kek@hoxna.UUCP ( K. E. Kepple) (09/03/85)
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< I am sick of this c**p that headlights do not need to be reaimed when
< the bulb is replaced. THINK! Perhaps this is why so many of you drive
< around with misaligned headligts. Let's think about what a sealed beam
< headlight looks like. Even if the glass case was of uniform thickness
< and shape, the filament is little piece of wire held in place by other
< thin pieces of metal. This is supposed to be at the focus of a
< parabola to get a well focused beam. Even minor variations in the
< placement of the filament will change the beam direction. I have
< changed lots of headlights (without disturbing the aiming screws) and
< every time the beam has been way off.
C'mon. Gimmie a break! We all know that the filaments aren't made out
of angle-iron, but if they were as fragile as you imply, they would be
knocked out of alignment when you back out of the garage. Not to mention
those fender-rattling potholes in the pavement. Auto bulbs are designed
and manufactured to withstand all these jolts and vibrations and changes
in temperature, etc. The lighting system is simple enough to be maintained
by gas-station grease monkeys (Can I change the trans-meesh-en, boss?).
If you can't change a bulb without screwing up the alignment, the car
must have a serious problem. If you have had this sort of difficulty on
more than one car, maybe the trouble is with the mechanic! ;-)
What do you use, a hammer and a bottle of Jack Daniels ?
:-)
Ken Kepple
hoxna!kek datakit: ho/bedrock/fred!kek
AT&T-Bell Labs - Holmdel NJ 07733 201-949-6525 Cornet 233
...!{hocda, ihnp4, floyd!vax135!ariel!houti!hogpc}!houxm!hoxna!kekdonch@teklabs.UUCP (Don Chitwood) (09/11/85)
I agree that the act of changing a headlamp can and almost certainly will change the alignment of the beams. That has been my experience everty time I change lamps. The point about the filament and support structure being wimpy points out the difficulties of fabricating such a structure reliably and cheaply, as opposed to pointing out a structural defect that will change your beam alighment with every bump. Besides, the mechanical alignment sytem of most cars consists of springs and, therefore, tensioned adjustment screws. I can change the alignment of my headlights simply by muscling the headlight enough to flex the springs which then take up a new fulcrum point, etc. I always align my lights by finding a warehouse or big parking lot with a wall. Once I've found a level stretch, I point the car at the wall which is a good hundred feet away, and adjust the lights to match the low-beam cut-off. With halogen lights, this is a snap because the cut-off is optically sharp. Don Chitwood Teklabs Tektronix, Inc.