ESU LokSound Micro Select Direct install in Atlas GP38-2

[RBrodzinsky]

After discussions with the client, I added keep-alive caps up front.  3 20V 220uF poly-Ta caps for a total of 660uF of keep alive.
These are AVX caps from Mouser, p/n 581-TCN4227M020R0100

There are two caps, stacked, in the "lightbox", and 1 cap sitting on the porch below the decoder

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[Steveruger45]

Steve, I did look at that, but anything more than 2.5-3mm would then interfere with the front light pipe. It extends back about half the light shield area. Plus the hassle of the motor contacts, I figured the custom enclosure was quickest.  Honestly, setting up for all the in process photos took about the same amount of time as actual assembly; and then add the loading of sound project and tuning/speed curve setup.

Thanks for that Rick. I figured you probably already considered that option and chose not to for some good reason.  BTW I have been checking out my new FVM GP60 and found that even the 73100 is TOO WIDE to slide in the frame contact slots.  It can be made to fit though but will not be a slide in, more like a hard wire job all round.

I have another question.  How do you set up the  aux1 and aux 2 to be the fwd and aft lights using the lok programmer?

Much thanks

[boisecity]

Great install Rick.

I can see where the rear piece of 0.020 styrene is lifting the rear of the board to give more room for the speaker, but I can't see where the styrene is placed at the front. Is it just to the rear of the front contacts?

thanks for sharing
JohnF

[RBrodzinsky]

Great install Rick.

I can see where the rear piece of 0.020 styrene is lifting the rear of the board to give more room for the speaker, but I can't see where the styrene is placed at the front. Is it just to the rear of the front contacts?

thanks for sharing
JohnF

It sits right under the contact point.  One reason it isn't visible is I used black styrene (I had a sheet of 0.010 handy) vs going out to the train shed in the rain to find a white sheet    .    The main portion (of both pieces) is the width of the frame that fits in the contact slots (7.65mm).  I then have a small tab (~1.5mm) cut narrower (~4.9mm) to extend in, under the board, from both ends.

Another small final addition I made was to put an extra piece of 0.060" styrene (I used a 0.060x0.100 strip, about 4mm long) on top of the speaker enclosure extension (over the fly wheel porch) under the board.  There is no circuitry there, and it helps prevent the end of the board being pushed into the speaker if one accidentally catches a corner of the board with the shell  (took me a couple minutes to figure out why the sound "was funny" all of a sudden - no damage, just the board was too close).  Basically, shortens the diving board.

[daniel_leavitt2000]

Funny, even thought I grew up (in Poland) immersed in the metric system, after living in USA for 38 years I am more used to the imperial measurements.  When doing woodwork or larger home improvement projects I do use the fractions, but for N scale I use decimal notation of the imperial measurements. After all, most scratch-building materials (like sheet styrene) come in imperial thicknesses (like 0.020").

I do almost all my modeling in metric.  It's just more precise and easier to convert ratios in my head on the fly. Our cars are made in Japan so I haven't touched an imperial socket wrench in years.

Our steadfast refusal to adapt to world standards is a perfect example of American laziness

Back on topic... Is the a train why the speaker is facing away Fein the enclosure? Does this product better sound?

[jdcolombo]

Back on topic... Is the a train why the speaker is facing away Fein the enclosure? Does this product better sound?

Hi Daniel.

I think your last sentence got a bit garbled, but let me try to answer anyway.

There are two ways to mount a flat cell-phone speaker (actually, this is true of ANY speaker).  You can mount it with the face of the speaker facing inward (into the enclosure), or you can mount it with the speaker facing out.  A speaker by its nature produces the same sound wave from the front and back as it the diaphragm moves in and out (the back wave is 180-degrees out of phase, but it's the same sound).  So in theory you can mount a speaker, any speaker, either way and get the same sound.  However, in practice, one normally mounts a speaker with the front facing out, because the speaker's superstructure (the structure supporting the diaphragm, the magnet, etc.) can interfere with the back wave and cause distortion at certain frequencies.  However, with the cell phone speakers we use in the environment we use them, I doubt it matters much which way you mount the speaker.  There is some evidence that mounting the speaker facing out produces better sound, but there is also some evidence of the opposite.  I tend to mount speakers facing out because that is the way manufacturers test them - if you look at the data sheets for any of these speakers, you will see that they are tested in a 1 cubic centimeter enclosure with the speaker diaphragm facing outward.  But I have used inward-facing mounting when the situation calls for it (usually involving ease of wire routing).

So . . . do what's best for you in the situation you are facing.  The difference in sound, if there is any, is unlikely to be noticed given how these speakers are used in the modeling environment, where nothing is optimal.

John C.

[daniel_leavitt2000]

Yeah that answers the question. I should avoid typing on my cell phone at 5am

[RBrodzinsky]

There is another reason why I prefer, if possible, to mount this way.  By having the wires and solder points inside the enclosure, you eliminate any possibility of shorting the speaker.  One should always ensure that the assembly will prevent this anyway, but a simple precaution like this ....

[peteski]

There is another reason why I prefer, if possible, to mount this way.  By having the wires and solder points inside the enclosure, you eliminate any possibility of shorting the speaker.  One should always ensure that the assembly will prevent this anyway, but a simple precaution like this ....

Actually, it would be the amplifier on the decoder that would short-out (and burn up). Speaker doesn't care if there is a short across it's terminals.    Yeah, I know what you meant - it is me jest being me.

[Steveruger45]

I do almost all my modeling in metric.  It's just more precise and easier to convert ratios in my head on the fly. Our cars are made in Japan so I haven't touched an imperial socket wrench in years.

I too prefer metric in our modeling for pretty much the same reasons.
I do hear though that the good old USA will go metric soon.....we will have 10 inches in a foot 😁

[wcfn100]

I do almost all my modeling in metric.  It's just more precise...

How is it more precise?

Jason

[MK]

I do hear though that the good old USA will go metric soon.....we will have 10 inches in a foot 😁

Hilariouis!!!  I'll have to remember that one!!!!!

[Steveruger45]

Hilariouis!!!  I'll have to remember that one!!!!!

It also works with other measures too.....10 pints in a gallon

[edge8300]

Please make a 3d print of this box, I would buy 20, and I think these could be used in a lot of stock frames, brilliant design. 

Nicely done, Rick.

What are the dimensions of the speaker enclosure?

@Lemosteam:

I ask because John LeMerise might be interested in doing a 3D print for a "generic" enclosure like this.  It might be useful for a bunch of different locos of the same general chassis size/layout as the GP38 (e.g., GP40, GP50, GP60 maybe even the GP35, Alco C420, etc.).   Also, I wonder if that enclosure could have come out another mm or so toward the rear.  I don't know how much room you need on the back shelf for the rear light/numberboard assembly, but that looks like more than necessary.

And I wonder if there is room to stash a couple of keep-alive caps in the "lightbox" up front . . .

John C.

[Lemosteam]

For any interested party, I have designed an enclosure in a two pack for this install similar to @RBrodzinsky 's concept for a 9 x 16 speaker at the request of @cbroughton67 .



https://www.shapeways.com/product/47AN33V3Y/gp-38-40-9x16-speaker-enclosure-2pk