Stripped screw in Colibri winding gear.

[Marco Gilardetti]

Good morning gentle fellows. In the end I purchased the Colibri about which we talked here and opened it to overhaul the motor. The spring has been adapted and doesn't engage very well, but it's not broken. Not without surprise, I had to find out that the problem with winding is in the winding gears, which are (supposed to be) screwed together one inside the other.

If you take a look to the attached picture, from right to left you will see the crank handle screwed into an intermidiate gear (this is where the latch acts) that, in turn, is screwed into that weird alpine-star shaped gear on the left. In other words, all of the protruding axels pointing to the left are threaded and screwed into the next gear.

Well, some idiot in the past overwound the coil with such a senseless brute force that the thread between the intermediate and left gear is completely stripped and the two gears revolve freely one in respect to the other.

The only thing that I may think of is to join them with a point of arc welding on the axle to the extreme left. This seems to me, however, pretty much a last resort as it will be then impossible to disassmble the gear, should I (or the next owner) need to do so for any reason.

Does anyone have a better idea to fix such a damage?

Thanks for any hint.

[gramophone78]

Marco, The Colibri (hummingbird) is a Belgian made portable of high quality. A real shame a previous owner was abusive to it.

I would consider trying "loctite" on the thread first. However, it may not withstand the torque over time. It will certainly not cause any further damage. You just apply it on the threading and tighten then let dry.

http://www.loctite.com/index2.php?cc=it

Your spot welding idea may be the next least expensive way to repair the issue temporarily. So long as you do not damage any other parts (like the crank). This way, if you should find a "parts" machine, you can replace the repaired part.

Having the part fabricated would be somewhat expensive. Also, being in Italy may be a concern regarding logistics.

You may want to watch Ebay for a parts machine. Colibri's do come up for sale in various state of condition. If you can find one in rough cosmetic condition.....you may get a great deal.

As an owner of one.....I consider them to be a great little pocket marvel of engineering.
Best of luck with your repair... .

[Marco Gilardetti]

Hello Gramophone78, thanks for your reply.

Have you ever come across anyone who handcrafts gears and may be able to copy these? I've never heard of anyone who can do this work, unfortunately.

Glue is not an option I'm afraid, as these parts are subject to a long leverage and high torque forces. The thread is so much stripped that the left gear revolves freely as if it were a washer, so basically the glue would have no surface on where to grip. As it seems that nobody has a better idea, I suppose that a pair of welding points are the way to go, unfortunately.

Have you ever opened your Colibri, perhaps? I'm asking because the gear that engages over the speed regulator wormgear has a very weird profile. It's embossed all along the edge. At first I thought it was so horribly worn-out to be unusable. But it seems to engage well on the speed regulator, so perhaps it was intentionally made that way. I've never seen one made with this shape before.

Also, it seems to me that the soundbox is one-piece. I inspected it closely and can see no joins. So how can the gaskets be replaced? By working from the front only? Will the mica diaphragm pass through the front hole and, once removed, give access to the back gasket?

[Curt A]

"Also, it seems to me that the soundbox is one-piece. I inspected it closely and can see no joins. So how can the gaskets be replaced? By working from the front only? Will the mica diaphragm pass through the front hole and, once removed, give access to the back gasket?"

The hardened rubber gasket closest to the front needs to be removed first using a metal pick or something that won't damage the mica. Once that is removed, you can remove the needle bar and mica intact. Then remove the remaining bottom gasket and finally re-assemble it in the same order. The new front gasket will have to be pushed into place after the mica and needle bar are back in place...

[Marco Gilardetti]

All right, thank you! Quite what I figured, except that I thought it was safer to remove the needle bar first. I will rehaul the soundbox as last thing, though: only if I can get the motor to run decently, otherwise there's no reason to touch it.

[gramophone78]

All right, thank you! Quite what I figured, except that I thought it was safer to remove the needle bar first. I will rehaul the soundbox as last thing, though: only if I can get the motor to run decently, otherwise there's no reason to touch it.

Marco, regarding the speed regulator....it has been many year since I looked inside mine. I just can't remember. However, if it works.....don't mess with it.
Although it is hard for me to tell exactly how bad the two gears are (better if in my hands... ). I would still try the commercial Loctite. It is very, very, strong. Just make sure the parts are completely free of dirt,oils,etc.....before you apply it.

It can do no further damage and if it works....a very inexpensive fix. If not, a good jeweler may be able to silver solder it together or you could always spot weld it.

I would leave the reproducer alone unless in really bad condition. I have never rebuilt mine and it sounds very load and clear.
http://youtu.be/THFM-M1IcZk

I know a man in Switzerland that may be able to recreate the parts. However, it would be quite expensive and he is very busy. You could try a clock maker near you. Using your gears....he may be able to copy them..??.
Again, the only other option is to wait for a beat up Colibri to show up on Ebay. Many come up for sale in Europe.

As always...best of luck..

[Marco Gilardetti]

You have a very nice setup. I have rarely seen it coming with its box and user's maual. Sometimes I've seen it with a leather case, but I don't know if that's a genuine Colibri item:

http://www.portable-gramophone.com/coli ... mophone.ws

(IMHO the choice of Tutti Frutti for exhibiting the gramophone is... er... "questionable").

Have you ever considered scanning the manual and create a .pdf?

[gramophone78]

You have a very nice setup. I have rarely seen it coming with its box and user's maual. Sometimes I've seen it with a leather case, but I don't know if that's a genuine Colibri item
Have you ever considered scanning the manual and create a .pdf?

Well, I must say, I have never seen another box. The leather case was indeed offered for the machine as an option. The instruction paper is in five languages.....English,French,Dutch,Portuguese and Spanish.

I think there is someone making copies... .

[Marco Gilardetti]

All right. With the help of my father-in-law, who is more confident than I am with the arc welder, the two gears have been soldered. After filing the welding and cleaning the slag, I could reassemble the motor and finally wind up the spring.

However, the motor still has problems. There is no way to find a good working point for the regulator wormgear: at its best the motor only runs a bit if fully winded and then stops. Don't know. Wherever I look I find traces of keen but not very clever repair attempts. For sure this machine had a lot of problems and probably its days were already over many years ago.

[Marco Gilardetti]

Still seeking to find out what's wrong with the motor. It may be the spring, which has been obviously replaced. Perhaps it's not stiff enough.

I also suspected the regulator gear since the beginning, because of its digged concave shape. I never came across some other gear of such shape, but I also have very little experience with Swiss motors. However, if this was the effect of a terrible worn out, the regulator wormgear would be far off and impossible to engage even with the eccentrics fully rotated. But it seems to engage pretty well instead. Also, the gear seems to be made of a sandwich of brass with a different material in the middle. Can anyone comment on this?