L&R Cleaning Machines

[watchweasol]

Hi John  A wipe down of the post with oil/light grease is a good idea to keep the motor slide free. Making the wavebreaksrs/baffles sounds like there will be a raid on the kitchen utensil front.  They are usually fitted to the lid under the motor so when the motor is inserted into the jar the breakers are also inserted and the lid seals the jar to avoid spillage when in use.

[oldhippy]

1 hour ago, JohnC said:

@oldhippy by baffles I mean the little metal pieces in the bottom of the jars that impede a vortex forming.

Oh those things. Now I know what you mean. 

[JohnC]

A stopgap solution made from an old aluminum pie dish. I think I will try to make some as @nickelsilver
suggests, using wire. Thanks guys

[HectorLooi]

You could look for a star shaped cookie cutter too.

[JohnC]

@HectorLooi
now there's a good idea! I wonder though - don't they need to have some tension against the side? Will a loose object "baffle?"

[JohnC]

A follow up question. Does anyone know whether the motor bearings need oiling on these? I have looked through this thread and I have not seen any mention of it. Thanks. 

[HectorLooi]

On 10/5/2021 at 12:43 PM, JohnC said:

@HectorLooi
now there's a good idea! I wonder though - don't they need to have some tension against the side? Will a loose object "baffle?"

I dunno. I'm baffled.

[oldhippy]

5 hours ago, JohnC said:

A follow up question. Does anyone know whether the motor bearings need oiling on these? I have looked through this thread and I have not seen any mention of it. Thanks. 

I had an old one something like yours that I used for very dirty bits and pieces and I never had to do any maintenance, I used it for nearly 30 years and it was very old when I stated.  Don't know if that helps or puts your mind at rest.  

[JohnC]

@oldhippy
 thanks, yes, that does reassure me actually

[rodabod]

On 10/4/2021 at 2:43 PM, JohnC said:

A stopgap solution made from an old aluminum pie dish. I think I will try to make some as @nickelsilver
suggests, using wire. Thanks guys

Be careful with aluminium and ammoniated fluids - I had an issue once when cleaning clock parts in an aluminium tray and it left deposits on some of the parts. Almost like electrolysis. 

[AndyHull]

Aluminium is quite reactive in some situations. In combination with acids or alkalis, I suspect it may cause some interesting side reactions with the zinc or other metals in brass or bronzes. 

This can be turned to your advantage if you want to clean silver, as a solution of baking soda coupled with some aluminium foil will remove tarnish.

I haven't tried this on silvered dials, as there may be some other effects, but I may add it to my list of experiments.

[JohnC]

@rodabod okay, good to know, thanks. I have not used the machine yet but perhaps I will find another baffling solution before starting. nickelsilver's suggestion about wire seems like a good way to go.

[rodabod]

Did I mention my tip of adding neodymium magnets to the wave breakers? It works. 

[SonnyBurnett]

Hello guys.  I have a L&R watch cleaning machine that works but the speed control rheostat knob doesn't work well.  Does anyone know of a replacement part for this?  or a good substitute?  I found one by Allied a RHS25RE.  It's a 1 amp 25 Ohm and good to 550 volts.  I know the Master machines are 115 volt at 75 cycles.  Would this work?

I would like to get my machine back up and running again.

[jdm]

5 hours ago, SonnyBurnett said:

 the speed control rheostat knob doesn't work well.  Does anyone know of a replacement part for this?

Normally, especially on conservative restorations, these are cleaned . You can drop it in e.g. Isopropil alcohol, then blow compressed air into it 

[JohnR725]

11 hours ago, SonnyBurnett said:

Does anyone know of a replacement part for this? 

Just like in watch repair a general description of I have a watch and it needs a part just doesn't cut it. We would really need to see what the original part looks like and its characteristics like numbers it has on it then we can pick a replacement because conceivably it's not the only one in the universe they ever used and I seriously doubt most people even have a clue of what that uses unless they ever replace there's providing they even have one.

 

11 hours ago, SonnyBurnett said:

RHS25RE

Then for all of us that don't grasp what that is by just the part number I have a picture and it looks expensive. Now that I can see what it is I think the cleaning device up above is good. 

 

https://www.digikey.com/en/products/detail/ohmite/RHS25RE/824061

 

[SonnyBurnett]

12 hours ago, jdm said:

Normally, especially on conservative restorations, these are cleaned . You can drop it in e.g. Isopropil alcohol, then blow compressed air into it 

Well I'd have to un-solder  to take it out, so if I'm going to do that, I'm going to replace it, especially since the brass band around the stem has broken loose.

 

6 hours ago, JohnR725 said:

Just like in watch repair a general description of I have a watch and it needs a part just doesn't cut it. We would really need to see what the original part looks like and its characteristics like numbers it has on it then we can pick a replacement because conceivably it's not the only one in the universe they ever used and I seriously doubt most people even have a clue of what that uses unless they ever replace there's providing they even have one.

 

Well, it's an L&R precision cleaning machine Master model.  The speed control rheostat is the knob in the very front that controls the speed of the motor.  I have it apart at work, I'll take some pics of it but it doesn't have any numbers on it that I remember seeing.

[HectorLooi]

If it is a wire wound rheostat, you don't have to replace it. Just spray it with contact cleaner and work the knob a few times to grind away the oxide layer on the wire coils and it will be fine.

[jdm]

15 hours ago, HectorLooi said:

If it is a wire wound rheostat, you don't have to replace it. Just spray it with contact cleaner and work the knob a few times to grind away the oxide layer on the wire coils and it will be fine.

Correct. I was one of these "take everything apart" guys, now with age better wisdom is growing.

[watchweasol]

Right on Hector contact cleaner will do the job...      If its not broke dont fixit    that's what I was taught   and its true.

[LittleWatchShop]

Back in the old days when you did not have a clicker to change channels on your TV, there was a rotating mechanical channel selector to perform this task (and back then, the reason people bore children was so that they could order them to get off the couch and change the channel!!)  The contacts would oxidize and result in intermittent continuity.  They sold "Tuner Cleaner" spray that you sprayed on the contacts as you spun the channel selector.  I cleaned a lot of tuners during my years as a TV tech.

Yes, I agree that a wire-wound rheostat should work perfectly fine after spraying with contact cleaner spray.  There is, of course, the possibility that the wiper is mechanically compromised...in which case cleaner will not solve the problem.

[LittleWatchShop]

I measured my rheostat and got around 850ish ohms.  Could be a little higher at max resistance.

[SonnyBurnett]

On 11/20/2021 at 7:19 PM, HectorLooi said:

If it is a wire wound rheostat, you don't have to replace it. Just spray it with contact cleaner and work the knob a few times to grind away the oxide layer on the wire coils and it will be fine.

Here is the Rheostat.  I can get the machine at work if more pics are needed. I'm an electrician for a hospital so I have it at work for the repair.  There seems to be a brass ribbon soldered to the wiper that is wrapped around the shaft.  You can't see it well in these pics.  I was concerned about creating a short if it touches the wire.

I haven't tried cleaning it yet and I won't mess with it until I solder on a new cord.  All the old rubber insulation has vulcanized and falls off if you breathe near it.

 

Edited November 25, 2021 by SonnyBurnett

[HectorLooi]

Yes, that's a wire wound rheostat. Looks frightening doesn't it. The coils are only insulated from the metal body by one piece of phenolic paper!

The coils look very oxidized. You might need to sand it lightly before using the contact cleaner.

[Plato]

No way I'd reuse that part, it's already been mucked about with, replace it with a new pot. I bet the knob is a standard size used today.

https://uk.rs-online.com/web/c/passive-components/variable-resistors/potentiometers/?searchTerm=potentiometer