glitching/cogging on new 4.5
 

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.....

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?

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.

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!!! :rules:)
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

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...

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.

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.

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.....!

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:party:) 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.

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?

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.

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.

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.

Looks worth a try for 100 bucks.

And he wonders why we call him Brain! My brain fogged out half through reading his post - just like in college when I was reading my EEET text books!

Thanks for the explanation though. He's heading to the LHS this afternoon to see if they will let him try a 75 in it. My best guess is that he's going to buy whatever they sell there. I'd go with him, but the wife is making me go to the Mariners game......100 million plus in salaries, and first one to lose 100 games.....at least the food and beer are good.

Someone on rcgroups is selling this radio for 100 and extra receivers for 25... Sounds like a killer deal to me! Cheaper than entry level Fm...

He ended up buying a Futuba 3PK, or PM....not sure which. The 2.4 model. We installed it yesterday, but he's still having some issues with it loosing signal periodically. It just stops, then a second or two later, it starts running again. Doesn't seem to affect the steering though. Gonna put my system back in it and see if its the radio or the ESC.

I have to say that Futuba manual stinks...Some of these companies need to hire English speaking tech writers that actually know a little about what they are writing when they do their translations. I wonder if manuals that are converted from english to other languages are as bad.

Seems like it could BEC on the HV Maxx causing a voltage dip to the RX which then rebinds and then goes again.

Either that or it is the batteries but when I had this issue it was more at initial start up than when it was actually running...

I had the same problem, I switched to a Rx pack and no more issues. The internal BEC can't handle much I guess.

An update to this:
After he added the Futuba 2.4, he still experience random issues - about every 2 or three minutes. I stuck my DX-3 in it, and same result. We then added a reciever pack (pulled the red wire). And that seemed to help.
We pulled the receiver pack, put mine back in, reprogrammed to eliminate the Lipo cutoff (that's new, so anyone else you might want to do that if you dont use lipos), and ran it on the bench a few times. After watching him do this, I realized that the reciever light was going out every time it "glitched". So we finally nailed it down to that.
Going to take it up to the LHS, and see if they will swap it out - otherwise he'll be sending it in to Novak.

UPdate: He ended up sending it back in to Novak, who sent it back after testing and said there was no problem with it. We put it back in, and it still does it. There is a little periodic cogging right at take off (but not enough to be an issue). However, every time he lands a jump it shuts down for a couple seconds. I put my DX3 back in it, and its the same result.

He tried emailing Charlie, but didnt get a response. Guess he needs to make a phone call, or try emailing again.

It could be the area you are running it in. You might want to try running it in a few completely different areas. Also, are you sure there are no loose screws, no bad connections on the battery side? (you might have to yank on all of your solder joints to test this or replace your connectors if they are being reused from a previous setup) All power wires should be neatly twisted around each other for best results.

We tried all that. Three different areas (10 miles different). Six different battery set ups. And the plugs on the ESC were changed (since Novak clips them as soon as they recieve it). Every different part on the truck has been changed, so we basically isolated it to the motor/esc. The fact that the only time we can 100% replicate it is on a jump tells me that something is loose somewhere. The only thing I thought of was possibly the sensor wires jiggling too much....everything else needs to be handled by novak.

I have a three step plan for you.

1. Sell the Novak on Ebay.
2. Use this money to buy a MMM combo.
3. Install in truck and let the stupid grins begin.....

I've been pondering that approach. :lol:
I'm sure he'll be up for it, but his wife is a little controlling with the funds. Yes, she holds his sack for him.

I have a buddy in the same position.....

Luckily my wife is very supportive and understanding, or maybe it's just because she wants to get here toys too!

Wow. So this saga is getting closer to an end I believe. I had him come over today so that we could try securing the connectors to make certain it wasn't his soldering that was contributing.
We hooked everything up, and I first tied down the battery connector to the chassis. I put out one of the ramps so we could run it over that to see what the effect was. He plugged in his battery, turned everything on, and started to run it out of the garage. He didn't get but 10 feet before smoke started rolling from under the body! The culprit - the capacitor blew.
http://i244.photobucket.com/albums/g...kcapacitor.jpg

So, he now has a burnt pile of crap to send back for retesting. I'm going to type up a synopsis of what we've tried, and he can attach that to the form, including the above picture.

After this occured, I put one of my old 4.5 systems in it, and it ran great. No cogging/glitching at all - even after landing a jump so hard that it snapped both rear shock mounts off the bulkheads! Yeah, he had a rough day!

Kinda sucks that this thing was returned once already - with a "nothing wrong" response.

Update part XXVX
 

Just thought I'd update this thread.

He recieved the system back from Novak a couple months ago, but due to all of our various vacations, we finally got around to putting it back in over the last week - in addition to converting his chassis to an FLM extended chassis.

Opening the box, it was the same system he sent to them, but with a new capacitor on it. I assumed that they checked and fixed "something" for the apparent BEC issue.

We put everything back together again, and dont you know it - same old glitching. :diablo: ESC shuts down, reciever shuts down, then comes back on.
I pulled his Futaba system off his, and put it in my Revo with the MMM/Neu, and it worked fine (after spending a half hour with the WORST manual in RC history).

I once again put my DX3.0 in his truck, and got the same glitching.

I then pulled my old HV-4.5 off the shelf, and put it in his truck. Worked GREAT!! Next step, I'll put his Futaba back in and run it, but I'm 99% certain that it will work.

Now, how in the @($* do we get Novak to replace this damn thing instead of just bench testing it to spec and sending it back. The Brother in law isnt a very technically minded person, and he's getting really frustrated with the hobby due to this one product. I'm trying to keep him positive, but the string is getting short I believe....

On Edit after sleeping on this: I was ranting a little here, so I'll kick my soap box to the corner now! I'll attempt to contact Charlie myslef tomorrow afternoon regarding this, and see what I can communcate. The first time it was sent back was through the LHS where it was purchased, so there is no way I can know what info was relayed to Novak. However, the second time, I typed up a synopsis of the events portrayed in this thread, so I know what was conveyed to them then.

Why not disable the BEC and run a RX pack? As Chris said, the problem is the BEC dipping voltage to the RX- effectively shutting the system down. This explains why the truck was "stalling" when landing jumps- the excess strain on the ESC to get the truck up to speed depleted the BEC voltage to the RX and "stalled" the truck.

FWIW, it's not just when landing jumps that it occurs. Its all the time.

Anyway, I think the reason he doesn't do that is because he shouldn't have to. Its never functioned since new, and should be replaced by Novak now, not just another stab at bench testing/repair. And on the old EMaxx chassis, there was a serious lack of room for another battery. Now on the FLM, there is room to do that.

i went through the same problems with my hv pro, after 3 returns to novak and it still didnt work, i decided i would never buy another novak product again.

this post should really be a lesson for everyone

you could make sure that its "well done" before sending it in...:whistle: