Crawler won't crawl, not enough power. Help

[HVrocksNY]

Hi All,

So, new to the forum and new to RC. I bought two used rigs for my son and I. Our Wraith is going great but I bought an old Crawler King with a Rooster ESC and 55t motor.

My problem is that the truck won't climb anything. As soon as it has any resistance against the wheel it just sits there and won't climb it. No wheel spin, nothing.

I took apart the motor and cleaned it up, brushes looked ok. Decided to try a different motor and threw in a new Integy 45t Lathe Motor. Same thing happens. I reset the esc with the transmitter per the instructions.

What could be the problem? Is the ESC worn out maybe? Could it be the transmitter/receiver? That's about all that's left since I know it's not the brushes.

I have googled and searched the forum but can't find any answers. Any help would be awesome!! Thanks!

 

[envious8420]

what gearing are you running? you could just be stalling it out if the ratio is too low. does it steer while its not climbing? anything making noise? also if you could list your equipment, that would help too.
(battery, esc, radio/rx, servo, whether or not you run a bec, etc...)

 

[HVrocksNY]

it's a 25 tooth pinion, are the large gears all uniform or do I have to count those teeth too?
It does steer fine. It hums a bit when it is trying to climb. It's like it's bound up but isn't. Running the Rooster Crawler ESC, Integy 55t, just changed to 45t (to see it that helped), Novak BEC, and Associated XP TRS401ss - Bound to an Associated XP3-SS.

The radio does cut out and the power lights drop from full to low and back. if you turn it back on or sometimes hit it, it goes back to full. Something is loose near the batteries I think.

It feels like the battery is very low but only when the wheel is up against a rock etc. It zips around otherwise.

Thanks

 

[Charlie-III]

It could be a couple of things.

1-Failing battery pack (what do you have?, chemistry, voltage/cell count)
2-Failing battery pack connector (If Tamiya, it's bound to fail at some point)
3-Overgeared motor. Does the motor get hot when the rig won't crawl?

The dimming lights indicate a power issue, as stated, failing pack or pack connector.

 

[xxx123]

Check epa and recalibrate esc??

 

[sickcivic95]

Are you running a bec? And as stated above it definitely sounds to be an electrical issue. I'd check the pack for failing or faulty cells then I'd check the Esc to be sure its good and not toasted from overheating or overgearing.

--Dan

 

[Dmillsaps]

I think your BEC may be causing something, if its an external BEC take it off, and try it.

 

[T_0_N_Y]

You said it runs around fine till you have it against something, sounds like it's over geared. The stock gears in a crawler king is 21 tooth pinion and 90 tooth spur. Somebody could have geared it higher before you got it to make it faster cause they didn't like going slow. Might want to check the slipper also, it could just be loose. Those would be the easiest things to check first in narrowing out the problem.

 

[HVrocksNY]

Thanks all. I'm going to try a few of the above suggestions starting with the slipper and work from there with the least inexpensive. I'll advise when I figure it out.

 

[Olle P]

Also check for friction! Do the drive shafts spin easily when there's no load? What about the gear mesh?

My crawler had quite a bit of internal friction when it was brand new, due to design issues as well as screws being overtightened at the factory.

 

[HVrocksNY]

Well, lots of interneting last night at work and I found that the slipper clutch is inside the box and not an external that is adjustable. I pulled the spur and pinion and found 87/25 which according to the manual is a bad ratio for any kind of crawling. Going to try that first with the 90/20 like stock. I also looked at my bec when I got home and found two on the truck. The bigger navak that only went to the batt plug spot on the receiver and a smaller one (both 3a) coming off the esc. Search more now. I don't think this is set up right.

 

[HVrocksNY]

OK, newbie learning as I go. Looks like I don't have an external BEC. The thing on the esc is the capacitor and IDK why the other one was plugged into the rec yet. I love learning new things.

The rooster crawler manual says it has a BEC but I'm guessing I should refer back to the YOU DO NEED A BEC post on the forum?

 

[Gravebane525]

I don't know much about crawler kings and wheelie kings but could lockers have been taken out to allow for better turning at speed? I know my mini summit kinda acts like he describes when its trying to crawl but it doesn't have lockers yet. I'm thinking bout maybe locking the rear, or both front and rear.

 

[hellbounder]

If there was already a cap on the esc and you said there was one plugged into the reciever also ? That one could be a glitch buster for the radio system . Take a pic and post it .

 

[HVrocksNY]

hellbounder, yup turns out it is the novak glitch buster. Just read up on how it works. The Rooster Crawler ESC has a 6v / 5a BEC built in.

 

[TrailSnail]

I had a similar issue with a monster truck, it turned out the pinion and spur gear were meshed too tightly together, so it seemed to run fine until put it under load on steep climbs. Proper mesh and some fresh gear lube solved my issues.

 

[HVrocksNY]

Well, Thanks all for the help. I finally got the 90t/21t spur/pinion in and put it on. Totally fixed the problem!! Now I just have to decide if I want to keep the new 45t motor in or put the 55t old one back. It is a little snappy on the trigger now.