L&R Master Watch Machine Wiring- unique case?

[proto57]

I had been looking around for a wiring diagram for my L&R Master Watch Cleaning machine, and found the ones here at the NAWCC. One is posted in this thread:
Electric WW - L & R Master Watch Cleaner Manual Needed

And a picture of the wiring, and other stuff, is posted in this thread:
L&R Master Watch Cleaning Machine Wiring Diagram

Mine is different. I didn't mind, because it works fine (I had to turn a new agitator shaft, and make a new brass thrust bushing for the motor). I cleaned it, repainted it... and yes, I do intend on grounding it. You see it is a very early model... one of the ones with the "milkshake" motor... I think it is a Hamilton Beach... before L&R started building them with more purpose-made motors. And that might be why my wiring is different...

Anyway, I didn't care, except that the agitator rotates counter clockwise (looking from the top). And that does not matter... and maybe it came from the factory like this... but it means the fluids are not driven DOWN into the watch basket (due to the design of the vanes), but pushed UP. So my first question is: Is that normal? I mean, maybe it is a false assumption I had, that the fluid WAS supposed to be forced down through the basket.

Anyway, I only had two wires coming from the motor... white and black. On the models with reversible motors, there are three wires: White, Black and Green. And the old L&R Master wiring diagram... which I copied to my own drawing, below... show this. I even opened my motor back up, to see if someone clipped a wire, making this a one-direction motor. Nope... I can see from the field and brush wiring, this was always wired this way. And the wire from the motor looks original, anyway, and is only white and black... no green in there. Here is a comparison of the two wiring's, with my schematic on the bottom:

So... I see no way to reverse the direction, unless I were to either rewire the motor, or install a bridge recifier and switch, and control the motor by reversing the polarity (I think this could be done, as I believe these motors are AC/DC).

One last thing: I do have the drilled out switch hole in the base casting of the unit, which is where the reversal switch usually goes on these. That is probably the one reason I thought this must have had the ability to change direction, out of the factory.

What do you all think? Does anyone here have an early machine, that is one direction only? And is that direction CCW? And does it matter? Thanks in advance... proto57.

 

[David S]

These are universal motors which as you state mean that they can run on ac or dc. and are polarity insensitive. So I don't think using the bridge rectifier will work.

The top picture is what we would refer to as an "unbalanced" universal motor in that it runs with only one field winding. However as you see the switching for reverse is very easy. We didn't use this configuration since it doesn't have the best commutation and can cause more electrical interference.

The way to reverse the motor shown in the bottom is to bring out the individual brush leads and with a DPDT switch reverse the armature with respect to the two field windings.

David

 

[proto57]

The way to reverse the motor shown in the bottom is to bring out the individual brush leads and with a DPDT switch reverse the armature with respect to the two field windings.

Well thank you much, David. One other thing: Since I would be now altering the direction of rotation when I do this, do you think that I would have any problem with (what I understand as) phasing? The way I believe some motors are wired is to have the brushes slightly out of phase where they would be in a perfect world, because arcing can be diminished by moving them (rotating them from a perfect alignment with the commutator contacts) slightly. But then, if rotated in the opposite direction, this offset phasing of the brushes would be going the wrong way.

But maybe there would is no such phasing in my motor, and the relation of the brushes and commutator would be the same in either direction? If that is OK, then, I will get to work and wire this sucker up, and let you know how it goes.

Thanks again, Proto57- Rich.

 

[David S]

Rich, after I posted I was thinking about direction and its effects. We call it the connection angle and you are correct, that in a motor designed for only one direction there will be a leading connection angle to improve commutation and efficiency. In electric drills that only turned one direction we had a certain angle and for those that were to be used in reverse, we still had a leading connection that wasn't as much as the single direction. This was a compromise since the operation in reverse is usually a lot less than the forward operation. For those that could be operated equally forward and reverse then the motor is wired with a neutral connection angle.

The other thing is cooling. If the fan is a straight radial type then direction is not important, however if it has modified vanes or is an axial type then the cooling can be greatly affected.

You would have to look at your configuration to see if cooling will be adversely affected. As for reverse direction commutation, you could just try and and observe the commutation. I think it would be ok for normal use. Perhaps there is a marking on your motor that could be compared with the marking on one that is know to be reversible?

David

 

[proto57]

Hi David: Thanks for the further information and points.

With this in mind, I opened the motor back up to see if I could simply switch the brush leads to test the opposite rotation. But the leads are not quite long enough, so to do this I would have to un-solder the connectors from the ends, then extend them and route them. That's all fine and good, but I think I'll make sure I have a DPDT switch on hand, so that I don't duplicate work (assuming the opposite rotation works OK).

I may also just leave it be. The reason I might is because it is clearly the way this came from the factory, and for whatever reason they were OK with the counter-rotating vanes and basket. I think I may have been working on an assumption, I mean, that the vanes SHOULD turn clockwise to begin with. But the purpose all along may have been to draw fluid UP through the parts... until they later added the dual-direction motors and switches, on later models.

But I'll still get a switch, and then when I feel like it can decide if I want to modify the machine. Meanwhile it cleans beautifully... no complaints... so really, I'm probably just over-thinking this whole thing.

If I do get back to it, and rewire it, I'll post in this thread. And thanks much again for your help and input.

Rich.

 

[David S]

Rich did you check out the fan? Would be interesting if you could post a pic.

David

 

[proto57]

Rich did you check out the fan? Would be interesting if you could post a pic.

Here is the fan. If it has any angle to the vanes at all, it is very slight.



A few things about that: The fan is on the bottom, where the casting does not have any air holes. Later Hamilton Beach motors do have bottom air holes there, but not the one L&R used on these early machines. So at best, the air in the motor was just blown around down there, causing some to make it out the top holes. In any case, I don't think there is enough angle to make a case for any one direction of rotation.

I'd like to see the rotation of the early HB machines this motor came from. Eleanor from L&R told me, last year, that she thought my machine was from the 1940's, and that, "Yes that was the old Hamilton beach motor. We use to purchase the motor but then we began making our own motors here at the Factory." But from other L&R machines, I think they went to the next model HB motor before making their own. Also, this motor is clearly from the Model 10 milkshake maker:



This machine dates from the 20's through 1930's. And the patent filing date in the 1930's, for L&R, leads me to believe my machine also dates from the 1930's:
US1872812.pdf

Here is my unit, after painting, so you can compare the motor (the yellow is just colored water I put in there for the shot at the time. And I had not yet made a replacement bottle seal plate):




I think it is telling of the small production facilities of L&R at the time, that not only did they need to buy a motor, but their motor mount does not exactly match the graceful decorative curve at the top of the motor casting. You can see the L&R bracket is square on the top corner, not rounded:



Anyway, I'm on a roll now, so I may as well post (for those interested in these machines), some other pics. First of all, these early models had a one-piece cast shaft and agitator. Mine was cracked near the set screw, and was missing an agitator blade! I turned a collar to squeeze the shaft crack together, and made a new blade from scrap aluminum. This, I notched, pinned, and epoxied in place. Here it is, rough, fitted but not yet epoxied:



And shown, completed (new vane at back I think), with reinforcing collar:



Anyway, it didn't work! The problems were that it was too hard for me to balance; and the hole for the motor shaft was too worn; and the damage to the old vane probably skewed the whole thing to the point that I couldn't straighten it... so there was too much vibration. Considering that L&R went to a different design after mine... they went to a separate shaft and agitator... I decided to buy an NOS agitator, and turn my own shaft. This worked well... the picture below shows it... I turned the shaft from 1/2" aluminum rod stock I got at Home Depot ($7 for 3 feet of it). The bottom is turned to fit the agitator casting, and drilled and tapped 8-32 on the bottom for a SS spring screw. The top is closely drilled and bored for a close fit on the motor shaft, and drilled and tapped for the set screw:



The balance is perfect. For those interested (if I haven't lost you all!), here is a pic of turning the above shaft:



The old plastic bottle sealing plate (not shown) was cracked in half, so I made a new one from aluminum plate. The rubber gasket I put on it was not soft nor thick enough to seal completely, so I tried a toilet sealing ring. But that slides in the L&R jars too far... it is supposed to just wedge in. So I'm going to look for another seal... any suggestions?

Hope this long thread will be of interest or use to you, Dave, or others...

 

[Dushan Grujich]

Anyway, I didn't care, except that the agitator rotates counter clockwise (looking from the top). And that does not matter... and maybe it came from the factory like this... but it means the fluids are not driven DOWN into the watch basket (due to the design of the vanes), but pushed UP. So my first question is: Is that normal?

G'Day!

Nope, it is not normal, and, it does matter.

Perhaps a few suggestions on the subject, based on observing the images provided. Judging by the way the basket locks onto the frame, the motor should turn clockwise looking from the top down, or the basket may get unlocked when the motor turns counter clock wise.

With universal motors, one should be able to easily reverse the direction of rotation by switching around the two wires going to the brushes. That is all that needs be done.

Cheers,

Dushan

 

[proto57]

Hi Dushan: Thanks for the input on this...

Nope, it is not normal, and, it does matter.

Well the thing is... the thing which seems to cinch the fact that it left the factory turning counter-clockwise (seen from the top)... is that the brush leads are clearly original and were never long enough to reach to the opposite brushes. I've thought about any other way, from all the input here, that this motor was ever intended to spin clockwise, and I just don't see how. So I think it may be normal... although I did wonder at your next points:

Perhaps a few suggestions on the subject, based on observing the images provided. Judging by the way the basket locks onto the frame, the motor should turn clockwise looking from the top down, or the basket may get unlocked when the motor turns counter clock wise.

Like I said, I did think of this also... that maybe the basket, turning this way, could unhook itself. But think of this: This basket design... the hooks and tensioning spring in this exact orientation... is the same on machines that can turn both ways. And I've never heard anyone complain that the baskets have unhooked in either direction. So I think that even though it seems counter-intuitive to both of us, they are more than tight enough on their hooks that it is not an issue.

With universal motors, one should be able to easily reverse the direction of rotation by switching around the two wires going to the brushes. That is all that needs be done.

I still may do this... but I've cleaned a couple of watches now, and there have been no problems the way it is. So really it would be a fun, but unnecessary exercise I think.