Reverse engineering the Epson M-32TL

Here’s a view of the “gearbox” side of the M-32TL:

In this photo I’ve already removed the retaining ring from the 24-tooth middle gear (which I’ll call gear #2) in preparation for sliding it off the shaft. The white gear on the right (I’ll call gear #1) is directly driven from the motor shaft, which only spins in one direction (counter-clockwise, from the perspective of this photo). Thus, gear #2 spins clockwise.

Gear #2 flipped over

In the next photo (above), I’ve pulled off gear #2 and flipped it over, so you can see the smaller 12-tooth concentric gear on its back face, which (when assembled) fits inside the hub of what I’ll call gear #3, the black gear behind it on the same shaft. The hub has interfacing teeth inside it (not visible in this photo), so as a result this gear rotates more slowly than gear #2.

Gear # 3 flipped over

In the next photo (above), I’ve flipped gear #3 over, exposing two planet gears on its back side, and an internal ring gear (gear #4) that these planet gears interface to, that sits on the same shaft behind gear #3.

Gear #5 removed, exposing coil

The next photo (above) shows a different view, with gears 2 and 3 still assembled, but with the black gear (gear #5) from the next axle over removed, exposing an electromagnetic coil connected to the other pair of black & white wires. This is what Reece and Arne call the solenoid, although it doesn’t seem to have a core that is actuated linearly.

Coil assembly removed

In the next photo above, the coil assembly has been removed, exposing another assembly consisting of a black plastic cam, a compression spring, and a equilateral Y-shaped metal piece – probably ferrous, as I think this is what the electromagnetic force actuates when the coil is energized. Behind the black plastic cam you can see a torsion spring, one end of which is resting on the nearest axle (which I’ll call axle #4; axle #1 has gear #1, axle #2 has gear #’s 2, 3, and 4, and axle #3 has gear #5).

You can see three holes in the metal Y, one on each leg, which interface to small pegs on each of three corresponding legs of the black plastic cam. Thus, when the metal Y rotates, so does the cam. When the force on the metal Y is removed, the torsion spring returns both the cam and the metal Y to their resting position.

Metal Y and compression spring removed

The photo above shows the black plastic cam on axle #3, with the metal Y and compression spring removed. There are actually two levers that the cam affects, one black and one brown.

More to come…

Leave a Reply

Your email address will not be published. Required fields are marked *