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): [video=youtube;4QVsPpiCLOU]https://www.youtube.com/watch?feature=player_detailpage&v=4QVsPpiCLOU[/video] 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. See next post. John C.
Here's the rest of the installation. 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.
John, You're becoming quite the sound guru. I just finished up an install in an Atlas GP-9 following your guidelines and it turned out fantastic, but it was a little nerve wracking grinding out the shell for clearance. What horn did you use on the RS-3? Sounds fantastic. Bob
Hi Bob. Glad the GP9 turned out well. The first one is always the hardest and yes, sanding the inside of the shell IS a bit nerve-wracking; I'm STILL afraid I'm going to sand right through one, even though most of the time I don't seem to be sanding ENOUGH. The horn is whatever the default horn is for the ALCO 244 sound file. It's probably a WABCO, but I'd have to check what the CV is set for. John
Nice work John! Did you connect one leg of the cap to the little solder pad in the bottom left of the decoder as suggested by ESU? Kyle
Yes. Positive to blue wire, negative to pad on back side of decoder directly opposite blue wire. John
Someone's done his homework.. ;^) I've recently dropped a microselect into a Kato C30-7 and noticed that the caps do help a lot with sound dropouts, at least on my track. Your install looks a lot cleaner than mine though..
I actually don't have many problems with dropouts, even on the units I don't have caps in. But I noticed some on slow-speed switching moves, so I decided that from now on, I'm going to add one. Interesting speaker placement - can't put one there on my RS-3's! John C.
Virtually none. Today's frames aren't made with a lead alloy. They are relatively light by comparison to diesel frames of the early and mid-1990's. I'm not cutting out half the frame, or even a tenth. Maybe 5% on the mods I did to the RS-3 frame, which were extreme compared to my GP7 or SD9 or even the VO-1000. My sound-equipped RS-3 will haul 15 of my NMRA-weighted cars (each of which weighs at least 1 oz., some more) around my flat layout that has one 16"-radius 180-degree curve. My non-sound-equipped RS-3 will pull . . . 15 such cars, plus an unweighted caboose that weighs about four-tenths of an ounce. I just don't find this significant. Plus I run my diesels in two- or three-unit consists, as did the prototype NKP. My maximum train length on my layout is 100 inches (about three diesels, 23 40-foot cars, and a caboose). Two diesels will pull this train easily; three is way overkill, but the NKP used 3-unit sets a lot. If I were really concerned about this, I could stuff some Tungsten putty in the sides and top of the cab to regain more weight than I lost. But it just isn't worth the trouble. John C.
I guess as long as you keep your track clean and have enough wheels to pick up power it really won't be much of an issue. As far as speaker placement goes - this was my first sound install and I was under the impression that the speaker should be able to point outwards in order to retain the higher frequencies, in my case the opening is in the tank cover. But listening to your RS-3 video it sounds just fine placed inside the shell. I'll remember that. I was thinking about a NW2 sound install next, but I might just give an RS-3 a try first. Having a small mill sure would be nice though!
