RS3 Sound Install (video link and photos)

[jdcolombo]

Hi everyone.

Yesterday I got my stash of 4 Atlas RS3's in NKP paint.  So my first order of business was to find a way to put sound in these.  It was fairly challenging, because there just isn't much room in these units, and they are not DCC-ready frames.  But I managed to figure out how to stuff everything in, including a 220uf "keep alive" capacitor. 

Again, for those of you that just want to cut to the chase, here's a link to the YouTube video (I'm using the ALCO 244 prime mover sound file for this):

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And here's the explanation.

To get stuff to fit, I had to do a fair bit of frame modification.  FIrst, I needed to cut off the "nibs" that stick out at each end, and then also cut of a bit of the center section of the frame near the rear, where the decoder is going to go (I put the speaker "up front" under the long hood, and the decoder below the cab area).  Here's a photo explaining where the cuts are made:



And here's a photo of the cut frame (notice that this is a photo of the other side of the frame, so the "cut this area out" part is to your left in this photo, not to your right):



I also wanted to create a channel in the top of the frame to stash the wires; DCC-ready frames from Atlas already have this channel, but this isn't a DCC-ready frame, so I had to cut it (I use a Dremel with a diamond cutting wheel to do all my frame mods, though I've got my eyes on the mini-milling machine sold by Micro-Mark).  Here's where I made these cuts:



OK.  Next it was time to wire up the motor.  For this, I flattened out the phosphor-bronze tabs that contact the frame, measured how long the orange and gray wires would need to be, cut them and then soldered them to the motor tabs.  Notice that because the NKP ran its RS3's long hood forward, I've reversed the "normal" wiring for the motor: the gray wire is going to the bottom motor brush, and the orange to the top.



After doing this, I removed the motor from the frame, and wrapped the mounting tabs with a narrow piece of electrical tap to avoid shorts:



Then I reassembled the worms and put the frame back together.  In the next photo, you can see where the decoder sits at the cab-end of the frame, and you can also see the "channel" I cut in the top of the frame:



Next, I wired the pickup wires.  Once again, I used some pieces of the original light boards to help here:



Now it was time to mount the speaker.  There just isn't room for the Knowles Fox in this installation, and anyway I wanted some room to mount a "keep alive" capacitor.  So what I ended up doing was using a Zimo sugar cube 8x12mm speaker in a custom enclosure.  Then I glued a 220uf tantalum chip capacitor to the end of the speaker enclosure, and then glued a surface mount LED for the headlight to the cap.  Because there isn't much height available, the speaker enclosure isn't very high: 4.5mm total.  But it still delivers pretty good sound, and everything fits under the long hood.  Here are two photos of the speaker/cap/LED arrangement:





Now it was just a matter of wiring everything up, using the "channel" to contain the wires.  Here's a final photo of the completed installation:



I'm going to do a second unit, but that's it for the RS3's - in some ways, this was just as hard as doing the VO-1000!

John C.

[skytop35]

Get out of town...........Wow!!!

[garethashenden]

That sounds amazing!

One quick thing though, the body on that piggyback trailer is on backwards...

[jdcolombo]

That sounds amazing!

One quick thing though, the body on that piggyback trailer is on backwards...

OOPS - yep, you're right!  Need to flip the trailer body around!

John C.

[6axlepwr]

John,

That is just sweet! Really enjoying these sound installs you are doing. Really inspiring.

[SSW7771]

Awesome

[bdennis]

Very nice!.
Love the sound of the Alco!

[Kentuckian]

Impressive.  Most impressive.

C&O in Eastern KY.

[BCR 570]

Wow - so it can be done.  Thank you for posting - these will be the smallest engines on my roster.  I assume this is an Atlas/China and not the older Atlas/Kato drive?  Mine will be the latter.

Two questions if I may:

1. Part number and retail source for the Zimo speaker

2. Part number and retail source for the capacitor.


Many thanks,

Tim

[reinhardtjh]

John,
  You're fast becoming my hero!  Looking down the list of locomotives I'd want to add sound to and you've done some of the most challenging ones: Atlas RS-1/RS-3, RS-11, GP7, VO-1000 and FVM GE ES44 are all on my want to do list.  So thanks!  Keep up the great work!

[keeper]

That sounds amazing!

+1

Thomas

[jdcolombo]

Wow - so it can be done.  Thank you for posting - these will be the smallest engines on my roster.  I assume this is an Atlas/China and not the older Atlas/Kato drive?  Mine will be the latter.

Two questions if I may:

1. Part number and retail source for the Zimo speaker

2. Part number and retail source for the capacitor.


Many thanks,

Tim

Hi Tim.

Zimo speaker is available from Litchfield Station, here:

http://www.litchfieldstation.com/xcart/product.php?productid=999007668&cat=436&page=1

If that link doesn't work, click on "Speakers" and then "Sugar Cubes" - this is the 8x12mm sugar cube.

I think other folks sell it too.  I've been looking for a bulk supply for this speaker, but no luck so far - Star Micronics will make me 1000 of them via special order from Newark Electronics at $2.70 each . . . but that's a few more than I need 

The speaker comes with a molded enclosure attached to the top of the speaker with some sort of double-sided tape (at least mine was).  I removed that enclosure, and then built one of my own around the speaker using my usual speaker-wrapping techniques.  But this enclosure can't be very high - I measured something between 4.5 and 5mm; essentially, the height of the speaker can't exceed the height of the center part of the frame.   I'd recommend taking some measurements after you do the frame mods to make sure you don't get the enclosure too high (and don't forget to add the thickness of the bottom of the enclosure to the sides).

The capacitor I used in this install was a Kemet, but Digikey no longer carries the Kemet caps that are only 3mm high (the last ones I ordered, which I thought were the same part number, ended up 4.3 mm high, which is fine for many uses, but not this one).  So I just ordered 20 of these, made by AVX:

http://www.digikey.com/product-detail/en/F931C227MNC/478-8258-1-ND/4005790

The part number is 478-8258-1-ND, and these are 3mm high (7.3 long, and 4.3 wide, which is the same as the Kemet that I used in this install).

A couple of other notes.  I did have to thin the shell just a tad.  My micrometer told me that the inside of the shell was 10.2mm; as you know, the ESU is 10.6, so I sanded a bit on the inside.  There's plenty of shell thickness in that area (around the cab), which makes it a little less nerve-wracking. 

I wired up the keeper cap with solid 30-gauge "wrapping wire" available from Radio Shack, but any thin wire will work.  I routed the wires around the sides of the speaker and taped them in place with some kapton tape.  Since the speaker with its enclosure is only 9mm wide, the wires fit nicely around the sides (in fact, I could have wired the LED this way, too, instead of routing the wires between the frame halves, which always makes me nervous about the possibility of them rubbing and shorting somewhere, since this is magnet wire with a lacquer insulation).  The + side of the cap gets wired to the blue common wire.  The negative side of the cap goes to the pad on the other side of the decoder directly opposite the blue wire pad.  If you look at this side of the decoder, you'll see a gold pad without any solder, and then next to it right at the edge of the decoder is a pad that has some solder.  The pad with the solder is where the negative lead from the cap goes, and you'll need to cut away enough of the protective plastic to get to it.  Not a big deal - since the pad is right at the edge of the decoder, it's easy to solder a wire to it without worrying about messing something else up.  Pretty thoughtful engineering by the ESU folks.

I honestly haven't had much trouble with the units I've done without caps, but I noticed that when doing very slow-speed switching moves, I'd get a few dropouts on my VO-1000 (I'm going to add a cap to it at some point).  So I decided that going forward, I'm going to add a keeper cap to any sound-equipped unit that I might use for switching duties.  The RS-3's probably will get assigned to either a local train or switching duty at Bellevue Yard, so I wanted to add a cap to them.  A single 220uf cap completely cures any dropouts, at least for me.  I won't retrofit caps to my road units, because they just don't have issues rolling down the mainline.

John C.

[primavw]

Another great install! I just ordered my first Loksound and am currently browsing speakers

[BCR 570]

Hi Tim.

Zimo speaker is available from Litchfield Station, here:

http://www.litchfieldstation.com/xcart/product.php?productid=999007668&cat=436&page=1

So I just ordered 20 of these, made by AVX:

http://www.digikey.com/product-detail/en/F931C227MNC/478-8258-1-ND/4005790

The part number is 478-8258-1-ND, and these are 3mm high (7.3 long, and 4.3 wide, which is the same as the Kemet that I used in this install).

Thank you John - I have ordered for my future RS-3 installations. 

I think I am going to use my NAR GP9 for my first install as it uses an Atlas/China drive which is no doubt identical to the GP7 install you did.  I will have to order a Micro Select decoder with the right sound and I am wondering for a GP9 which version of the 567 sound file I should order?

Thanks,

Tim

[peteski]

MBK also started carrying Zimo speakers.  They are out of the 8x12x6, but they have plenty of 8x12x8 speakers.
http://www.modeltrainstuff.com/Zimo-Small-Speaker-Sound-Chamber-p/zmo-ls8x12x8.htm