Headlight beam orientation

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Model T Ford Forum: Forum 2011: Headlight beam orientation
Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert E.(Bob) Blackbourn. Gautier, MS. on Thursday, December 15, 2011 - 11:16 am:

Just about ready to install the headlights using new bulbs and sockets. I noticed the filaments appear to be incorrectly aligned. I found some discussions that mention this problem but none that really address the problem. I was thinking about cutting a new slot in the tube that holds the socket and drilling a new hole for the focus screw. Anyone else tried this or other fixes?

Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By George - Cherry Hill New Jersey on Thursday, December 15, 2011 - 01:26 pm:

Bob,
I am curious as you are correct, today bulb's probably do not have to proper focus point to be "correct"

I have tried to research original 1129/1130 bulbs to determine what bulb designers call "Lcl" length without too much success.

The answer to your question is that the difference in "Lcl" between the current bulb offering and original 1129/1130 IS the amount the thimble/focus point would need to shift.

Folks from time to time show they have found an original 1119/1130 and if I could ever get them to work with me for 5 minutes we would have a real answer!

What say you guys?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick on Thursday, December 15, 2011 - 01:56 pm:

There are two filaments. One centered and one offset. Please correct me if I am wrong, but I believe I am correct in assuming that the centered filament is for the high beam and the offset filament is for the low beam and that the offset filament should be on top so that the beam is reflected downward from the upper reflector. In connecting the plug up you simply need to be aware of which wire is which an which goes where. Jim Patrick.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Fred Dimock Newfields NH on Thursday, December 15, 2011 - 02:13 pm:

Whoopeee I know something about filiment alignment!!

The USofA had the filiment aligned parallel with the ground and left to right. i.e. parallel to the lines defining a crosswalk.
The light pattern from this gave a bowtie shaped light beam with a parobolic reflector.
The fluting on the lense then took the the upper left light and put in down to the right so it would not get in the eyes of oncomming traffic.
The fluting also put some of the light toward the edge of the road so the driver could see it.
The high beam was the same but brighter and because it was offset from the low beam it put more light toward the upper left.

The European filiments were also parallel to the ground but followed the axis of the vehicle. i.e. parallel to the line in the road.
The parabolic reflector gave a column of light.
They then placed a shield over the filiment to stop the upper left light from getting into the oncomming traffic - except for the UK where they stopped the light from going to the right.
Lense fluting was added to put some of the light toward the edge of the road.

H4's were the European bulbs -

Today most bulbs are of the European design.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Fred Dimock Newfields NH on Thursday, December 15, 2011 - 02:21 pm:

PS - George - I'm off to Shanghai at the end of Jan and again in early March after spending a few day in San Diego.

Can you believe my luck? I'm going to San Diego while folks in New England are still shoveling snow. :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robert E.(Bob) Blackbourn. Gautier, MS. on Thursday, December 15, 2011 - 02:45 pm:

Jim,Fred,
I'm with you. Problem as I see it is that the new lamp and new socket makes the filaments run vertical rather than horizontal. In other words rotated 90 degrees. This would result in a "straight ahead" for one filament and "left" or "right" for the other filament.

Bob

PS, the '30 Willys Knight my dad owned in New Zealand had the shields in front of the bulbs also. I suspect the lamps were produced in England.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George - Cherry Hill New Jersey on Thursday, December 15, 2011 - 02:56 pm:

Fred,

I too will be returning through Shanghai at the end of January...prob leave thru Newark the last day of Chinese New Year or so. Who knows...maybe we will cross paths for that 13 hour 'lock-down' :-):-) Then again, maybe I can come home thru Tahiti in the spring and we can share notes on how to avoid winter in global warming peculiarities :-)

Good points mentioned on the bulbs and the differences in the 'alignment conventions'. Someday I'll finish my 'Model T bulb spotters & why' paper. It's 99.5% done, just need to find that elusive 'LCL' value of the original 1129/1130 on which the parabolic reflector 'parabola' was based. Someday, I'll get lucky and for 5 bucks, I'll find a box of original bulbs :-):-) I have been up/down/left/right/over/under on every archive that MAZDA Lamp Company ever had in its own archives...yet no luck with the documented 'LCL'...it must have come along later in evolution as a basis. Short of cutting a reflector in half with the laser cutter or EDM and reverse engineering the focal point from the 'curve' I'm sort of stuck and for the most part this comes under this hobbies, 'For who/for what/who cares' view anyway :-)

I am already certain tho' that ANY modern replacement bulb is in fact 'wrong' to take advantage of those things you mention influence what the final 'light' is, and 'where' it goes with stock socket-thimbles and focus screws. Call my project now 'grins & giggles' as there are way too many hours in it for me to take a 'For who/for what/who cares' view now :-):-)

If someone who has the 1129/1130 would just part with one as a 'loan' or even sell me one, the 'spotters guide' and 'why' would be done in less than a week...it IS that close!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Fred Dimock Newfields NH on Thursday, December 15, 2011 - 03:42 pm:

I have a box of old bulbs somewhere in the garage -

If I can remember anything that happened after Jan of 2010.. I'll look this weekend - :-)

The fix for the filiment rotation is easy - turn the T on it's side! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Thursday, December 15, 2011 - 03:57 pm:

I don't even worry about it. I just set the high beam to focus and leave it alone. I very rarely drive at night, and the lights are so much dimmer than modern headlights, that I don't think they will blind anyone. Some of the modern lights should be banned. Those with the blue tint are much brighter than standard lights and usually they are on a jacked up pickup which likes to get right in back and blind the rear mirror, or come toward you. I don't know if those blue tinted lights are on low or high, but they are too bright.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Doug Money, Braidwood, IL on Thursday, December 15, 2011 - 07:44 pm:

Not sure if this helps. LCL refers to LIGHT CENTER LENGTH. LCL is the measurement from the base plane to the middle of the filament (or light field if not a Filament bulb).

LCL measurement I found for Mazda 1129 and 1130 bulbs are 1.25 inches or 31.8mm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Brown on Friday, December 16, 2011 - 08:51 am:

I'm running a 12 volt system on my 25 and can't tell any difference between high and low beam, so I "brilliantly" wired both filaments to burn together. They are nice and bright, but still can't see compared to modern cars.


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