Best Of Keystone Customs announces Angled numberboards for your SW Diesels

[peteski]

On my SW1500 kitbashes with lighted numberboards, I had to address light-leak issues as well. Granted, the plastic used in those was not as translucent but I was able to address it by painting the numberboard box and surrounding areas black first and by using a pretty high value (proper term?) resistor with those LED's to make them pretty dim as numerboards are dimly lit anyway. I think I even had to turn down the brightness level CV's (Zimo decoders) quite a bit on top of that before I could not see any more light leaks while observing it in total darkness.

Hopefully when you do light them up you will post a pictorial of what you did.

As far as resistors go, you can easily get a resistor with a value high enough to make the LED as dim ad you need. It might take one that is 10k or 22k to get there.  All you need to do is experiment.  For that I usually use a potentiometer that has a high enough value to get me even below the desired brightness (with an additional series-connected 1K resistor, so if I accidentally crank the pot to zero Ohms nothing will burn out). Then I adjust it to the desired brightness, then measure the total resistance. I can then order an equivalent fixed-value resistor. Since I dabble in electronics I'm lucky enough to own lots of electronic components already (liek all the standard resistor values from 0.1 ro 10,000,000 ohms, so all I have to do is pick the one I need from a little drawer.

[tehachapifan]

If memory serves, I believe I used 63k resistors for the numberboards in these models but, like I mentioned, I even had to turn down the brightness CV's on top of that....and I think I turned the brightness CV's WAY down too.

[peteski]

If memory serves, I believe I used 63k resistors for the numberboards in these models but, like I mentioned, I even had to turn down the brightness CV's on top of that....and I think I turned the brightness CV's WAY down too.

Um, that is higher than I suspected.  Well then, you could still go higher.  But I'm wondering if it was 6.8k resistor. If we assume DCC voltage of 12V, voltage drop of 1V at the decoder's rectifier, and around 3V at the LED, the current would be (10-1-3)/6800=0.00088A or 0.9mA.  That would be fairly dim but clearly visible. With 68K the LED current would be 0.000088A or 0.09mA or 90 microamps.  That would be really dim.

[Lemosteam]

So here is the latest.  Had to cheat just a little on the overall box dimensions to obtain proper wall thickness for trouble free printing.

The yellow pads are 0402 LED glued to the back wall of course optional.  The shaded front represents a 0.010" thick white styrene lens that the LED's should make glow, with black letters, I think it will work.  There are two magnet wire passages out of the bottom, one on each end.

The spherical depression has a tapered hole out the back to the inside that should allow the ambient LED light inside pass through.  I would fill that with clear substance  letting it dome to act as a lens and into the hole to act as a light pipe.  Clear epoxy?  IDK.

If Joe does not wish to light his, just a lens is in order and a way to "plant" the parts on the shell.

If you guys agree, I will make this design available instead of the original.

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[Chris333]

Whoa     but where's my shoes? 

[C855B]

... The spherical depression has a tapered hole out the back to the inside that should allow the ambient LED light inside pass through.  I would fill that with clear substance  letting it dome to act as a lens and into the hole to act as a light pipe.  Clear epoxy?  IDK.

Tamiya Clear. A little dab'll do ya'.

[Lemosteam]

Tamiya Clear. A little dab'll do ya'.

Mike is that thick enough?

[coosvalley]

I see nothing wrong with it! I look forward to seeing others light them!

Just curious, did you change the box sizing at all, and if so, what changes were made?..Again, just curious, as even the last version was acceptable, and this one seems to be too!

[peteski]

If it was me, I was envisioning utilizing making the opening for the LEDs on the bottom of the housing and simply using the Shapeways-printed resin as the number board "glass"  It is translucent and yet it should diffuse the light from the individual LEDs.  The LEDs would be installed from the bottom and then the entire cavity could be filled with clear resin mixed with talcum powder (to further diffuse the light). Then mask the numberboard "glass" area, paint the rest of the housing until it is light-tight, then decal the number board.

In the current design the modeler has to carefully make the "glass" area to fit the opening in the housing (including rounding the corners).  It can be done but it will have to be very precise.

[coosvalley]

I hadn't noticed that...I would prefer to have something there, to attach decals to.

[C855B]

Mike is that thick enough?

Yes. The transparent colors are quite viscous.

[Chris333]

But some areas of FUD are clear and some are white.

[tehachapifan]

Changes look great! Any chance of getting those leg brackets set on a 45 degree angle to the housing as on the prototype?

But some areas of FUD are clear and some are white.

White or clear would be OK, as the numbers are easier to see with a white backing anyway and I'm sure light will illuminate the white just fine. I tend to agree that not having to add separate "glass" would make things easier.

[peteski]

I also suspect that not many modelers are adventurous enough to install two 0402 LEDs in there. I would make sure there is enough clearance for a single 0603 LED (yes, I know that will most likely result in a hot spot in the illumination.

FXD and FUD (both are the same) resin is a slightly milky translucent resin. It appears white in the areas where it is deposited over a layer of wax while being printed. That makes the resin surface porous, scattering the reflected light making it look white. That surface is not good for decals and it needs to be smoothed out first. A coat of white paint should do the trick and will also act as a diffuser.

[Lemosteam]

If it was me, I was envisioning utilizing making the opening for the LEDs on the bottom of the housing and simply using the Shapeways-printed resin as the number board "glass"  It is translucent and yet it should diffuse the light from the individual LEDs.  The LEDs would be installed from the bottom and then the entire cavity could be filled with clear resin mixed with talcum powder (to further diffuse the light). Then mask the numberboard "glass" area, paint the rest of the housing until it is light-tight, then decal the number board.

In the current design the modeler has to carefully make the "glass" area to fit the opening in the housing (including rounding the corners).  It can be done but it will have to be very precise.

@peteski Unfortunately the housing is not wide enough for an underside insertion of the LED's.  This thing is just over 1mm thick, and by the time you subtract the SW minimum wall thicknesses of 0.31mm it would be damn tough to stuff LED's up there with wires soldered to the back.  plus, the LED would be against the "glass" preventing an ambient illumination.

This design allows the lightboard to be away from the front surface of the LED by just a bit.

I will look at redesigning the opening to be a standard width of evergreen strip so all one has to do is cut to length and round the corners.

I also think it will be easier to paint the interior of the housing using your sliver/black method from the larger opening in the front.  I think I would leave the black off though to allow more reflection inside the housing.

I also suspect that not many modelers are adventurous enough to install two 0402 LEDs in there. I would make sure there is enough clearance for a single 0603 LED (yes, I know that will most likely result in a hot spot in the illumination.

FXD and FUD (both are the same) resin is a slightly milky translucent resin. It appears white in the areas where it is deposited over a layer of wax while being printed. That makes the resin surface porous, scattering the reflected light making it look white. That surface is not good for decals and it needs to be smoothed out first. A coat of white paint should do the trick and will also act as a diffuser.

Pre-wired 0402 LED's are quite plentiful now for very reasonable prices.  I would do it myself, but this is not really a factor anymore IMHO.  I bought 30 for $25+ recently.

Again, the housing is not thick enough for an 0603 for sure.

I hadn't noticed that...I would prefer to have something there, to attach decals to.

@coosvalley , unfortunately that surface will not be smooth enough for decals beacuse it would be inset and would get the wax artifact surface.

I think it might actually be easier to put the decals on the light board after cutting and before installing into the housing.  This also prevents the modeler from having to try to "fit" a cut decal into a recess and allows one to coat the decal lightboard with dullcote before installation.

Changes look great! Any chance of getting those leg brackets set on a 45 degree angle to the housing as on the prototype?

White or clear would be OK, as the numbers are easier to see with a white backing anyway and I'm sure light will illuminate the white just fine. I tend to agree that not having to add separate "glass" would make things easier.

@tehachapifan , yes, if you requested that already, I apologize.  That will be easy to do.  Agree on the white lightboard.  I think it will glow better.

See my reply to Joe for your last point.

Yes. The transparent colors are quite viscous.

@C855B , thanks for the tip on the clear Tamiya.