Glitching with a Novak brushless ???
 

Hi guys,

I am having terrible trouble with glitching in my JRX-S with one of those new Novak GTB 5.5r brushless systems.

I have a FM JR R1 Radio that i also use for my 2 other nitro cars on the same channel as the JRX-S with no problems.

It is happening at 2 exact points on the track. They are coming out of tight corners on the farthest parts of the track and when i accelerate hard out of these corners it starts to glitch only for a second or two sending my car off into the grass :( The steering just snaps full lock to one side.I have already taken out a few guys who where trying to pass me on the outside when i get one of these glitches :eek:

What do you think is the problem?

I have tried moving the receiver, changing the receiver, re-wiring everything and moving the wires around, changed crystals.... Nothing has worked.

Its not interference from someone as it happens all the time even by myself. And my nitro cars use the exact same receiver and crystals and they work fine.

Only thing else i can think to do is maybe change the steering servo ??? Could a bad steering servo cause this? :confused:

Or get a Spektrum module for my R1 radio? Or can they be affected by glitching too? :confused:

Please help if you can. It has cost me a major titles race already and is really starting to bug me. :flaming:
Thanks.

We have a track here that does the exact same thing to multiple people, first check with other racers and see if they have the same problem.

Spektrum fixed it up for me :)

Yeah i checked with all the other guys at the track and none of them have any problems.

I was having similar problems when i was using a brushed motor but i later found out it was the brushes arcing on a badly worn comm.

That's why i got a brushless to stop that ever happening again :lol:

I have had only 1 good run with the brushless and that was with an old 2000mah NiCad pack. That very same day for my main races i use new IB 3800 NiMh packs and that is when the problem first started.

Surely the NiMh packs couldn't have been the cause :weird: I refuse to believe so anyway. :lol: It must be something else. :confused:

Timox-I had one bad servo that caused me similar problems. It was over loading the Battery eliminator circuit of the speed control. This reduced the voltage to the receiver and caused the glitch. This problem would be worse when the motor is drawing maximum current reducing battery voltage.

From my personal experience, usually when you get only a few spots on the track glitching, it's an install problem, or just a plain old fashioned bad receiver.

Try to Not bundle any of your input harnesses.

If you can email me a picture, I'd love to have a go at this for you. :)

Thanks
Charlie

sounds like a radio power problem to me. the faster brushless systems out there can draw a ton of current when accelerating and that drops the main packs voltage down. You say the problem happens comming out of tight corners when the car is farthest from you. So there are two things going on here, your car is farthest from your radio so you have the weakest signal and you are dumping tons of power into the motor. you might be able to use a capacitor on your receiver to help smooth out the power. It would work just like a receiver pack. Put a battery plug on the capacitor and plug it into the battery slot on the receiver. When the motor is taking lots of power the cap will help the receiver ride through the lows. For a test your could also try running a receiver pack, just remember to pull the red wire out of the ESC harness before you use the receiver pack!! This will help eliminate the receiver as a possible cause. It will also feed your servo from a power source other than the BEC on the ESC. So if you have a bad servo this may mask it. My friend once had a HiTech servo that did this same thing. It was a digital, but I don't know the number. It cost him a shot at the Tamiya National Race.

I run at an indoor carpet track and have never experienced any glitching. And I run a tc3 with a 2pl.

Charlie, I just sent you some pictures in an e-mail

Kaufman, Your idea sounds like what is happening. My servo is not a digital one though. Its just a cheap standard FET JR servo i got with some helicopter radio.

If i very slowly and gently accelerate in the places where the glitching happens i can JUST drive the car past the dead spots and then continue on racing like normal till the next dead spot

I do have the brushless motor geared UP a LOT higher than is recommended so i can see that it would be drawing some big current. Its fast though. Like a 6 turn brushed

What type and size of capacitor would i need on the receiver if i wanted to try that?

And if this is the problem will a Spektrum not work either?

I have had the same problem with my system, but it is the Sphere/Neo combo o the Spektrum. Try adding the capacitor kit that spektrum sell that plugs into the receiver. I bought one for mine and it solved the problem for me. I don't know the part# off-hand.

Any other thoughts?

Well guys i have done some testing with a multy meeter on the BEC side of the ESC and found it is putting out about 5.95 volts sitting still.

I then sat the car on the ground and held it down while i punched full throttle. The voltage dropped down to 4.1 volts. Is that enough to starve the receiver?

And another thing, The cap on the speedcontroll. Shouldn't that be helping out? Or is the cap on the speedy not connected to the BEC part in any way?

I have a GTX speedy that has a cap on it. Can i use the cap from that to use on my receiver?

Something to try..
when i have problem like yours....


I mount the ESC , reciever with out double stick tape.
I also unsrew the servo ....


Then turn car & radio on...


as you rev thottle check to see if servo horn is moving...
if it is, thats is because of the giltch...

Now rev thottle...
same time lift reciever off chassie , & again look at servo horn for movement...

If the servo stops moving when you lift, its a good sign either the reciever has issues or the reciever is mounted to close to ESC....

Wild Cherry,

I just tried what you said to do. I have no glitching like that to start with. So its not a receiver mounting problem.

I live 600 kilometres ( 372 miles) from the track so is a bit hard to do some testing. So i put all the electrics in an Losi off-road XXX buggy to try.

HOLY CRAP THIS THING IS FAST :eek: :eek: :eek: :eek: I have never seen an off-road car move so fast :lol: It was doing wheelies on loose gravel :eek: :D Then stripped all the gears in the gear box :o I couldn't get it to glitch though. Maybe because i couldn't get the power to the ground so couldn't load up the motor enough.

I think i need to find myself some of the black grippy stuff to try it on :nod:

But so far i don't think its a servo problem or a receiver problem.

WoW! I would have to say that is really Faaaaar! :eek:

Yeah you can imagine my dissapointment after driving all that way only to have glitching problems all day and not even finish 1 race. :flaming: