[Lotuswins]

Hi Luke,

Now that my T55A, Panzer F, and Elefant are all OP powered and working great, I thought I would try to get my StugIII going on it rather than going back to the TK22 that I had in it before.  So, everything is wired up, and as with the Elefant, I'm using the 45A ESC's by Hobbyking to power the two 260 motors w/positive removed from servo plugs.  I can get it to start, shoot cannon (Airsoft not hooked up yet, nor are the lights and IR stuff). 

The problem is when I go forward on the throttle, it will start moving but then will shut down, complete with shut down sounds.  It will eventually start back up, but will repeat.  These are pretty small motors, but I could do a measurement on current, but it is curious that I'm getting a shutdown sound like I am doing it on command.  Is there something internally I am triggering that will give it the shutdown sequence?  I'm on a NiMh battery freshly charged.  Shutdown is set at 6.3 volts.  BEC is rock solid at 5.0 volts. 

Any ideas? 

thx, Jerry

[LukeZ]

but then will shut down, complete with shut down sounds.

What sound card are you using?

It will eventually start back up, but will repeat.

Meaning, it starts back up automatically without you doing anything? This doesn't make sense. Do you have "auto start engine with throttle" set?

BEC is rock solid at 5.0 volts.

What BEC is that, and what is it powering?


I'm sure your motors are not drawing too much current and even if they were it shouldn't cause the behavior you're seeing unless you have a very weak battery - which is definitely something worth checking. Swap it out for the battery in your Elefant for example, just to be sure.

Check that you don't have an extremely short "Auto Stop Engine when idle" setting specified.

Ultimately you're going to have to do more troubleshooting on your end. Do the basics. Re-flash firmware. Make sure you have Radio Setup parameters saved correctly. Ensure you don't accidentally have some secondary trigger assigned to turn off the engine. Try loading an OPZ file from one of your other models that is known to work into this Stug and see if that fixes it. Or, load the OPZ from the Stug into your Elefant and see if the problem transfers or goes away. Try to observe this behavior while the TCB is connected in Snoop. Is the engine shutting down or is the whole board rebooting? Keep digging until you can find something more specific.

[Lotuswins]

Hi Luke,

Sound card is Taigen V2

I have to restart it, sometimes it will after waiting a bit, sometimes I have to cycle the battery turn on switch.

The BEC I refer to is the one coming from the OP TCB.

No short idle time, it will idle for a long bit. 

I've switched TCB's, recharged the battery (2000mah Taigen NiMh, but fairly old), reflashed the firmware, reloaded the file, redid the stick centering and max/mins. 

I hooked up an ammeter, and put it on Min/Max reads and I can peg the 10A maximum of the ammeter.  It seems to be able to get to around 3 amps, and the board will go still, I guess it is reset.  I'll try snoop next, sorry I didn't think of that, maybe it will show something.  Funny that it will happen with only one motor too, either one. 

I'll try a different battery/program file/ and snoop tomorrow.  thanks for the help.  jerry

[LukeZ]

Beyond 10 amps seems like a lot to me for a Stug, maybe you have a short somewhere. I have a metal PIII that probably weighs 8 pounds with 5:1 brass gears and it doesn't draw 10 amps.

It is quite likely your old battery is unable to keep up with that kind of current draw. As current draw increases battery voltage decreases. If your NiMH voltage drops below ~7 volts under high load, even momentarily, the TCB is going to black out. That would cause the behavior you're seeing.

I don't think this has anything to do with the TCB. Replace your battery and check your motors/ESCs to make sure there isn't a binding issue/electrical short somewhere.

[Lotuswins]

Hi Luke,

I think I have things sorted, at least for the near term.  I replaced the leads from the battery connector to the switch, and the switch, thinking that they were perhaps too much of a voltage drop (measuring at the TCB connector I was getting about 1/2 a volt drop on my Fluke 115 with min/max).  No joy, but it seemed like the TCB liked that.  I tried a different, much newer battery first, which had no effect (drat!!).  So then I changed from the 12v 360 motors to 6v 360 motors (I needed the short can to fit the gearboxes into the Stug - Waltersons 3 in 1 gearboxes....worst boxes ever).   Now it will drive at least, and it will go to shutdown if I keep the throttle at 100% and flog it, but I lowered it to a realistic speed at 50% throttle max, and it seems that is okay.  Also, for some reason, I didn't have any caps on the motors so I need to do something about that too, perhaps spiking has contributed to the issue? 

BTW, speaking of caps, what are the recommended ones to put on the motors??  I need to get a bunch, as I seem to keep swapping them around, and there is no consensus on the internet that I can find.

I think I'm going to swap out these dreaded gearboxes with the 5:1 Taigen ones, if I can find them, since the low speed control is so much better with this TCB.

Are the 4:1 bronze boxes you have in your PIII still available?

Thanks again for the help.  Jerry

[LukeZ]

Also, for some reason, I didn't have any caps on the motors so I need to do something about that too, perhaps spiking has contributed to the issue?

Possibly, I would think unlikely but it is a good idea to have caps on the motors anyway and it won't hurt.

BTW, speaking of caps, what are the recommended ones to put on the motors??  I need to get a bunch, as I seem to keep swapping them around, and there is no consensus on the internet that I can find.

This I do not know but you can Google it.

I think I'm going to swap out these dreaded gearboxes with the 5:1 Taigen ones, if I can find them, since the low speed control is so much better with this TCB. Are the 4:1 bronze boxes you have in your PIII still available?

I misspoke, the gearboxes I have are brass, not bronze, and were sold as 5:1 (I will correct my original post). They were made by Asiatam and are no longer manufactured although it seems like someone is usually asking for them to be every so often in threads over on RCU. You can still get the equivalent boxes in steel version (louder) from Torro, RCTank.de, and maybe elsewhere.

[Lotuswins]

Hi Luke,

So I googled the motor cap size, hard to find, but had some and measured them at 100 nano farads, so that's easy to order up a bunch from digikey.

I've also ordered up the gearboxes you mentioned from Germany, which should be here in a week or so.  The Waltherson's sound like tin cans being dragged down the street.  Also, the motors are supposed to be 360, short can ones, so perhaps they will even fit the Stug......with the airsoft, it is really cramped in there so much so I don't have room for a smoker...

Thanks again,  Jerry

[Lotuswins]

Hi again Luke,

Okay, got the new gearboxes installed, and they seem to work better though noisy until I lubed them.  So this morning I pulled down the Stug to see how things are and the thing started okay, after which I raised and lowered the barrel and it shut itself down.  At least it went to shutdown on the sound.  So I raised and lowered the barrel after it shut down and it would be intermittent on running the motor.  I suspected maybe some interference on the airsoft case hitting or rubbing on something, so I removed the top of the tank, and it was still intermittent.  I then pulled the motor out of elevation gearbox and it still ran intermittent.  I removed the bell housing, cleaned all the oil off the commutator and brushes and reassembled.  Still ran intermittent, even worse now as it would pulse on/off.  So I put a motor on off the Hooben Elefant elevation gearbox, and this motor worked fine.  So I reassembled everything and it now seems okay. 

So my question after all this is: Does the board sound shut down if the current is exceeded on the A & B (turrent/elevation) motor outputs?? And would it pulse the motor if exceeded as above?? 

Thanks,  Jerry

[LukeZ]

So my question after all this is: Does the board sound shut down if the current is exceeded on the A & B (turrent/elevation) motor outputs?? And would it pulse the motor if exceeded as above??

Something seems haunted about this Stug. Can the board shut down if you exceed current limits on the onboard motor drivers? Yes, but indirectly. The onboard motor drivers are fed directly from your battery, they do not share the same voltage as the TCB processor which is running at 5 volts. However, if you draw too much current from your main battery its voltage will drop, and since the main battery also feeds the TCB processor, if the voltage dropped enough that could indirectly cause a brownout. However, it is not clear to me that you have actually experienced a reboot - your sound card played the engine shut-down sound but that is not necessarily the same as the board rebooting. You should be able to tell if an actual reboot happened by watching the red/green LEDs on the TCB closely, or experimenting with this stuff while Snooping. I agree that a reboot could indicate an over-current condition but if you are not rebooting then there is probably something else going on.

I can't account for the pulsing motor behavior but as the problem seems to be fixed after replacing the motor I can only assume the original motor was faulty and causing the pulsing itself. The TCB should not generate any kind of pulsing signal unless something is really wrong (possibly a bridged solder joint over multiple processor pins for example).