Quark/Neu brake lock-up

I finally got my Neu 1515/1y in the 8ight-t last week and attempted to race with the Nitro's Sat. night. The motor is awesome as far as power, top speed, and temps went. However, the brakes kept locking up and then it would take about a second and a half to let me have the throttle back. I have reverse disabled, no drag brake, soft settings on torque and braking, and I dialed the brake down on the radio from the initial max of 150 all the way to 30 with no improvement. As i saw Serum suggest on another thread, I checked the motor conections(3.5's) and they seemed solid. Anyone have any other ideas on what might be causing this issue? Or set-up changes that might help?

[supralover72]

Make sure you don't have too much electronic noise around your chassis. Try covering your wires in aluminum and twisting them. That's all I can think of. Check to make sure your radio isn't glitching too.

Maybe I should try programing it with the "noise" filter on and the neutral range set to wide?

[supralover72]

That may work. I'd try it and see.

[Patrick]

Are the brakes locking up without you touching them? If they are, it possible that it's the thermal cut off (even though it might not seem that hot). Mine did that even after I went to a spektrum. It was doing it when I used a 7xl on 14 cells for racing, I ended up burning out two quarks. Now my third quark runs a 1515 2.5d (1700kv) on 5s lipo and I haven't had that problem again.

It's definitely not thermaling. Motor is about 135, controller about 145(at it's hottest point by the motor wires) and the batts. about 105 after a 5 min. qualifier. It occurs mainly when I'm really cookin' and start to slow the truck down quickly; not so much from slow or moderate speed stoping.

[BrianG]

How long does it take for you to regain throttle control? Does the steering also lose functionality when this happens? If so, you could check your BEC as it may be overloaded causing your receiver to "reboot".

Do you still have the ferrite bead on the throttle cable and the power wires?

It only lapses for a couple of seconds, max. I don't think it's re-booting. I am almost sure it is retaining steering control, 90% anyway. And yes, the ferrite beads are on the throttle and power wires. The settup is almost identical to the one I was running with the p.o.s. FD XLT motor with the exception of having the Quark mounted to an elevated plate off the chasis, instead of the rear shock tower. I have re-programed wiht the noise filter on and the neutral range set to wide but it's been pouring rain all morning. Probably will go to the parking garage to test again this evening. Thanx for the suggestions, so far. Keep em comin' if ya'll think of anything else.........

[BrianG]

I had a VERY similar issue with my Quark and Neu in my Hyper8 and the UBEC was at fault. I added a little better cooling to the UBEC and it hasn't happened since. To find out that this was the problem, I used a receiver pack temporarily.

Good luck in finding the culprit! And make sure to let us know what you find.

Oh, and even though the receiver "reboots", your steering will come back right away because the receiver doesn't take long at all to reboot, but the ESC might need a little longer to re-sync to the throttle signal. Just a thought...

Thanx Brian, I'll try the reciever pack if the new programing does'nt help.

Well Brian, you are an excellent diagnostician. I got the lectrics back in the 8ight-T again with a Nmh reciever pack and the brakes worked without locking up or causing the quark to reboot. They are still capable of locking up but now have some "feel" tuned in @ about 50% on the radio. Unfortuneately, my UBEC is already mounted in the best ventalated area of the truck(atop the center diff.) and I certainly don't want to install a fan, as I've been avoiding fans from the time I started this brushless adventure. It worked perfectly with my last set-up but was in the truck when my original 125b went up in smoke so I'm thinking maybe it was damaged when that occured. I may try the Castle BEC or just run the reciever pack till I get a MGM, MMM, or R1MT with a built in "switcher". Anyway, thanx again for the diag.