Table of Contents

Introduction

These instructions do not purport to cover all details or variations of the product and do not claim to provide for every possible contingency in connection with installation, operation, or maintenance. Self-repairs performed by the customer may lead to damage or loss of your product. Should further information be desired or should particular problems arise which are not covered sufficiently or if repair services are desired, please contact The Tail Company (contact@thetailcompany.com).

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

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.

Installing the Control Board

Early production issues with the power button and/or USB-C connector mechanically separating from the control board were corrected with hot glue to protect the connector.

Assembly of the control board can be made easier by reaming out the case hole for the button to be slightly larger. This can help prevent the button from being broken off the board and requiring a full board replacement.

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.

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.

When reassembling the case halves, pay close attention that there is a slot for engaging the PCB board on the other half of the case as well. This will sometimes keep the halves from mating completely, and should not be forced. Offsetting the case forward or backwards from the belt attachment lug and seating that end first may assist in getting the PCB to seat correctly in the case slot. Check for swarf in the PCB slot, or hot glue traces on the PCB, if getting it to seat completely is proving hard.

Installing Batteries

The MiTail Battery is a 3.7V 103665 LiPo battery. There are two of them.

The positive lead for the batteries is oriented to the left for J1 and J2 (closest to the corner of the PCB).

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.

The foam pad faces towards the other battery, but it's not structurally critical. Both batteries are constrained fully in the slots in the ABS case (and care should be taken not to crush the battery ends or wires when closing the case), and won't come in contact with each other or the metal rod around the spine.

Be aware that, although the JST-PH 2.0 connectors used on the batteries and across industry are polarized, the polarity that any one battery is set up for is EXTREMELY RANDOM. Positive and negative should be correctly indicated by red and black wires, but the position of the wires in the connector may not be correct for the MiTail (or whatever device you plan on using the battery in), because there's actually no real standard. Plugging in the battery with the polarity reversed can, depending on a lot of factors, be quite bad for the device and/or battery.

Testing Servos

Servo failures can cause the tail not to move (or to curve to one side because one servo is not working), to stop moving after a certain time of operation (thermal issues), or the controller to shut down or reboot (brownout of the ESP32).

Servos should be tested separately from the control board to ensure that they are operational. An inexpensive tester, such as the 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.

Long-term testing can be performed with Casual Mode set with a short intra-move delay, to try to replicate irregular problems.

Installing Servos

The tails use two 5521MG-equivalent 180 Degrees 20KG digital (PWM, not serial) servos. They are 4.5-6.4VDC standard hobby servos

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.

The board servo connectors are designated as below:

The “bottom” (Servo 2) servo cable goes to the bottom (closest to the board itself) PCB pins.

The visible shiny edge of the servo connectors go up (facing the viewer, away from the PCB):

Avoid connecting the servos to the LED pins on the end of the header block. These pins are reserved for the Glow Tip LEDs.

Before removing the servo cables, it’s recommended to mark the Servo 2 cable (closest to the PCB) with a black marker stripe for reference, as it’s easy for the cables to get confused and difficult to trace the cables when they are bundled.

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). 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):

Glow Tip - Installing LED Lights

The tails use 3 or 4 5V SMD 3528 LED strip lights, connected to the first pair (closest to the edge of the board) of pins on J5 (positive pin is up, negative pin is closest to the PCB).

Charging

MiTail requires a USB Power Delivery (USB PD) capable charging adapter. PD charging is only possible using a USB-C to USB-C cable and a USB PD chargers together. Adapters with USB-A output, even with a USB-A to USB-C cable will NOT charge a MiTail. The adapter should provide at least 9V - almost all PD adapters can. If the adapters’ rated power is less than 24W, charging will take around 3 hours.

If the MiTail red LED is not “breathing” red, it is not charging!

This will NOT charge a MiTail (but will charge an EarGear 2).
Even though this is a PD charger, it's using a USB-A to USB-C cable,
and the tail and charger can't negotiate. 		This WILL charge a MiTail AND an EarGear 2.
This is a PD charger, with a USB-C to USB-C cable.

Indicator Lights

The following visual indicators are presented by the firmware on the board:

Please make sure the PCB has the latest firmware. Firmware may be updated from The Tail Company app, support Python utility, or directly (e.g. using PlatformIO).

Board-level Repairs and Modifications

The tail PCB uses small surface-mounted components, and is not generally considered a repairable unit (replacements are available for order from The Tail Company). Users who are experienced with surface-mount board rework may attempt repair at their own risk, but the Tail Company is unable to provide specific assistance with this.

The most likely repair would be to replace the USB connector or tactile switch, which are reinforced with hot glue. Removal of the hot glue is possible, but requires care to prevent components from being removed from the board, along with the glue. The best method to remove the hot glue is high-concentration Isopropyl alcohol (IPA), also known as rubbing alcohol. Soak a Q-Tip in rubbing alcohol, and working your way from the edges in, brush the dried glue gently with the Q-Tip. As the alcohol weakens the adhesive, lift the edge and peel the hot glue away from the board surface, reapplying the alcohol as resistance is met from the glue.

Function Check

The MiTail should be checked with the tail oriented as if hanging from the belt mount. Testing the tail with it horizontal will cause the tail to move unpredictably. Upside-down tails (with the black vinyl-coated pull cables towards the floor) won't appear to work at all.