IS removing the headlamp in and Athearn BB good advice or bad advice?
I guess it Depends on who’s telling it:
This makes no sense since the Athearn motor and bulb are wired in PARALLEL and draw from the same source. I THOUGHT I’d check this theory out and learn “a thing or two” so I tested a late model SD40 T2. (I’d forgotten how to tough it is get the shell off from the tabs, not having done it for a long time). Athearn has made very few changes in these design’s in 50 years.
THE SETUP:
Pure DC power and external v. and a. meters on a dedicated block.
THE TEST:
At a reference 10 volts the motor pulls .6 amps
At a referance 10 volts the bulb pulls .05 amps - less than 1/ 10th and not a factor
2.Stalling voltage was between 4.26 and 5.11 volts - depending on the direction. Starting voltage was 5.6 volts or 6.3 volts depending on direction - typical Athearn.
At STALLING (Max voltage with Engine not moving), I removed the lamp.
No increase of voltage - no inprovement.
At 6 volts (running): connecting and disconnecting the lamp also made no difference.
CONCLUSION: 1. Engine speed is determined by voltage. There were no changes. 2.'Smoothness" is the mechanism overcoming friction - illumination notwithstanding. 3. Removing the headlamp in an Athearn BB darkens the cab, and little else - except maybe to keep the Engineer ‘in the dark’.
D.G.
In theresting conclusion. I’ve considered taking out the light bulb, hiding a White LED in a black construction paper or styrene box with a reflective inside, punching holes for fiber optics, detailign the cab, and then running one light over the center of the cab provding a soft glow instead of the large amount of light. I’d also run fiber optics to the number boards, ditchlight, headlights ect. might work, and it would draw much power either.
A much simpler solution is to get a $10 JSR lighting board (Caboose Hobbies has them) for Athearn engines. They ‘snap’ on. 15 ma bulbs you’ll have to connect up.
I’ve painted the inside of the cab windows black so I don’t get the “cab’s on fire!!!” look with a decent effect & look & still keep the headlights lit.
I’ve removed the bulb in a few of my locos - usually where it lights the cab windows (as in most of their low-nose GP and SD units), and can’t say I’ve noticed any change in running qualities. It has, however, made a major improvement to the looks of the loco as there’s not a massive bulb filling the cab!
I intend to fit Leds in place of the bulbs, rigged so as to only light the number boards/headlights by using brass sheet and tube to make “baffles” (as on the Athearn PA - planning the exact same system on my F7A). Why brass? Leds do get warm (not hot) in use, so I feel the brass should be of help as a heat-sink, especially as some of the leds will be in quite confined spaces. I’ve already replaced the metal strip on top of the motor with flexible wiring - this does make a major difference to both current collection and tracking, as the trucks have more freedom of movement. It transformed an SW7 that previously stalled everywhere (and made an impressive spark show from the pickup strip when I ran it with the shell off!)
I usually just replace mine with a 15v grain of wheat bulb from Radio Shack, and wire it in the same way. The light is a little brighter, and draws about the same as the stock Athern bulb that came out.
ONE Improvement for ‘Stock’ Athearn B/B engines is (4) 15ma. bulbs glued in the holes and a JSR 101 light board ‘snapped’ onto the top of the motor.
It provides directional fwd / rev , and constant (if you want to keep the light in the cab), plus makes better connections. A side benefit is it slows down the overly fast Athearn to a more prototypical speed. ALL for $10 plus bulbs.