Re: Started on the Roberts Bestone
Posted: Fri Jan 19, 2024 12:18 pm
@CarlosV
@Oedipus
@ Any other Bestone owners
NB: I would also be pleased if anyone else were to chime in with helpful advice.
The Big Question
Does the reproducer rotate up to ease needle changing or is it fixed in place?
The housing has milled reeded edges which suggests that they are there as a grip assist, either to turn the repoducer for needle changing or for assembly/disassembly if the reproducer and back-plate are threaded and screw together.
On my reproducer, the reeded edges would seem to be entirely decorative. The reproducer seemingly cannot turn nor does it screw together. The back-plate is held on with screws.
Discussion:
The design of the reproducer is eccentric and perhaps needlessly complicated with a lot of parts and gaskets.
Here is an exploded view:
The diaphragm should probably be replaced. There is mica separation around the screw hole in the middle. It could be made serviceable by using an old trick I noticed on one of my Aeolian Vocaiion machine diaphragms-light shellac application in the damaged area--thin shellac can be quite searching and can penetrate between the lays of mica. But it is better to replace it-replacements readily available. It is 2 and 1/16 inches in diameter, sadly 1/16 of an inch smaller than any spares I have.
Curious things:
There is no rim gasket between the back-flange and the back-plate. Mine appeared to have been sealed with bees wax. There is, however, a small circular gasket, which if not shrunken, would seal against a smaller insert flange/tube inside the larger exterior back-flange. The insert flange/tube goes into the end of the tone arm and is held in place with a set screw in the tone arm.
There is a slot cut in the back-flange for a pin which is inserted into the smaller insert flange/tube. The outside end of the pin is covered with a small piece of gasket tubing. This pin prevents the reproducer from rotating on the internal flange tube. I am wondering if Bestone was trying to figure out a way to have the reproducer rotate for needle changing and just gave up, inserting a pin rather than a click lock mechanism.
There is another gasket between the back-flange and the insert, one made of gasket tubing.
This reproducer has so very many places of potential leakage. It will be a challenging rebuild, I think.
Corrosion:
I will have to give some parts, the back-flange, screws, etc, a rust remover bath.
I don't know what this will do to the plating on the exterior back flange. I may end up sanding it down, filling pits, and giving it a good coat of aluminium rust pait. The paint would match the general aluminim look of the machine.
The screws, easy peasy--rust remover bath and rebluing.
The back-plate, however, cannot go into a rust bath because of the paper Bestone logo glued to it (see above). I will need to be careful and inventive here. Ideas/suggestions?
@Oedipus
@ Any other Bestone owners
NB: I would also be pleased if anyone else were to chime in with helpful advice.
The Big Question
Does the reproducer rotate up to ease needle changing or is it fixed in place?
The housing has milled reeded edges which suggests that they are there as a grip assist, either to turn the repoducer for needle changing or for assembly/disassembly if the reproducer and back-plate are threaded and screw together.
On my reproducer, the reeded edges would seem to be entirely decorative. The reproducer seemingly cannot turn nor does it screw together. The back-plate is held on with screws.
Discussion:
The design of the reproducer is eccentric and perhaps needlessly complicated with a lot of parts and gaskets.
Here is an exploded view:
The diaphragm should probably be replaced. There is mica separation around the screw hole in the middle. It could be made serviceable by using an old trick I noticed on one of my Aeolian Vocaiion machine diaphragms-light shellac application in the damaged area--thin shellac can be quite searching and can penetrate between the lays of mica. But it is better to replace it-replacements readily available. It is 2 and 1/16 inches in diameter, sadly 1/16 of an inch smaller than any spares I have.
Curious things:
There is no rim gasket between the back-flange and the back-plate. Mine appeared to have been sealed with bees wax. There is, however, a small circular gasket, which if not shrunken, would seal against a smaller insert flange/tube inside the larger exterior back-flange. The insert flange/tube goes into the end of the tone arm and is held in place with a set screw in the tone arm.
There is a slot cut in the back-flange for a pin which is inserted into the smaller insert flange/tube. The outside end of the pin is covered with a small piece of gasket tubing. This pin prevents the reproducer from rotating on the internal flange tube. I am wondering if Bestone was trying to figure out a way to have the reproducer rotate for needle changing and just gave up, inserting a pin rather than a click lock mechanism.
There is another gasket between the back-flange and the insert, one made of gasket tubing.
This reproducer has so very many places of potential leakage. It will be a challenging rebuild, I think.
Corrosion:
I will have to give some parts, the back-flange, screws, etc, a rust remover bath.
I don't know what this will do to the plating on the exterior back flange. I may end up sanding it down, filling pits, and giving it a good coat of aluminium rust pait. The paint would match the general aluminim look of the machine.
The screws, easy peasy--rust remover bath and rebluing.
The back-plate, however, cannot go into a rust bath because of the paper Bestone logo glued to it (see above). I will need to be careful and inventive here. Ideas/suggestions?