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Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 6:10 am
by Disarmamant
I’m currently restoring an HMV table top machine. I don’t know the model number as there is no label anywhere.

The two spring motor has the the sticking spring problem with clonking noises as the springs unwind. I stripped the motor with the intention of cleaning and re-greasing the springs. However after I removed the two spring drums I found I cannot get them apart.

The cover of the each spring drum appears to be pressed into the top lip of the drum, there are no retaining clips for each of the lids. The covers are flush with the top of each spring drum.

In all the YouTube videos I have seen on line I’ve never seen a spring drum without a retaining clip on the cover. How can I get these apart to service the springs? Anyone seen this before?

Thanks

Martin

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 6:21 am
by Phono48
Can you post a photo? That would answer two questions, the model of your machine and the problem with the spring drums. I can't think of any HMV motor that had sealed spring!

Barry

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 7:19 am
by Disarmamant
Pictures

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Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 8:34 am
by JerryVan
Yes, the covers are pressed in the barrels. You have to press them back out. Hold the barrel with the cover facing down. With a plastic hammer, or rawhide mallet only, strike the edge of the barrel at a 45 degree angle, being careful to hit the barrel edge only, and not the cover itself. When struck, the weight of the spring within will be forced against the cover and pop it off. May take a few attempts. You can also try placing a wood dowel* in the arbor hole and resting it against the inner sleeve that attaches to the spring. Hit the dowel with a sharp blow and that too should pop off the cover.

*(Use a wood dowel with a diameter that passes through the hole in the cover only, and does not simply fall through the hole in the inner sleeve.)

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 10:09 am
by Disarmamant
Thanks for the reply.

I’m assuming that the outer lip is part of the cover, so that striking the lip itself with a hide mallet should force the cover off?

To me it looks like the cover is a flat plate that is pressed into the inside of the spring drum, unless the outer lip is part of the cover plate?

Looking down the bore of inner spring ferrule I can see a small side hole in the bore. I guess I could use a soft metal drift lodged into the side hole to drive the cover off?

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 10:28 am
by Phono48
Disarmamant wrote: Sat Aug 19, 2023 10:09 am

To me it looks like the cover is a flat plate that is pressed into the inside of the spring drum, unless the outer lip is part of the cover plate?

The outer lip is part of the drum. not the cover. You are right the cover is simply a flat disc that is pressed into the drum.

Barry

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 10:42 am
by Disarmamant
I just managed to remove both of the covers. I used my method of a soft metal drift in the side hole in the bore of the spring drive bush. I ground two flats on the end of an 8mm diameter aluminium rod and ground a groove behind the flats. I lodged the bar in the side hole of the drive bush and tapped with a hammer, the plate came off quite easily.

Now the messy bit! Getting the springs and the drums cleaned up. There’s quite a lot of metal particles in the old grease inside the drums, so I’m hoping the springs are serviceable.

Thanks for all the help!

Martin

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 11:18 am
by Oedipus
I've always found the dowel or drift method better than trying to hit the rim with a mallet. But on this particular motor (circa 1920), with its sleeve arbor, I recently opened one by simply putting a screwdriver through one of the slots in the arbor and levering up, as shown (I hope), in the photo attached.

I have never seen metal fragments in a spring barrel -- are you sure they are not graphite?
G18 spring 4.JPG

Re: Sealed spring drums HMV Table top machine

Posted: Sat Aug 19, 2023 11:31 am
by Disarmamant
Looks like fine metal particles to me, but it could be graphite. The original grease is very black, but I suppose it's been in there for a 100 years.

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Re: Sealed spring drums HMV Table top machine

Posted: Sun Aug 20, 2023 9:07 am
by Inigo
Nah! it's hardened dry graphite grease. The springs look great, probably if you take them off the barrels and manage to clean them thoroughly, adding new fresh grease, you can reuse them.