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Q&A Using MECHA - Common issues with quick resolve.

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  • Q&A Using MECHA - Common issues with quick resolve.

    Q0) My issue is not listed here.
    A0) contact for support at mecha(at)
    The preferred language is English but you can write in other language, if you feel don't know English good enough for this purpose.

    Q1) MECHA seems to rotate more than 360 or less than 360 instead of exactly 360.
    A1) When MECHA is idle, enter these codes on each Controller according with the rotator used :E1, E2 or P1
    23131< to set E1 as preferred rotator
    23132< to set E2 as preferred rotator
    23121< to set P1 as preferred rotator

    Q2) When press [>] then [2] MECHA roates 90° then press [<] then [2] MECHA rotates -90° but do not ends up in the same position.
    A2) Enter in /config a backlash value (around 24-34) then [Apply]
    or execute the backlash compensation calibration procedure
    12321< for backlash compensation calibration.
    After the code is entered, MECHA will turn slowly to right, then power LED will start flashing.
    After that, is need to press [p] (power button) when you see/feel the MECHA starts moving very slightly to left
    You can use the viewfinder, LIVE view with zoom, other devices attached like a laser pointer, so on..
    or simply feel by hand when that small movement begins.
    At the end, the LEDs will show, say, ":24" where 24 is the new calibration factor, is around this value.
    You can repeat the code if you want to do it better or have more precise ways to determine the small movement.
    You can cancel the procedure with any other button when [p] flashing, or press power button right after it starts flashing to have no compensation at all or it will time-out in 5 minutes if no buttons are pressed.

    Q3) The rotator seems to have a play, it moves very easy by hand.
    A3) For E1 and E2, tighten this little screw just enough until the play is reduced, do not over-tighten:

    Click image for larger version  Name:	silver-screw.jpg Views:	2 Size:	30.8 KB ID:	33088

    Q4) MECHA seems to not be precise enough
    A4) Follow the steps A1, A2, A3, provided above, for increased precision use uStep without "+" like 16, 32, 64, 128, they have increased precision than 16+128, 16+64.. for current FW

    Q5) At powering up, MECHA moves a bit forward and back.
    A5)This is normal when the backlash compensation value is set, if it doesn't moves, then is a sign that the value is not set and is better to set it as described in (Q2). This is valid only for the E1 or E2 rotator.

    Q6) I don't like the Sound FX MECHA has at starting up.
    A6) That is not a Sound FX, is the sound caused by movement MECHA does for compensating the backlash for E1 and E2

    Here is a simplified and exaggerated representation of backlash.

    Click image for larger version  Name:	bkls_01_a.png Views:	0 Size:	36.1 KB ID:	33090

    To rotate your camera you need to touch it, unless you're Jedi or use MECHA.
    In the same way, the motor needs to be in touch with camera part to rotate it.

    So the ideal situations will be the follows
    Click image for larger version  Name:	bkls_02_a.png Views:	0 Size:	35.5 KB ID:	33091

    Click image for larger version  Name:	bkls_03_a.png Views:	0 Size:	35.2 KB ID:	33092

    The green arrow is the value of backlash compensation known by MECHA, so it knows, when the direction is changed, the extra movement needed, as big as the green arrow, to be able to rotate the camera.
    E.g. for 1 deg. of rotation, when the direction is changed, MECHA needs to rotate "green value" + 1 deg.
    For better precision, the green value is in steps of the motor.

    The initial movement made by MECHA at starting up is in order to exit from a possible situation with unknown "red arrows", situation which can be created by handling or mounting when moving the gear on field.

    Of course the camera part need to stay in place when motor is not moving, that is the purpose of the friction ring (Q3), so it should be tightened enough to not allow play even when pressing the MECHA's buttons, and the later is for:
    a) comfort, if MECHA has play when pressing the buttons, the movement in opposite direction will feel un-pleasant, like a jump
    b) prevent some camera movement when pressing the buttons of the camera itself.

    Click image for larger version  Name:	bkls_04_a.png Views:	0 Size:	19.6 KB ID:	33093

    About touch due gravity.

    If no friction ring is used for vertical uses of E1 and E2, the gravity will keep the motor in touch but still will allow some play at Zenith and Nadir, or even can cause some extra movement if the weight of the grip pulls the camera over the Zenith a bit.
    Is good to understand this first to see what solutions are suitable, one is to use Zenith at 85 instead of 90.
    If no friction ring is used for vertical applications, the backlash value can be set to 0 for that particular E1 or E2 rotator.

    to be continued..
    1. Mecha it possible.
    2. Mecha it easy.
    3. Mecha team up.

    4. ..

  • #2
    Q7) I'm using MECHA DAC with a wide angle lens and parts of controller are visible in frame.
    A7) If using MECHA with controller toward the lens, is easy to fix by using MECHA with the controller toward camera instead.

    1. Mecha it possible.
    2. Mecha it easy.
    3. Mecha team up.

    4. ..


    • #3
      Q8) I cannot update MECHA FW beyond C1E_01485.
      A8) As update from C1E_01485 to next C1E_02NNN (the 2nd generation of FW) is done with formatting of the internal storage, in order to double it, MECHA wants to be sure that you did a back-up of data first.
      However, if you did that and/or don't know to do that, or it seems that it didn't work as expected,
      please send a message to mecha(at),
      as there are ways to force the update remotely regardless of the back-up being done or not.
      1. Mecha it possible.
      2. Mecha it easy.
      3. Mecha team up.

      4. ..


      • #4
        Q9) I can force the rotator in one direction only, to cancel the backlash thus I can have then a loose friction ring. Right?
        A9) Wrong. Here is why. The backlash value needs to be as close as possible to the green arrow, when the direction is changed MECHA to compensate the best and to cancel the backlash.

        However, the friction ring has a purpose which helps in dealing with backlash regardless of the direction is changed or not.

        Beside the purpose of keeping MECHA steady when the motor is not moving, purpose mentioned earlier, the friction ring needs also to stop MECHA from keeping moving on its own when the the motor is slowing down before stop completely.

        For horizontal applications, with no gravity to work strongly against the movement, without or with loose friction ring, when the motor slows down, nothing but friction will slow down MECHA as the red arrows starts to grow in 1st uS after the motor starts to slow down, so the friction ring is responsible for main friction.

        E.g. with one direction only, MECHA needs to stop at 0, 5, 10, 15.. deg.
        with proper tension friction ring will be indeed 0, 5, 10, 15
        with no or a loose one instead, might be 0, 5.2, 11, 15.3.. that's because the friction from ring being low,
        three elements play a role in variations (but there are others, will not mention):

        a) the small component of gravity (rig not perfectly level) can play a role in variations, though the component is to weak to cancel the backlash, but can produce variations,
        b) friction from moving parts of gear, which varies, hence the variable noise you can hear.
        c) the rotation speed
        1. Mecha it possible.
        2. Mecha it easy.
        3. Mecha team up.

        4. ..