B4.1 Problem any ideas anyone? (Weird Noise)
 

Hi,

I have had my B4.1 for a couple of weeks now and I have taken it out twice. no major incidents but I seem to have developed a granching type noise at low speeds which Im pretty sure it was silent at slow speeds on my first run out (apart from the r2d2 tweets from the motor =D).

I am new to R/C stuff so I have not really any experience with stripping/building so just wanted some advice.

I took all the wheels off to make and check they were on ok and check all the ball cups. When i put it back together I still had the noise. I am at a loss at to what to do next so was hoping someone could give me some advice.

It still seems to run ok but just doesnt sound healthy , going to be gutted if I managed to break it in 2 runs =C.

Also wanted to ask if its normal to have a little wheel wobble in front wheels, if I freeroll them with my hands there is a slight wobble on the wheels. I made sure they were tight on so its not loose.

Thanks in advance for your help.

Not sure if this works but I added a video onto my facebook and set it so everyone can see it.

http://www.facebook.com/profile.php?...p?id=826803227

Hopefully you guys can hear what I am talking about

Have you checked ur diff is tight after its bed in

Hi thanks for reply how do i check that?

Sorry im totally new to this

Another problem now =C (i suck at this lol)

I thought i would readjust the slipper clutch, by follow the manula to reset the nut so its at the end of the rod, but when i tried to retighten it the three turns it just stays in the same place?

Any suggestions?

Getting so frustrated not as simple as i thought lol

Sorted the slipper clutch now and no adjustment would make the noise go away, so maybe it is the diff but I have no idea where or how to check that =C

P.S In the manual it say to do thre turns on the slipper clutch nut is that a full revolution ( i.e from 12 o'clock to 12 o'clock) or is one turn from 12 o'clock to 3 o'clock.

did you build this?

one turn is 360 degres

diff adjustment is in the manual

Hi, no i did not build it was a b4.1 RTR kit. Wishing I had built one now so id know how to do every thing.

I will recheck my manual but i couldnt see anything in there earlier, google didnt provide help either.

The B4.1 RTR should have a gear diff, so I don't believe that you can adjust it.

Can't access that link you posted, is the sound definitely only at low revs or is it there all the time? It's possible the motor moved and the gap between spur and pinion has closed up. Would be worth checking the mesh anyway.

If it's not that is it brushed or brushless motor in there?

Yup rtr has gear diff.

It is a brushless model.

When you say gear mesh do you mean the cogs underneath the plastic cover?

If is I checked that they lined up ok when I readjusted the slipper clutch

The noise is most notable at low speeds but u can still hear it at high speed too just not as bad.

K i started a youtube acct so i could add the video that way, hopefully this link will work:

http://www.youtube.com/watch?v=7HqvPWCkGpY

The clutch gear is the spur and the motor gear is the pinion.
It's difficult to tell from that video, but it does sound like the mesh is a little tight. There should be a little play between the two gears, just not too much!

It's very difficult to explain this over the internet, do you know of anyone near you that could help? (or your local club?)

Not joined any clubs yet but its something I will do, I have one friend who hopefully may be able to help.

Weirdest thing as was silent on first run then on second the noise started.

That's why I was wondering whether the motor had moved, perhaps after a heavy tumble, it only has to move a fraction for the mesh to be wrong.
Good luck, I'm sure it'll be great once it's sorted.

Losen the motor two screws at top and bottom then place a peice of paper between the pinion gear(on the motor) and the spur gear (the big black one) and push them together and tighten the motor screws. This will give you the right mesh there should be some backlash between the gears (slight movement). Remember to take the paper out after LOL.

K , i will find these motor screws and give that a go.

Just to check before i start the gear mesh is the bit of plastic inbetween the motor and the slipper clutch? (as ins motor --> Plastic--> slipper clutch and the smaller cog)

Ty in advance

the spur gear is the larger gear, which also has the slipper clutch at part of its' assembly. The pinion is the gear on the motor.

Does that help? ... or was that something you already knew?

Ah brilliant ty very much. So the mesh is what they both sit in i get it now =D

Cheers I'll have a go at it tomaz after work and let you guys know how i got on.

nope - not quite.... the "mesh" is a term for how the pinion is positioned against the spur.

If you loosen the 2 motor screws and push the motor RIGHT up to the spur, then it will be too tightly meshed. Conversely, if you set the motor so the tips of each gear (pinion & spur) are only just touching one another, then it would be described as loosely meshed and you're then in danger of losing the tips of the spur gear.

As said above, you're going for somewhere in between - the trick with the piece of paper sounds a good one, but not something I've done myself.

have you tried it with the arms as they would be if it were on the floor,it might be the drive shafts are at such a big angle

hi guys,

I tried adjusting the gear mesh tonight but didnt cure the problem (i think that paper trick will come in handy tho ty).

I have tried to listen more closly and I think the noise may becoming from the dogbones (i think thats the right term), Is this possible you think? Thought I would check before stripping them.

P.S Whats the easiest way to get the ball caps off?

I noticed the noise while running it outside on floor , when I made the video i had it off the ground so that i could make the vid.

Could it just be the sound of the Dogbones slapping around a little ? If so, i would've thought that your pretty much stuck with that sound.

You could try a Non dirt attracting grease on the cup that goes into the hub, but even that could be risky, cause no matter how good they are at not attracing dust etc, they still attract a bit and this could then wear out parts quicker...

:thumbsup:

best advice - get down to your nearest club, and there will be a line of racers eager to diagnose your problem, now they're not skimming motors and balancing their cells!!

I reckon the gearbox needs opening up to get to the bottom of it properly. If you've checked the mesh and nothing else is visibly obvious, it needs a strip down.

20 minute job on a B4. Some will even do it blindfolded!!

Ok I took the dogbones out and ran and the noise is def coming from the gearbox.

Do you think since this model is only 2 weeks old and only been ran 3 times (first run was pretty silent, and noise from 2nd run onwards) i should just run it back to the modelshop? Cost me a fair whack so didnt know whether i should try get them to exchange or is this sort of thing normal?

I think It's reasonable to expect your model shop to take a look for you. if they specialise in 1/10th off road they will probably be ok to open it up and have a look for you.

Like I say though the best advice and help you get will always be at your nearest club. Figure out which it is and I'll bet somebody from that club will crop up on here.

Try the following:

Disconnect the driveshafts by removing the top turnbuckle. (pair of pliers and twist)

Try the throttle to see if the noise has stopped, this will rule out the drive shafts.

If its still there take the pinion off the motor, and turn the spur by hand to see if it turns smoothly, if not the problem is in the gearbox. (check for tight spots etc)

Its also worth lifting the wishbones up to a more realistic angle as someone else has already said.

He's already done the test without the driveshafts in - it is something inside the gearbox. So it basically needs a teardown. What you can't see, you can't fix.

could it be the ticking diff that some of the sc10's and 4.1's suffer from weve had a few at our club they need a shim adding in the gear diff casing

Hi Guys,

Ye i took everything down and noise was still there, been a nice learning experience doing all that actually.

Going to take it back and see what modelsport say as I shelled out 280 quid so I want to make sure its all ok for peace of mind.

My thinking was if the gearbox did need stripping down then It shouldn't need that after just three runs on tarmac, is that unreasonable?

not unreasonable at all.

Modelsport you say?

That mean you're in good old West Yorkshire?

Aye I live in Menston.

havent joined any clubs as yet was going to try Batley but been rained off past couple of times hehe, Might try York as my mate found an indoor place that runs on a sat so may be a safer bet what with winter.

Going to run it over to them on my lunchbreak tomorrow as my m8 is picking up a diff for his touring car.

Last Sunday I tested my brand new B4.1 and I had the same experience mentioned in this topic. The car after 3 runs started to have some strange sounds in the rear, acceptable of course but slightly different compared to the previous one.

My first tought was, this car is fast enough and precise but it is suffered understeer.

I'll test soon and I'll remove some shims under the front camber link and reduce the rear caster, standard set-up has 2 shims.

Best bet would be to pop over to York and have an ask around, I'm always about to help if you need any :)

I took it back to modelsport today and they said they have sorted it out. I seems it was how the gear were meshing in the gearbox. ill find out more precisely what it was and let you guys know.

Must say though I love this little buggy hope to get a chance to learn to control it enough soon and get on a track somewhere.

when u pick it up ask them to show you what they did, then you will know for next time.

good to hear you got it sorted! Next stop York?

Will prob try and get over to york sometime defo, Just need to find time to learn to control it better lol, I think id be laughed off the track at the moment hehe

got same car
 

take it back to shop let them do it !!!!!!!!!!!!

Sorry for the really late update been really busy, took it back to the shop and they sorted it out for me. They said it was the mesh like you guys thought. They told me how to fix it if it happens again so thats cool.

Ty for help guys