Losi Night Crawler 2.0 help!

[C0LTERGEIST]

I am new to the crawling game and picked up a Losi Night Crawler 2.0....it was great out of the box but I was crawling around on the wood pile in my backyard and it seemed like it had no power and was stalling out on any obstacles that it would normally crawl over. So I took it inside and let it sit for a while guessing that either the motor or ESC had overheated (neither of them were really too hot to the touch) and after letting it sit for a while it seemed fine. I have since made some upgrades (added 6oz. to each front tire and 3oz. to each rear tire and put the proline chisel tires with memory foam) and am in moab utah right now and did some crawling and after about 5 minutes of running it started to stall again, it was about 35 degrees outside so I have a hard time believing that anything overheated in that amount of time, and I have only had it for about a week so I doubt lack of grease in the worm gears is part of the problem either. Everything is stock other than the added weight and tires/foam. I would imagine that the added weight puts quite a bit more stress on the motor but it was still stalling out before that was added. Can anyone help me figure this out?? I would like to crawl for more than 5 minutes lol

Stock Setup

Motor: Dynamite 35t motor
ESC: Dynamite WP 60A
Battery I am using: Venom 2s 40c 5000Mah Lipo

[Olle P]

Motor temp? (Touch it!)
Worm pinions' temp? (Touch them where they're attached to the drive shafts.)

The worm drives need supervision and care!

[GiJoe]

It sounds like worm stall to me. I know its new and it "should" be greased, But open the axles and check anyway. My experience has proven that worms like to be OVERGREASED!

Pick up a tube of Moly Grease from an auto or farm store and really pack those worms full. It will bathe them and dissipate heat.

There are also several threads here that explain how to do the grease port mod. That way, you can add grease with a syringe instead of disassembling the axles.


Also, check out the Reducing Friction Sticky at the top of the page. Good info in there!

[C0LTERGEIST]

Ok thank you for your help and input everyone, I really appreciate it! When I get home I will definitely pull the axles off and grease them up good and look into that mod! Do you think that the stock motor and ESC are ok with the extra weight that I have added or do you think it would be a good idea to upgrade those too?

[mudholestomper]

I don't think the added weight in the wheels should present any problems whatsoever - how did you add the weight? - if you used stick on weights inside the wheels (not inside where the foam is, but inside the wheel near where the hex fits into the wheel), make sure the weights are not rubbing on anything (like the knuckles on the front or the lockouts on the rear) - also, make sure that your steering servo endpoints are set so that the tires do not rub the shocks or the body (or anything for that matter) when at full lock in either direction

I don't know much about the esc on the 2.0, but it wouldn't hurt to double check the settings on it and your radio - in particular, it's really easy to re-bind the radio to the receiver, just to make sure there is no issues related to that - secondly, make sure the esc is properly calibrated to the radio (as far as forward and reverse endpoints) - make sure the esc is properly setup as far as being in lipo mode (as opposed to nimh mode) - also, many escs allow adjustment of the lipo cutoff…it's possible the voltage cutoff is set too high and the esc is cutting down to 50% power because it's hitting the lipo cutoff voltage voltage under full power

In "the old days", most lipo cut offs would completely shut off power to the motor when the esc detected low voltage - nowadays, many escs cut power to 50% (to allow you to drive the vehicle back to yourself) when the voltage stays below the cutoff for 3 seconds…then, when the esc detected low voltage for a longer period of time (say, 5-10 seconds), the esc would then cut power to the motor completely

So, the reason you may lose most of the power, then, after a short wait, be able to run at full power again, could be the lipo cutoff being set too high and/OR the esc detecting low voltage momentarily as the battery is pulled down below the cutoff under a high voltage draw scenario (full throttle or high amp draw from a steep climb, binding from tires rubbing on shocks/chassis or getting stuck in a hole, etc)

When you lose power (or get reduced power), what are the LEDs on the esc doing? - most escs have some kind of specific led pattern/sequence that occurs when, not only the low voltage cutoff occurs, but when there is any other issue that crops up - over voltage from the battery, over heating, loss of signal from the receiver, even protection from a motor that is bound up/has a short

The only other thing I can think of that may be an issue would be to double check the connectors between the esc, motor, battery, servo, receiver, etc - if the esc and motor are not getting hot, what about the battery itself? - when you lose power, check the battery wires and the wires running from the motor to the esc individually to see if any of them are excessively warm (at several points along the entire length of each wire) - what type of connectors are used and are any of them getting really hot? - is the servo or receiver really hot? - lastly, check the solder joints closely and make sure none of them is wiggling/loose

I suspect that the lipo cutoff is the problem and, if you can't adjust it, there is a good chance that gearing down (smaller pinion) would positively affect any excessive amp draw from the motor due to being over-geared

A 40c lipo with the mah rating of yours should have absolutely no issues running the motor/esc setup of the stock nightcrawler, but the worm gears and other high friction aspects of the model's design can and will stress a lipo pack more than the low speed, low gearing of the truck would seem to - because of it's inherent low speed, many nightcrawler owners spend a good deal of their driving time with their throttle finger buried - add in the friction with the extended full throttle operation, and you have a recipe for draining a battery quickly - repeatedly (and for extended periods of time) asking the battery to deliver its full capacity for delivering amps/voltage will cause it to drop its voltage below 3volts/cell fairly easily, thus triggering the lipo cutoff on the esc

hope this helps now and in the future

mudholestomper

[84yoda]

You need to feel the axles for temp as well, im sure its a lack of grease in axles. Factory may have put a light coat of grease in. Do the grease port mod and shoot some in each time your about to run. You seriously can't over grease them, they just eat grease like crazy. Also check shims on the big gear (side to side play) and make sure they didnt add an extra shim and its causing drag aka heat.

[GiJoe]

Mudholestomper is correct, and also jogged my memory.

Its possible you are also experiencing "Brown Outs" from the stock BEC in your ESC.

A crawler puts lots of strain on the steering servo, which may be overtaxing the internal BEC.


As habit, I run the Castle 10amp external BEC (UBEC). This essentially powers your steering servo with its own dedicated circuit so to speak.

It will be the best $20.00 you ever spent!

[84yoda]

Its 100% stock rig, no way its browning out. And the fact that it doesn't do it in the beginning of his run shows that.

[vitamindimo]

Funny I live in Moab and just bought the LNC 2.0. Weights/foams and a slightly better servo are the only mods. If you're still in town you can swing by and try your rig against mine w/ same battery. Mine died pretty quick on the trail today but i'm chalking it up to cold and not charging it enough.

[vitamindimo]

btw how did you add 6 oz to each of the front wheels? the stock rims are pretty narrow and I was only able to get 3oz added inside the tire sticking to the rim (12x7g pieces). was able to cram about 2oz more in between the spokes but it's pretty ghetto. did you do 2 layers of weights on the inside?

[C0LTERGEIST]

I started taking the axles apart tonight and will finish them up tomorrow and will do the grease port mod while I have them torn apart and will keep you guys updated on whether the added grease helps. I also did some research on my esc today and pulled up the manual online and it says that the led light on the esc will blink when there is overheating and will also blink on low voltage and so I drove it around for a little bit until it started to stall again and looked at the light and it was just solid which means full throttle. I picked up some grease so I hope that fixes it and I can get back to crawling!!

[C0LTERGEIST]

vitamindimo, I came back home to Ogden today unfortunately!! I would have loved to meet up and do some crawling and compare it against yours!!

And for the weight I actually used lead wire that I picked up from the local outdoors store in the fishing department and wrapped it around the wheels and then used electrical tape to wrap around it to keep it from rattling around. The lead wire that I found was hollow so to get the 6oz. I had to cut a 48" piece for each wheel and for the 3oz. it was a 24" piece for each wheel. If you can find solid lead wire that would be a lot better cause you wouldn't have to use as much and it wouldn't be so crowded but I made it work

What servo did you end up going with?? That will be my next mod once I get this problem all figured out.

[vitamindimo]

i got a ls-60d from the lhs in Grand Junction, was an impulse buy (they sold me on it) for $27. dont know anything about the product but it is certainly an improvement. that said the 2 times I've taken it out since the batter died quickly - not sure how much the outside temp has to do with it so I'm guessing the new servo's drawing a lot more power? I'm new to RC...

Let me know what you figure out, also can you send me the ESC user's manual link? And give me a shout when you're in Moab next.

[C0LTERGEIST]

I am new to the crawler game so I don't know a whole lot about it either but I have been reading a lot on servo upgrades and have read that people buy a BEC (battery eliminator circuit) when they upgrade the servo to help with that stuff.

Here is the link for the ESC:
http://www.dynamiterc.com/ProdInfo/F...nual_MULTI.pdf

I will definitely let you know what I figure out and when I will be in moab again. I am hoping to make it back down there in the spring!

[mudholestomper]

Originally Posted by C0LTERGEIST

I started taking the axles apart tonight and will finish them up tomorrow and will do the grease port mod while I have them torn apart and will keep you guys updated on whether the added grease helps. I also did some research on my esc today and pulled up the manual online and it says that the led light on the esc will blink when there is overheating and will also blink on low voltage and so I drove it around for a little bit until it started to stall again and looked at the light and it was just solid which means full throttle. I picked up some grease so I hope that fixes it and I can get back to crawling!!

Were you actually running the truck at full throttle when you looked at the led that indicated the truck was at full throttle? - in many cases, an led pattern that is telling you that you have activated the low voltage will be happening with the transmitter at neutral with the truck not moving with the esc turned on

What do you mean the led was solid indicating full throttle? - that makes no sense in the scheme of the truck losing a lot of power (but not all of it), all of the information you've been presented with by people in this thread, and your reason for starting the thread in the first place

If you aren't going to offer specifics with regard to the troubleshooting and aren't going to put the effort in communicating your findings, then there is no point in trying to help you solve the problem - instead of finding and fixing the problem in a few posts through back and forth communications that contain the information we need to help you, it leaves those trying to help you ending up having to write post after post trying to pry information from you…information that, if I was asking for help, would happily volunteer to provide - it's common sense, common courtesy, and blindingly obvious common sense

That being said, given the lack of useful info you provided and your plan to fix your problem, I'll say this:

If the worms not having enough lube on them was causing your truck to lose power after a short time into your run, the power loss would be due to FRICTION - whether the worms are rubbing too much, are shimmed too tight, or a bearing in there has failed, the bottom line would be an increase in friction - but if you have friction issues related to the worms, the only reason that it would cause the truck to lose power would clearly manifest itself in excessive amp draw, voltage drop, etc - the sure fire, without a doubt indication that excessive friction was causing power loss would be a hot motor, battery, axle housing, or esc (or any combo of those)

You said the electronics were not hot at all - You didn't offer up any info with regard to excess heat on any part of the truck (as those that have tried to help you suggested) - do you see where I'm coming from now as to how you not making the effort to communicate, in full, what troubleshooting suggestions you've looked into and what your findings were for each item checked makes it very difficult to help you?

I can say, with damn near 100% certainty, that if you grease the worms to reduce friction, but have seen or reported NONE of the side effects that friction would cause with relation to the direct results that a high friction issue would have on your electronics, then lubing the worms is not going to solve your problems

While taking steps to grease the worms and modding the axle to make it easy to do in the future is definitely something I'd agree should be done and I think it is a smart move on your part, the fact is, if your problems were related to friction in the axles, it's a simple cause and effect situation - and if you have friction problems, it would result in some aspect of your electronics being overworked - and this, in 99% of the cases, would result in heat in the motor, heat in the esc, heat in the battery, a puffed or dead lipo cell, or heat in the wires or connectors

Now, if I'm wrong here, someone please correct me and I'll be right back in here with my tail between my legs - but, dude, if you want help/troubleshooting advice, it makes it very difficult to help you if you don't give us something more to work with - I, for one, am not going to beg you for the info

Signed,

A Slightly Annoyed mudholestomper ;)

[mudholestomper]

If you read the troubleshooting and low voltage protection section of the esc manual you posted a link to, I think what I've been saying will make sense to you - if the voltage drops to 3.3volts, the esc goes to 40% power - in a vehicle like the nightcrawler that could very realistically have excess friction in the drivetrain, all but the highest c-rated lipos could and would EASILY drop to 3.3volts under load - understand that, under full throttle/heavy load, the battery will hit that 3.3volt limit easily, but the battery you are using will return to the nominal 3.7volts per cell within a few seconds - and, by the time you can take a look at the esc for the blinking led, the battery will return to a voltage level above the cutoff - a 40c lipo will hit the 3.3volt limit but, if you continue to drive it with the esc only asking for 40% power from the battery, could easily stay above the 3.1volt limit that would cut the power to the motor completely

While reducing all friction will certainly improve the situation by cutting down on excess, friction related amp draw, therefore helping the battery maintain a higher voltage level while under duress, I stand by my first theory that your primary issue is due to the esc cutting power because it is detecting low voltage from the battery

How old is the battery? - it's also possible you have a cell going bad

Signed,

A Slightly More Relaxed But Still Defiant mudholestomper

[C0LTERGEIST]

I definitely can see what you are saying and it does make sense, but is there much that I can do about it? From what I have seen and read about my ESC I cannot reprogram any of the cutoff settings.

The battery is brand new, I have only had it for about 3 weeks. I am ordering some new SPC racing lipos soon that are 2s 70c 7200mah, would those be any better?? I am very new to this, sorry.

[XtrmTJ]

I have a new 2.0 version of the LNC and just opened the axles, almost NO grease in them ! Very, very little grease added at the factory. I am using Marine Grease and packed them as full as I could get them.

[Olle P]

Unfortunately I think the ESC can be to blame. I've never heard anything good about ESCs from Dynamite, and the one I used myself (Tazer 10T, IIRC) gave up in half a year of use.

[mudholestomper]

COLTERGEIST - sorry if I came off a little hostile - definitely read through the post on reducing friction in this forum and apply the knowledge therein - try to run the truck close to you so that when it cuts power, you have a good view of the esc - see if it blinks like the low voltage cutoff is kicking in when it loses power - remember, when you let off the throttle, the battery will recover very quickly and the esc will therefore return to normal mode quickly - if the truck loses power and you see the LEDs indicate that the low voltage protection is indeed kicking in, even for a second or two, then it is just a function of the way the esc is programmed from the factory and you can't do anything about it, short of replacing it with something better

Losi has a maintenance list/schedule in the vehicle manual and, as long as you are taking the steps to reasonably follow them, you should not have problems with the vehicle - before you drill holes in the axle housings, just lube and grease everything per Losi's instructions - also, remove the pinion and test the motor in forward and reverse - listen for any strange sounds, anything rattling around inside, and for excessive sparking - it's possible that it may be damaged

Don't drill the axle housings yet because you are not doing anything to/with the vehicle that is outside of the warranty parameters and I believe you should contact Losi about the problem - if you are following their advice in the manual for maintenance, you have a great case for a warranty claim - if you drill the axle housings, you may just void the warranty

Losi will try to troubleshoot the problem with you before they have you send it in for any repairs - you want to be armed with as much information as you can be when you are speaking with them - you never said if you tried to rebind the radio and receiver or if you tried recalibrating the esc and transmitter - if you read the manual for the vehicle and the esc, you'll notice a pattern in the troubleshooting sections of both - you'll see it repeatedly mentioned, for several different problems, to rebind the radio and recalibrate the esc as the fix for those problems - these are the very first things that Losi is going to have you do before authorizing you to send it to them for repair - my advice, as mentioned several posts before this one, is to do both of these steps and test the truck before calling them

There is no reason a stock vehicle should be doing what yours is doing (when operated within Losi's guidelines in the manual) and, although it's a bit of a pain, it's on Losi to fix the problem

Hope this helps and good luck!

mudholestomper