glitching/cogging on new 4.5

[JThiessen]

We installed my B'in Laws new HV-4.5 Pro system in his E-Maxx tonight. All items are located in stock locations, and the wires are run along the motor side. But he's getting some significant glitching from about 10 to 15mph mark - under acceleration, it stutters-bucks-etc (I dont know the technical difference between glitching and cogging). Both of my HV systems have never glitched, so I'm stumped on how to pursue this. I read in the manual to check the sensor harness (which is a little short BTW Novak...need to add about an inch to it). The capacitor is intact..we zip tied to the backside of the fan (that actually worked nice - I may change mine to put them there).
Any help would be appreciated....he looked like a kid that had his candy taken away after one bite.....

[lincpimp]

Have you programmed it to the radio correctly? Also, what radio is he using. Will it cog/stutter off the ground with the radio at various distances away from the vehicle?

[JThiessen]

Originally Posted by lincpimp

Have you programmed it to the radio correctly? Also, what radio is he using. Will it cog/stutter off the ground with the radio at various distances away from the vehicle?

I cant positively say that its programmed correctly. I was standing nearby halfassed coaching him. It had forward/reverse/ and braking when he ran it. We'll redo that tomorrow. We also didnt try it with the wheels off the ground (the destructions say Not To Do That!!! )
He's using the stock TQ-3 system. I'd like to use this as a reason to talk him into a 2.4 system, but I think his little lady might have some issues with that right now!

Based on your description E-Revonut, its cogging. Running about 10 to 15, it gets very short stutters of power for a few feet, then runs fine. I thought at first he was doing it, but it did it on me too.

I'm hesitant to blame this on batteries. There is in fact life without Lipo's guys....and not all failures are due to cheap batteries (MMMMMMMMMMMM!!!!!)

I'm going to throw one of my old recievers in too, just to eliminate that possibility.

the stock tq3 is crap i had the same problem with my e-maxx only got 15-20ft of range without glitches after i went to brushless

[lincpimp]

Try a different radio system and see if it still does it. You may be able to rearrange the wiring and get it to work...

[E-Revonut]

What batteries are being used? If the batteries aren't great that may be a problem.

Glitch - is a term used to describe a radio system cut out, loss of signal, where the vehicle behaves irradically

Cogging - is a stuttering type of motion at start up, not an issue with a sensored motor/esc, this happens as the esc and motor are "talking" with each other at start up to determine rotor position

Of course these aren't technical terms but as you can see I would guess more of a glitch than a cog, the whole point of a sensor based motor/esc is that you will have a smooth start up. If you pulled on the senor cord to much you may have damaged it. Try a good set of lipos, or any lipos for that matter, any of them should be able to keep up with a Novak motor, of course you may already be doing that. Also try contacting Novak, Novaktwo in here is generally helpful, if he doesn't know the answer he will get the answer for you.

[BrianG]

And a cap on an unused receiver slot and/or a ferrite bad on the throttle cable may help. TBH, BL almost requires a non-AM radio - AM is just too sensitive to noise.

[E-Revonut]

I agree with all post since my first one. IMO it's def not cogging, 10-15MPH the esc knows the rotors position already, cogging is more like 0-5MPH. I ran an HV4.5 with a tq radio system for until I could buy the DX3R but I had the receiver and esc at opposite ends of the truck. I had some range issues still but nothing else. Make sure the antenae is no where near a HV wire and seperate the esc and receiver as much as possible. If your radio system is 2.4ghz stick it in it and try it quick.

[JThiessen]

Yeah, his stuff is in the stock 3906 layout - so the ESC and reciever are as far away as they can be - however, the reciever and motor are right next to each other. I think I have some of those snap on ferrite things here at work. Never knew what they were for (they came with all the plasma TV's we've installed).
I'll try one of my TQ-3's first, if that doesnt work, I'll put my DX-3 in it. I talked to him at about 9 last night and he's all kinds of excited about getting it running so we can go run this weekend. I had to bite my tongue about the as yet untested MMM V2 I have installed in my Revo.......maybe I'll have to bring along a spare.....!

[JThiessen]

Well we tried a few things tonight:
I replaced and relocated the the traxxas reciever with another traxxas reciever and the result was the same.
I then put three ferrite rings on several different wires (ESC-Reciever wire, motor wires, and sensor wire). Same result.
I then put my 2.4 Spektrum on it, and that ran good.

So this brings up serveral questions:
1) Is this an expected upgrade for people when they purchase one of these? Most of us (the sick ones on the dark side) already have them, but there is a large population of RC'ers who save avery penny just to get this $300 piece of speed and justifiably cant afford to drop another 300 on a 2.4G radio system. I've run all of mine with the stock TQ-3 system, with no issues - is it a random thing?
2) I found one solution to the issue (2.4). I didnt find the actual problem. Does anyone have any experince with 75Mhz FM? I'd like him to be able to try that before looking at the 2.4G stuff. I know just the difference in AM to FM radio (yeah, the one in your car!) is huge. Maybe this is a better/cheaper solution.

NovakTwo, I know question 1 is kinda putting you on the spot (if you choose to respond). My intent is to get a feel from the members here on this, but would also value your feedback.

[BrianG]

Originally Posted by JThiessen

Well we tried a few things tonight:
I replaced and relocated the the traxxas reciever with another traxxas reciever and the result was the same.
I then put three ferrite rings on several different wires (ESC-Reciever wire, motor wires, and sensor wire). Same result.
I then put my 2.4 Spektrum on it, and that ran good.

So this brings up serveral questions:
1) Is this an expected upgrade for people when they purchase one of these? Most of us (the sick ones on the dark side) already have them, but there is a large population of RC'ers who save avery penny just to get this $300 piece of speed and justifiably cant afford to drop another 300 on a 2.4G radio system. I've run all of mine with the stock TQ-3 system, with no issues - is it a random thing?
2) I found one solution to the issue (2.4). I didnt find the actual problem. Does anyone have any experince with 75Mhz FM? I'd like him to be able to try that before looking at the 2.4G stuff. I know just the difference in AM to FM radio (yeah, the one in your car!) is huge. Maybe this is a better/cheaper solution.

NovakTwo, I know question 1 is kinda putting you on the spot (if you choose to respond). My intent is to get a feel from the members here on this, but would also value your feedback.

It does seem hit-or-miss with the stock TQ system (probably mostly miss), but doesn't surprise me that it didn't work.

With the tests you did, you eliminated noise being induced on the throttle/BEC lines. Putting ferrite rings on the motor wires is pretty much useless.

The only other things you could try is 1) use a capacitor (1000uf+ 10v+) in an unused receiver slot, and 2) use a receiver pack to eliminate the BEC causing problems. But to me, it sounds like the noise is coming in through the antenna.

BL motors/wires are producing lots of noise because of the current they are pulling. Not only is it producing the noise at whatever frequency it is running at, but also harmonics (mutiples). So, there is all kinds of noise.

If you look up AM, you'll see that the signal rides on the top and bottom (amplitude) of the carrier radio frequency. Upon reception, the radio simply filters out the RF portion leaving the control signal. Unfortunately, noise affects the tops and bottoms and washes out the good signal. The reason why some TQ systems work ok and some don't could simply be the crystals being used. If the harmonics of the BL noise is close to the crystal frequency, it will be affected more. The filters in a radio are pretty narrow banded, so the further away the frequency (and the harmonics) are, the better. This assumes it's not just an issue with RF washout.

FM varies the frequency of the RF in proportion to the embedded signal. Upon reception, the radio chops the tops and bottoms of the RF signal (where the vast majority of the noise is), and decodes the shift in frequency to get the control signals. However, even though FM is much better at rejecting noise, it can still have issues if the noise is bad enough. 75MHz FM is further away from BL system noise, so it should work better.

2.4GHz systems are all together different. They are packet-based and use pretty complex dsp to verify and error-correct. Not only that, but the ferequency is wayy higher than the noise from the BL system, even with the harmonics. These systems may be more expensive, but you could get one that will control several different vehicles with just the addition of another receiver. Totally worth it IMO, and that's not even counting all the extra bells and whistles of a good system.

[E-Revonut]

A Spektrum DX2.0 isn't that expensive and it comes with 2 servos, or get on ebay. I sold a Losi 2.4 transmitter for $25 and a 2.4 rx for $40 or 45. A 2.4Ghz setup can be had for less than $100, may not be top notch stuff but you can always upgrade the tx later on.

for cheap 2.4ghz i found this
http://axonracing.com/catalog/produc...products_id=33

looks like a mx-3 shell anyone know?

[JThiessen]

Tower and A Main both have the MX3 2.4 systems for 149. Seems a decent price for what seems to be a popular radio.

[hobbimaster]

When I ran my new E-revo the first time it glitched right off the bat with stock electronics, hows that for quality control? Anyway, I had planned to stick my Spektrum Rx in it any way, and added a Novak Pro HV system. She's rock soild now.
For a cheap 2.4 radio check here www.axonracing.com Its only $100 and if you look at the pic you will notice its a Rebagged Airtronics MX3 2.4 that tower sells for $149.