LCC Tips and Tricks

[sideshowbob]

Originally Posted by ghtpdm5

not gonna rip ya sideshow, thought about the same thing while i was sitting in the tractor one day. problem lies in the sealing of the diff, and with an oil cooler, you're not going to have enough airflow to make a difference. with a fan, i think the oil would cool too much, become too viscous and then not want to flow properly.

the grease you use in the diff's make a huge difference in the performance and heat build-up. you want to use something made for sliding metal friction, which is exactly what you face in the worm system. i used grease for the end of the bar of a chainsaw for about a year, made to combat the friction you see there. that worked well, but nowhere near as well as the john deere heavy-duty moly grease i use currently. the hd moly is specifically designed for sliding metal friction, i've used it on combine harvesters for a long time, and if it does its job great on a $250,000 machine, i have no problem using it in my crawler.

if you wanted to run an oil bath setup, i would first try a thin grease that goes to a gear oil consistency when worked. john deere special purpose corn head grease is designed to do that, its made for low speed 90 deg pinion gear setups. starts as a grease bath and then after a short go, it turns to a gear oil, but only in the places its worked, meaning that it would form a small buffer zone around the bearings.

hi
thx for your reply

the grease you mention sounds like what im looking for , in fact during the last hour between our posts ive had the worms out again de-greased and re applied a high speed lmp spindle grease made by kluber of germany , the results are shocking the temps have dropped from over 100c to under 35c approx measuring on the outside of the worms cv cup!
im very pleased with the results from a 20 minute run of my home course with plenty of dig use and measured on the front axle which is where my temps are always highest ( i say this like i have huge experience but ive only driven it since xmas day when mrs santa claus ie the missus gave it to me lol)
anyway ive now had the worms out 5 times to adjust backlash and grease etc
and have the process down to under 20 mins a piece , not that it makes up for losi /santa giving me a "pre built kit" that requires re building because you just ruined the worms in 2 hours because they didnt tell you that the worms go over 100c and seize up ! seriously ! i had been driving around with no previous knowledge of the worm problem thinking it was my old lipos were on the way out and the lcc was getting slower and slower i kept checking the motor , then the pinion ,esc etc never even had a thought about the worms until it burnt my finger off when i picked it up with the axle.
rant over , i think ive halfed the life of my worms in under 2 hours of owning a brand new lcc , they have a great big notch through them now.
what do u think my chances are of losi giving me a new set being as its only 8 days old???????????
thanks in advance, i think we can forget the oil cooler idea , as you say the right grease and the wrong grease is extremely important and easily overlooked by many, including me (auto mechanic)
cheers bob

[ghtpdm5]

i don't know what losi would say about it, wear is a normal part of worm driven life, but excessive wear is a bad thing as you know. i don't know what the availability of the grease from deere would be in the uk, but i'm sure claas, new holland, or jcb would have a suitable substitute for sliding metal on metal, in fact since jcb is a construction equipment company, they would probably be the best place to start. most people run lucas oil red and tacky, but i've seen quite a few seized bearings that still had that red hell in them, so i'd never run it in anything. most automotive greases are made for bearing application as i'm sure you know, and they just don't do as well as a grease purpose made for sliding friction.

[losikid]

team3six rock lube has been working good for me.

[Olle P]

Originally Posted by Weasel

... what sizes of wrenches are need for the LCC (stock).

The only extra tools required are:
- 1/4" wrench, to work the nuts.
- That regular R/C tool used to remove the wheel nuts.

All the other hex-tools required come supplied with the crawler.

[Olle P]

To me it seems odd to use high speed motors with a crawler. Sure they're high power, but for slow running they just use lots of amps. On top of that the LCC doesn't have much room for batteries to deliver all that electrical power.

The Night Crawler come with a 35T motor (oddly enough named "55T") and 21T pinion, and nobody seems to think bad about that. Why not run the LCC on a similar setup?

[ghtpdm5]

the difference in gear ratio between the lnc trans and lcc trans is drastic at best. simple fact is, the worm gears work better with a high speed input, the worms are the gear reduction in truck, neither trans is over 2:1 internal (sans pinion ratio) so running a high turn motor would result in running the motor at full tilt for most driving. with the higher speed motor, you run the high speed into the 25:1 or 21:1 hd worm at a rate that you don't have to run the motor all out. now a low wind motor will pull more amps, especially when you factor in the inherent friction in a worm drive system. which in the case of brushed motors, results in higher comm and brush wear, not a bad thing if you have a lathe and like turning arms, but it is a problem in the lcc after a bit of running. seeing as that the only wear part on a brushless motor are the bearings, this makes for a natural fit to the losi platform. my stock pinion was a 20t btw, i do have an older one though.

the amp draw is also not as bad in crawlers, the only place you really have to worry is in a hard bind, i run 850 or 1000 30c 3s batteries in mine and the packs are still cool after a clean run, get a touch of heat after a bad run. batteries in crawlers are not really the same as go-fast batteries in terms of use, you should just get a second or 2 bind in a crawler, enough for the burst rate of the battery to cover. in a go-fast, you are correct, the pack size does really matter, in my vendetta, i run my crawler packs. the same packs that never get warm in my crawler come out warm from that little mini, reason being that the gearing on it pushes the motor, drawing more amps, and heating the pack.

so to sum up here, the battery theory you present is indeed valid information, but in crawling, we don't draw near the amps as a basher or a racer. also, the worm drive system requires a lower turn, preferably brushless motor to get the needed speed into the diffs so you're not running into a high amp draw situation of running the motor full tilt.

[Olle P]

Originally Posted by ghtpdm5

... running a high turn motor would result in running the motor at full tilt for most driving. ...

With a low top speed that's normal, yes. I don't see that as an inherently bad thing, unless you want to have a rock racer.
With a high wind motor you can also increase the top speed by increasing the voltage.

Originally Posted by ghtpdm5

with the higher speed motor... you don't have to run the motor all out.

Depends on the terrain and actual gear ratio, doesn't it? Too high gear and you'll need everything to get sufficient torque, at abysmal efficiency to boot.

Originally Posted by ghtpdm5

... now a low wind motor will pull more amps, especially when you factor in the inherent friction in a worm drive system.

A low wind motor will pull more amps, no matter what type of gears are used!
The worm gear friction just adds to the mechanical power required from the motor to run the car at a certain speed, and low wind motors can provide more power at a given voltage. Low wind motors are also less efficient, so the increase in mechanical output power is exceeded by their increase in electrical input power.

To sum it up:
- In an ideal case with no mechanical friction whatsoever (apart from that between the wheels and the ground) you'd get the same "level ground top speed per volt" from any windings/pinion combination where the "windings per pinion tooth" is kept constant. But the world isn't that ideal...
- Worm gears are (to some extent) power hogs.
A car with worm gear will therefore run slower than a car with regular cog wheel transmission, given all other factors equal. (The regular transmission will cause more torque twist though, and doesn't provide inherent drive brake.)
- Low wind motors provide more mechanical power than high wind motors, and can therefore make the car run a bit faster (at the same voltage feed). They will also use considerably more electrical current to do so, reducing the available run time.
- The stall current of low wind motors is considerably higher than that of high wind motors, making them less ideal for very tough terrain where stalls are probable.

Originally Posted by ghtpdm5

... the amp draw is also not as bad in crawlers, ... i run 850 or 1000 30c 3s batteries in mine...

Providing how many hours of run time?
The peak current is irrelevant to me, but average consumption is an important issue when taking the car for a three hour spin.

[ghtpdm5]

i get a little under an hour with the 1000's and the losi was never meant to run that long in the first place, they do require a cooling time, it was designed for comps. the efficiency of brushless motors also comes into play there, with a brushed motor, i was lucky to get 15 minutes off the same battery. the friction of the worms is the thing with the losi, its a blessing for competition, and a curse for those how want to run for hours without cooling. each pack change, i give my truck 10-15 minutes of cool time, after that, its good as new. the stall current is higher with a lower turn brushed motor because of the copper density in the arm (and in most cases the steel density as well). you have to pipe power in there like no tomorrow to overcome the magnet strength in the can. a good brushless rotor will spin very freely on the bearings, still not like spinning nothing, but much, much lighter than spinning a brushed arm in can. this combined with the copper wind in the cans being packed in efficiently means that the whole system is easier to start than a low turn brushed motor. you also seem to be forgetting about the wind number to kv relation difference with brushed and brushless motors. my motor is a 17.5T tekin, looking on tekin's website, you'll find that its a 2500 kv motor. this roughly goes to a 27-35t brushed motor. it may appear that we're running wicked race motors, but in fact, its just the efficiency and low wear factor of brushless. some are switching to 13.5 and 10.5 motors, and don't know those off the top of my head, but guessing between a 19t mod motor and a 27t brushed motor.

also, the brushless motor performance is LARGELY a part of the programming of the esc. for instance, i have my esc set with start power low to save parts, if i stall, i try something else. also have my throttle curve set to ease into power, with a 15deg timing boost after 10k rpm i think (been a while). the rest of the time, i run the motor at 2 deg timing. know i'm sure you know what timing does to amp draw and motor heat. that's the reason i can run as long as i do, i like power, but conservative settings save parts, and brings efficiency up a touch. a quality handwound can nip at the heels of a well setup brushless system, but never equal it. reason being the switching method. brushed of course uses a comm and brushes, in a brushless motor, the esc does all the switching, also why sensored systems are needed. quickly switching the the the can pole around, in conjunction with the hall effect sensor in the endbell means that you have smooth efficient power that isn't wasted in the brush to comm interface. this is also why brushless motor winds are the way they are, there's really not much room in the can to wind all the copper you would need in a brushed motor to get over the detent strength in the can.

worm gear drives are power hogs, i make no bones there, but in the previous paragraphs, i think that my point about brushless motors powering them was stated.

[The Panda]

hey guy's

i'm thinking of buging the losi comp crawler,
now what for motor is the best a brushed or brushless
and how many Turns

Thanks

[Lou-Dog]

Originally Posted by The Panda

hey guy's

i'm thinking of buging the losi comp crawler,
now what for motor is the best a brushed or brushless
and how many Turns

Thanks

If you look around the forum you will find that a common set up is the Novak Goat 3S with a Novak 18.5 motor. This works well for some but many have complained about it. One option is a Mamba Max Pro (Castle Creations) and a Tekin redline 17.5 combo seems to work well on the LCC. I like Tekin and have used it for over 2 years now.

[melonpeel]

Originally Posted by Lou-Dog

If you look around the forum you will find that a common set up is the Novak Goat 3S with a Novak 18.5 motor. This works well for some but many have complained about it. One option is a Mamba Max Pro (Castle Creations) and a Tekin redline 17.5 combo seems to work well on the LCC. I like Tekin and have used it for over 2 years now.

Tekin 17.5, Mamba Max Pro, Castle Pro BEC(20A), on 3s with 14t pinion has been a great setup for me.

[ghtpdm5]

alright, to make it a little easier for people to find i'm posting the complete lcc bearing list here, and where they go on the truck. every time i read back in the manual the list was just wrong. these have all been checked with a caliper. also included are all the bearings for an lnc transmission in the second list.


i will say that i recommend the 5x11 mod in the steering knuckles, stronger stuff and for the same price at least from avid.


7x.....5x10x4.....4x for rear lockouts, 2x for outer steering knuckles, 1x for the inner top shaft in the transmission. *edit: the top shaft bearing can be a pain to get out, i use a small needle nose pliers, and open the jaws to the inner race and pull. stock are metal sheilded*

3x.....6x12x4.....2x for inner steering knuckles, 1x for outer top shaft (spur side) trans.

4x.....4x8x3.....all go in the outdrives of the trans

2x.....6x10x3.....spur gear bearings

2x.....10x15x4.....go on the outside of the outdrives

4x.....5x11x4......these are the pinion (worm) bearings in the axles, order extra and check often, i usually order 8 when i do so i have spares here. replace after any slop develops

4x.....12x18x4....spool bearings in the axles, these tend to last longer than the pinion bearings.


for the lnc the only real differences come with the transmission, the axle bearings remain the same.

2x.....5x11x4.....transmission main shaft

2x.....4x8x3.......spur gear bearings.


if more than a couple are failing, i order a new set of bearings, clean the old ones out, and salvage what i can. bearings are dead cheap compared to the parts that could grenade in the case of a bearing failure. this has been posted in my thread, i just wanted this information easier to find.


*if you can get bearings in rubber sealed, do it. the rubber seals create negligible friction, and protect the balls and races from debris. this is extremely important in the diff bearings, its a harsh environment and metal shielded bearings will get debris in them, and they will fail. full rubber sealed is what i order, and in a crawler, you won't notice the difference, especially in a losi*

[St33v3]

I got myself a Comp Crawler recently

What are the mandatory upgrades?

This is my 1st crawler, what do I need to check before/after each run?

It will run on a Novak Goat 3s 18.5t (already installed) and 11.1v LiPo (coming form hobbypartz).

Any recommendation on steering servo? Hon much torque recommended?

[Frikenwoodro]

Originally Posted by St33v3

I got myself a Comp Crawler recently

What are the mandatory upgrades?

This is my 1st crawler, what do I need to check before/after each run?

It will run on a Novak Goat 3s 18.5t (already installed) and 11.1v LiPo (coming form hobbypartz).

Any recommendation on steering servo? Hon much torque recommended?

Star cut the foams. Weight the wheels.
I check all the nuts and bolts every time I run them.
Look into a slipper elimination.
Grease the worms and put a filler plug on the axle housing. They love GREASE
Browse the fourm look at build thread use ideas on what works and what doesnt and go with it

[Mad Dawg]

Originally Posted by Frikenwoodro

Star cut the foams.

Don't waste your time star cutting the foam. If you want ready to run foams, check out Crawler InNovations.

Greasing the worm gears is the most important thing to do on your LCC.
Double check shim count the first time you take it apart.


It's pretty capable and tough right out of the box, I wouldn't worry about dumping money into fancy upgrades.

I got 800+ hours on mine and it's still going strong. The drivetrain is all stock except for the 20* chubs and knuckles.

Slipper clutch elimination is just plain retarded....... just snug it up a little. Your drivetrain will thank you!

[St33v3]

Thanks guys

[AlexG]

Originally Posted by Mad Dawg

Slipper clutch elimination is just plain retarded....... just snug it up a little. Your drivetrain will thank you!

Not that retarded, man we're crawling not racing. Why don't you put a servo saver on yours

[straydog24]

I a website selling a dig servo relocator. Does any one have an opinion on weather or not this would be a useful mod?

[sideshowbob]

Originally Posted by straydog24

I a website selling a dig servo relocator. Does any one have an opinion on weather or not this would be a useful mod?

id like one who sells them?

[Olle P]

Dig servo mounts are sold by RC Bros.
I don't use dig, but if I go that path I'll definitely consider using this mount or something similar to lower the COG.