Turnigy TrackStar 18A ESC

[rossrov]

Hi guys. I'm not happy! More to these Trackstars than would first seem. Hopefully it's something I'm missing or not doing carefully enough. First having trouble with just the one ESC/motor, now other 2 are playing funny buggers too, though not as bad. Odd thing is, all 3 were working in beautiful harmony at one stage.

Power supply: Short wires to a 7.2 Ah 12 volt SLA battery and a 200uF capacitor right at the ESC's supply wires. Adding the cap did nothing to help. Have not tried dropping the voltage yet to see what that does.
Motor wires: These are about 250mm long and twisted so look like rope. Untwisting them on the one motor seemed to help, so perhaps in future will avoid twisting. Thinking of noise upsetting the sensing bit here.
Noise on micro supply: Checked 5V rail and also PWM outputs with scope and looks OK.
Micro code: Checked this and then tried different PWM period. This really scrambled all ESCs so reprogrammed with card
Swapping ESC and motor: Did nothing. Maybe just the other two ESCs are really good ones/have different tolerance.

Programming: Card alone won't set up the ESC as required, so first did manual program then used card. Strange thing happened when plugging card in - lots of lights came on that shouldn't have. Either I am doing something really wrong when manually programming first up, or the card and ESC aren't as compatible as would be hoped. If the latter, then I guess you get what you pay for. Had enough for now - brain hurting.

Heatsink in plastic idea.

Aluminium sheet plate, large as possible or, if housing tubular, an unrolled aluminium can/mug well glued to inside of plastic then ESC pressed onto aluminium. KR2's heatsink compound very important.

[dna1990]

Not encouraging news. But hang in there.

I did order an extra unit (unless they decide to use two dive/surface motors) on the chance we fry one during testing and initial programming.



As to heat sink, I am thinking about an aluminum sink that is potted thru the side of the otterbox. But first I plan to just monitor temps and see just how hot they get in air, then again sealed in the box.

[rossrov]

Thanks DNA. Had a bit more of a play. I think one ESC was dud or different tolerance to others and that threw me. Alot of variables, considering I'm not using a radio for programming, just relying on my microcontroller and PC control of that. After going through things, was happy to find my S/W was initially pretty accurate WRT emulating an RC set. Used a servo to set it up before trying the ESCs. More fiddling needed. Still think the Trackstar 18 shows promise once the programming is sorted. Keep yers posted

Ross

[dna1990]

Good points. I did order the programming card, but many folks in the drones or rcgroups state it wasn't that helpful. Our control unit is an arduino, but we have just run basic example programs with a hobby servo to learn the concepts. We don't have much experience with pwm. While the basic commands work, the details and outlier expections are what often separate a DIY/hobby solution from the higher end commercial offerings.

I do have an older RC car radio and receiver. I may pull in out and dust it off while I wait for the ESC order to arrive. In case like you described, the microcontroller approach needs something to compare to or troubleshoot with.

[KR2_Diving]

Hey guys! Great discussion going on here. Have eaither of you tried the SERVO library for the Arduino? This is what I am using, and it seems to work out fine... Once I got the ESC programmed. I wrote a seperate program that sent "Full trottle", "neutral" and "full brake" (in RC terms) to the ESC to help with programming.

Using the Servo Library, I have each setting set as:
Full throttle = 180
Neutral = 92
Full Brake = 0

I was haalf tempted to add a microphone and intrepret the beeps to automate the programming... Only half tempted!

I'm away on business at the moment, but ill post all the code and maybe even a few vids of the programming and operation when I get back.

[rossrov]

DNA heatsink: If penetrations are going to be made for a heatsink, then maybe consider, if area permits, drilling with a hole saw a hole large enough to take the ESC's own heatsink. Then on the OUTSIDE (pressure working for you, not against you) of the box, stick on an aluminium plate to cover the holes. Use a semi-flexible sealant, but note that polycarbonate (Otterbox stuff) can be affected by certain adhesives. Internet search will show suitable/not suitable.

Good idea using the car RC to get started.

KR2: Funny you mentioned automating the programming using a mic...No I didn't do it either. Unless there is some obscure combination of settings to get the optimum results, programming is very straightforward

Reliable Slow-Start Problem:
Guess I was expecting too much slow-start capability from the ESCs. On searching the RC car forums, (sensorless) brushless technology is not real good at slow starts. Given that with a plane or copter the motors are always running, this is not an issue, and the times slow starts would be needed with cars rare.

Slow starting is working the limits of the ESC's ability. I found that I still have one ESC that starts better than the others, and one that is noticably less good. Put this down to normal tolerances, not actually anything wrong with the ESC

Tests of first motor and ESC, identical to those I later purchased to use on the ROV, were done using stop, mid-revs and flat out (fwd and reverse), and no slow starts, and showed no signs of hesitation on startup. All testing on the current motors/ESCs was done using software that slow-started. This contributed to the starting problems.

An obvious solution to this is to command a short burst of medium revs to get the motor spinning, a split second later revert to whatever the joystick is actually set to. Easy enough to do in the micro. Given the inertia of the ROV, the short bit of extra thrust may not even be noticable.

Embarrassing for an electronics tech: What added to the starting problems was a dodgy battery connector. OK initially, but with the repeated plugging in and out during ESC programming, went intermittently high in resistance

Keen to see how others go with different motors and batteries with the same ESC. Saw someone over on another topic using the same ESC but different motor.

Present Trackstar 18 settings: beep, beep , beep...
Brake/reverse 3
Brake Amount 1
Reverse amount 4
Punch Control 5 (disabled = full punch)
Drag Brake 1
Deadband 2
Voltage Cutoff 1
Timing 1

[dna1990]

Re: heatsink

That big of a hole worries me. I have a 1/2" aluminum tube, I was thinking of drilling two holes in the box to allow this tube to go in one aside and out the other. Seal well around both intrusions (well noted about reactions to certain checmicals). Then thermal paste the ESC's heatsinks to this.

It has the added colling of water flowing thru it.


But any penetrations will be a last resort after doing some termperature monitoring. Items should be in this week to begin testing.


Re: slow start

Are you saying the ESCs do not respond until say 35% or something...and that 0-34% power is not enough to turn the prop? In other words the motors sort of 'jump' to life at some point...? But if already running...you have better luck in throttling down to a lower settting? If so, is this behavior showing itself just in bench testing in air, or once under the load of pushing water?

(One) of the reasons we are doing this next version using Arduino/joysticks/ESC route - is to have more precise motor control. So I am anxious to see how smooth the thrust output really is over the span of joystick/throttle resolution.

[rossrov]

DNA, I was worried I had maybe disillusioned others with my mad ranting - this was certainly not intended. You read my last post pretty well spot-on re the start-up characteristics, but note sometimes the motors start up immediately at even very low revs (so low you would never use them) and other times not. Also I meant to note that testing was done in air, not water. The earlier tests with the stop-medium-fast were done in water. Bear in mind that my test setup consists of a particular combination of motor, ESC, microcontroller, interconnecting wiring, batteries etc. I hope and expect that your setup will be a fresh start and the results better. At present I have no intention of experimenting with different motors - the motors I have were chosen over larger diameter but similar spec motors so they would fit into a 40mm housing.

Other things yet to try, such as placing ferrite beads on the ESC wires to the micro. Somewhere I recently read that these ESCs are a copy of Castle Creation's units. Unfortunate to see ripoff of intellectual property if that's the case. Instructions are word-for-word the same too. Anyway, CC and some others use beads, which is common practice with power supply technology to stop interference from high-current switching.

The holes in the box suggestion would have one hole for each ESC heatsink, so not that big. One plate say 4 to 6 mm thick, depending on size of plate, covers all holes. Water tube idea sounds good, and could simplify attaching the ESCs, but watch that where the tube is glued to the walls of the box the walls don't press in and cause the seal to fail.

Looking forward to hearing how you go when the bits turn up.

Ross

[KR2_Diving]

So I have been struggling to enter programming mode on an ESC that I programmed a few weeks ago...

While looking for some tips, I discovered that this ESC is actually a rebranded TORO ESC.

You can see the original on this site. The instructions are word for word...
HERE.

Although, I am not convinced this is the original maker either...


Anyway... Anyone else struggling to re-enter programming mode after the first connection?

[bikerbones1968]

I never had any issue with programming my 4 ESC's (different than these ones) I have used both methods, a programming card and directly with the throttle channel on a radio. Oh by the way good work on your project Ryan when will you be getting that rig wet? Soon I hope.