Sankyo 101 120V 60 hz motor questions

[Werner1111]

Thanks Johan. That's a great idea about the gel and toothpick.

I'm feeling less down on this today and will share a few more details. To repair the gear adjacent to the center drive gear, I put the pair of connected gears in a 5C collet on my lathe. Then I cut down the larger of the two gears, which had a broken tooth, until the OD of the old gear was 0.105".


I drilled a 0.105" hole in the middle of the new gear and slid it onto the old gear and secured it with a bit of superglue. This picture below isn't the best, but it shows the result. I later put the gear in my ultrasonic cleaner and it looked much nicer, but I didn't snap a picture.


I was feeling pretty good at this point. However, after getting super glue on the gear, and subsequently breaking one of the teeth on the above gear, I lost the wind in my sail. I think I screwed up the center drive gear too.

I think, also, that while I understood what needed to be done, I was lacking the experience to do it cleanly. I learned something about technique during the process and know how to do it better the next time. I'm going to give it a break for a few days and then regroup.

Is there any reason not to replace the center drive gear and the gear pair in the above photo with brass gears? They're only E1.90/gear more from kkpmo, or E5.70 for the three gears. I would feel more confident working with the brass gears, for some reason. I may even ask kkpmo if they have the capability to make me the gear pair in the above photo.

Cheers and Merry Christmas!

[Werner1111]

Also, Johan, regarding your post https://www.flipclockfans.com/forum/...aled-can-motor

How is the new gear connected to the axle? And are you not worried about it sliding on the axle so that it is out of contact with the adjacent gear?

[Johan de Jong]

The rotor axle in the Sankyo motor has a ribbed profile at the position where the plastic gear sits. This provides enough friction for it to stay firmly in place. The trick is to carefully widen the drill hole until it is a tight fit, but not so tight that you need excessive force to slide the axle in. Note also that although the rotor has quite a bit of play in in the axial direction, once in the coil magnetic forces will keep it in place.

In the Tamura motor the rotor axle does not have these ribs and there I made the mistake to widen the hole just a bit too much. I then still could get it firmly in place by help of a little super glue. But better avoid that as it is tricky

I have no experience with brass gears. It might be indeed easier to work with if you have the right tooling. My biggest worry is that the brass gears could wear away the connecting plastic gears.

[Werner1111]

The rotor axle in the Sankyo motor has a ribbed profile at the position where the plastic gear sits. This provides enough friction for it to stay firmly in place. The trick is to carefully widen the drill hole until it is a tight fit, but not so tight that you need excessive force to slide the axle in. Note also that although the rotor has quite a bit of play in in the axial direction, once in the coil magnetic forces will keep it in place.

In retrospect, I believe I widened the hole in the drive gear a little too much to catch the ribbing, hence my need for superglue. To be honest, unfortunately, at the time I completely forgot about the ribbing on the gear-shaft. Well, as I like to simply say, "One learns by doing." I'll likely order a few more gears, probably plastic, and give it another go with my new-found "wisdom". Thanks for your continued support Johan.

I did not quite figure out why there was too much friction in the gears to let things move smoothly. I think it likely was either bit of superglue in the teeth, or i may have damaged the teeth in another way. I'll give it a think before placing the order.

[Werner1111]

Well it's time to get back up on this horse and ride again. I'm going to order 3 new Delrin gears, again, and try to make this work.

In my prior attempt, I struggled to combine the two separate gears using a less viscous super glue. As suggested, I will use a more viscous glue and a tooth pick to apply it. Also, I'm going to make the gears a bit wider, so that the two combined take up almost all the space on the axle shaft. Therefore the gears won't be able to move around and out of contact with their neighbors and I won't have to use any spacers.

I do have one issue I'm contemplating, related to the gearing. I believe the gears are supposed to be M0.16, thanks to Johan's research and work. The gear seen a few posts back is the first gear in the train after/adjacent to the motor output gear, and consists of a pair of gears. The issue is with the smaller gear, which measures in at OD=2.35 mm. When I run the size for a M0.16 10-tooth gear on www.kkpmo.com, I get an OD of 1.92mm. I'm worried that the the replacement gear with a OD of 1.92mm would have a radius that is 0.21mm smaller than the original gear Is that too much difference?

I looked at the OD of an M0.2 (next size larger) 10-tooth gear, and it has an OD of 2.40 mm. However, I suspect that you shouldn't mix gear modules.

[Werner1111]

Well I'm back after 70 days with good news. I just now tightened up the last screw and the clock is back in service. The bad news - I spent around $60 in gears over the course of 3 separate orders before everything worked correctly. Thank goodness I only paid $15 for the clock. I lost one gear, had a gluing problem with another and finally got the last one right.

Per the immediately prior post, I was struggling with the OD of the 10-tooth gear. When using the smaller M0.16 gear, the diameter was too small and it did not interact with the mating gear. I ended up increasing from the M0.16 to M0.2 size in order to get the correct OD. I was not sure whether the different Module sizes would mesh correctly, but they did. In fact, the gears where just a tiny bit tight and I removed a small amount of material from the outside of the new gear teeth with sand paper, which was enough to make it work.

My last remaining struggle was to recreate the two gear unit back from my post 11. One can only purchase one gear at a time from KKPMO.com, so I had to order two gears and glue them together with super glue. The minimal amount of lateral surface area on the small gear made this impossible for me. Instead, I drilled out a recess 1/2 way through the center of the larger gear with an OD slightly smaller than the OD of the smaller gear. I then pushed the smaller gear into the recess, lining them up with an axle. Finally, I placed a small amount of super glue into the recess to hold the two gears together. I used very viscous glue and the tip of a wooden toothpick to apply the glue in the correct spot. I let it sit over night and it worked.



Once I had the motor back together, I let it run over night before installing it into the clock. The next morning, my wife came into my office and said, "Did you know there's a little motor running in your shop?" that was music to my ears.

After that, all that was left was to reconnect the wires and install the 2 nuts and 5 screws that hold everything together. And just like that, the 6 month saga is over.

The only thing that isn't working correctly is the alarm function. It looks like all the pieces are in place and the alarm on/off switch moves correctly, but I'm not getting any buzzing. To me, it looks like there is a thin strip of metal that is somehow supposed to vibrate creating the alarm sound. When the alarm is switched on, that piece of metal sits freely. When the alarm switch is turned off, another piece of metal swings in to dampen that strip of metal in order to keep it from vibrating. At least that's how I think it's supposed to work, but it isn't doing much of anything. Any info is welcome.

I'm glad I was able to bring this clock back for a second lease on life. And so, here it is in its full glory.

[Johan de Jong]

Congratulations! It was a tough journey but the end result is worth it. And you have gained a lot of experience on the way. The next one will be a breeze!
Regarding the alarm I think this post may be helpful: https://www.flipclockfans.com/forum/...-401#post26923

[Werner1111]

Congratulations! It was a tough journey but the end result is worth it. And you have gained a lot of experience on the way. The next one will be a breeze!
Regarding the alarm I think this post may be helpful: https://www.flipclockfans.com/forum/...-401#post26923

Thanks Johan. You've been a great help along the way. All your prior efforts made my work extremely easy by comparison to having to figure it out on my own.

I reviewed the other post and my alarm does look complete. The wheel does slide over and click into place at the appropriate time. I suspect the problem is the second issues you mention regarding the spring. Would you mind sharing a picture with an arrow pointing to where I should bend the spring mount, please?

[Johan de Jong]

You can bend (or rather twist) the mount of spring as indicated in the picture. You can use pliers, but only a very small adjustment is needed. Do not try to bend the spring itself. Make sure the alarm is engaged, so the lever on the far right is down. The goal is to fine tune the distance at the place where the spring meets the motor until it starts to buzz. Once you get it buzzing try to enable/disable the alarm to check if it properly stops/resumes.

[Werner1111]

You can bend (or rather twist) the mount of spring as indicated in the picture. You can use pliers, but only a very small adjustment is needed. Do not try to bend the spring itself. Make sure the alarm is engaged, so the lever on the far right is down. The goal is to fine tune the distance at the place where the spring meets the motor until it starts to buzz. Once you get it buzzing try to enable/disable the alarm to check if it properly stops/resumes.

Thanks Johan! I'll give it a try later and report back.

[Werner1111]

You can bend (or rather twist) the mount of spring as indicated in the picture. You can use pliers, but only a very small adjustment is needed. Do not try to bend the spring itself. Make sure the alarm is engaged, so the lever on the far right is down. The goal is to fine tune the distance at the place where the spring meets the motor until it starts to buzz. Once you get it buzzing try to enable/disable the alarm to check if it properly stops/resumes.

It worked like a charm. Thank you!