ROK Challenger - lubricating the idler wheel motor and VU meter.

[JohnnyF]

HI All,

Its been a loooooong time since I have been able to work on restoring the lathe I have, almost a decade in fact. Anyway I have it all apart and I'm wondering about the General Industries motor that spins the idler wheels. It spins ok, but I'd like to lubricate it, and I don't see any obvious points to add the lubricant. There are 4 tiny holes near the bottom of the post - which seems like they could be it, but I'm not sure. I was thinking about pulling the post up - it gives a bit - and then adding the lubricant around the bottom. Has anyone lubricated this motto before?

Next, the VU meter is dead. Any leads on a replacement that will drop right in?

Thanks, it feels good to be back at this.

[EmAtChapterV]

If it's anything like my Model V, each idler shaft should have a divot in the center, which holds a wick that runs down inside and out to lubrication holes.

If the idlers are really gummed up, remove them and clean them and the shafts thoroughly, then add a tiny droplet of oil to their brass bearings and to the shafts before you put them back on. Otherwise, a couple of drops of oil in the divots will carry down. Mine also has felt washers above and below each idler, and the lower ones stay oily for years.

The VU meter is going to depend on what's between it and the amplifier in terms of resistance - 0.8V = 0 dbVU is the modern standard, and if it's a tube amp it's going to be putting out a great deal more than this. Drop-in replacements are going to be tough to find unless you can locate some new old stock.

[JohnnyF]

If it's anything like my Model V, each idler shaft should have a divot in the center, which holds a wick that runs down inside and out to lubrication holes.

If the idlers are really gummed up, remove them and clean them and the shafts thoroughly, then add a tiny droplet of oil to their brass bearings and to the shafts before you put them back on. Otherwise, a couple of drops of oil in the divots will carry down. Mine also has felt washers above and below each idler, and the lower ones stay oily for years.

The VU meter is going to depend on what's between it and the amplifier in terms of resistance - 0.8V = 0 dbVU is the modern standard, and if it's a tube amp it's going to be putting out a great deal more than this. Drop-in replacements are going to be tough to find unless you can locate some new old stock.

Thanks. It isn't the idlers that I want to lubricate, but the motor that spins them. While there is opening in the shaft, I'm unsure that it goes anywhere - or maybe it looks solid because its full of crud.

As for the VU meter, its the original that came on the RA8 tube amp as part of the Challenger model. I'm hoping to find an original one I can drop right in.

[EmAtChapterV]

Minus one point for reading comprehension for me, whoops.

The motor on mine has two little tubes off the side, one at the top, one at the bottom as pictured here. They take a drop of oil every so often, and fold down when not in use.

[JohnnyF]

Minus one point for reading comprehension for me, whoops.

The motor on mine has two little tubes off the side, one at the top, one at the bottom as pictured here. They take a drop of oil every so often, and fold down when not in use.

Ha. It was Monday, so no worries.

I wish mine had tubes, it would make things so much easier. Looking at it, I see no points of entry.

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[markrob]

Hi,

Many of these motors have Oilite bronze bearings that don't need lubrication. Is the motor running badly or making too much noise? If not, then it might be best to leave it alone. Even though you are not supposed to lubricate this type of bearing, if the motor is running badly, you might as well try to hit them with some oil. especially given the age. You should be able to get a drop or two into the bearing sleeves at each end of the motor without disassembling the motor. Don't use WG40 for this as its not really a lubricant. Use a detergent free oil, maybe SAE 20.

Mark

https://en.wikipedia.org/wiki/Oilite

[JohnnyF]

It doesnt running badly, I can just feel a bit of resistance when I spin the shaft, so I was hoping to loosen it up - the same way when you oil the turntable and the platter will spin seemingly endlessly, I was hoping for that.

Thanks for the recommendation of SAE20. I have an electric motor oil which I've used in the past and may give that a shot. Or maybe get it all back together and not mess with it, because the last thing I want to do is destroy that motor because I'm dumb.

[markrob]

HI,

As far as you can tell, is the speed correct? If it runs slower when first powered on cold and then rises to speed as it heats up, that might indicate a need for flushing out the old lubrication and then re-lubrication.

Looks like you motor is not a synchronous type like you would fine on the higher end Presto's. The speed regulation of the simpler AC induction motor is dependent on the load. As the motor ages, along with lubrication drying, you can have more drag and slower speed. I say if its running at speed and not noisy, I'd let it go and just keep an eye on it. You might be able to find someone local that could give it a once over.

Mark