Something wrong with my Rock Force?

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Hey everyone.

I've just finished building my Kyosho Rock Force 2.2. Completely stock.

I found my RF always making noise like "kah kah kah...pah pah pah...", sounds like gear slip, RF can't move or moves like a snail and shaking. I checked both pinion and spur gear, they look fine but shaking, it should be the source of that noise. This especially happens when the motor is at a low speed and RF faces a climb(even a very small one), if I hit the gas much more(almost fully), no shaking, no noise, RF just go forward and climb. Besides, my 4500mAh battery runs out pretty quick, about 15 minutes total(On my drift RC with same electronics they last more than 40 minutes.)...is there anything wrong with my setup or other problems?

My electronics: Hobbywing 60A 8.5T brushless with no sensor, Corona 2.4G CR4D RX, ACE 4500mAh Ni-MH Battery Pack.

It's funny to have a crawler can't crawl...Hope someone can help me out. Thanks a lot.

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Two more problems:

1, Links of my RF feel a little tight, is it because of the cold weather or they designed to be like that? How to fix it? I don't want to use hairdryer...:-P
2, Shocks feel tight too, I have to compress all the shocks one or two times to make them act normal...

[Reflection]

Tight gear mesh can be noisy,loose gear mesh can be noisy. Tight gear mesh nets lower run times and hot temps. Double check your gear mesh,may be it. Worm gears will always be noisier than a standard ring gear type axle.

Worm gears are a double edged sword. For one,they are noisy. Two,they are stupid low. Therefore you need a faster motor at higher voltage to even get decent performance. Faster motors typically net lower run times.

I've never used the rod ends that come with this kit. Some rod ends do in fact have a tighter fit than others. Cold weather can effect them as well. Leave it in the house for a few hours and see if they loosen up.

What weight oil are you running in your shocks? Are you sure you were able to bleed all the air out? Sounds like you may have a small air pocket.

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thanks for your advise raptorman57.

i will recheck my gear mesh tonight then see if the noise gone. the driveshafts have huge spinning resistance while the truck is not on flat surface, seems theres big friction force between worn gears and ring gears. is this normal or maybe i used wrong grease? i used silicon based grease, no clue of the actual type but it says this is for sealling and lubricating use so i used it.

the damper oil im using weights ok, it has perfect compressing and rebound speed actually(of course after compressing them few times manually), im wondering if the pre-installed seals are not very smooth? or maybe they will be smoother after sometime of abuse? they round like have air bubbles in them when compressing, i'll rebleed them when i got time. by the way, air bubbles make them sticky?

about the rod ends, i dont have heaters in house and the temperature is just few degrees higher than the outside, leave it at home might not work out well. can i lube them? might get very dirty though...

[Tanis]

I bet it's your motor/esc combination, being unsensored and designed to go fast.

[JOOTZ]

you dont need air in your shocks. recheck your diff install by the book, you may missed something or didnt seat bearings.

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Originally Posted by Tanis

I bet it's your motor/esc combination, being unsensored and designed to go fast.

yeah, might be so, that motor was for my drifter, i just put it on to see if it works fine with my rf, after all the instructions suggested 20-27t brushed motors and i supposed my brushless motor and esc performances just like those. now i'm trying to order a set of hsg, 78t spur and 25t pinion gears, maybe change into those to make fast gear ratio and setup a set of 90t motor with futaba mc330cr esc will work? there should be enough low speed torque then.

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Originally Posted by JOOTZ

you dont need air in your shocks. recheck your diff install by the book, you may missed something or didnt seat bearings.

thanks for reminding me. i went over it again and found no problem with the diff and bearings.

[JOOTZ]

Originally Posted by afterdot

yeah, might be so, that motor was for my drifter, i just put it on to see if it works fine with my rf, after all the instructions suggested 20-27t brushed motors and i supposed my brushless motor and esc performances just like those. now i'm trying to order a set of hsg, 78t spur and 25t pinion gears, maybe change into those to make fast gear ratio and setup a set of 90t motor with futaba mc330cr esc will work? there should be enough low speed torque then.

try the 27T with stock spur and a 26T pinion with the stock gears or the high speed gears you will find good improvement over the current set-up. there are a few here have the set-up and like it.

[Tanis]

The issue with your drifter motor/esc combo is they don't like to start up(being unsensored), especially in a bind, where a comparable brushed motor with a decent esc will.

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Originally Posted by JOOTZ

try the 27T with stock spur and a 26T pinion with the stock gears or the high speed gears you will find good improvement over the current set-up. there are a few here have the set-up and like it.

Originally Posted by Tanis

The issue with your drifter motor/esc combo is they don't like to start up(being unsensored), especially in a bind, where a comparable brushed motor with a decent esc will.

thanks jootz, thanks tanis.

i observed my motor's performance with no load at all, i found it shakes when the output amp from esc are not above a certain level and once over that "level", it runs well. i even tried my kawada 23t brushed vtr stock motor on the rockforce, and it does the same thing as hobbywing brushless motor do. they really are high speed motors.

i think i shoud just change two sets of hsg and a brushed motor with more turns, to get more low speed torque at the same time maintain wheel speed, maybe can save some battery?

do you guys think it is crazy if i change into hsg and also 78t spur, 25t pinion, to run a 90t brushed motor? it should have load of low speed performance.

i can buy spur and pinion gears and 90t crawler motor right now, but ordering the hsg needs two weeks, hope it worth the wait.

i think i finally "fixed" the problem. really appreciate your help, thanks!

[Tanis]

Did you use the same ESC when you tried the 23t brushed? I would say most of the issue is the ESC's programming. I haven't ever used an MC330CR, so I don't know what the low speed control is like on it. I run Castle Sidewinders.

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Originally Posted by Tanis

Did you use the same ESC when you tried the 23t brushed? I would say most of the issue is the ESC's programming. I haven't ever used an MC330CR, so I don't know what the low speed control is like on it. I run Castle Sidewinders.

im running hobbywing 60a sl v1.1 esc for the 8.5t brushless motor and a top racing 320a esc for kawada 23t brushed motor. point is, my top racing 320a esc has no set button to set the trigger positions, it always leaves me standing there pushing the trigger and not responding while i'm trying to go backward, it driving me mad.

i just figuring to buy a mc330cr esc, futaba makes good products i think. kyosho rock force don't need special esc that designd specifically for crawler because of those worm gears, it stops when i loose the trigger. what i need is only to go ahead and backward. besides, i can only find futaba mc330cr, mc230cr and yokomo 6712 brushed esc in local hobby stores.

oh, one more choice now, i found someone on the web selling hobbywing 35a crawler brushless esc with a 32t brushless motor, the price is just the same as a mc330cr with a team atlas brushed crawler motor.

i've seen some threads and noticed that a silver can motor is good to go with original gear set, anyone got a clue how it performs while go slow and climb up and how much time can it run with a 4500mah battery pack?

Tanis, can you tell me the spec of your castle sidewinders? maybe i can find one with similar specs.

[sally1800]

just pm David K he will help you out.

[Tanis]

Here's a link to the Castle site for the Sidewinder Note: those motors don't work for crawlers, just the ESC's.


http://www.castlecreations.com/products/sidewinder.html

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Originally Posted by saydee1800

just pm David K he will help you out.

well, thank you for telling me this, i know david is experienced and very helpful, but i'd rather discuss this in this thread, may help someone just like me.:-P

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Originally Posted by Tanis

Here's a link to the Castle site for the Sidewinder Note: those motors don't work for crawlers, just the ESC's.


http://www.castlecreations.com/products/sidewinder.html

Thanks for the link. But I've been in a local hobby shop after supper today, there's no ESC similar to the Sidewinder, and I bought a new brushed one, it works better and not that stupid as my old one, it even possible to run 2 motors, great. Boss of the shop gave me a Tamiya CR-01 original 40t silver can motor, and it just so much better than Kawada 23t, cooler, longer run time and more torque. I think i'll use it in the next few days.

Also, I ordered HSG and a Team Atlas Rock Climber 100t motor. GL to me.

[Reflection]

Originally Posted by afterdot

Also, I ordered HSG and a Team Atlas Rock Climber 100t motor. GL to me.

Glad to hear it's getting better. 100t motor though?.....holly crap!. That things gonna be slow as molasses. I was gonna guess around a 35-45t after you install the high speed gears. Even with the stock pinion and spur,it should still be a touch to slow with a 45t motor. In any case,the higher turn motors should net you some longer run times and less heat,so that'll be a plus.

[sally1800]

If you want to buy a combo get the Tekin FXR 35t
stormer Hobbies has is for $99

that the best you will find. you can run 3s lipo. If you go Brushless I would get the Tekin 21.5 RS combo I have that in mine with the High speed gear It is a very capable rig.

good luck

If you go dig make sure you get a 333 oz servo (I really think it is crap sending $100+ on a servo for a dig). Alot of my buddys laugh because there bergs have $6 switch for there dig and it works twice as good.

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I changed the grease of those worm gear set, replaced old silicon based grease into lithium based grease (it's for 1:1 car actually, less than 2USD for 1kg....now I'm figuring how to use the lefted grease...). The world just changed! For more than 20 minutes run time with a dead battery (for RF before the regrease), I can't feel a thing of the silver can motor, ESC is in a normal temperature level, my Rock Force gained like super torque power! If you got some cogging or heat problem, check your grease! It's extremely important to worm gears! Hah hah hah~~~~ I'm so happy now