L&R Cleaning Machines

[MikeEll]

On 3/26/2015 at 10:06 AM, dalarry said:

hi Adam, i buy from uncle Larry often.

you must remove the hairspring from the balance before cleaning!

DO NOT put the hairspring in your machine.

i have a 3 jar unit myself. works very well.

don't spin too fast, not neccessary

Todd

No reason why a hairspring cant go through the machine.  Just need to make sure its adequately isolated in the baskets.  Follow up with a post-clean dip in hairspring cleaner before drying.

[linux]

On 10/19/2024 at 12:58 PM, LittleWatchShop said:

I have printed lids without threads. However, it would be easy enough to make threaded lids. If I get some free time, I will explore it.

Did you ever get time to look into adding threads to the lids?  No rush at all, although I am curious what 3D machine you're using.  I still thinking about buying a machine even though I shouldn't

I'm actually about ready to use my L&R cleaning machine for the first time.  I've purchased a few HDPE (#2) plastic bottles off of Amazon to capture the fluids (in my case naphtha and IPA) after cleaning to save them.  They have real lids!  It's be nice to just be able to cap the big wide-mouth L&R jars and not have to do transfer operations.

Also, not knowing anything about the 3D world, did you have to write a program for the lids or did you find something similar and tweak it from there?

[LittleWatchShop]

On 11/9/2024 at 10:03 PM, linux said:

Did you ever get time to look into adding threads to the lids?  No rush at all, although I am curious what 3D machine you're using.  I still thinking about buying a machine even though I shouldn't

I'm actually about ready to use my L&R cleaning machine for the first time.  I've purchased a few HDPE (#2) plastic bottles off of Amazon to capture the fluids (in my case naphtha and IPA) after cleaning to save them.  They have real lids!  It's be nice to just be able to cap the big wide-mouth L&R jars and not have to do transfer operations.

Also, not knowing anything about the 3D world, did you have to write a program for the lids or did you find something similar and tweak it from there?

I designed a lid and now have an stl file.  I have attached it here.  Replace the extension ".pdf" with ".stl"

It is a little tight, but works.

LR screw on lid-Body.pdf

[linux]

Ha, very cool and another reason to dive down yet another hobby rabbit hole.  Hmmmm.

Thanks.

Oh, and what CAD program do you use?  Asking for a friend

[LittleWatchShop]

FreeCAD

[Curiouscalibre]

Hi all, hoping someone here can help me. I have a previously working L&R Master that had been restored with the reversing mod and I was working on wiring in a fuse and a power switch when I lost my pictures of how it was wired. Currently how it's shown is the best I've been able to do where the heater lights appropriately but the motor runs no matter the position of the direction switch.  I also have to turn it off quickly bc the Rheostat gets way too hot. I know this machine worked correctly before disassembly so hoping its just something I'm missing.

[LittleWatchShop]

10 hours ago, Curiouscalibre said:

Hi all, hoping someone here can help me. I have a previously working L&R Master that had been restored with the reversing mod and I was working on wiring in a fuse and a power switch when I lost my pictures of how it was wired. Currently how it's shown is the best I've been able to do where the heater lights appropriately but the motor runs no matter the position of the direction switch.  I also have to turn it off quickly bc the Rheostat gets way too hot. I know this machine worked correctly before disassembly so hoping its just something I'm missing.

The proper way to figure this out is for you to buzz out all of the wiring and draw a schematic. One of us might get lucky, looking at your pictures, but you need to do the upfront work. Then you will have accurate documentation. Alternatively, disconnect everything and rewire it correctly. I have posted schematics somewhere here. You need to add the reverser to my schematic, though.

[Curiouscalibre]

Sure thing, I followed this schematic online as it is the same reverser referenced where it was posted.

Edited December 1, 2024 by Curiouscalibre

[Curiouscalibre]

ignore the pictures, realized I posted some older ones, but the schematic I followed exactly. My symptoms are the reverser runs, heater runs, but motor can run if I have the speed all the way up but when it's in reversing mode it just kind of slows to stop and the rheostat gets very hot even at full speed (no resistance). Motor was prev rebuilt/rewound.

[Curiouscalibre]

Welp, I think I figured it out, I tried powering just the motor and no luck. Tested the resistor inside the motor cavity and it measures 240ish ohms which I think is correct based on what I've seen online. My current guess is it's something with the motor shaft/rotor or the stator/windings. At this point I'm above my head so probably just going to part it out unfortunately unless someone has an idea.

[AndyGSi]

You could try removing the reversing circuit and just wire the motor forward as standard.

[Geotex]

If the motor is stock (re)wired and the only mod that was performed was adding the auto reversing gadget using the small clock motor and micro switch ratchet, then you should have three leads coming from the motor, one common and one for running in each direction. If you disconnect everything else but the rheostat you can then try running the motor in each direction using the two directional leads temporarily connected one at a time. This will help you find out 1) if you have the rheostat correctly wired and 2) if there is a difference between the two motor windings, showing whether one is bad or not.  

I do know that the eBay seller had sent around revised directions to some people who had purchased the auto reversing kit, so there might be more than one version of that wiring diagram or the wire colors that are called out.

How did you determine the addition of an onboard fuse would be important? You could also address the addition of a redundant power switch and overcurrent protection without internal modification by putting it upstream on the power cord as an inline modification or using an external outlet box. 

Edited December 1, 2024 by Geotex

[LittleWatchShop]

I have a hunch that the bearings on the motor are the problem.  With poor bearings, the motor will have trouble starting at low current.  You have to crank it up to high current to get it started and then back off.  I have seen this behavior.  After replacing the bearings, the motor starts as soon as the smallest current is applied.

Disable the reverser and see how far you must turn the rheostat before the motor starts.  If it is near half scale, bearings are your problem.

[Curiouscalibre]

So just running power to the motor with only rheostat connected I just get humming but no movement. Bearings are fine too and feel perfect.

[Curiouscalibre]

I actually just pulled the shaft and wondering if this is causing the issue. Is there anyway to test the shaft with a multimeter?

[LittleWatchShop]

8 hours ago, Curiouscalibre said:

I actually just pulled the shaft and wondering if this is causing the issue. Is there anyway to test the shaft with a multimeter?

I have refurbished a few of these motors an never seen this red material. Looks like some vestige of repair work. I have never tried to reverse engineer the armature. I

Which motor is this...show a picture of the housing.

[rjenkinsgb]

9 hours ago, Curiouscalibre said:

Is there anyway to test the shaft with a multimeter?

An AC motor with brushes and a commutator is classed as a "Universal" motor.

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

Use probably the lowest resistance range and measure across directly opposite segments on the commutator. Check each pair over 180' rotation; the readings should be fairly consistent.

A sudden drastic change, near 2:1, (or it reading completely open) means one or more of the windings is open circuit.

It may be the winding resistance is too low for some multimeters to give accurate results though, sometimes just a fraction of an ohm.

That's not an exhaustive test, you would need a growler (a magnetic induction device) to test further. 

https://en.wikipedia.org/wiki/Growler_(electrical_device)

 

The other possible fault is a shorted or wrongly-connected field coil. For a normal  single direction universal motor similar to that, the two coils are in phase and in series with the armature brushes, so power goes through the coils to get to the brushes. If one of the coils is reversed or power is only fed to either the brushes or field, or will take excess current and buzz.

For a bidirectional one with three wires, the two sets of field coils must be connected together in series, with the centre point to a brush.

Feeding one or the other coil end and the opposite brush should make it run.

 

(A four or six wire reversible universal motor has the field connections completely separate; the correct combination of field polarity and armature polarity set the direction).

 

Edit:

Just re-reading the question - if it runs OK in one direction but not the other, the problem is almost certainly to do with the field coil connections; either both connected (and cancelling each other) or neither connected when it's not working?

 

[Curiouscalibre]

@LittleWatchShop I'll grab a picture of the whole housing later tonight, its a Master model with 60W motor. @rjenkinsgb currently does not run in any direction just hums.