LCC noise

[Sick87XJ]

I recently got into crawling, I have a LCC I got lightly used. I'm not new to RC but new to crawling and I feel like I'm starting from scratch. Anyway, has anyone ever experienced a chirping, squealing metal noise while going forward and worse in reverse? It sounds exactly like tank tracks in a world war two movie if that makes sense.

Also, I noticed the crawler is a lot peppier in reverse then forward.

Lastly, I've been having a problem with low speed glitching or cutting out. Its almost like when a lipo is going dead but if I throttle it more it has plenty of power. I've tried 3 motors, 2 different ESC's and 3 batteries. It is just typical of these things?

I tried the search and looking through some posts but any input would be great! Not sure if a lot of those things are just normal or if I should start fixing problems? FYI, I took the axles and the tranny apart and everything looks fine, no dirt, plenty of grease and no abnormal wear...

THANKS!

[Jslick]

They are a noisy beast. If you want a quite rig you got the wrong one. I have had my LCC for 3 years and the only time it is "quiet" is when it is PACKED full of grease. Are you using LNC or LCC driveshafts? What motor/ESC are you running?? Do you have metal or plastic gears in the tranz? They do best with brushless, I have a Goat 3 and it has done well for me. Do you have a BEC on your steering servo? That might be the cause for you brownouts.

John

[Sick87XJ]

Originally Posted by Jslick

They are a noisy beast. If you want a quite rig you got the wrong one. I have had my LCC for 3 years and the only time it is "quiet" is when it is PACKED full of grease. Are you using LNC or LCC driveshafts? What motor/ESC are you running?? Do you have metal or plastic gears in the tranz? They do best with brushless, I have a Goat 3 and it has done well for me. Do you have a BEC on your steering servo? That might be the cause for you brownouts.

John

I can deal with noise as long as its normal. I will try and post a video later once my junk is put back together. The DS's are LCC, the first motor was a 65t brushed motor from a local hobby shop and some random no name ESC. I tried two of those "crap" ESC's and motors and now got a Novak Eiger 35t Rock Star combo. Worked great but the ESC seemed to burn out after 10 minutes.

I've been building planes and playing with RC cars for 15 years so I know I wired everything up correctly per my experience and the instructions. Not sure what happened. Anyway, after this issue is resolved I should be up an running again. Seemed sweet though, just enough wheel speed and tons of tq. No BEC on my steering servo. I did notice sometimes when the steering is at full lock AND the wheels are bound up in a tight situation the car shuts down. Perhaps I'm beating the hell out of it too much? Not sure...

I wasn't sure if perhaps the noise was related to too much drive train resistance and making the motor and ESC work too hard? Everything seems silky smooth, looks good and my "used" LCC didn't even have scratches on the axles or steering, its hard to believe this basically "new" crawler has anything wrong mechanically.

-Alex

Also, what is BEC in crawling terms? Is that the same as flying, BEC is when we use a separate battery for the receiver and another battery for the motor, servos, etc.

[JavelinSST390]

Originally Posted by Sick87XJ

I can deal with noise as long as its normal. I will try and post a video later once my junk is put back together. The DS's are LCC, the first motor was a 65t brushed motor from a local hobby shop and some random no name ESC. I tried two of those "crap" ESC's and motors and now got a Novak Eiger 35t Rock Star combo. Worked great but the ESC seemed to burn out after 10 minutes.

I've been building planes and playing with RC cars for 15 years so I know I wired everything up correctly per my experience and the instructions. Not sure what happened. Anyway, after this issue is resolved I should be up an running again. Seemed sweet though, just enough wheel speed and tons of tq. No BEC on my steering servo. I did notice sometimes when the steering is at full lock AND the wheels are bound up in a tight situation the car shuts down. Perhaps I'm beating the hell out of it too much? Not sure...

I wasn't sure if perhaps the noise was related to too much drive train resistance and making the motor and ESC work too hard? Everything seems silky smooth, looks good and my "used" LCC didn't even have scratches on the axles or steering, its hard to believe this basically "new" crawler has anything wrong mechanically.

-Alex

They are VERY noisy compared to regular R&P axled crawlers, but there should be NO metallic squeling/squawking noise. Take the axles off, and tear them apart and inspect everything. It sounds as if you've lost a bearing. Heavy-duty grease, containing Molybdenum, for the worm gears and spools is a MUST on these rigs. I've had my Diff inputs read as high as 140 degrees on an infrared temp gun without being greased. And I know your rig might be new, but mine was too. Search for "losi grease mod" and you will find how to drill a small hole in the axle housings that will allow you to pump a little grease in each axle before every run. The losi's are higher-maintenance than most R/C's to keep them running right.

As far as the Eiger system, if it smoked after 15 minutes, I'm not surprised. Novak has been notorious for bad products lately. Also, LCC/LNC rigs don't work the best with brushed systems. I've heard of LCC's overheating and killing a brand-new 35t in under ten minutes. Get a Tekin Havoc 17.5 brushless, an external-mounted cooling fan for the motor, and be done with it.

The BEC, go to Castle Creations website and look up "BEC". But for our purposes, we use it a little differently. What we use it for for crawlers, is to by-pass the voltage-and-amperage limited BEC's in most ESC's. Most are limited to only an amp or less, at 4v. Using a Castle adjustable BEC, running directly from the battery plug to the batt plug on the reciever, allows us crawler guys to crank the voltage to the servo up to 6+ volts and 3-to-5 amps (most servos won't take more than this without burning up with a quickness, there are high-voltage servos out there that can take more, but they are big $$$). Get one, install it (check on here for the many, many guides on how to properly wire in a BEC on a crawler) and be AMAZED at how much steering power you have.

[Sick87XJ]

Originally Posted by JavelinSST390

They are VERY noisy compared to regular R&P axled crawlers, but there should be NO metallic squeling/squawking noise. Take the axles off, and tear them apart and inspect everything. It sounds as if you've lost a bearing. Heavy-duty grease, containing Molybdenum, for the worm gears and spools is a MUST on these rigs. I've had my Diff inputs read as high as 140 degrees on an infrared temp gun without being greased. And I know your rig might be new, but mine was too. Search for "losi grease mod" and you will find how to drill a small hole in the axle housings that will allow you to pump a little grease in each axle before every run. The losi's are higher-maintenance than most R/C's to keep them running right.

As far as the Eiger system, if it smoked after 15 minutes, I'm not surprised. Novak has been notorious for bad products lately. Also, LCC/LNC rigs don't work the best with brushed systems. I've heard of LCC's overheating and killing a brand-new 35t in under ten minutes. Get a Tekin Havoc 17.5 brushless, an external-mounted cooling fan for the motor, and be done with it.

The BEC, go to Castle Creations website and look up "BEC". But for our purposes, we use it a little differently. What we use it for for crawlers, is to by-pass the voltage-and-amperage limited BEC's in most ESC's. Most are limited to only an amp or less, at 4v. Using a Castle adjustable BEC, running directly from the battery plug to the batt plug on the reciever, allows us crawler guys to crank the voltage to the servo up to 6+ volts and 3-to-5 amps (most servos won't take more than this without burning up with a quickness, there are high-voltage servos out there that can take more, but they are big $$$). Get one, install it (check on here for the many, many guides on how to properly wire in a BEC on a crawler) and be AMAZED at how much steering power you have.

I wonder if a bearing did fail. I popped them out of the axles and they all seemed fine but it sure does sound like a bad bearing, I'll have to look again. Novak seemed like a good choice, the product looks good and they seem to be in every hobby shop and every other crawler. I'll see if I can return it, honestly the quality looks good, the power the motor had was great and the tuning on the ESC was nice but I'm not impressed at all. I wasn't even crawling it, it happened at my shop on the bench after I got done driving it on flat ground for 10 minutes. Lame.

Whats everyones take on greasing the transmission? Mine is dry, clean and looks great. And yes, it has plastic gears.

I just want to use my dang LCC already...

[Grabbem88]

On the tranny I always used white lithium grease and that's even on my sc trucks and rustlers.

If it was me I'd replace all your bearings with a better qaulity and soaked them in silicone spray overnite before install..

The metal to metal sounds to be bearings but I'd disable one drive shaft then the other till you find the noise...

[Sick87XJ]

Is there a brand or kit that will service the entire rig if I wanted to redo all the bearings? I will drill some service ports so I can regularly grease my junk and make plugs, etc. I might as well tune up my chassis since my dang ESC is still in hiatus with the local hobby shop...

[JavelinSST390]

Fast Eddy bearings. Complete kit that covers EVERY bearing in both an LCC and LNC. $27.99

Team Losi 1/10th scale crawler Bearing Kit

[JavelinSST390]

You have a comp crawler right? Check the slipper clutch. I just read in the tips and tricks thread that the slipper can make a squealing noise.

[Olle P]

I had this same problem when I got my rig almost a year ago...

Noise come from friction, and for me it was the motor overheating (due to high friction) rather than the noise that was the worrying part.
Anyway, I began the quest of friction reduction, and here are my findings this far:

Lubricants
The LCC (excluding the motor) can do with only two lubes:
1. A spray-on dry film lubricant (DFL) based on either PTFE (Teflon), which is great but expensive, or Silicone, which is good and cheaper.
2. A water resistant grease that can handle high pressure and beatings. "Marine grease" or something Molybdene Sulfide based will do nicely.

What to check
(Going from the motor out towards the wheels.)

1. Pinion.
The pinion should mesh nicely with the idler gear. With the pinion in place you should be able to rotate the idler a little (like 0.2mm or 0.01") without it touching the pinion.
Lubrication of the pinion, as well as all other cog wheels in the LCC, isn't necessary. If you want to do it use DFL.

2. Gearbox center plate.
The three screws holding this plate to the housing are typically drawn too tight, which cause an axial strain on the main bearings and thereby friction. The screws should be drawn all the way in, and then losened ~1/4 rotation.

3. Dig forks.
If you actually use the dig apply DFL (or a thin oil) on the dig plates where the forks run.
If you don't use the dig, remove the dig forks!

4. Drive shafts.
The joints do wear a bit. Dissemble and apply DFL (or just apply some thin oil without dissembling, risking dirt to stick and make the situation worse).
While you're at it, apply DFL to the entire exterior of both shaft halves to make them slide easier over obstacles.

5. Worm drives.
Make sure the spools are properly seated by pushing them side to side. There should be a hint of room to wiggle the spool between the bearings. Adjust by adding/removing shims if necessary.
Apply a liberal amount of grease.
(It gets even better if you also replace the front drive with HD parts, since they have a different gearing causeing the front wheels to spin slightly faster than the rear. The difference in speed decrease friction while turning, which is what you do most of the time.)

6. Rear axle.
The long screws holding the rear hubs are often overtightened, making the spacer press against the bearings causing axial pressure and friction.
The proper way to mount the rear hubs, axle and bearings is to
a) place the rear axle (shaft) into position (inserted in the worm spool).
b) place a bearing at the inner edge of the hub.
c) thread the bearing and hub onto the axle and push it into position.
d) add the long spacer and the outer bearing to the axle.
e) mount the hub end by turning the screws all the way in and then back them out ~1/4 turn.
f) add the short spacer.

7. Wheel hexes.
In their standard shape the ring like "shim" on the inside of the hex will press against the bearings if you draw the weel nuts tight, causing friction and gradually wearing down the bearings.
The easy fix is to not tighten the wheel nuts.
A better fix is to grind off the rings from the hexes, like this:

That way you can tighten the wheel nuts as much as you like.

Results
I've done all of the above, including removing the dig forks, and there's a huge difference compared to its original state!

Yesterday was the very first time I had a chance to compare my crawler to any other, in this case an SCX10.
Truth said, my LCC was the quieter rig of the two!

[Sick87XJ]

Well, I finally had time to look into that noise. I thought it was the tranny but I narrowed it down to the rear axle. Disconnected the drive shafts and spun the front...turned smoothly, spun the rear while loading the tires and its notchy, inconsistent and just nasty. Pulled it apart and found the center section of the worm gear sharpened and grooved.

So...what gears are ideal? I'm running obviously 2.2 tires, a 35T brushed motor and the stock LCC tranny. Obviously I'm going to be crawling it but some wheel speed would be nice when I need to get a little momentum on the slippery stuff or spin the tires to get up some slick rock.

I want the most reliable brand or set up. Thanks!

[Olle P]

See bullet 5 in my previous post.

First
a) Get a HD worm drive (LOSA3187) for the front axle.
b) Move the hopefully less worn current front worm drive to the rear axle.
c) Add a liberal amount of grease to both drives.
This will reduce the strain on the rear drive and make the rig generally run better.

Gearing:
I run my brushed 35T motor on 2S LiPo with a 12T pinion, and that setup provides more than sufficient torque while the top speed is ~2mph and the motor stays luke warm. I might get up to 14T pinion to get a bit more speed.
If you run it on 3S you could go up to perhaps even 16T pinion and reach speeds close to 4mph!

[Sick87XJ]

Ok cool, Im running a 14t right now. It seemed pretty decent with my new motor and ESC until it crapped out. Who knows, maybe my rear axle made the motor and ESC pull to many amps and fried it. Although, lots of people seem to dislike Novak ESCs. Guess I'll see what happens when they send me a new one.

Im sure there is a procedure for setting the shims correctly, right? I've found some info but not official Losi procedures for setting up the tranny, slipper clutch or axles. Id like to do everything to the best of my abilities to minimize reliability issues.

[Olle P]

Originally Posted by Sick87XJ

... maybe my rear axle made the motor and ESC pull to many amps and fried it.

Quite possible, when added to all the other little "power eaters".

Originally Posted by Sick87XJ

Im sure there is a procedure for setting the shims correctly, right? ... Id like to do everything to the best of my abilities to minimize reliability issues.

To my knowledge it's only the shims at the worm spools that can be a mounting issue, described above.
The worm pinion shims have to be the right number to leave just a little wiggle.

With everything described in my longer post checked you should be fine, but don't expect the LCC to be anywhere near "fast", because worm drives consume quite a bit of motor power (30-50%) even when properly lubricated!

[stephenwhimire]

I run a 35t in my lcc on 3s and found that with anything bigger than a 13t pinion the motor would get warm fairly fast, and for a cheap solution to putting grease in the axles I modified a baby's medicine syringe with a basketball needle glued on the end.

[Olle P]

Originally Posted by Olle P

If you run it on 3S you could go up to perhaps even 16T pinion and reach speeds close to 4mph!

Originally Posted by stephenwhimire

I run a 35t in my lcc on 3s and found that with anything bigger than a 13t pinion the motor would get warm fairly fast, ...

That seems possible.
The power output from the motor at a given throttle setting is a little more than doubled when going from 2S to 3S. Running on more than 2/3 throttle will therefore add a considerable amount of heat compared to running on 2S.

My estimate about using 16T pinion is based on the higher torque available with higher voltage, but does have a time (heat) constraint to it.
It does allow for higher speed/torque in short bursts (a few seconds) with cooling off time (minutes) in between.

Originally Posted by stephenwhimire

... cheap solution to putting grease in the axles ...

A syringe is an easy way to just add grease, but I never want do add grease without first cleaning out the old grease and inspect the drives. If there was a measurable leakage of grease I'd might consider adding more in-between inspections, but as of now I don't have that problem.

[Sick87XJ]

Well, I ordered a HD worm set from a place in SoCal. Should be here in a few days. I'm going to do some research on how to set them up properly. Anything I should know for long term success on the gear life?

-Thanks

[Olle P]

At the first install of new worm gears just mount the spool and worm, with proper shims and lubrication.
Screw the two housing halves together. Don't add hubs and axles!
Use a power drill or electric screwdriver attached to the worm spool to "run it in" for 15 minutes or so. Do expect some friction at first.
Dissemble the axle housing, clean out the used grease and add new.
Now you can mount all parts to the crawler!

[Sick87XJ]

Thanks for the tips and tricks and advise! I got my junk running, the noise, slow speed jerking, lack of power and speed going forward was all related to my rear worm gear. I installed new HD gears and my motor and esc combo and its running sweet! Now its time to crawl!

[kayakdoug]

Thanks for the detailed responses in this thread. I have had similar issues and look forward to trying out some of the things listed above.