 2400 kv..

On 4s...

[gbisht]

Hi as iamahuman suggest motor model, he can opt following motors

4068
====
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=19682   52.65$
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=19743   53.69$    and 50.80$ with buddy code

4074
=====
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17697   47.39$
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17699   47.39$
http://www.hobbyking.com/hobbyking/store/__17697__XK4074_2000KV_Brushless_Inrunner.html   47.39$   and    44.83$ with buddy code
Both motor are branded Product Turnigy TrackStar

[iamahuman]

No offence intended but Trackstar motors don't have the best reputation out there. And their Kv rating is too high for a 4s setup...

[gbisht]

Sooorrryy........

[rajathv8]

Hey please post a review of your nexx8 in a separate thread with pics when possible

[prateek13]

Please help me people to select a motor.....
the person i was going to buy one motor from said that the stock will arrive soon but kept me waiting till a long time and ultimately quoted a very high price...

can you suggest the kv,turn and power ratings for a motor to be used in a NEXX8.
Please help me... my buggy is lying with no motor and i want to put it into good use... please help

[iamahuman]

Budget, vendor preferences? You're on 4s, right? The stock ESC won't run a new motor very well. You will have to upgrade both.

[Propfella]

Hi prateek13,

Before worrying about the new motor try to repair the old one. Regluing a magnet is a minor thing. As long as no further damage has happened it's possible to apply a good quality mix of epoxy and replace the magnet. even if it's broken in half. Make sure you get the polarity correct and check your rotor for damage to the windings. If the damage is just a nasty scar on the metal between the wire windings a small file can remove it to make it flush so it doesn't rub against the other magnets. Make sure you dont overdo the epoxy and have it sitting higher than the magnet and make sure the magnet is stuck flush with the can and sits evenly.

When filing away any marks make sure you clean the filings before reinserting the rotor and keep the can holding the remainder of the magnets clear when you are filing. Lubricate both bearings with high qualty grease or fine oil, reassemble the motor and rotate to make sure nothing is rubbing, make sure the epoxy is completely cured and try it out on low revs to start and take it no further than roughly half speed. High speed with no load could possibly cause the same problem.

Don't worry, replacing a magnet is very common and most continue to give a good life. Sorry something I forgot, check the rest of the magnets to see if any others are loose whilst it's apart.

Unless you are running over voltage there's no reason why anything else can go wrong. Obviously I can't guarantee it won't but I've seen motors throw two magnets in one hit but after repair continue to run as normal. If you are worried a thin layer of epoxy around the remaining magnets won't hurt. At least it will be in balance.

That's what these hobbies are all about, keeping things going, repairing and maintenance, not just going out and buying a new one every time you have a small problem.

Good luck and best wishes  Stu

[iamahuman]

Since he doesn't have a temp gun, it's hard to say whether the magnet will perform as before. IMO, it's better to upgrade. If it de-bonded (due to poor adhesive), what you suggested is a good idea. In a 1/8 vehicle, the loads are really high. If the power system isn't working as well as it can, it will stress and over heat. Repairing it would be a great lesson in working with motors but it won't work as well as it did.

@Prateek: Can we get a picture to show the extent of damage? A small bit of advice here... time your runs and try to have a temp gun on hand and temp your ESC, motor and battery to make sure your equipment is running fine. I'm lucky to have someone around with a temp gun so that I can borrow it to check temps but I need to get one soon.

[prateek13]

I am going to school now and when I get back I will up a few pics..
..@propfella: I am sure that the magnets are beyond repair......

[prateek13]

 what about this motor guys?
http://www.leaderhobby.com/product.asp?ID=9394001224195
and this - http://www.leaderhobby.com/product.asp?ID=9394001225380