Differences

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--- en:manuals:service-notes-for-mitail [2025/09/03 18:29] – [Installing Servos] darkgrue
+++ en:manuals:service-notes-for-mitail [2025/09/03 19:17] (current) – [MiTail Case] darkgrue
@@ Line 5: / Line 5: @@
 For the purposes of this manual, “left” and “right” references will refer to the MiTail’s orientation when worn on the body, relative to the wearer. So, the “left” side is the side of the MiTail on the wearer’s left.
-===== Case Screws =====
+===== MiTail Case =====
-There are eight Phillips-head self-tapping screws holding the case together, in addition to a serial number foil that must be cut or removed to open the case. One of the screws is behind the left actuator cable, and is easy to miss.
+The MiTail case is injection-molded ABS. Replacements may be ordered from The Tail Company, or installed by a repair depot.
+==== Case Screws ====
+There are eight Phillips-head self-tapping screws holding the case together. In addition to a serial number foil may be present that must be cut or removed to open the case. One of the screws is behind the left actuator cable, and is easy to miss.
-{{ :en:manuals:mitail_case_8_holes_.jpg?400 |}}
+{{ :en:manuals:mitail_case_8_holes_.jpg?600 |}}
+==== Case Replacement ====
+Replacing the lower case half (with the belt hook portion) is the most common reason for replacing the MiTail case. This requires that the case be opened, the two batteries taken out of the case, the control board removed, the four servo frame mount screws be removed, and the servo pulley be removed from the servo. The cable must be removed from the pulley to remove the case half from the cable.
+The disassembly is then reversed. Note the procedure in [[#Resetting Servo Home Position]] to reset the pulley position on the servo shaft correctly.
 ===== Installing the Control Board =====
@@ Line 20: / Line 28: @@
 Check for plastic swarf on the interior of the case edge around the power button from post-manufacturing rework that may interfere with installation of the control board.
+{{ :en:manuals:case_bottom_tabs.jpg?400 | }}
 Firmly squeezing the sides of the case to cause the button-facing edge of the case to bow out slightly can afford a small amount of extra space to manipulate the control board into place.
-{{ :en:manuals:board_squeeze.jpg?nolink&600 |}}
+{{ :en:manuals:board_squeeze.jpg?nolink&400 | }}
 <WRAP round tip 90%>
@@ Line 29: / Line 39: @@
 </WRAP>
+{{ :en:manuals:case_top_tab.jpg?400 | }}
 ===== Installing Batteries =====
@@ Line 37: / Line 48: @@
 The positive lead for the batteries is oriented to the left for J1 and J2 (closest to the corner of the PCB).
-{{ :en:manuals:battery_connectors.jpg?nolink&600 |}}
+{{ :en:manuals:battery_connectors.jpg?nolink&400 |}}
 The plugs can be difficult to remove from the board. It’s suggested to pull out and slightly down towards the board (somewhat of a slight rolling motion) helps the plugs release better, instead of pulling straight back.
@@ Line 54: / Line 65: @@
 Servos should be tested separately from the control board to ensure that they are operational. An inexpensive tester, such as the [[https://smile.amazon.com/gp/product/B08K7SVXRZ|Barnabas Robotics Servo Motor Tester Kit, 180 Degree 9g Servo Motor + RC Servo Tester Controller + 6V Battery Holder]] (approximately $16.95), is sufficient to determine if the servo is weak, shorted, or dead.
-{{ :en:manuals:servo_tester.png?nolink&600 |}}
+{{ :en:manuals:servo_tester.png?nolink&400 |}}
 <WRAP round tip 90%>
@@ Line 66: / Line 77: @@
 {{ :en:manuals:servo.jpg?nolink&600 |}}
+==== Servo Connections ====
 Internally, the firmware refers to the servos as Servo 1 (the "top" servo) and Servo 2 (the "bottom" servo). The bottom (the one that emerges from the "bottom" of the case when the servo bracket is installed) servo cable goes to the bottom (closest to the board itself) PCB pins.
@@ Line 79: / Line 92: @@
 The visible shiny edge of the servo connectors go up (facing the viewer, away from the PCB):
-{{ :en:manuals:servo_connectors.jpg?nolink&600 |}}
+{{ :en:manuals:servo_connectors.jpg?nolink&400 |}}
 Avoid connecting the servos to the LED pins on the end of the header block. These pins are reserved for the Glow Tip LEDs.
@@ Line 89: / Line 102: @@
 If a fresh servo is being installed, you will first need to modify the replacement servo to remove the mounting tab furthest from the servo shaft (so that it can fit into the case).
-{{ :en:manuals:servo_tab_cut.jpg?600 |}}
+{{ :en:manuals:servo_tab_cut.jpg?400 |}}
+Remove the pulley from the old servo, dismount the old servo and mount the new servo in it's place, and reattach it to the new servo, making sure that the new one is in the correct starting position.
+==== Resetting Servo Home Position ====
-Remove the pulley from the old servo, dismount the old servo and mount the new servo in it's place, and reattach it to the new servo, making sure that the new one is in the correct starting position. To do this correctly, first power up the PCB with the new servo attached directly to the board. That will center or "home" the servo before you reattach the pulley. Secondly, make sure the pulley is in the following "ten minutes to the hour" position; the topmost screw head will also align with the servo mount rib below it (note that the servo splines may not line up perfectly and may land a tooth to the left or the right slightly or a particular trail might bias more towards the center screw):
+ To do this correctly, first power up the PCB with the new servo attached directly to the board. That will center or "home" the servo before you reattach the pulley. Secondly, make sure the pulley is in the following "ten minutes to the hour" position; the topmost screw head will also align with the servo mount rib below it (note that the servo splines may not line up perfectly and may land a tooth to the left or the right slightly or a particular trail might bias more towards the center screw):
 {{ :en:manuals:pulley_alignment.jpg?nolink&600 |}}