new XB-E: issue with transmission?

[big_scot_nanny]

Hi All,


Been lurking for a while, just bought an XB-E, but of course my first post is to ask for help with an issue! Sorry.


It appears that the transmission is locked/heavily binding.


Running the car for the second time yesterday, on grass, was swining about quite the thing, then it just stopped. thankfully, I didn't just keep jamming on full throttle to get it moving.


All electrics OK, right beeps from ESC, servos turn the wheels.


On the stand, with everything off, I can "just" manually turn the wheels (i.e. in the same direction), but there is a lot of resistance, so much so that they barely turns. The resistance, and noise (not grinding, more a heavy friction noise) seems to come from the motor area.


If I turn it on, I can get a bit of forward movement but it sounds terrible, so I don't do that anymore.


Does this sound like spur/pinion mesh? or something more serious?


If spur/pinion, can anyone direct me to a guide as to how to access and adjust? Been googling but haven't found much.


Thanks all!


Kev

 

[landmissle]

Check the mesh between the motor pinion and drive gear. I'd loosen the motor and move it to open up the mesh to see if that solves your issue with binding. Then reset it with using a pc of paper or till these is just a bit of backlash.

 

[big_scot_nanny]

OK, pinion/drive gear cover off, motor loosened, it is not the gear mesh.

When I tak the motor out everything moves smoothly in the transmission, and ger mesh seems about right.

It was when I try to turn the shaft of the motor by hand that you feel the issue. It's is extremely hard to turn, with increasing resistance, until just before one revolution the magnets seem to let go and it finishes the revolution easily. Repeat as before, either direction.

Am I being a complete noob here? That doesn't seem right? I am sure it didn't do that before and my brushed emaxx sure doesn't feel like that.

Am I mad?

Kev

 

[bigfol]

I know what your talking about, mine did the same thing, losen off the pinion/spur gear mesh until it runs smooth, the meshing on mod 1.5 gears does not need to be close in order for it run smooth.....

 

[big_scot_nanny]

I have eased off a bit on the mesh, but really, it appears to be quite horrendous cogging from the engine.

Remember, when I take the motor out and turn the shaft by hand, it is incredibly difficult to turn.

Can I overcome by increasing punch? It is horrendous!

Kev

 

[big_scot_nanny]

OK, so after easing the mesh a tiny bit took it out for a trial.

It cogged and stuttered terribly, even at full throttle, for about a foot, then stopped, then moved another foot, then stopped. Then it really stopped and there was a wee puff of smoke from under the shell. aaaahhhhh!

Turned everything off, ESC seems fine, not hot, but motor is cooked. It was insanely hot (remember, was driving for about 15 seconds), and smelled badly of burning although there is not outward signs of damage.

Can one assume that it is ****ed?

What the hell happened?

Kev

 

[bigfol]

Well you found out what the problem was all right, sounds like the bearings might have seized or the rotor magnets let go, was it the original motor that came with the vehicle? If so, lets just say it not the best motor on the market, get yourself a TP 5692 1300kv motor from here:

http://fightercatracing.com/index.php.

They are the same cost as the leopard, but run cooler and have a lot of torque.

 

[big_scot_nanny]

Hey bigfol, yes, it was the original motor, haven't hopped anything up yet.

Fightercat site is down, but have made a rash move and gone for a 1717 off ebay. Hope it is OK, but the comments on this site, esp from Landmissle on this here site, plus on Uk sites for the maverick Vader version of the XB-E, suggest that it should be pretty good.

Getting a warranty replacement motor anyway from rampageshop.com, good to have redundancy, but a bit sad things let go so quickly.

When i think of the abuse dished out to my poor little e-maxx, and it just keeps on truckin', I am bit dissapointed this was bad out the box. Ho hum.

Kev

 

[DemonRC]

You also have to watch out for the pinion gear setscrews backing out and catching the motor mount. It will lock the motor and make it almost impossible to take the pinion gear off.

 

[big_scot_nanny]

Thanks DemonRC, I will look out for that also.

 

[bigfol]

If its the new black 1717 out of the traxxas xo1, it should be fine if you don't gear it to tall, just keep on checking temps unit you find the sweet spot,gearing wise......

 

[big_scot_nanny]

OK, wee update from me. After feeling like I have become a qualified electrical and mechanical engineer, I got the 1717 fitted.

Whooooo-eeeeeee! That thing is faaaaaast. But gives lots of room to control the speed, nice progressive build up. All standard settings as per landmissile - standard pinion, ESC settings etc. Only difference was to solder 6.5mm bullets onto the ESC connections to the motor.

Issue - Heat. That get's really hot. batteries warm (gens ace 5000mh 40C 3S), esc warm, but motor is hot! Have ordered CC fan for the top to see if that helps. any other ideas? What difference would gearing up or down make?

Batteries - clearly 5000mah is just enough, looking at 8400mah nano-techs, but the standard batteries were very warm indeed and a little puffed after tonights run. (makeshft race track on longish grass). Too much draw now?

My abilities - sadly lacking!

Kev

 

[big_scot_nanny]

thanks all for the support by the way, most helpful

 

[landmissle]

I'd go with a larger gear or smaller pinion.

 

[killajb]

Hope the following helps (borrowed from another thread but still applies here):

Hot motor, cool controller, cool batteries = undergeared

Cool motor, hot controller, hot batteries = overgeared

Warm motor, warm controller, warm batteries = happy components

Hot, warm, and cool vary as well, so here's another general rule:

Hot for a motor = generally over 160F (71C)

Hot for a controller = generally over 150F (66C)(or "thermal" range for the controller)

Hot for batteries = generally over 150F (66C) for nimh, 130F (54C) for lipo

Warm for a motor = generally 100F (38C) through 150F (66C)

Warm for a controller = generally 100F (38C) through 130F (54C)

Warm for batteries = generally 100F (38C) through 130F (54C) for nimh, ambient temp through 120F (49C) for lipo

Cool for all components = generally ambient temp and up to 10 degrees F (5.6C) more

 

[big_scot_nanny]

killajb - very useful, Landmissle - I get your drift... i think!

Sorry folks, but a question:

so, just to work through the logic, and I know there are hundreds of threads on this, but stick with me.

stock spur/smaller pinion or larger spur/stock pinion = higher ratio = higher revs = less top speed but cooler motor?

Is that right? I am having an embolism thinking about it.

Would the stock housing cope with a 44T spur? or would i need a complete new housing package from 7075?

Kev

 

[bigfol]

Good question on the stock housing fitting the larger spur gear, I'm not sure on that, maybe someone else can measure it for you, I would advise going to a 48t spur gear though with that motor and leaving the stanard pinion, adjust the motor timing to the lowest it can go, you will see a big differance in motor temps.

 

[strykerpilot66]

Hey Kev, running on grass is also known to strain the power system noticeably more than dirt or asphalt...any chance you can cut the grass lower or drive elsewhere?

Also, don't sweat it that you're somewhat new to this...we ALL were there at one point, and used the info here to get better. I used to think I would be stuck buying RTR's but after breaking/lurking/fixing/learning, I feel like I'm a Master RC Mechanic!

 

[bigfol]

+1 we all have to start somewhere....

 

[big_scot_nanny]

Cheers guys!

You know, my other major sport is mountain biking, I live out in Switzerland so it's all types . which of course means multiple bikes (DH, AM, XC, commuter....) and I think I almost enjoy tinkering, maintaining (inc for my three kids!) and building bikes as much as I do riding them.

Feeling a bit like this with the XB-E as well. It is a completely new skill set, never worked on electrics before, was very proud of my soldering the 6.5mm bullets onto the ESC, my first ever sodlering (well, after a quick trial run with some spare wire). God bless google and you-tube, the best classroom available!

Kev