John Deere 9560R by Tomek

This topic contains 12 replies, has 2 voices, and was last updated by RC Tractor Guy RC Tractor Guy 1 year, 8 months ago.

Viewing 13 posts - 1 through 13 (of 13 total)
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  • #1218

    Tomek
    Participant

    Some time ago I have decided to convert Siku John Deere 9560R to RC Model

    I have four N20 motors:

    Those motors are installed:

    and wheels as well

    Also steering servo

    So it is time to start with lights

    • This topic was modified 2 years, 2 months ago by  Tomek.
    • This topic was modified 2 years, 2 months ago by  Tomek.
    • This topic was modified 2 years, 2 months ago by  Tomek.
    • This topic was modified 2 years, 2 months ago by  Tomek.
    • This topic was modified 2 years, 2 months ago by  Tomek.

    #1224
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    This is a great build, what is the little orange cap you use in the second picture? And are those tiny smd LEDs on the end of the wires in the final picture? You must have very steady hands to solder those, I tried before but my hands were very shaky and I ended up with bad solder joints which broke easily.

    #1247

    Tomek
    Participant

    That little orange cap is a drilled and polished LED 5mm.
    If you have problem with shaking hands during soldering I have only one solution. You can buy that solution usually in half liter or one liter volume bottles. Dosing is individual thing, so some trials are necessary.
    Anyway this is what I have done and in my opinion ver3 is the best one.

    ver1

    ver2

    ver3

    #1254
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    Those are brilliant looking beacons, how many LEDs are actually inside the beacon? Version three does look good, the difference between them is simply in the code right? If so you could include all three versions in the code and select which one you want to use with your controller, that is something I plan to include on my Massey.

    #1256

    Tomek
    Participant

    I have 4 LED inside.
    The difference is in the code, but I need do design circuit board to be installed in the roof. Also I want to use PCF8574 to reduce number of wires to 4 between arduino and the roof. For that I need more or less such a board:

    I can probably remove 2 transistors and 4 resistors because for the lights I have now four (front left, front right and same for the rear lights).
    For version 1 I can connect all the beacon LED into one transistor so in such case I need only three transistors in the roof.

    #1258
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    That’s a good idea, a very nice way to expand your outputs. Are you planning to mount your XBee in the cab too?

    #1259

    Tomek
    Participant

    I was thinking about that as well, but if you look at that board there is no place. Maybe after changing transistors to SMD ones, but those are really small ones.

    #1261
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    Yes it does look like it would be difficult to include the XBee. You must be comfortable with smd soldering, I have only soldered discrete components so far but I plan to try a few smd chips at some stage. I’ll probably make a board with some TB6612FNG chips on it to make wiring to an arduino easier.

    #1262

    Tomek
    Participant

    There are a lot of tutorials on youtube about soldering. This is not very difficult.

    #1429

    Tomek
    Participant

    Recently I really have no time to play with that toy, but after changing servo to Hitec 5087 (the strongest small servo I found), changing voltage to 6V and installing the driver (probably most important) it turns much better.

    Special thanks to my son for supplying me with driver.

    #1437
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    Looks great, all those wheels would be hard to turn but man are you going to have great grip.

    #1597

    Tomek
    Participant

    After some trials it seems, that I cannot run 4 N20 motors using only one TB6612FNG. After some reading I know I need four. Unfortunatelly I need to use SMD ones because lack of space. The electrical diagram looks like this:

    I wonder if I can reduce number of capacitors. They should be as close as possible to the TB6612FNG, but what does that mean? Do anybody have an experience with that?

    #1613
    RC Tractor Guy
    RC Tractor Guy
    Keymaster

    Hi Tomek,

    You should be able to drive two motors from one TB6612FNG provided you need less than 500mA continuous current per motor I think. What brought you to the conclusion you needed one per motor?

    The reason you put capacitors close to the chips is because the traces introduce resistance and inductance, more so the inductance because an inductor resists change in current flow. So if for example you switch in a relatively high current load like a motor at high frequency the small inductive element of the traces resists that current flow and that can be enough to drop the voltage in that location causing weird effects on your power rails that can cause chips to reset even though back at the input the voltage appears stable. I think that is what happens and why it is considered good practice to provide bypass capacitors as close as possible to the chips. The reason you usually have different capacitor capacities of 10uF and 0.1 uF in parallel is to deal with different frequencies, a 10uF (probably electrolytic) has more capacity but wont respond as quickly as the 0.1uF (probably ceramic) capacitor so the smaller capacitance handles higher frequencies and larger cap handles voltage changes at lower frequencies.

    That said we aren’t working on very sensitive electronics so you probably would get away without most of the capacitors if you are tight for space but if you have the space for them it definitely wont hurt to include them.

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