Large Scale Central

SMOKE! Mr. Mallet gets his beard trimmed

Problem Solving
#1

I had a chance a couple weeks ago to bend Navin’s ear, so I asked him about my annoying smoke unit. Symptom: Sometimes it works beautifully. Runs 45 minutes or more and turns off till I add fluid and reset it. Sometimes. Sometimes it runs only 10 minutes or so, then turns off. I reset it and it turns off. I reset it and it turns off. “Is it out of fluid?” “Eww, there’s fluid dripping out the bottom of the loco.” Sometimes I can’t get the smoke unit empty, so it pours out in the box. The loco practically swims in it. I’ve found over time that smoke fluid dissolves CA glue, red locktite and paint.

“How long is the wick? Some were made way too long.” Navin said. He rather griped about it. “Pretty long. You kindof have to stuff it in.” “Oh. It should only be 1/2 an inch.” “You mean 1/2 inch below the element?” “Yes. It should just reach the bottom and spread a little bit.” So I took it apart.

Below the element, or below the brass ring? I measured 1/2 inch from the brass ring 'cause it’s easier to cut more off than to grow some more. I’ll spare you the painful and traumatic surgery photos. Does it work? I dunno. I have a train show all weekend, so I’ll let you know.

#2

I’m real interested to see if this works. I put one of those in an Annie and it works great, for a few minutes.

#3

Get yourself a pipette or something to measure 2 1/2 to 3 1/2 ml of fluid. That’s too many drops to count.

(http://www.outsidetrains.com/mls/pipette.jpg)

I find these at Hobby Lobby back among the science toys.

#4

Capacity of the reservoir is 4.5 ml… of course that is right at the brim.

Fill to 4 ml and do not shake the loco is practical max.

That is from completely empty.

Tom, I see you have posted this on several sites, I would say that there’s been a lot of investigation and testing of these units. (I have personally done somewhere between 9 and 12, forget now), and so has 2 other friends, a while ago.

The length of the wick is not going to affect your run time unless you make it so short it will not wick up the last of the fluid, or you damage it.

The run times you mention are problems with the unit shutting off because it thinks it’s out of fluid… reducing the fluid flow lets the element run hotter and it will shut off sooner, not later.

Again, you really will not impact fluid flow unless you damage the fibers (they can be brittle) or impact it’s ability to get all the fluid.

Let us know your results.

(And I really want to know who told you that the wick was too long)

Regards, Greg

#5

I thought he said that Navin told him it was too long.

#6

Ahh, my mistake, did not see that Bill!!! (I mistakenly assumed the post was identical to the other forums)…

Well, several of my friends returned their smoke units and normally they were either returned with no improvement, or, more often, a new one.

My friend RJ kept sending his back until they all ran over 20 minutes, there was a “pool” of 9 of them!

He also marked them so he could tell when they were the same one returned or a new one.

The shutdown logic and the resistance of the heating element are the factors. I did a lot of measuring, and RJ sent me a number of units. We spent a couple of months testing, and basically concluded that the system was measuring the voltage drop across the heating element to try to know when it got hot, and integrated that over time. I watched the volts and amps with a lab grade power supply that read to hundredths of a volt and thousandths of an amp.

There is a characteristic change in power consumption just before it shuts off.

I believe that there is no calibration of the resistance (thus voltage drop) of the heating element, so small changes in it will change the operational characteristics.

I found no way to repair these except swap elements to see if it would run better, and this did not always work, I suspect there are some other circuit elements involved in the “reading” of the heater that affect this.

Regards, Greg

#7

Now last weekend at Trainfest, the thing worked and worked and worked, turning off 45 minutes after loading it with fluid. You could set your watch by it.

#8

To be clear: not disputing you Tom… but I have a couple of questions:

How many 45 minute cycles did you execute last weekend, as you have said sometimes it works beautifully and sometimes it shuts down in 10 minutes.

Could you duplicate the 10 minute behavior at will or was it random?

Was there any constant condition (same layout, same speed, same power system) that was in common with the times it only ran 10 minutes?

I’m not disputing that it ran last weekend, just interested in more testing and more data.

Regards, Greg

#9

Tom,
THis is the trimmed down one then? Just 1/2" long?

#10

How many cycles? 3 or 4.

Yes, this is the trimmed one.

Sometimes it works just like it’s sposed to. Others…

#11

7 Hours today, just like it’s supposed to. Once, I tought it had quit early, but when I checked the clock, it was right on schedule.

Once I noticed it wasn’t smoking and thought it was a little early. I climbed up the ladder to wait for it to arrive so I could investigate. It was out of battery, not smoke, and I had to take the ladder over to the high bridge where it stopped.