Refurbishing another L&R cleaning machine

[LittleWatchShop]

Thought I would start a new thread rather than tag on to my last one about a broken motor.

This is my second L&R restoration project.  Harder than the first because of the bad wiring and broken brush housing.  As noted in the earlier thread, I 3D printed the housing fix, and performed a complete rewiring of the motor.

This thing was hacked by some previous owners--not unusual for this old stuff.  The lamp was replaced with a neon one.  The heater appeared to be taken from a coffee machine!!!  Geez!  What a mess it was.  All of that is removed and I have ordered the correct lamp.

This model L&R used a 220 ohm 50 watt resistor as the heating element.  Impossible to find so far, so I may opt for a PTC heater (ordered one from China).  No final decision on that.

The cleaning basket interface is not shown in this picture, but I do have it.  What I do not have is the three-tine spring that interfaces between the spinner and the basket.  I stole it from this unit for the earlier one I restored.  These are impossible to find--at least so far.

I think this was originally black, but not sure.  Should I paint it????

Anyway, it is at a stopping point until I get the needed parts...maybe finish next year.

[Geotex]

Those 220's are huge power resistors and they fetch "collector" prices on eBay when they come through, just like the original L&R jars and lids!  But there is room to solder together two or three smaller power resistors in series to get you to the wattage that you'd like to use as a heater. The voltage drop and the resulting power dissipation is then spread out between them, so you can use components rated somewhat lower than 50W depending on the calculations. When using the small L&R parts basket, it seems that a bit less heat may be fine, especially if you turn it on to preheat a bit earlier in the process. I'm working on an L&R Junior (adding a heater and chimney and rewiring it to allow motor reversal like your Master) and have started out with a 3-resistor 275 Ohm array - it does get fairly hot (~30W of power).

[Vinito]

On 12/2/2022 at 2:55 PM, LittleWatchShop said:

This model L&R used a 220 ohm 50 watt resistor as the heating element.  Impossible to find so far, so I may opt for a PTC heater (ordered one from China).  No final decision on that.

By "resistor", do you mean a specific resistive heating element or will a wire-wound power resistor do?

If the latter, an ebay search for 50W resistor showed these two on the first page. Not 220Ω, but close enough?

https://www.ebay.com/itm/224936453056

https://www.ebay.com/itm/163673519584

And these on any given day: https://www.ebay.com/itm/144468074390

I doubt this is helping, but I'm trying.

[LittleWatchShop]

10 hours ago, Vinito said:

By "resistor", do you mean a specific resistive heating element or will a wire-wound power resistor do?

If the latter, an ebay search for 50W resistor showed these two on the first page. Not 220Ω, but close enough?

https://www.ebay.com/itm/224936453056

https://www.ebay.com/itm/163673519584

And these on any given day: https://www.ebay.com/itm/144468074390

I doubt this is helping, but I'm trying.

The first two will work.  The last one is physically too long.

I finally bought a "collector" resistor and so the issue is behind me.  I also bought one of the Chinese PTC heaters.  It has arrived and can also work.

 

Edited December 28, 2022 by LittleWatchShop

[Geotex]

The original version used by L&R is much wider than the typical wire-wounds you see in tube-era tabletop equipment. Most of the thinner-bore common versions just end up being too long to fit under the chimney of the dryer station if they are built to handle the equivalent load. I have one of the originals (top of the photo) and you can see how squat it is compared to the longer one typical for tube circuits, etc.  I'm saving the big one for a future project so I used an array of smaller resistors in series for a recent Junior refurb. 

[LittleWatchShop]

I am going to use this PTC on my current refurb.  It is longer but will fit well enough I think.  Your solution is fine.  Looks like you went for a higher resistance, but not sure...maybe you put two 75's in parallel and then in series with the 200?

[Geotex]

That looks like a good modern solution!  

Mine is all series wiring, so it's 350 ohms total giving ~40 watts of heat, which seems to be enough for the Junior. The shaft is configured to only mount the small basket, so the mass of rinsed parts won't be large.

These are fun units to rehab. This is an L&R Junior, an entry-level machine with unidirectional rotation, no heater and the old Hamilton Beach "milkshake motor." The wiring was falling apart, the single toggle switch was broken and, believe it or not, when I opened up the motor for a cleaning and lubrication I found a wasp nest inside...

As I started working on it I realized that I wouldn't need all three jar stations because I plan on performing the first rinse separately in an ultrasonic unit. Since this machine had the old school open-frame design, I was able to add a tin can chimney and install the heater (cobbled together from some high-wattage wire wound resistors in my parts bin) to the third jar position. I also rewired the motor so that the brush leads are now brought down individually to a reversing switch. With the installation of a new speed control and a few pilot lights it now has similar functionality to an old L&R Master model.

[LittleWatchShop]

12 minutes ago, Geotex said:

These are fun units to rehab.

Yup.  I have a couple more that I am working on.  So far they have had issues with the brush housing.  I have solved them using 3D printed solutions in addition to turning square brushes to round ones.  The rotor and stator on these things are quite robust...probably last several lifetimes.  The wiring can crumble, so that is the weak point. 

40W is plenty.

[Vinito]

I wonder if something like this could be useful if a guy needed to replace his L&R heating element?

https://www.ebay.com/itm/264676696678

or

https://www.amazon.com/Bestol-220Degree-consistant-Temperature-Thermostatic/dp/B07VHP5RMG

you'd have to search and make sure you get one with the desired specs, but they do make them to suit various voltages and watts. Just thought I'd toss this out there in case it widens the options. There are probably other physical configurations of heating elements that might suit as well.

Edited January 2, 2023 by Vinito

[LittleWatchShop]

1 hour ago, Vinito said:

I wonder if something like this could be useful if a guy needed to replace his L&R heating element?

https://www.ebay.com/itm/264676696678

or

https://www.amazon.com/Bestol-220Degree-consistant-Temperature-Thermostatic/dp/B07VHP5RMG

you'd have to search and make sure you get one with the desired specs, but they do make them to suit various voltages and watts. Just thought I'd toss this out there in case it widens the options. There are probably other physical configurations of heating elements that might suit as well.

I have one that I bought for this purpose.  Have not installed it.  I got a 50W one that uses 110V, so it is a little longer than the one you show.

[joelcarvajal]

On 12/29/2022 at 10:44 PM, LittleWatchShop said:

Yup.  I have a couple more that I am working on.  So far they have had issues with the brush housing.  I have solved them using 3D printed solutions in addition to turning square brushes to round ones.  The rotor and stator on these things are quite robust...probably last several lifetimes.  The wiring can crumble, so that is the weak point. 

40W is plenty.

Can I have a copy of the brush housing/holder STL file?

[LittleWatchShop]

5 hours ago, joelcarvajal said:

Can I have a copy of the brush housing/holder STL file?

PM your email and I will mail it to you.  You have to type: name <at> somewhere.com otherwise this interface will block it.

[Darthkram]

On 1/3/2023 at 9:49 AM, Vinito said:

I wonder if something like this could be useful if a guy needed to replace his L&R heating element?

https://www.ebay.com/itm/264676696678

or

https://www.amazon.com/Bestol-220Degree-consistant-Temperature-Thermostatic/dp/B07VHP5RMG

I used one of those (although in a different spec) to replace the heating element of my National Electric Watch Cleaner and it works great. I turn it on when I start the cleaning process and by the time I'm around to drying it's nice and hot.