Granite New Granite 3s cogging

[needbout350]

Just got my son a new granite 3s v2 this weekend. Been running it on 2s and 3s at 50% throttle and it is cogging a ton at start up. Some times it won’t even go until we give it a push. Once it’s moving there are no issues until we come to a stop again.

I tried it at 100% on 2s and 3s still the same issue. The truck is 100% stock.

I checked the mesh and felt it was a little tighter than I liked but not tight enough to cause these problems. I adjusted it a bit and still the issue persisted.

My guess is the esc is junk. Is this a common problem with the blx100 esc or do I have a fluke failure that arrma should replace?

I also have a spare hobbywing 10bl120 I was considering mounting up but I wasn’t sure how it would like the 4 pole sensorless motor.

What do you guys think I should do?

 

[Crunchy Gears]

Something is wrong. Whether it be your particular esc or the drivetrain. If the gearing is stock it should be able to move on its own just fine. I never had issues with my esc, I only swapped it to run 4s. Yours might be defective if your gears are all good.

 

[Cheez]

What is Cogging in a Brushless Motor​

As mentioned above, we know cogging of a brushless motor starts with the interaction of the permanent magnet on a brushless motor and the windings. Looking more specifically at the winding section of the motor, cogging occurs in a slotted stator. A slotted stator is made up of thin steel lamination’s that are stacked up and the motor windings are placed in the created slots. It is these iron slots that create the cogging torque on brushless motors.

The permanent magnet as it is rotated by the motor shaft, passes by these slots. The magnet then interacts with the steel lamination’s creating that bump that you know of. If you don’t know what I am referring to here, you can grab any slotted brushless motor and try it out. Grab a brushless motor and slowly rotate the shaft. Depending on the motor, you will feel the strength of the cogging torque applied by the interaction of the iron core and the permanent magnets. I have noticed that 6 Pole inrunners tend to have the strongest cogging torque.

 

[Crunchy Gears]

Are you a bot? How is this helpful? Lmao

 

[Cheez]

Are you a bot? How is this helpful? Lmao

No…trying to decide whether or not your being rude. Regardless, point being sometimes there is information on the web that can be helpful. Could be the pinion.

 

[Crunchy Gears]

You can decide what you like, the OP isn't talking about your run of the mill cogging that ANY non sensored motor/esc would have and your posting a wiki definition of Cog just sounds like you think he's stupid to me..I mean since you're not a bot and your post was intentional.

 

[Cheez]

Sorry needabout350 , I was just trying to share information. I bow out. There are far smarter people around that should be able to help you out. I have about 20 rigs and none of them “cog” , well it’s been a decade since any have. I just remember it’s usually something involving permanent magnet and windings. Otherwise it’s something in the drivetrain.

 

[Velodromed]

You can decide what you like, the OP isn't talking about your run of the mill cogging that ANY non sensored motor/esc would have and your posting a wiki definition of Cog just sounds like you think he's stupid to me..I mean since you're not a bot and your post was intentional.

Wow, his intent was trying to help. It’s pretty obvious. Yours however… did you forget your meds today or did someone piss in your cheerios?

Sorry needabout350 , I was just trying to share information. I bow out. There are far smarter people around that should be able to help you out. I have about 20 rigs and none of them “cog” , well it’s been a decade since any have. I just remember it’s usually something involving permanent magnet and windings. Otherwise it’s something in the drivetrain.

No dude you are fine. Don’t let some jerk run you off.

 

[RCbuzz]

If you pull the power module does the drive train move smoothly? Not too much resistance? If so, check that resistance on the spur and motor as well and make sure no roasted bearings or binding/rubbing of the spur.

It could be the esc or it could be the motor. If you temp in your spare esc and it works fine I would definitly contact Horizon Hobby as the BLX100 isn't half bad for a stock esc. We have a small amount of cogging but nothing like what your talking about.

 

[Crunchy Gears]

Hey maybe I just misread your post, because to me it looked you only read the Title and then said "Use the Search Bar", Just with more steps. If I got it wrong then I apologize. I am a jerk, but not without reason and I own it when I'm wrong.

On topic:
Stock gearing, which it should be since it's brand new, should absolutely not require a push to get the truck moving.

Check the drive train through make sure there is no binding any place. I have this same truck, it does not do what you're claiming when everything is good on it. Hell, even when it's not I've never had it do that.

While the motor is out, run it without anything attached, see if it still cuts out. If not and your drive train is all free..then it must be a faulty esc.

 

[Velodromed]

Just got my son a new granite 3s v2 this weekend. Been running it on 2s and 3s at 50% throttle and it is cogging a ton at start up. Some times it won’t even go until we give it a push. Once it’s moving there are no issues until we come to a stop again.

I tried it at 100% on 2s and 3s still the same issue. The truck is 100% stock.

I checked the mesh and felt it was a little tighter than I liked but not tight enough to cause these problems. I adjusted it a bit and still the issue persisted.

My guess is the esc is junk. Is this a common problem with the blx100 esc or do I have a fluke failure that arrma should replace?

I also have a spare hobbywing 10bl120 I was considering mounting up but I wasn’t sure how it would like the 4 pole sensorless motor.

What do you guys think I should do?

pull the drive shaft and see if it acts the same when you accelerate. Check all connections closely. Pull the motor, does it run freely when out of the vehicle? Push the car without the motor in it, does it move easily? Can you post a video of what it’s doing? You’ll have to upload it to YouTube first then post the link here.

I’ve no idea if your sensored hobbywing will work with a sensorless motor. Maybe someone here knows.

A new rc shouldn’t have those issues. If you got it at a hobby shop take it back and have them check it. If through Amazon you can return it and get a new one. You can also warranty it. Email is the best way I’ve found for that.

[email protected]

Send a copy of the receipt, pictures of the truck, brief description of the issue and include your name and address. You’ll probably get an auto response asking for all the info again so just do it, jump through their hoops and you should be taken care of. Good luck bud!

 

[needbout350]

Something is wrong. Whether it be your particular esc or the drivetrain. If the gearing is stock it should be able to move on its own just fine. I never had issues with my esc, I only swapped it to run 4s. Yours might be defective if your gears are all good.

I looked over the truck and everything seems smooth. I don’t think the drive train is to blame.

I may have figured out the issue. I’m pretty sure it’s my old batteries. I’m using a 5000mah 20c 2s and 6400mah 30c 3s. For some reason I thought they were higher c rating than that. They are both more than 5 years old so I would bet their c ratings are even lower than stated. They may just not have enough juice to get it started causing it to cog until it gets moving. I turned the punch down to 1 to see if that helps and I’ll buy some new batteries too. I’ll report back once I tested it again.

What packs are you all using in this thing?

 

[RCbuzz]

I looked over the truck and everything seems smooth. I don’t think the drive train is to blame.

I may have figured out the issue. I’m pretty sure it’s my old batteries. I’m using a 5000mah 20c 2s and 6400mah 30c 3s. For some reason I thought they were higher c rating than that. They are both more than 5 years old so I would bet their c ratings are even lower than stated. They may just not have enough juice to get it started causing it to cog until it gets moving. I turned the punch down to 1 to see if that helps and I’ll buy some new batteries too. I’ll report back once I tested it again.

What packs are you all using in this thing?

I think you may be on to something but, the esc does have a low voltage cutoff so if the voltage drops below LVC it kills power to the motor and only the steering works.. I have a couple goldbats that seem to do the job. Keep in mind the C rating on these cheaper batteries are usually inflated. Even a true 30c should be plenty for this rig.

 

[Crunchy Gears]

I'd go with what Velodromed said if a modern battery doesn't automatically and immediately fix the issue.

I have 80c zeeees from Amazon. Cheap, hard case packs. They work well for me

 

[RCbuzz]

When lithium cells get weak and have trouble maintaining voltage under load you would think the truck would just hit LVC immediately. That being said if the batteries are really that tired maybe the esc is just cranky that the voltages is sagging lower than it would prefer

 

[needbout350]

I have used both of these packs in my trusty rustler for years but maybe it’s just been one run too many for them. The stuttering and refusal to move didn’t start until about the 4th run on both batteries. My 4yo son is in love with this truck so he has been driving it non stop all weekend with me and my K8s. I don’t think they have been cycled that many times over such a short period in probably a few years. He may have been hitting lvc with them and just restarting the car to get it going again. If that’s what’s going on hopefully we didn’t hurt the esc in the process of killing these old batteries. I’ll test tomorrow and report back.

 

[RCbuzz]

Ahh, that sounds like a blast!!

 

[Kla912000]

Wow, his intent was trying to help. It’s pretty obvious. Yours however… did you forget your meds today or did someone piss in your cheerios?

No dude you are fine. Don’t let some jerk run you off.

Couldn't have said it any better! You just beat me to it. You're the man. I think it's funny when these new people come here and think they know everything.

 

[Velodromed]

Couldn't have said it any better! You just beat me to it. You're the man. I think it's funny when these new people come here and think they know everything.

You and me both I can’t stand Internet bullies. There is no reason to shut someone down like that when they are simply trying to help in their own way. Now he probably won’t try again, which is a shame. I hope he understands that dude does not represent the attitude of the majority of people on here.

 

[Kla912000]

You and me both I can’t stand Internet bullies. There is no reason to shut someone down like that when they are simply trying to help in their own way. Now he probably won’t try again, which is a shame. I hope he understands that dude does not represent the attitude of the majority of people on here.

Yep yep. Most of the members here are cool. A few bad apples but very rare. Great group of people here.