I think I'm beginning to like scenery?!

Today was another day in the roundhouse.

This time it was with #21 the 0-4-0 switcher from Life-Like that draws 1.75 stall amps.

If I was going to be able to use this engine I needed to drop this stall current below 1 amp. I tried adding a 10 ohm in line resistor which dropped the stall amps to just under 1 amp. But here comes the problem. This resistor must dissipate 13 watts of energy and a resistor that large will not fit in the loco! The only other size resistors Radio Shack had were 1/2 watt. The 10 ohm 1 watt variety was out of stock, of course. The 10 ohm 1/2 watt resistor I did the test with got pretty hot when I held the motor to do the test but ran cool during normal operation.

However still not being satisfied with the stall current I went back to Radio Shack and purchased 22 ohm, 33 ohm and 47 ohm 1/2 watt (of course) resistors so I could try different combinations in parallel. The combination 22 ohm and 47 ohm in parallel gives a total resistance of 15 ohms {RT=(R1xR2)/(R1+R2)} and reduced the stall current to just over 1/2 amp and they didn't get as hot during the stall test.

They are now installed in #21 and the engine wiring harness plug has been soldered. The wiring harness plug for the decoder has been soldered to mate up with the engine plug. I still have the speaker harness, tender power pickup harness and the backup light harness to solder and then we are ready for a test!

I noticed an interesting thing during this process. At the time I purchased the Life-Like 0-4-0 I also purchased a Model Power 0-4-0. I tore down the Model Power unit to see if its motor stall current was less but found the same style motor. A different manufacturer but the same basic unit. As a matter of fact the two engines are almost identical with the exception of the motor manufacturer name and the style of the weight. The boiler is identical. The cab is identical. The frame is identical. And the cylinder block and value train are identical. These two units are made by the same manufacturer using the same dies!

As I'm working on #21 #31 is in the process of getting a cam to control the chuff rate. The decoder in #31 is a DSD-090LC which according to the documentation supports a cam. However I could not get it to work so I emailed Soundtraxx. Seems the CV value I need to use is not the one listed in the DSD manual and the DSD-LC manual does not discuss cams. So once #21 is running I will go back to #31 and hopefully get the cam working.

If #21 comes online then #31 will be assigned to mail service and #21 will replace #43 at Thorny Point.

And if all of this comes to pass then I will move over to the replacement for #40 which is a DCC ready Manuta 4-6-2 with a Vanderbilt tender.

If all three of these are operational for the next session we should not have any motive power shortages and we should be able to assign the primary engine to each job.

All of this engine work is beginning to make scenery work look like fun!