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Need replacement light/LED/lends for F7

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  • Member since
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Need replacement light/LED/lends for F7
Posted by ChrisVA on Monday, November 1, 2021 5:01 AM

Any recommendations on bulb/LED/lens for this?
Internal diameter is 5mm.

Thanks

snout

 

 

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Posted by tstage on Monday, November 1, 2021 7:15 AM

Chris,

There are 5mm LEDs.  Is there no lens in the headlight opening?  It's difficult to tell from the photo.

If there is a lens I would suggest a 3mm "warm-white" or "yeloglo" LED and hand-drill the back of the lens out with a 0.116" OD (#32) drill bit in a pin vise.  (With the pin vise you'll have more control since you only want to drill a 1/4" deep hole - i.e. the length of the clear LED bulb.)  And I would also start out with 3 or more smaller drill bit sizes first to ensure the hole is centered and to remove most of the material before drilling out the final 0.116" OD hole.

The 3mm LED will press fit into the hole - NO glue or any mounting apperatus required!  I would also add black heatshrink to the back end of the LED to minimize extraneous light inside the cabin area.

Do you also need to add a resistor?  1K ohm is the general rule but I would suggest even higher values (e.g. 3K or >) to reduce the intensity of the LED and make the headlight look more prototypical.

Tom

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Posted by richhotrain on Monday, November 1, 2021 7:22 AM

I agree with Tom on this. You do want to use an LED, not an incandescent bulb, but a 5mm LED would be relatively huge and unusual for this application. And, yes, as Tom suggests, warm white or yeloglo would be most appropriate. 

Rich

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Posted by 7j43k on Monday, November 1, 2021 2:11 PM

I will be using acrylic rod/optic fiber for the class lights.  I will attach an LED on the end of the rod, inside.

I've done it to make status indicator lights for reefer trailers, and it works great.

 

Ed

 

PS:  My goodness.  I totally misread this as referring to class lights, not the headlight.

I'll leave it here in case someone is considering doing the class lights.

 

 

I'm pretty sure those engines had twin sealed-beam headlights after they received those horns--horizontally arrayed.

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Posted by Overmod on Monday, November 1, 2021 4:06 PM

On a modrl that nice I'd replicate actual structure.  Use thin sheet or coverslip glass for the 'lens'.  Make the internal reflector out of aluminum rod and turn the OD to a good fit, then form and polish the 'parabolic' shape of the inner reflector.  Cut that off the stock and center-drill from the back side until only the 'scale' bulb-size hole is open in the face of the reflector -- drill out 'behind' to accommodate the 'rest of the story' -- trim the LED if needed so it is bright through the small hole or has a visible clear 'nub'

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Posted by woodone on Monday, November 1, 2021 8:19 PM

Why not just insert a 5 MM LED into the 5 MM hole?

No need for a lens, has the LED has a dome shape so it should look just fine- Not sure why Rich thought the 5MM LED would be too large. A 5 MM hole is a 5MM hole! The LED should just fit.

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Posted by richhotrain on Monday, November 1, 2021 8:24 PM

woodone

Why not just insert a 5 MM LED into the 5 MM hole?

No need for a lens, has the LED has a dome shape so it should look just fine- Not sure why Rich thought the 5MM LED would be too large. A 5 MM hole is a 5MM hole! The LED should just fit. 

Not too large but as I said, "relatively huge and unusual". A 3mm LED would be more common in these locos.

I do think that you would want a lens in place since that would be prototypical on an F7.

Rich

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Posted by hon30critter on Tuesday, November 2, 2021 2:15 AM

woodone
Why not just insert a 5 MM LED into the 5 MM hole?

If I may elaborate, the actual headlight in the F7 was smaller than the 'lens' opening in the shell. That's why folks are suggesting using a 3mm LED. The best appearance would be obtained by installing a 5mm flat 'lens' in front of the 3mm LED. Lenses are available from Laser Kit (American Model Builders):

http://www.laserkit.com/laserkit.htm

7j43k suggested that the headlights should be twin sealed beam units. That could be accomplished by using a pair of 0402 warm white LEDs.

https://www.ebay.ca/itm/123830865927?epid=1956060094&hash=item1cd4e51007:g:-rUAAOSwqrtWneKz

Dave

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Posted by gmpullman on Tuesday, November 2, 2021 5:38 AM

hon30critter
7j43k suggested that the headlights should be twin sealed beam units.

I've done twin sealed beam headlights on a few of my covered wagons and even a few steam engines. B&O was an early adopter of them.

 IMG_8934_fix by Edmund, on Flickr

Note that this is an upgraded E9 so the headlight glass and gasket is on the outside of the housing as opposed to the recessed glass the earlier Es and Fs had.

Detail Associates, HighLiner, KV Models and maybe a few others make adapter plates:

 IMG_8922_fix by Edmund, on Flickr

I flare the ends of 3mm fiber optic tube and make a lens on the end. I do about a dozen then pick the best ones for final use.

 EM1_headlight by Edmund, on Flickr

 BnO_EM-1_headlight by Edmund, on Flickr

It's fussy work but the end results are worthwhile.

Good Luck, Ed

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Posted by Water Level Route on Tuesday, November 2, 2021 5:39 AM

woodone

Why not just insert a 5 MM LED into the 5 MM hole?

No need for a lens, has the LED has a dome shape so it should look just fine- Not sure why Rich thought the 5MM LED would be too large. A 5 MM hole is a 5MM hole! The LED should just fit.

 

Acknowledging this isn't necessarily prototypically accurate, this is what I would do, and in fact have done.  I don't look that closely at the headlight of the locomotive and to me, the oversized coupler is more obvious.  I think it comes down to where your tolerance for compromise sits.

Mike

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Posted by richhotrain on Tuesday, November 2, 2021 6:01 AM

Water Level Route
 
woodone

Why not just insert a 5 MM LED into the 5 MM hole?

No need for a lens, has the LED has a dome shape so it should look just fine- Not sure why Rich thought the 5MM LED would be too large. A 5 MM hole is a 5MM hole! The LED should just fit. 

Acknowledging this isn't necessarily prototypically accurate, this is what I would do, and in fact have done.  I don't look that closely at the headligfront ht of the locomotive and to me, the oversized coupler is more obvious.  I think it comes down to where your tolerance for compromise sits. 

Can you post a photo of your loco? It seems that the LED bulb would protrude out the front of the opening.

Rich

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Posted by woodone on Tuesday, November 2, 2021 8:17 AM

A 5MM  LED will protrude out of the hole in the loco. If you prefer a flat lens, flatten the LED by filing so it will be flat and then polish it. More than likely you will need to use some type of glue to hold in place. I would use a tub/tile caulk so if need be it could be removed.

 

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Posted by tstage on Tuesday, November 2, 2021 8:19 AM

You could always cut off/file down the protruding portion then polish the end to make it look like a lens.  That would take a bit of work though to get it to look right in the headlight housing.

Drilling out the back of the lens and using a 3mm would be quicker to me and NO gluing required.

[Edit: Looks like woodone and I had similar thoughts on that.]

Tom

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Posted by Water Level Route on Tuesday, November 2, 2021 8:45 AM

woodone
A 5MM  LED will protrude out of the hole in the loco.

Mine didn't.  The tip of the dome of the LED comes just to where the lense sits, at least on an Athearn Genesis.  That's how I lost the lense in mine.  I pressed an LED into the headlight opening.  All was well.  Gave it one final snugging into place as I didn't want to glue it or run the chance of it working back, and the lense popped off.  Lost to the floor somewhere.

richhotrain
Can you post a photo of your loco? It seems that the LED bulb would protrude out the front of the opening.

I don't have a photo of it right now, but will try to remember when I get home tonight.  No promises though!  CRS you know. Laugh

It's not perfect having a rounded end on the LED, but it works.  I would prefer a flat topped LED, but didn't have one.

Mike

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Posted by RR_Mel on Tuesday, November 2, 2021 9:54 AM

I used a piece of #226 Evergreen tubing to sleeve the 5mm hole for a 3mm LED in my Cary E7 bodies



The 226 tubing is 4.8mm OD and 3.2mm ID.



A bit of silver paint and it’s good to go.

Mel


 
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Posted by Water Level Route on Tuesday, November 2, 2021 3:45 PM

richhotrain
Can you post a photo of your loco? It seems that the LED bulb would protrude out the front of the opening.

What do you know, I remembered!  Here are my two Genesis F units that I replaced the incandescent bulb with a 5mm LED.  The black one lost the headlight lense, the gray still has its.

  5mm LED Headlights by Michael, on Flickr" alt="" />

  5mm LED Headlights by Michael, on Flickr" alt="" />

  5mm LED Headlights by Michael, on Flickr" alt="" />

You can see the lense is gone if you look close enough, but from a normal distance it really doesn't stand out.  Turn the headlights on and forget seeing a difference.

  5mm LED Headlights by Michael, on Flickr" alt="" />

  5mm LED Headlights by Michael, on Flickr" alt="" />

They even project nicely without the reflector.  Headlights off:

  5mm LED Headlights by Michael, on Flickr" alt="" />

And on:

  5mm LED Headlights by Michael, on Flickr" alt="" />

These are what I'm using.

  5mm LED Headlights by Michael, on Flickr" alt="" />

  Untitled by Michael, on Flickr" alt="" />

Hope this helps.

 

Mike

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Posted by richhotrain on Tuesday, November 2, 2021 4:36 PM

Mike, great set of photos. Thanks for posting. There does not seem to be any protusion of the 5mm LED from the housing. So, let's see what the OP decides to do and what his results turn out to be.

Thanks again.

Rich

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Posted by Water Level Route on Tuesday, November 2, 2021 4:55 PM

Thanks Rich.  I can't even really say for sure that the LED knocked the one lense off.  I may have caused it when I gave the LED one last snug into the opening.  Maybe distorted it just a touch when I did it?

Hoping the OP chimes back in soon.

Mike

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Posted by gmpullman on Tuesday, November 2, 2021 6:05 PM

Water Level Route
It's not perfect having a rounded end on the LED, but it works.  I would prefer a flat topped LED, but didn't have one.

I keep a bunch of flat-top LEDs on hand. They're out there if you do a search for them, for example:

https://www.amazon.com/100pcs-3mm-white-Light-light/dp/B00M7700GS

There's also "inverted cone" type. Not so much suitable for a headlight but for interior structure lighting they diffuse the light a little better than the round-top.

Regards, Ed

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