Watch Winder Repair

[neuhoover]

(Originally posted on the old RWG, 5 Oct 2005)

Intro

Many months ago I purchased a four watch winder off of Ebay. These are the cheap variety that can be had for $100 or so +/- $50. The box has two winder platters, each holding two watches. A few weeks ago one of these platters stopped turning and I initially thot "great, I'll have to chuck this winder and buy another one." But then I decided to try to fix it, figuring one of the cheap motors died. Here's how I fixed mine.

Tools Needed

Philips screwdriver

Needle nose pliers

Soldering iron and solder

Flathead jewelers screwdriver

Steel wool or other mild abrasive

Instructions

Remove the screws from the bottom of the unit (Pic 1). Once you remove the bottom plate, you will see the insides of the unit (Pic 2). It consists of two motors and the control module. I figured the control module is probably working fine since one motor was working fine.

Pic 1 & Pic 2

Back on the front of the unit, remove the holders for the watches from the platter and then grab the platter molding and pull straight out. You'll end up seeing the bare platter with a screw. Take out that screw (Pic 3), carefully remove the platter, and then remove the bearings assembly (Pic 4) - it's a black plastic ring with ball bearings in it with lots of grease. Carefully place the bearings assembly on a clean piece of paper or something and make sure none of the bearings fall out.

Pic 3 & Pic 4

Now you'll notice that there are two screws holding the plate down. These screws hold the gearing assembly onto the plate. Tilt the unit so that you can get to the motor and unscrew the front screws at the same time. The screws are from the front and they're held in place with nuts in the back. Use needle nose pliers to hold the nuts (Pic 5) and then use a screwdriver to unscrew the screws. Careful as you unscrew the second screw - you'll have to hold the motor assembly otherwise it'll drop out. Remove the motor assembly and pull it out to work on (Pic 7). Heat up your soldering iron and heat up the solder holding each wire to the motor - when the solder warms up gently pull on each wire to remove from the terminals (Pic 6). Note that it matters which wire goes onto which terminal - this determines which direction the motor will turn. Mark the black terminal by putting a permanent marker dot next to the terminal to insure you re-solder it the same way when you're done.

Pic 5 & Pic 6

Pic 7

We now need to get to the motor. The motor assembly consists of a motor and a gearing assembly that is contained in a cylinder. The motor needs to be replaced, but I couldn't find a replacement. So we're going to fix the motor. Locate three screws mounted on a black plastic ring that holds the motor to the gearing assembly. Remove these screws (Pic . Separate the motor from the assembly, and then remove the two screws that hold the black plastic ring to the motor (Pic 9).

Pic 8 & Pic 9

Use the pliers to gently pry off the gear on the motor axle (Pic 10). Make sure you note where this gear sits on the axle (use a permanent marker to mark the location). Then turn to the back of the motor where you'll notice two tabs that are folded over onto the plastic end cap. Use needle nose pliers, a flat head screwdriver, or whatever you need to pry these tabs up. Once you have these tabs up, you should be able to slide the plastic end cap off of the motor housing (Pic 11).

Pic 10 & Pic 11

Now, there's not much to a motor and very little that can break in there. On the axle is a form over which a thin wire is wound making up a three part armature. The two ends of this wire attach to the commutator contacts (see Inside Motors 1). These commutator contacts then make contact with the brushes that are attached to the plastic end cap (see Inside Motors 2). Usually motors go bad when the contact between the commutator contacts and the brushes gets bad or dirty.

Carefully clean the brushes using either cleaning alcohol or a mild abrasive (steel wool). Also carefully clean the commutator contacts on the armature (Pic 12). Then use the pliers to squeeze the brushes as close to each other as possible - when you put the armature back in you want full contact between these brushes and the commutator. When I did this I actually bent each brush way past the mid-point and they were almost touching. Once this is done, carefully seat the armature between the two brushes. This is a bit delicate and tricky - make sure you don't mangle the brushes and also make sure the brushes make full contact with the commutator contacts (Pic 13).

Pic 12

Pic 13

Then carefully slide the motor housing back onto the axle and line up the housing with the plastic end cap (Pic 14). Once it's all lined up press the motor closed and bend the tabs back on. Then slide the gear back onto the axle (Pic 15).

Pic 14 & Pic 15

The rest of the reassembly is pretty much the reverse of the disassembly process. Remount the plastic ring to the motor, slide the motor back into the gearing assembly and screw the two pieces back together. Then re-solder the wires (note that if you want the motor to turn in the opposite direction, simply reverse the order of the wires and terminals from what it was originally). Then re-attach the assembly to the case and use the two screws and nuts. Finally, reseat the bearings assembly, screw in the platter, and put back the forms.

Conclusion

This took me about 30 minutes or so to do and it fixed the motor. Both winders are working now. I was in a hurry at the time, but a near future project will be to put switches on the back of the unit that will control the direction of each winder.