HELP! LOSI Crawler LOOSING TORQUE / POWER youtube vid link

[wkumale]

I have a losi crawler. I was told it was a LCC but i dont think it is. It doesn't have lights either as the LNC so i dont know. As you can tell i am new to crawling. I traded for thi used losi crawler. It dies when going up a hill. It originally had a 55 turn motor so i changed it out to a 27 but it still did the same thing. I changed the ESC and motor to a Velinion off of my slash 4x4 vxl and I thought ok its gonna fly... please see vid ( Losi Crawler with Velineon SLOW no power - YouTube ) VERY DISAPOINTING.... I searched about this on these forums and others and was told it the worm gears greased. So i broke down both axles completely and installed and grease port. Then I cleaned them and lubed them with some recommended grease and reassembled. The video is actually after the fresh grease. I dont know what to do. I cnat get it to go fast or have torque. Could the transmissions be binding up? Nothing gets hot so i dont know what to do from here. Any recomendations. I love crawling but this is getting me frustrated. PLEASE ADVISE!!!!!!!!!!!!

I forgot to mention.. I am only using a 7 cell nimh 3600 .. i dont have any lipos. battery does fine on my slash 4x4

 

[DRTMI]

It does look low on power not wanting to climb up the wall. If it is a lcc it has a slipper clutch on the gear the motor gear meshes with. Either crank the adjusting nut down or get the slipper removal kit. What kind of programming does your speed control have, and have you tried calibrating it to your radio again?

Sent from my Galaxy Nexus using Xparent Red Tapatalk 2

 

[wkumale]

it does not have a slipper clutch. i am not sure what you mean when you ask "What kind of programming does your speed control have" but i have not reclaibrated the radio. When i switched to the traxxas velineon system i used a new transmitte and reciever.

 

[BJoe]

Do you have any pics of.it so we can see it better? That might help at least figuring out wht you have and what the issue is.

 

[ghtpdm5]

well the motor is spooling up well enough, being an lcc, i would bet on the slipper being loose enough to just slip as soon as power is applied. from there, you can go check the driveshaft set screws, they do back out occasionally if you don't loc-tite them. if those are tight, you're going to open the trans up, make sure the pinion is tight on the motor shaft, make sure the spur is in good shape, the inner top shaft gear and also the dig mains gear. if all of those are tight and correct, you have to go through the entire truck with a fine toothed comb, rooting out any problem in your path.

also, the velineon motors are not sensored, sensorless systems have trouble with low speed start up....i noticed the distinctive sound of a motor cogging while you were attempting the climb. when i did some sensorless trials after getting my setup put together (i was bored), the low end torque was terrible, once you got to a decent motor speed, it kicked in.

EDIT: just caught your slipper comment, the stock slipper and the slipper elim kit look look a lot alike, double checking that the elim is installed would be worth the 5 minutes to do it.

 

[annedecke]

7 Cells in a LCC is not enough. It should be 3S.
55T in a LCC is very slow. 27T on 7Cells has no torque.
The Velinion System is nice but not designed for a crawler.....and not with 7Cell for sure.
Sensorless sucks in a crawler....especially in a LCC.
Which pinion do you use with the different motors?
Only grease for the worms is not enough. When they´re ne it´s no problem but older ones like to be shimed well because they like to stall a bit.

 

[wkumale]

Guys, let me say thanks for the responses.


I will upload some pics maybe late tonight.

 

[wkumale]

heres a link to my tranny and motor. I just put the brushed set up back on.

Pictures by wkumale - Photobucket

 

[ghtpdm5]

that would be an lnc trans. there is a drive pin behind the 54t mainshaft gear, check that its intact.

 

[wkumale]

it is intact... with the motor off i can spin the trans and both axles work good. Nothing restricting it.

So i have a LNC.. i guess the lights were taken off becasue i dont have any lights on it.

 

[ghtpdm5]

lights do not an lnc make :wink: when we refer to the lnc and lcc, we are just referring to the transmissions. there is only real reason an lnc trans should cause any fuss is due to a stripped gear. beyond that, the axles are the first place to look (as you have), and after that, the driveshafts (mentions previously) and then the axle drive pins (should be ok during your axle run through, but shit happens, pins break) and if all that checks, you have to look at the electronics. try it for a while with the 27t motor, if it does ok, the velineon system is confirmed as the culprit.

 

[wkumale]

should this work with a 27turn motor running 7 cell nimhs? or do i have to use 3s lipos?

I really appreciate all your advise and help

 

[ghtpdm5]

voltage is voltage as far as the motor is concerned. its the esc that may cause a problem. to run lipo, you either need an esc with lipo cut-off, or an external cut-off so you don't over discharge the pack. over discharging a lipo pack can easily result in damage to the pack, possibly even a fire. if you are happy running the nimh pack you have, then run it. to swap to lipo, you need to cover the over-discharge problem, a lipo compatible charger (preferably one that does cell balancing as well) and of course the packs. i will say that swapping to lipos does decrease your weight (smaller, lighter packs) and you can move the battery around for better distribution.

i recommend doing some serious reading if you choose to go the lipo route, the research you do before your purchase lessens the risk after. if you want some more info, pm me, but you'll still be reading quite a bit, i drone on a bit.

 

[tdevilman2009]

Wow that is not good what I don't understand is I've got the lnc an have the trx brushless system an a 7cell 4600 an mine don't slow down till batt dumps on mine the gears r stock an a 20 tooth pinion gear motor not overly hot an esc just warm to the touch I'm running masher2k on stock wheels rest is stock minus tx/rx as I didn't like the stock no weights in either but I don't go to comps I would check the shims an clean an degrease the axles hope this helps some

 

[RivBlueNoma]

Just a thought but have you borrowed a battery that is known to be good from someone to try? I've had some packs before that seemed fine in my 1/10 go fast trucks but fell on their face when used in higher amp draw situations. Turns out they were getting old and lost their grunt.

 

[DemetriM]

Just a thought but have you borrowed a battery that is known to be good from someone to try? I've had some packs before that seemed fine in my 1/10 go fast trucks but fell on their face when used in higher amp draw situations. Turns out they were getting old and lost their grunt.

i was able to get a couple years out of my lipo's. after that they slowly lose their kick for sure.

 

[NFG]

voltage is voltage as far as the motor is concerned. its the esc that may cause a problem. to run lipo, you either need an esc with lipo cut-off, or an external cut-off so you don't over discharge the pack. over discharging a lipo pack can easily result in damage to the pack, possibly even a fire. if you are happy running the nimh pack you have, then run it. to swap to lipo, you need to cover the over-discharge problem, a lipo compatible charger (preferably one that does cell balancing as well) and of course the packs. i will say that swapping to lipos does decrease your weight (smaller, lighter packs) and you can move the battery around for better distribution.

i recommend doing some serious reading if you choose to go the lipo route, the research you do before your purchase lessens the risk after. if you want some more info, pm me, but you'll still be reading quite a bit, i drone on a bit.

Making the jump to Lipo was a great upgrade for me. As mentioned above they are smaller and lighter giving you many options on placement.

I too read a ton of write ups on Lipos before I made the switch. What I found was that if you charge them slow they are far less likely to give you issues. Sure you can bang a quick charge in them but most of the charging fires I hear about came from this sort of treatment. Slow and low works best.

The only mistake I made was not getting the smallest 3 cell I could get away with on my axle. Mine are a tad to large forcsing me to run them at an angle. My MOA will have that fixed. Comp rigs run for 5 minutes at a time. A small cell switched out after each run works best.

 

[Olle P]

... if you charge them slow they are far less likely to give you issues.

Agreed, but somewhere there's a limit to how slow you should go.
- Extremely low charge rate, like < 0.02C, can result in pretty much no charging at all.
- Low charge rate, like 0.1C, is very good for the battery unless it's overcharged. Overcharging is likely with delta cut-off at these low rates, since the voltage dip supposed to trig the cut-off can be too slow and small to get noticed.
- 0.5C will be gentle to the batteries and prevent overcharging.