Granite Did I get a lemon granite 4x4 blx?

[tgorfido]

Hello to all. I am fairly new to the RC world as I got a brushed granit mega 4x4 for my son for Christmas, he is 5 so I had to drive it for him lol. But he now is driving very well so I went and picked up a granite 3s blx so we had something to do during this covid 19 lockdown.

The brushed granite has been great, only had to change a servo and tighten the pinion gear, runs like a champ.

The new granite blx I have only had a week and hasn't been able to do a full run, the steering was never quite right, constantly had to adjust the trim. Then the steering block on the right front tire broke. After I replaced that the steering was a little better but still not as good as my brushed granite. Then the servo went 3 mins into the next run, replaced that, steering is usable but still not great. Then less than 15 mins into the 3rd try at a run the motor was turning but not the driveshaft. So tonight I took the transmission out and the spur gear was basically ground smooth, no teeth left. I haven't ever "meshed" a gear (if that is what you are supposed to do) but should I have even needed to do that for a new truck? The bearings are also toast from all the ground plastic teeth dust so I will need to replace them as well.

I've spent 6 to 8 hours repairing the blx and less than 30 mins driving. Is this common for a new truck to be this messed up? I don't mind learning and fixing things but it's becoming a hassle and I would love to be able to run at least one full battery without something breaking.

Anyone have a similar experience?

 

[jondilly1974]

Those are common issues but not normally all this quick. You can buy the 4S spur gear as it’s metal and will hold up longer. You have the castellated pads already, so you just need the spur gear and one more slipper pad. The steel spur needs a fourth pad and yours only includes three pads.

 

[SrC]

If its that new with little use, Call Horizon Hobby and they may assist with some/all of the parts. (poorly built) No reason why you should be throwing this much coin into a new rig like that. I have had issues new out the box several times, I catch a lot of flubs, running them on the bench before I take them out. If you don't catch assembly issues first on the bench then they crap out in minutes. And costs way more. These are RTR's supposedly ready to drive...but sometimes they are flawed. You are not alone. More common than you think. From experience.

 

[Surchaufeur]

I think the servo was junked from the begining and the spur gear maybe due to a bad gearmesh . Ussualy the granite is a tank out of the box

 

[crimsonfancy]

Don't hesitate to call Horizon Hobby in this case. They'll get you in good shape.
Sorry this happened.

 

[tgorfido]

Thanks, I was going to run by my hobby shop today to see what they say and of course I cant find the receipt so I was hoping they could reprint it and then I will call Horizon. If my first Granite Mega was this much of a pain then I wouldn't have purchased another one but the first one is a tank like you said so I was pretty sure the blx one was going to be even tougher as I was told it already featured upgraded parts when compared to the brushed mega.

 

[3d-rc.myshopify.com]

Not that it matters I am curious if you hit something harder then normal?

 

[tgorfido]

Not really, we have been jumping on some little hills, maybe 2 feet hill at the highest. If the steering wasn't off from day one and the spur gear wasn't stripped then I would think it was my fault but I'm not sure. I've got things much harder, multiple times with the Mega and it is fine. Would the spur gear get stripped from hitting something or jumping it? The hill really is only like a foot where I drove it, mostly a big flat dirt lot.

 

[jondilly1974]

Not really, we have been jumping on some little hills, maybe 2 feet hill at the highest. If the steering wasn't off from day one and the spur gear wasn't stripped then I would think it was my fault but I'm not sure. I've got things much harder, multiple times with the Mega and it is fine. Would the spur gear get stripped from hitting something or jumping it? The hill really is only like a foot where I drove it, mostly a big flat dirt lot.

Yes if you bent the motor mount on a bad landing will trash the spur gear.

 

[tgorfido]

Well ended up being a bad bearing in the motor which had a little wobble in it so the pinion gear wasn't just spinning it was wobbling. I would have never figured that one out but I took it back to my local shop and the owner took it all apart and figured it out. Ran great tonight and finally got to have some fun!

But.....of course the brushed granite mega stopped at the end of our run! And of all things it was the spur gear! But that one I had just changed the motor on and I guess I didn't put the spur gear on exactly right. Maybe it wasn't on the motor shaft deep enough but I really don't know.

 

[Surchaufeur]

Well ended up being a bad bearing in the motor which had a little wobble in it so the pinion gear wasn't just spinning it was wobbling. I would have never figured that one out but I took it back to my local shop and the owner took it all apart and figured it out. Ran great tonight and finally got to have some fun!

But.....of course the brushed granite mega stopped at the end of our run! And of all things it was the spur gear! But that one I had just changed the motor on and I guess I didn't put the spur gear on exactly right. Maybe it wasn't on the motor shaft deep enough but I really don't know.

Maybe plan on getting a ceramic hybrid bearing or another sealed good quality bearing to remplace the front bearing of the motor in the future.
The front bearings is shielded not sealed so dirt gets inside the bearings over time and that thing spins at what 40 000 rpm?

 

[Cheapbastard]

Well ended up being a bad bearing in the motor which had a little wobble in it so the pinion gear wasn't just spinning it was wobbling. I would have never figured that one out but I took it back to my local shop and the owner took it all apart and figured it out. Ran great tonight and finally got to have some fun!

But.....of course the brushed granite mega stopped at the end of our run! And of all things it was the spur gear! But that one I had just changed the motor on and I guess I didn't put the spur gear on exactly right. Maybe it wasn't on the motor shaft deep enough but I really don't know.

The Arrma bearings are crap. Get a rubber sealed bearing kit for both of your Granites. The spur on the Mega could have been your fault but honestly, I would get a couple of adjustable motor mounts or slot the stock mount holes for better gear mesh.

The motor burning out could have been because of tight gear mesh or just the fact that brushed motors usually don't do too well in 4X4's. If you do burn out another motor I would look at going brushless. You don't have to go with BLX brushless power if you do decide to move on from the brushed motors.

 

[tgorfido]

Good advice on the bearings, I actually already ordered new rubber sealed bearing kits for both the brushed and blx. I will have to research what sloting the motor mount means because I have no idea. And don't the granites already have adjustable motor mounts? I know they different holes for different pinion gears.

 

[suchtragedy]

I will have to research what sloting the motor mount means because I have no idea. And don't the granites already have adjustable motor mounts? I know they different holes for different pinion gears.

By slotting he means taking a Dremel to the stock mount removing the metal between the holes to make a long channel so you can mount your motor with any pinion you want and position it where you want to set your own mesh (gear gap) and make sure it's perfect. This is the "free" way of upgrading your motor mount to be adjustable and it probably won't be pretty but it works. The other method is buying the adjustable mount which costs like 17 bucks or so. Arrma makes one and so does hot racing. Both are direct drop in replacements.

*Edit* Saw you say you had the mega truck which is all plastic mount and holes are different from the metal BLX mount. If you do want to buy an adjustable mount then get the kit from arrma, it includes everything you need. The hot racing one is just a metal plate and doesn't include the plastic pieces you need to make the change.

 

[tgorfido]

By slotting he means taking a Dremel to the stock mount removing the metal between the holes to make a long channel so you can mount your motor with any pinion you want and position it where you want to set your own mesh (gear gap) and make sure it's perfect. This is the "free" way of upgrading your motor mount to be adjustable and it probably won't be pretty but it works. The other method is buying the adjustable mount which costs like 17 bucks or so. Arrma makes one and so does hot racing. Both are direct drop in replacements.

*Edit* Saw you say you had the mega truck which is all plastic mount and holes are different from the metal BLX mount. If you do want to buy an adjustable mount then get the kit from arrma, it includes everything you need. The hot racing one is just a metal plate and doesn't include the plastic pieces you need to make the change.

Gotcha. Thanks for the info. I am wondering if I didn't put the pinion gear on deep enough and if that is what the issue was, been running it for 4 months with no problems but then I just changed the motor two days ago to a Traxxas and the pinion gear came off because I forgot the loctite. Put some on the set screw about an hour before we ran it so I know the spur gear was fine then.

 

[suchtragedy]

Try to give your loctite about 24 hours to set before running or it's gonna come loose. Also brushless has a lot more torque so the plastic mount will flex a little. Probably a combination of a few things led to what happened.

 

[tgorfido]

Try to give your loctite about 24 hours to set before running or it's gonna come loose. Also brushless has a lot more torque so the plastic mount will flex a little. Probably a combination of a few things led to what happened.

It was my brushed grantie lol, the brushless BLX ran great yesterday with its new spur gear and motor bearing...just figures that as soon as one is fixed the other one which was running great strips the spur gear!

Well I think it is kind of funny but I am seeing a patter..
1:run the car and have some fun
2: something breaks
3: google the symptoms to figure out what is wrong
4: watch YouTube tutorials on how to repair the issue
5: run to my local hobby shop for parts
6: fix the issue
7: Repeat steps 1-6!

Gives me and 5 year old son something to do during this Covid-19 craziness that we both like so its all good.

Anybody know of a good tutorial on how to disassemble the slipper clutch? I tried using a 2mm allen wrench down the clutch shaft but couldnt get anything to catch so I am a little worried about getting it pulled apart. I found videos on how to reassemble but nothing on how to get it apart.

 

[jondilly1974]

It was my brushed grantie lol, the brushless BLX ran great yesterday with its new spur gear and motor bearing...just figures that as soon as one is fixed the other one which was running great strips the spur gear!

Well I think it is kind of funny but I am seeing a patter..
1:run the car and have some fun
2: something breaks
3: google the symptoms to figure out what is wrong
4: watch YouTube tutorials on how to repair the issue
5: run to my local hobby shop for parts
6: fix the issue
7: Repeat steps 1-6!

Gives me and 5 year old son something to do during this Covid-19 craziness that we both like so its all good.

Anybody know of a good tutorial on how to disassemble the slipper clutch? I tried using a 2mm allen wrench down the clutch shaft but couldnt get anything to catch so I am a little worried about getting it pulled apart. I found videos on how to reassemble but nothing on how to get it apart.

The Mega slipper uses the red wrench to adjust, not a 2mm hex. Not sure which one your trying to adjust?

 

[tgorfido]

The Mega slipper uses the red wrench to adjust, not a 2mm hex. Not sure which one your trying to adjust?

I have to install a new spur gear on the Mega so I have to take that assembly apart which I have never done. I have to go to the hobby shop to see if one is in so I will ask them to show me