More Mato IR Emitter Issues

[quitcherbitchen]

Glad you figured out the servo was dying. Usually the endpoints are controlled by the transmitter. The programmer won't be able to adjust the endpoint, but is very useful to have if you have Clark Boards. As they say, "Your in the (Army)hobby now" so owning that piece of kit will be a good thing later on. As far as servos go, the Emax are OK. There are better ones, but I think for the price you should be fine. Why it failed is always a mystery unless you remember jamming the barrel or something that was obvious. Usually friction will slowly kill a servo so check to see if you have too much in whatever mechanism you are using it in. Also, you can always set the endpoints mechanically by changing the geometry of either the connector or servo arm. That is the old school method before smart radios. Adjustable linkage like they use on model airplanes can be used to dial in the exact amount of throw. If you don't have enough room then you have to try bending the wire or use a Z bender to make your own custom length linkage. I would try using a different hole in the servo arm to change the throw. If you have to drill a new hole you can do that too. That cost nothing as long as you don't mess it up When you get the new servos they come with extra horns. Try using a new horn with a new hole to set the geometry. Mechanical geometry is harder to to do but superior to using the radio as the radio can always get the setting messed up by accident. Have fun with your tank. Fixing it is half the fun, even though you sounded like you wanted no part in tinkering with it. Maybe fun is the wrong word. Satisfying.

[Tang - RC.Senshado]

Okey dokey...

I think I have successfully got all of this figured out amazingly enough. This has actually been keeping me up at night to some extent if you can believe that. Mainly because these things aren't cheap, and the overall lack of support available on these is non-existent. I never thought buying one of these would lead to having to take a crash course in electronics diagnostics and repair lol...

It was the servo that controls the cannon barrel elevation. It's possible it failed on its own, and it's also possible I caused it to fail but improperly connecting the metal linker that runs from the cannon chassis to the servo horn.
In any case I swapped the elevator servo for the recoil servo and the glitchiness is resolved. The faulty servo seems content performing the cannon recoil function, for now anyway. I will swap that out at some point.

Now for more questions. Someone mentioned a servo tester to check the servo, is this what I want: https://www.amazon.com/Controller-Fu...%2C354&sr=8-17

What exactly will that tell me about the servo ?

Also, the servos I ordered were the ones that were originally supplied with the tank. They are EMAX ESOMAII Analog servos. Is there are better one out there or are these the better ones ?

Lastly, when the servo I am using for the cannon elevator reaches the extremes of its end points, I can tell it is still " working ", for now I am just not pushing it to those endpoints, I tried using the controller to set them to go no more than 20% ( default was 100% ) but that doesn't seem to do anything. Will the remote I am waiting on that adjusts the clark board allow me to tell the board where these endpoints are ? Or is that something I need to go back and tweak further by doing some more adjustments on the servo horn.

Also, thanks again for ALL the feedback and tips. Without this forum ( as well as RCtankwarfare) I would have been at a loss as to what to do.

Servo tester: This is a nice luxury item to have but you can also deduce whether your stuff is working by any which method you feel is practical. The servo tester can check if 1) it's dead, 2) it's working within its range if the servo is out of the tank and the horn is not connected to anything), 3) you can test its range of motion manually with it all hooked up to see if you are hitting any resistance along the travel/end points or that you need to adjust the horn or where the pivoting piece on the horn should be repositioned, all without having to power up your tank or hitting fire a bunch of times. Also with the tester, let's say you do have a clearance issue with your tank all hooked up and pressing fire on your radio. You're forcing your servo to work against a path of resistance each time you fire it, thereby increasing the chance you burn it out while you trouble shoot. The tester allows you to turn the gear manually via the knob, within it's limits, as slow and as deliberate as you like.

Servo models: There are better servos but I just buy $15 ones on amazon with a kg rating rather than grams cause I want more torque. It's also what helps budget crawler RC trucks maintain steering pressure with the weight of the truck, whereas a weak servo will make you lose that steering and possibly roll your truck. Really just look at the voltage range of the servo matches your system/battery voltage, the number of degrees it can go (60 degrees is the norm), and the rating (torque) it has. The ones I use are about 9kg for example and can drive a heavy/long barreled tank like a tiger and get bashed into stuff constantly and still be reliable after many uses. You can easily spend $100 a servo for airplane ones since they are more demanding. Metal gears on these servos are a plus. The cheapest ones are all plastic and the torque is in the grams range. That is okay with a very light and short barreled tank, for example, I said that Coolbanks have sucky servos yet I've been running the same servo for my Stuart for 1.5 years now for recoil and elevation (and I drive it hard and 1-2x a month at our club events).

End points: the Clarks don't have end point adjustments, just direction. For recoil you're gonna be stuck with that. The only way to manipulate that like quitcherbitchen said is the old school way via modifying the geometry. Using a shorter horn or moving the linkage down 2 holes for less throw is the way you do it. Easier to understand with all components laid out rather than thru trial and error with it all hooked up, but you can figure that out. The #1 rule here is it's all about clearance. If you have a mess of cables running alongside the setup and rubbing, you might create resistance so you should observe good cable management where possible. Also, this is where the servo tester would be handy cause you won't run the risk of damaging the servo in the trial and error process. You can adjust the end points of the elevation servo via remote but under one method I can think of: The servo has to be plugged and set up in a way that it self centers when you let go of the stick (which is not the standard way to do it), but you'd go through one of your receiver channels instead of off the board. But that is not the normal way you would hook up to a Clark. Typically you are hooked up to the board and you have no end point adjustment. Instead, when you adjust it via remote, you really just affect the acceleration on that channel. So instead of going up and down at 100% speed, you're cutting it down to 20% or whatever. It does it by giving the servo less voltage so to speak. When you set it too low via this method, you run the risk of not giving the servo enough juice to do its job and it'll stall. No danger of damage, it'll just act like it's under powered. This method, you tune by feel, but again, this does NOT manipulate the end points.

[Tang - RC.Senshado]

Oh I should add, if you do the method of plugging the servo direct to the receiver, you can adjust the end point to whatever and it will limit the travel even at full stick deflection. But it will return to center when you let go. That's sort of the way I did it, maybe there's another method.

[glocke12]

Yesterday I tackled the servo replacement for the cannon recoil servo that was failing. How naive was I to think this would be a simple " plug and play " replacement..🤣

I now know why the recoil servo was acting " jittery " when only the cannon elevation servo was plugged in. Mato has these wired together. I should have snapped a photo but didn't, from memory the positive wires of both are soldered together, and I think the signal wire of both are soldered together. The negatives of both remain independent I think. Since these wires were all traveling through a " hub " ( see image ) that I couldn't figure out how to get apart, my first instinct was to host cut what I thought were the unneeded wires from the old servo away. Thankfully I didnt do that as something was telling me I should look more closely at how things were setup. I ended up cutting away only the wires feeding into the old servo and soldered the wiring of the new servo onto the wiring harness and while that worked, I think I am going to have to replace the other servo now as that is showing signs of getting " jittery ".

Unfortunately this has led to further questions:

1) Why would Mato wire these two servos together in this manner ? Given that cannon elevation and cannon recoil are two separate functions, I can't think of a plausible explanation for this. I have not asked Mato ( yet ), I've got questions about a few other things in with them and am waiting for their responses to that.

2) In the first image below, there is a plastic barrel/wire harness type thing. Since the wiring in there is starting to become a bit of a mess, I suspect I am at some point going to want to redo the wiring so it's not as much of a mess. Does anyone know how that thing comes apart ?

3) With regards to the servo arm/horn, Mato (matomart actually) did get back to me on that and informed me that the horn was installed incorrectly. The metal linkage needs to be below the horn as shown in the second photo. Since that servo is still jittery at the endpoints no matter what I do, I am guessing it is on its way to failure as well, but before replacing that I wanted to experiment with repositioning the metal linkage that is shown. Since it has a right angle bend in it as it exits the horn, I don't think I can easily remove that without risking damage to the linkage and I don't see anywhere that I can get a replacement. Does anyone have any tips on removing that from the horn or where I can get a replacement linkage to have on hand ?

[tank_me]

I'm only making an educated guess here, but I would assume it has to do with the 360 degree rotation slip ring. Since the slip ring has a limited amount of wires, they combined functions to try and get it to work. If they would have wired each servo independently, that would have eaten 6 wires. You can power servos off of the same voltage source if the source can handle the draw of multiple servos. Each servo has a DC motor in it so each servo draws a specific amount of current when they are in use. The signal wire is the one that usually needs to be seperate if I'm not mistaken. I have seen circuits that are activated by using the ground wire to turn it on/off. I know on my Maus, I have two servos coming off of the recoil port with no issues on a Heng Long TK7.1. I've never put multiple servos on the same circuit on a Clark board so I can't speak to whether or not the circuit can handle multiple servos. I'm sure an Email to Clark could answer that question.

It could also be the noise induced by the slip ring. The slip ring is basically piece of metal in a circle that has a wiper arm that makes constant contact with it while rotating. Metal on metal contact while moving creates small electrical arcs that we would call "noise". Digital circuits use a high (usually 5V, but can be lower) and a low (0V) to determine on or off. The closer the voltage values are between a "high" and a "low" are, the more susceptible they would be to noise. Pulse Width Modulation (PWM) is a technique for controlling analog devices (like motors or LEDs) using a digital signal by rapidly switching power on and off. If the noise created in the slip ring is interpreted as a signal (5V or on), it can cause the device to actuate. I don't personally use slip rings in my builds because they induce noise that might interfere with the battle system signals. Since I do IR battle my tanks, I don't want to take that chance.

[glocke12]

I'm only making an educated guess here, but I would assume it has to do with the 360 degree rotation slip ring. Since the slip ring has a limited amount of wires, they combined functions to try and get it to work. If they would have wired each servo independently, that would have eaten 6 wires. You can power servos off of the same voltage source if the source can handle the draw of multiple servos. Each servo has a DC motor in it so each servo draws a specific amount of current when they are in use. The signal wire is the one that usually needs to be seperate if I'm not mistaken. I have seen circuits that are activated by using the ground wire to turn it on/off. I know on my Maus, I have two servos coming off of the recoil port with no issues on a Heng Long TK7.1. I've never put multiple servos on the same circuit on a Clark board so I can't speak to whether or not the circuit can handle multiple servos. I'm sure an Email to Clark could answer that question.

It could also be the noise induced by the slip ring. The slip ring is basically piece of metal in a circle that has a wiper arm that makes constant contact with it while rotating. Metal on metal contact while moving creates small electrical arcs that we would call "noise". Digital circuits use a high (usually 5V, but can be lower) and a low (0V) to determine on or off. The closer the voltage values are between a "high" and a "low" are, the more susceptible they would be to noise. Pulse Width Modulation (PWM) is a technique for controlling analog devices (like motors or LEDs) using a digital signal by rapidly switching power on and off. If the noise created in the slip ring is interpreted as a signal (5V or on), it can cause the device to actuate. I don't personally use slip rings in my builds because they induce noise that might interfere with the battle system signals. Since I do IR battle my tanks, I don't want to take that chance.

Yeah, I think you are spot on. After I created that post I figured out what that object is and now I understand why different servos/LEDs share the same hot/ground leads. it cannot be opened/is not "user-serviceable" so if I want to clean up the wiring I need to get a replacement and make all of those connections again.

So if. you do not use a slip ring in your builds, how do you manage the wire and keep them from getting twisted up when the turret moves ? especially iff it moves 360 dg ?