Jump to content

Directional lighting


Recommended Posts

I'm willing to bet there is a simple answer to this but I can't find it.  I have a loco (actually a GWR railbus) which will go in either direction and I wish to add lights to both ends such that when going forward to front lights are white and the rear red. When in reverse the lights should change accordingly but how?

 

Thanks

 

David

Link to post
Share on other sites

Thanks for that but it uses separate LED for red and white. The railcar seems to have only one lamp (or pair of lamps) each end which glows alternately red or white depending on direction of travel. In 12" to 1 foot gauge this is probably a dual filament bulb but the only bi-colour LED I can find is a 2mm one which may prove to be too large.

 

Anyone done this on regular diesel loco for example?

 

 

Link to post
Share on other sites

You need a red/white  3-legged common Anode led. The smallest I have seen is 1.8 mm but you can sit it back to shine through a smaller hole in the body, with a drop of PVA glue as the lens.

 

The common anode (middle) legs connect to the decoder blue positive each one via a resistor - 1K ohm will do and the front white and rear red legs are joined together to operate from the white wire. The rear white and front white are joined to operate from the yellow wire.

 

F0 switches on the lights and the direction dictates which colours show.

 

Older DMUs used a Yellow/Red combo, which you can also get in 3-legged form.

 

Common cathode leds are more readily available but of no use in a DCC fit as you need the positive on the middle leg.

Edited by RAF96
  • Like 1
Link to post
Share on other sites

The real GWR Railcar generally used 3 lights, a pair of white lights either side inline with the buffers and a central red light as modelled in the Dapol DRC

You don't need dual colour LEDs

The actual position varied depending which series railcar and they sometimes carried a normal oil lamp on a bracket.

e.g.

GWR_No.22_AEC_Diesel_Railcar_at_Didcot_G

dapol-4d-011-004-streamlined-railcar-8-g

 

Edited by melmerby
Link to post
Share on other sites
8 minutes ago, melmerby said:

The real GWR Railcar had 3 lights, a pair of white lights either side inline with the buffers and a central red light as modelled in the Dapol DRC

You don't need dual colour LEDs

The actual position varied depending which series railcar and they sometimes carried a normal oil lamp on a bracket.

e.g.

GWR_No.22_AEC_Diesel_Railcar_at_Didcot_G

GWR_Diesel_Railcar_No_4_(23864520449).jp

 

You may well be right, problem is that I can't find an image of the rear of one any where. The Hornby one has one end with the lower lamps painted red. Confusing

 

 

Link to post
Share on other sites
24 minutes ago, rynd2it said:

only bi-colour LED I can find is a 2mm one which may prove to be too large.

 

You can get these

DT0605RW 20pc Pre-soldered litz wired leads Bi-color RED/WHITE SMD Led 0605 DUAL

about 1 to 2 mm square

  • Like 1
Link to post
Share on other sites

An alternative approach is to use fibre-optics.  The fibre/filament is readily available in a variety of diameters.  With those, you can put LEDs along side them (touching, putting a small flat on the fibre helps), or at the inboard end.  Mask them by glue (eg. araldite) around the finished assembly, then paint the outside to stop light leakage where not wanted.  This gives a choice of colour down the same optic.   I used that many years ago fitting lights to some 2mm scale diesels.   

 

- Nigel

  • Like 1
Link to post
Share on other sites

On closer examination, the Hornby version has the lower lights painted silver on both ends, a red light in the middle just below the windscreen and another just above the windscreen not painted. The Lima version is similar but no paint on any of the lights.

 

Now to find out how the GWR actually used them.

 

 

Link to post
Share on other sites
1 hour ago, rynd2it said:

You may well be right, problem is that I can't find an image of the rear of one any where. The Hornby one has one end with the lower lamps painted red. Confusing

 

 

There isn't a "rear", both ends are the same.

There is an A end & a "B" end because the internal layout isn't symmetrical but the cab ends with the lights are the same.

Link to post
Share on other sites
22 minutes ago, melmerby said:

There isn't a "rear", both ends are the same.

There is an A end & a "B" end because the internal layout isn't symmetrical but the cab ends with the lights are the same.

Yes, as I said above.

But how were they used?

 

Link to post
Share on other sites

The white lights always show to the front, a red light to the rear in direction the unit is travelling (either way)

 

As to DCC wiring

The white lights one end and the red light the other are connect to the first decoder function output (white wire) the alternate pair are connected to the next function output ( yellow wire) - which are the default front and rear lighting outputs on a decoder. Blue is common positive

That way you only have two states to consider and the decoder does it automatically. (F0 switches them on/off)

Edited by melmerby
Link to post
Share on other sites
15 minutes ago, melmerby said:

The white lights always show to the front, a red light to the rear in direction the unit is travelling (either way)

 

 

 

 

Yes, I know that but which of the middle lights are used to indicate red, the lower one by the logo or the one above the windscreen?

 

Link to post
Share on other sites
4 hours ago, rynd2it said:

Yes, I know that but which of the middle lights are used to indicate red, the lower one by the logo or the one above the windscreen?

 

The one by the logo is red, AFAIK all others are white.

The white lights approximate to normal loco headlights although the DRCs are usually depicted with the outer pair lit (express passenger).

(I suppose some workings could be considered stopping trains and may need a different lamp arrangement alight)

 

Which period are you depicting?

Under BR the normal practice seemed to be a standard oil lamp for the tail, rather than using the electric lamp.

 

e.g.

https://zenfolio.page.link/iBGHi

 

https://zenfolio.page.link/iXcMx

 

Link to post
Share on other sites
On 31/08/2020 at 21:47, melmerby said:

The one by the logo is red, AFAIK all others are white.

The white lights approximate to normal loco headlights although the DRCs are usually depicted with the outer pair lit (express passenger).

(I suppose some workings could be considered stopping trains and may need a different lamp arrangement alight)

 

Which period are you depicting?

Under BR the normal practice seemed to be a standard oil lamp for the tail, rather than using the electric lamp.

 

e.g.

https://zenfolio.page.link/iBGHi

 

https://zenfolio.page.link/iXcMx

 

That's very helpful, thanks. My model period is likely to be immediate pre or post- WWII, so still GWR, and the two railcars I have are the later ones, not the original streamlined one. One of them is the Express Parcels - I'll check the head codes for that one.

 

Thanks

 

David

Link to post
Share on other sites
4 hours ago, rynd2it said:

That's very helpful, thanks. My model period is likely to be immediate pre or post- WWII, so still GWR, and the two railcars I have are the later ones, not the original streamlined one. One of them is the Express Parcels - I'll check the head codes for that one.

 

Thanks

 

David

I have two of these DRCs

One is the recent Dapol# version which comes with lighting already in place so there is little to set up.

The other is an original Lima version*. I have fitted interior & cab lighting but not yet marker lights.

 

*It's got a replacement Black Beetle motor bogie in place of the awful Lima pancake motor.

# the Dapol one has the option of using a (dummy) tail lamp in place of the red rear light

Link to post
Share on other sites
14 hours ago, melmerby said:

I have two of these DRCs

One is the recent Dapol# version which comes with lighting already in place so there is little to set up.

The other is an original Lima version*. I have fitted interior & cab lighting but not yet marker lights.

 

*It's got a replacement Black Beetle motor bogie in place of the awful Lima pancake motor.

# the Dapol one has the option of using a (dummy) tail lamp in place of the red rear light

I have just obtained a replacement motor for the Parcels version and I'm also adding DCC, the Hornby is DCC ready. And then converting to EM gauge as well.

 

I did find a good link for head codes:

http://www.uksteam.info/gwr/hcodes.htm

 

so two whites would seem appropriate for the Hornby and maybe a single white for the parcels DRC.

 

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.