Sanyo RM8400 (Copal GG-2499 motor) reduction transmission gears wanted

[Matthew]

Hello everybody,

I have recently bought a Sanyo RM 8400 for 300 crowns (13$/10€). It was quite filthy so I took it apart and cleaned it - I also straightened the knobs for setting the time, alarm and snooze time. Something must have fallen on the clock or the whole thing was dropped, the knobs were quite twisted. I found out that someone was poking his little fingers in this, because one of the screws holding the case together is missing and also I feel that there may be some screws missing inside - the circuit board is held in place by only one screw.

The main problem is that the flip clock is not working. The flipping mechanism is okay, even the light underneath the clock works. But there is a serious problem with the motor. One of the transmission gears is dead. I took out the motor, took it apart, took the transmission apart to have a closer look at the gear. It is a double gear - 60 teeth on the outside gear and 19 on the inside gear. The shaft size is approximately 0.9 mm. The gear is destroyed, it looks as if it reacted with some chemical and shrunk in size.

Does anyone know where could I get a replacement gear? I searched the net, there are tons of gears for robotics and models, but it's difficult to find a gear with the correct number of teeth and to figure out the dimensions I would need.

Any help is greatly appreciated. Thanks.

Matthew

PS. Oh, by the way, here are the pictures. Flip clocks are extremely hard to find here, very rare.

[Matthew]

I forgot to add that the outer diameter of the damaged gear would be probably about 1.4 cm and the smaller gear would be about 4 mm.

[Matthew]

Update. I fixed the clock some weeks ago, I had the broken gear made. I'll be posting pictures and a full video soon.

[Chief13]

Matthew - where did you have the gears made?

[Matthew]

I found an RC models forum, I think, and there was a guy who was making plastic gears. I called him and after some talk he agreed to make the gears for me. I told him to make me two, in case I mess something up while installing them. In the end this turned out to be a good idea - the gears he produced were sort of rough and not exactly the module I needed. But after I had put the transmission together, everything seemed to be turning properly. I'm still not sure if I overpaid or underpaid, because he had asked me for the price and after I told him, he went silent for about 10 seconds.

[Chief13]

If he can make them...why can't I? maybe I'll have to start experimenting with making plastic gears...

[Matthew]

I don't know what machines are needed, but I guess they have to be quite specialized - the gears are tiny. I wish you a lot of good luck in finding your gears.

[Mackey]

Update. I fixed the clock some weeks ago, I had the broken gear made. I'll be posting pictures and a full video soon.

I just saw a GG1632 motor on eBay. Looking very similar.

[Matthew]

Finally, after a year, here are the pictures I promised. The video will be soon. Really, really soon. And also the rest of the pictures I have of my beloved RM8400 (before, after, inside and so on) but you will find that in the "Flip clocks on display" section of the forum.

I know, I am a lazy procrastinating bum.

[Detroitsteel]

Well Matthew, that's one fine looking unit you got yourself there ☺
Must be a good feeling finally getting it done...especially considering that there's been a cogwheel replacement with one what had to be made by hand...
This model by the way is the one model I'm really looking for... I think it has a great design...
almost got myself one on a Belgian site...but unfortunately I was to late with my bid 😢

[Matthew]

Absolutely - I still feel that fixing this clock is one of my best repair achievements so far After I first took it apart I realized that if I can fix this, I can fix anything :-D It's been running for more than a year, keeping perfect time. So far so good.

About the design - at first I didn't like it that much, but it was my first flip clock and that was what mattered (flip clocks are rare in Czech Rep.). But as I was working on it I began to like it. Now I like the clock very much, it is my main clock and it has its place of honor on my right speaker where I can see it very well

[Matthew]

Detroitsteel Right now there is an RM 8400 for sale on eBay.de, but it's V E R Y expensive. Search for "Sanyo RM 8400 Klappzahlenwecker."

[Detroitsteel]

Thanks...I'll look into it 👍

[azimuth989]

Any pics of the replacement gear(s)?

[oldclockradios.com]

Hello everybody,

I have recently bought a Sanyo RM 8400 for 300 crowns (13$/10€). It was quite filthy so I took it apart and cleaned it - I also straightened the knobs for setting the time, alarm and snooze time. Something must have fallen on the clock or the whole thing was dropped, the knobs were quite twisted. I found out that someone was poking his little fingers in this, because one of the screws holding the case together is missing and also there are some screws missing on the inside - the circuit board is held in place by only one screw instead of the original three. But not a big deal.

The main problem is that the flip clock is not working. The flipping mechanism is okay, even the light underneath the clock works well. But there is a serious problem with the motor. One of the transmission gears is dead. I took out the motor, I took it apart, I took the transmission apart to have a closer look at the gear. It is a double gear with a strange number of teeth - 60 on the outside and 19 on the inside gear, if I counted correctly. The shaft size is approximately 0.9 mm. The gear is quite destroyed, it looks as if it reacted with some chemical and shrunk in size.

Does anyone know where could I get a replacement gear? I searched the net, there are tons of gears for robotics and models, but it's difficult to find a gear with the correct number of teeth and to figure out the dimensions I would need.

Any help is greatly appreciated. Thanks.

Matthew

PS. Oh, by the way, here are the pictures. Flip clocks are extremely hard to find here, very rare.

This is a really cool model, I just found one this week while on travel in Spain. it's in super condition, just needs some contact cleaning and face plate cleaning. My only souvenirs from Europe are flip clock radios!!