I noticed my P2K 0-6-0 headlight beam ius way off up and to the left. A boxcar coupled to the tender had a light spot just in the middle of the car end; but one coupled to the loco pilot has just a trace of a spot on the upper left corner. Manipulating the bulb inside the smokebox makes no difference. Is there any cure for this? Is it usual, or just luck of the draw, or a flaw in the light pipe? Does it need corrective lenses?
BF&D,
Is it an incandescent bulb or an LED? If you are “manipulating” it then I’m gonna guess an incandescent.
I would start out by just replacing the current headlight bulb. If it is an incandescent, I would also switch it out for an LED. It’s also possible that the lens could be part of the problem.
Tom
I’m pretty sure it’s a bulb, not an LED. Not sure of the voltage - maybe I can get probes in there without shorting it. It looks to me most likely that the problem is the light pipe. If the voltage is OK, I could probably run wires to an LED well back in the headlight itself, so it would still illuminate the number boards; have you ever seen decent lenses or do you have an suggestion for one - a slice of appropriate sized lucite rod?
If the light looks right as it is running, why should you need to adjust the spread/ focus of the beam. You’re running it, those little guys in the model don’t need to see where their going.
Details West and others offer lenses. Give the Walthers catalog a try for more.
Joe
I would suggest that the light pipe is the likely culprit. There may be a bubble in it which is playing foul with the light transmission. I wouldn’t take much distortion to cause the problem because there isn’t a whole lot of pipe directing the light to the headlight lense.
I had a similar problem with a Proto 1000 0-8-0 wherein the headlight was very dim. To solve the problem I tried to mount a 3mm warm white LED into the actual headlight. It didn’t work out very well because the LED was too big and getting the leads to follow the correct route into the boiler was difficult to say the least. However, that was several years ago, before the ready availability of 0603 SMD LEDs. (FYI - 0603 = .060" x .030". SMD = Surface Mount Device meaning that the LED is designed to be soldered directly to a circuit board. You don’t need a circuit board. Wires can be soldered to the SMD LEDs quite easily.) If I was doing the same project today, or if I was in your shoes, I would install a warm white 0603 LED right into the headlight. If you need more details just ask.
Having said that however, you should be aware that the ability of the small 0603 LEDs to project a focused beam of light is not quite as good as the 3mm LEDs, but it will likely be better than what you have. If the original headlight lense is part of the light pipe molding then I would suggest cutting the lense off and polishing the back so it can go back into the headlight. That will help focus the light from the LED.
Dave
Running in the dark, the misalignment is quite apparent - a beam of light hitting buildings off to the side, or the upper left corner of a tunnel portal. Not concerned about the LPB’s - their eyes aren’t painted in,anyway.
GThank you for a detailed and insightful reply - very he;pful in thinking out the problem.
Looking into the light pipe - there appears to be no separate lens, as such, just the complex clear plastic molding that extends from the back of the smokebox front up into and filling the headlight barrel - I can see what looks like it may be a bubble. I was going to send you a pic of the part, but finding such basic support info on Walthers’ site is next to impossible.
If the voltage works - or not, I’ll just wire in a resistor - going with a 3mm warm white LED might be the ticket, although the size of tte headlight barrel may not allow that.
It might work to remove the back part of the light pipe molding and stick an SMD up against the back of the headlight barrel, but I’m not sure that the bubble or other distortion is not in the part that’s inside the barrel.
I’ve seen articles on soldering to SMDs, in Model Railroad Hobbyist most recently.
I’ll look at Details West and others who might have lenses available. And I might see if Walthers will send me a replacement part that hopefully was cast without the distortion.