I used the same speaker enclosure as you … the difference is the fact you are using the light tubes, and that is what is restricting the speaker from fulling fitting up into the shell.
I turn down 3mm LEDs so they fit right into the holes of the shell. This leaves only about 3/16" of LED protruding into the interior of the shell.
I prefer this way of lighting engine headlights. The original polished end of the LED makes a perfect lens for the headlight, and they are extremely bright (if you want them that way) unlike the light loss through a plastic tube.
Somethings’s not in the right place if you have to force the body on even with the speaker removed - the decoder isn’t that tall, and with the weight cut down there should be absolutely no clearance issues over the weight (with speaker removed). If it’s close you can take a little more off the weight, and also gain a small fractio by sanding the bottom of the speaker enclosure. Sounds like there is trouble elsewhere though if it still needs to be jammed on with the speaker removed, it’s interfering over the front weight, or else you have a LOT of excess wires. TCS has some tiny plugs you can use that would allow you to shorten the light wires yet still completely seperate the shell.
I agree with Randy - sounds like you have way too much excess wiring as well. The chassis in my picture is fully wired and operable. The only extra wires not shown are the three wires (white / yellow / blue) from the shell for the headlights to attach.
There is very little clearance inside the RS3 - you need to get a little creative to get those wires out of sight.
Another thing you may have missed … make sure you’ve trimmed off any tabs or posts on the inside of the shell that may be interfering with things. Keep at it - you’re almost there, just need some tweaking. You won’t be as happy with that smaller speaker in the cab.
Lastly, make sure you seal the speaker itself to the enclosure. Those open goles in the corners need to be filled, it will really affect the sound if you don’t. Silicone works great for this.
After I posted I reviewed your photo of the speaker mount and it hit me that none of the weight overhangs the gear tower, just the end of the enclosure. And it looks like the weight is shifted up against the decoder as well. I’ll take another look and see what if any difference it would make for me. I’ll also cut off all the original positioning stubs as you suggested.
I measured from the frame to the top of my speaker enclosure (with it mounted to the cut down weight over the gear tower) and compared it to the inside depth of the body. Major difference…like, nearly 1/4 inch difference without any interference from the LED and leads mounted to the body.
The original light pipe is approximately 1/8" thick and was mounted flat to the body over the original board with the small lamp in the top center of the board. The Soundtraxx decoder snapped into the same holding tabs and but was slightly thicker accounting for the components. This means at best I have just under 1/8" clearance space for my 4 LED connecting wires with shrink tubing over the resistors and 2 speaker wires soldered to the board plus about 5 inches of folded slack in each LED wire pairs to gi
As I mentioned, there is really very little room in the RS3. On this particular RS3 my client wanted the hood fan to be opened up to “let the sound out” much to my disagreement. This opening was ultimately sealed back up from inside once he discovered the sound was indeed weaker with the open fan.
If you look closely, you can see the speaker under the grill - it’s right up there very close to the hood …
For the rear weight, it was cut down to the point when the rear truck was rocked upwards from the rear, it just touched the bottom of the speaker enclosure. It’s a “just fit” to be sure. I’d still be surprised if you would be able to get the speaker up in there WITH the shortened light tube and LED in place, although it might just sneak in the end cavity if your speaker is snuggled up as tight as possible to the decoder.
One trick for avoiding the rats nest of wiring is to run your wiring under the decoder. Feed the wires up through the holes in the decoder and solder in place. Shorten each wire so you have just the length you need and not a bunch of extra you have to tie down somewhere.
Mark… I just measured the depth of the hood again where the speaker sits atop the shortened weight - it’s 23mm from the bottom of the hood to the center top of the hood - the maximum depth to work with. The frame to the top of the speaker enclosure mounted to the cut down weight - leaving only 1mm clearance above the gear tower - is 26mm. There’s absolutely no way to find another 3mm and even if I could there’d be no room for even a turned down LED let alone wiring back to the board.
The only possible difference in your installation is the overall height of your 16mm x 32mm enclosure. The QSI enclosure I have
Still can’t understand why you can’t make yours fit. (?)
I just measured the speaker / enclosure and mine measures 10.36mm total height. I did have to bevel the sides of the enclosure on the top edge to make it fit - it IS that tight. I also measured the interior (don’t forget to include the thickness of the walkway in your calculations) and I get 26.26mm from the bottom of the walkway to the top center of the shell interior.
You did remove those two posts inside the shell that held the original light bar in place ? And you’re sure it’s not hitting your cut down light tube / LED ?
I’m not just guessing this “should” work - I KNOW it should work as I’ve done a few of them just like this.
And I wish it did fit Mark. As I wrote, the depth of the hood where the speaker is mounted is 23mm max measured from the bottom edge of the hood to the top center. I’ve cut the weight to where there’s no more than a mm space above the gear tower and the measurement from the frame to the top of the enclosure is 26mm - there’s just no way to squeeze a 26mm object into a 23mm space. And, yes I did cut off all the protruding stubs although there weren’t any above the enclosure mount. I also sanded the bottom of the enclosure (gained maybe 1/2 mm) and beveled the long side top edges of it to help conforming to the shell curvature.
Looking at your photo again I noticed the flywheels on your engine are brass - mine are steel…and confirmed with a magnetized part grabber. And my motor enclosure looks different than yours including where the brass motor stub is located in your photo. At this point I’ve got to say it appears this isn’t an apples to apples conversion scenario. This leaves the only conclusion being I indeed have an earlier model Atlas RS3 given the steel flywheels vs brass in yours plus what I can tell from
You keep saying you are measuring the interior dimension from the bottom edge of the hood to top center. The shell sits ON the walkway assembly - are you taking into consideration the thickness of the walkway ? That raises the shell up that much more.
I’ve searched my files, but I can’t find te reference right now - but somebody does make a thinner speaker enclosure for that speaker. I’m thinking it was Litchfield Station, but I don’t know if they are still around or not - website doesn’t work.
Another method I would suggest would be to scrap the enclosure and mount the speaker itself with the magnet against the top of the shell - wires can be routed on either side of the magnet. You need to seal the sides and ends of the speaker to the shell so the back of the speaker is air tight to the shell’s interior.
Are we getting mixed up over which end is which? The long hood end - the one with the radiator fan opening - to me is the front since most roads ran them long hood forward. Some didn’t. There’s more space for the speaker under the long hood. I assume that’s where everyone is trying to put the speaker, regardless if you call that the front or the back of the loco.
There should have been some plastic posts there which the original light bar clipped to. For my non-sound ones I just left them, in fact I only cut the light bar back to just inboard of those posts so the light bar is still held in place the same way. For a sound install, they definitely have to be removed and the light bars cut back much shorter, or else removed entirely and the lenses repalced. I’m not big on turning LEDs - it defintiely can be done, just do not disturb the fragile wire whisker inside that runs fromt he one lead to the top of the actual junction inside - hold a clear LED up to the light and you can see it in there. In fact I had an idea, which I might try. If the light bars are cut almost completely off, leaving just the lenses, some Microscale Crystal-Clear would hold the little remnet in place to act as a lense, and some surface mount LEDs attached behind it - Richmond Controls and others have the LEDs with wires already attached. Or since the lens holes re so small - Crystal Clear can actually form lenses and small windows by itself. Doesn;t seem that all that should be necessary though.
Really wouldn’t make any difference, front or rear with the Atlas RS3 - the cavity is identical inside for either end - there are no cab protrusions to be concerned with.
Regardless, I still can’t help thinking something is amiss here. Yes, it is a tight fit, but he is still out by more than a little. (?) The size of the flywheel and motor / cradle have nothing to do with it as they aren’t even near the speaker.
@ OP - Look at this picture below - does your speaker enclosure align vertically with the decoder board the same as this ? …
First, just to confirm for you and Randy I am trying to fit the enclosure to the radiator end of the hood.
To answer your question, yes, my enclosure appears to be at the same level relative to the board. However from this angle it looks like you totally removed the white metal overhanging the gear tower - plus barring distortion in the photo it looks like the weight has a slight slope toward the coupler end so the enclosure rests tilted downward at the coupler end??
I spent 3 hours this afternoon (after I got back from the hobby shop) trying everything I could think of to gain the room needed. The first thing I tried was making a 3/8ths right angle “L” shaped stub from the light pipe leftovers with the 3mm LED attached to one end that was glued it to the top of the body and the downward facing portion of the light pipe just covering the lenses (I flush cut them). Even with the 3mm LED flush against the underside of the body above the enclosure I was still not able to snap the body in place.
The next thing I did was shave the portion of the weight overhanging the gear tower to just over 1mm thickness left. I mounted the enclosure
The only experience I have with the MRC sound decoder was one I put into an Atlas ALCO switcher. Because of the small speaker, the sound quality isn’t all that great. The big improvement was that the decoder package included a headlight for the cab. I would much rather use Soundtraxx decoders for larger units. You have to provide your own speaker. I believe you could mount a 3/4" round speaker in the cab without having to reduce the weight.
I think that’s where you haven’t gone far enough. You need to go down even further, eliminating that shelf and a bit more - I mentioned this in the middle of page two. This is a newer set of weights that screw on, but the approach is identical …
When you are done, all that overhangs the gear tower is the speaker enclosure itself, and it should just clear the top of the gear tower. You’re almost there - don’t give up just yet. You haven’t picked the easiest engine for your first install, but once you have this one under your belt, the rest will be much easier.
Trust me, you’re not alone in the learning curve - I’ve spent many fitful nights trying to figure out how to shoe-horn sound in something. I’ve even accomplished headlights / tail-lights / DCC sound decoder / speaker AND a stay-alive capacitor in a hi-rail truck !
Success!!! … I hope. I trimmed the (2) plastic molded protrusions at both ends of the body where the weights slide up into it, cut off the remaining thin section of the weight overhanging the gear tower, beveled the bottom “legs” of what was left of the weight to tilt the enclosure downward toward the coupler end, then filed the bottom of the end of the enclosure over the gear tower to a slant opposite the tilt in the mount and gained just enough wiggle room at the top of the body where I had the LED mounted while providing just enough room so the
Congratulations ! - I knew you could do it if you just kept at it. You solved a very tight installation and you should be very pleased that you got it to work.
As for the hissing sound, I don’t know exactly what you are hearing, but most engines have an intermittent air release sitting or running. Does it sound like that may be it, or does it it sound like something that really doesn’t belong ?
A better description would be a brief “static” or "crackle sound … again, it’s random, moving or idle. Maybe some motor brush arcing being picked up by the decoder?.. The engine runs quiet otherwise with the sound off with good slow speed control.
Perfect, now I’m all set to do mine. I have about 6 Atlas ones to do, if I put sound in them all, by the time I do the last one I should be able to do it with my eyes closed.
I’ll have to measure the Loksound speaker I have, I’m pretty sure I checked it all out with a caliper to make sure it fit - although I may have measured it for my brass one and not the Atlas.
In the process of all your cutting and grinding, you didn’t get anything in the speaker ? Errant particle in / on the speaker could cause a static sound. Are all your decoder wire connections tight (soldered) ? Positive NOTHING is touching the surface of the speaker ? - even a wire laying lightly against the cone of the speaker will create some odd sounds.
Don’t forget to seal your speaker to the enclosure when you’re all done, even the four corner holes - makes a night and day difference if it isn’t.
