Strange winding issue

[GabrielePfr]

Hello all, I hope one of you has already had this issue and will be able to help. I recently replaced a broken HMV 99 spring, and when I wind it, it feels perfectly fine, with resistance building ever so slightly, but then it seems it releases/ unhooks, and all the resistance is gone, it feels like the spring unwound completely. However, if I release the turntable, it spins for quite a bit. So I guess the spring doesn't unhook? Then if I wind it again, it takes the exact same amount of winds till the same happens.
I opened up the drum a few times and it seems the spring hooks on fine. I'm just clueless what this issue could be.

[Mormon S]

Make sure the crank is the correct size and that the threads are in good shape. My guess is that the crank doesn't fit well and turns without rotating the spring shaft at a certain point.

Hope this helps
Martin

[Orchorsol]

I had similar trouble changing the spring in an HMV portable a couple of years ago - the end SEEMED to be engaging fine on the mandrel, but would let go every time when about half wound. I had the spring out and back in 4 or 5 times getting more and more puzzled and frustrated, then asked advice from soundgen from whom I had bought the spring (he's endlessly knowledgeable and experienced with these things!) - occasionally a spring change needs a bit more fiddling and fettling, and in my case the hole at the end of the spring needed "dressing" slightly to form a sharper edge.

[soundgen]

I had similar trouble changing the spring in an HMV portable a couple of years ago - the end SEEMED to be engaging fine on the mandrel, but would let go every time when about half wound. I had the spring out and back in 4 or 5 times getting more and more puzzled and frustrated, then asked advice from soundgen from whom I had bought the spring (he's endlessly knowledgeable and experienced with these things!) - occasionally a spring change needs a bit more fiddling and fettling, and in my case the hole at the end of the spring needed "dressing" slightly to form a sharper edge.

yes spring is not being attached to the outside rivet, the rivet may not be "proud" enough or may be worn , the rivet can sometimes be rotated 180 degrees with long nosed pliers to present a new face to the spring , or even made more "proud " by hitting it on the outside with a large hammer , don't hit the gears though

[GabrielePfr]

Hello again! Hard to believe, but that machine has been put away for nearly a year now. Today I got around to opening it up again to finally fix the rivet issue.


Got a question -

Is the rivet supposed to fall out so easily? I only took a push to take it out of the... Part it's inserted into. Could that be the issue why it's not engaging properly?

Thank you all for reading, really hope I can get it running once and for all!

[JerryVan]

Got a question -

Is the rivet supposed to fall out so easily?

No. Does the rivet go through the shaft, so that you can see the it poking through the back of the shaft? If so, maybe you can peen over the back end to secure it in the shaft?

[GabrielePfr]

Got a question -

Is the rivet supposed to fall out so easily?

No. Does the rivet go through the shaft, so that you can see the it poking through the back of the shaft? If so, maybe you can peen over the back end to secure it in the shaft?

Ah. That's good to know. Unfortunately it's completely flush with the shaft in the back.

[Phono48]

Make sure the crank is the correct size and that the threads are in good shape. My guess is that the crank doesn't fit well and turns without rotating the spring shaft at a certain point.

Hope this helps
Martin

The 99 doesn't have a threaded crank, it has three "splines".

[soundgen]

Hello again! Hard to believe, but that machine has been put away for nearly a year now. Today I got around to opening it up again to finally fix the rivet issue.


Got a question -

Is the rivet supposed to fall out so easily? I only took a push to take it out of the... Part it's inserted into. Could that be the issue why it's not engaging properly?

Thank you all for reading, really hope I can get it running once and for all!

The central rivet is just a push fit and does come out easily , your problem is almost certainly you are not locating the outer hole on the drum rivet and it slips off , if this is happening you can see this as it will score the back of the spring