RC Novice need help with Granite BLX

[Tadey14]

HI everyone. new to the hobby, looking forward to getting some great advice from you folks and perhaps one day in the near future I might even contribute with some of my own.

I got a Granite BLX for Christmas from Tower. Drove it for about 4-5 minutes with the supplied NiMH battery, loved every moment of it, that is until I crashed.

However before I had my first crash, I did notice that once or twice when I engaged the throttle, the truck would not respond immediately and the rear wheels would shake and a rattling kind of notice could be heard before the truck would travel forward or backwards.

Having read some glowing reviews about the Granite's toughness, I was very disappointed when I broke a front turnbuckle only after my first head on collision with a stop sign post. the truck was not even traveling that fast. Frustrating but, no big deal, it gave me an opportunity to get to know the truck, order some spare parts, battery packs and peak charger.

I replaced the turnbuckle last night and everything seemed fine until I tried to drive the truck today. this time the issue with the shaking rear wheels and unresponsiveness when the throttle is engaged is more pronounced. I cannot operate the vehicle for longer than 45-60 seconds before this issue comes up. when it does, the truck does not run, the wheels turn but, unless I turn it on and off, the truck will not run again. when it does run again, it only does so for a minute or less. the last time this occurred I noticed the ESC's blue light was blinking. My manual says this is the low voltage alert. However, I have a fully charged battery in the truck.

Did I get a faulty unit or am I doing something wrong?

Thank you guys in advance for your insight it will be really appreciated.

 

[Tadey14]

happy 2016 folks!

Update.....so I tried to drive to drive the truck once since my original post, 10 seconds into it my servo arm came off at the junction with the steering assembly. This has now happened more than once, i popped the arm back in place, had my wife operate the receiver to simulate driving in circles or zig-zag patterns while I held truck in hand w/o front end installed. within a minute or two, the truck is unresponsive to the throttle, rear wheels shake and make rattling noise, servo arm pops off and truck's ESC blue light blinks.

please help!

 

[ajdragon]

Hi

When you say rear wheels shake and make rattling noise, what exactly do you mean? There are two different types of shake and rattling noises that can be created. The first is when the ESC is not working right and it causes the motor to freak out and makes the rest of the drivetrain shake and rattle. The second type is when there is something wrong with your drivetrain, you might have a blown bearing, a striped gear, or my favorite a axle pin that is just a hair to long to fit inside of the wheel hex's. So you need to figure out whether it is the ESC and Motor or the tranny and axles that are causing shaking and rattling.

Also do you have the metal geared servo, if so you may want to check to see if the screw that is holding the servo arm on is to long or not? The one that come with my Raider XL was too long and was bottoming out before the servo arm was tightened down. So if your servo arm is loose in any way you may need to shorten the screw or do what I did and put some tiny shims on the screw before tightening the servo arm down.

 

[Tadey14]

Thanks for taking the time Dragon.

I'm afraid that due to my inexperience my assessment of the noise would be an uneducated guess at best. having said that, I think I am experiencing the first type of noise you described, don't know why, just do.

As for the servo. I have the metal geared, factory included ADS-7. The factory arm was loosely attached with the supplied M3x8mm Button head screw. It was very loose, it only took me a couple of turns to remove it. My fix couldn't be this simple, could it?

I am going to reattach the servo arm, make sure it's tight and give it another go later this afternoon. If that doesn't work. I'm taking it to a nearby LHS tomorrow to seek professional help. Originally I was comfortable replacing the turnbuckle but, now I'm afraid to continue messing with vehicle for fear or making matters worse.

It's very disappointing to say the least to experience these setbacks with a new unit out of the box with less than 7 minutes of continuos driving time. Trying really hard not to give up on the truck but, this really sucks.

By the way, Just realized that I received the 2013 discontinued version of the truck. Does this help explain what I'm experiencing?

Thanks

 

[FatherSonRC]

Did you happen to figure out the reason for the blinking blue? Mine was running great for the 1st run but took it out today and it stalls after 30 seconds or so and the blue light blinks...

 

[MSgt]

Blue light blinking indicates the battery low voltage cut off, the esc protecting the battery. What C rating is the battery in question? Maybe an issue with the battery or ESC (most likely) or possibly motor/servo issue.

 

[FatherSonRC]

So I'm now wondering if the batteries are not fully charging on the Primal. The truck was running awesome just yesterday...then took it to an open field to let it loose that's when the problems started... I've reset the ESC to factory settings because my book says it should of come ready for Lipo but the Online book says it came NiMH ready. They should probably fix that. I may end up calling support tomorrow but really appreciate seeing what others have done and suggest on this forum.

 

[Rooles]

Tadey check out this thread i created. i think its going to help you.
http://arrmaforum.com/threads/esc-shutting-off.487/#post-4905

as for the shaking that you see its called cogging. as far as i have read its pretty normal for non senored motors.

 

[springboardz]

@FatherSonRC First step I would recommend is testing with a second battery (fully charged). You'll see a number of comments from a few of us scattered across the forum in relation to that silly blue light. In my case, I am waiting for warranty replacement with my Talion's ESC.

 

[Tadey14]

Rooles thanks for the link, lots of good information on there. will have to examine if connectors are part of my issue.

Father, I've tried testing with 4 separate NiMH packs all fully charged, same result each time, within 20-75 seconds truck becomes unresponsive and blue light flashes. last couple of batteries measured around 7v and 7.1v after truck stopped working.

Guy at my LHS took one brief look at my truck while it was having the blue light symptoms and automatically determined it was the ESC, he suggested I ask Arrma for a replacement Servo as well since the ADS-7 has been discontinued and my truck is under warranty. I Called Arrma, they are going to send me a new Servo and ESC as soon as I return the faulty units in my truck. Hopefully this will be all taken care of in a couple of weeks.

thanks guys for the advice and suggestions.

 

[Rooles]

Glad i could help!

 

[MSgt]

Is you ESC jumper set for Nimh? It could be in the Lipo position. If so, it'll cut the motor off and blink blue to save lipo batteries from going below 3.2V. This would be normal operation for the ESC.