Continuing my banana whistle adventure.
I began last night with the fix to the jammed armature. I bought a couple of taps, drilled out the three holes 3/32 and tapped 4-40. Fortunately only one of the three posts broke and I put it back together with epoxy.
Thanks to Jagrick for leading me to McMaster Carr. It's an old line hardware supply firm that shipped my order on credit and I had the taps in a few days. A really old fashioned business - how many remember the standard invoice terms of 2% 10 days, net 30 ?
Here's a photo of the result - armature now spins with a loud rattle - not perfect, but at least not jamming.
Talked with Dr. Tinker about pin vs. screw mounting. His take is that Lionel was doing both in 1935-36 and a 392 might have had either of them.
So the motor is running but no whistle sound. Just a faint ghost of whistle tone as the motor starts. Next step take the back off - you can see the four screws holding it. Pried the back off losening the glue with my King Kut. Only one cracked corener - you can see the one in the upper left is cracked and held only by the glue on the cardboard.
Now that I have the back off, the impeller and armature drop right out. So I didn't really need to take off the brush plate to service the brushes and commutator. Brushes come right out with tweezers.
Note that the impeller is plastic. Must have been a repair job, as is indicated by the glue holding things together. Next I hold the whistle up to my mouth and blow ., That produces a good steam whistle tone.
With no chamber obstruction, maybe it's the impeller and now I see what should have been obvious to me at the start of this. The daimeter oft he impeller blades is 1 3/8 and that of the chamber is 1 3/4, a gap of 3/16 in the chamber - and that is why the impeller isn't generating the air pressure to blow the whistle. Just to check, I take apart a more recent whistle and find the chamber diameter is 1 7/16. It looks like the fellow who tried that repair must have not had a working whistle.
Does anyone have an old impeller and can check the diameter ? Is it possible to find one, or should I tell may repair customer that if he wants a working whistle he'll have to give up on the old style and use a standard Lionel whistle ?
