Pro Pulse B100 Jitter, Help Please!
 

Hey guys, I bought a Pro Pulse B100 buggy a couple years ago and it worked great for months and then one day the steering servo got messed up and would only turn left. So I put it in a box and forgot about it. I pulled it out yesterday, took it to a nearby hobby shop where the guys suggested a metal-geared steering servo which I promptly bought along with an additional battery pack (7.2V 1600mAh NiMh). I got home, put in the new servo, charged up both packs and took it out to the driveway for a test run.

It ran like a dream for the first 30 seconds and then started exhibiting the exact signs of a very low almost dead battery pack. Under full throttle it would just jitter really bad and barely move forward. The steering still worked fine as long as I wasn't giving it throttle at the same time. So with no throttle, the steering responded precisely and very quickly but then with some throttle the whole thing jittered, including the steering servo. I assumed it was either bad batteries in my remote control or that the old battery pack was toast.

So I replaced the remote batteries with fresh ones and put in the new pack I just bought which was reading 8.39V on my multimeter. It ran great for about a minute this time before exhibiting the exact same symptoms. I checked the battery pack and it had dropped to 7.9V which seemed like a FAST drop for a minute of driving but I know the voltage drops faster at the beginning of a freshly charged pack.

So I'm thinking the possibly problems are that I either have a bad receiver (although the steering works flawlessly so I doubt it) or a bad ESC or possibly I have a bad battery pack and the one I JUST bought is bad too? Although that last one seems unlikely.

So do you guys have any suggestions of some tests I could do to narrow down my problem?

Thanks!

So it turns out that my issue was ignorance because I simply wasn't charging my battery packs enough. I assumed a 7.2V pack should charge to 8.4V but it turns out that both of my packs will charge all the way to about 8.8V, so I charged them up and tried again and the car ran great for 10 or 15 minutes which is awesome!

However, it still exhibits a bit of a stutter even at full charge when you first accelerate with full throttle. If it's sitting still and you gun it stutters for like half a second and then shoots forwards, it tends to only do it from a dead stop, not if the car is rolling and then you floor it.

Any ideas here?

Is it a sensorless motor or sensored?
Sometimes when the sensor or the cable is broken you can have this problem.
Did you tried a other motor?

I don't know whether it is sensored or sensorless. This is my first and only hobby grade RC car so I'm still a bit new to this. It is a clone of an Associated RC18 if that helps. My gut tells me that whichever one of those motor types is less expensive is what this one is.

I don't have another motor to try. If I had any spare ESC's, Radios, or motors then I'd try them to isolate the issue.

This is the same setup as the brushed RC18.

380 with a brushed ESC. The problem you have is the RX/TX, Radio and trasmitter. They are junk, hit up the US warehouse on hobbyking and get a cheap 2.4ghz system and you will be set.

I have had a few of these and they are great for what they are. I liked them better than the RC18's and HPI copied them part for part on the mini recon.

All you need is a new RX/TX and it will work 100% like new.

Thanks for the answer!!!

A few questions:

1) I know 2.4ghz is good but is it AM or FM and what is the stock RX/TX?

2) Does getting a new radio mean getting a new controller and receiver or is it just a new box and then a new "channel" card for the remote?

Thanks!

How about this one? Seems pretty great for only $20!

http://hobbyking.com/hobbyking/store...arehouse_.html