ESU LokSound 5 wired in an Atlas FM H16-44 (video added)

[jdcolombo]

Hi everyone.

A friend asked if I would be interested in installing sound in his Atlas FM H16-44 engine.  Sure, I said, thinking this was the Atlas Trainmaster that I had two of sitting on the shelf.  Then the engine arrived, I realized it WASN'T the Trainmaster, with it's vast expanse of chassis to work with, and upon removing the shell, I said "uh-oh". 

The frame on this engine is . . . fragile.  Without the motor, it weighs a mere 19 grams, and the metal is very thin around the motor mount area.  I took some measurements, and concluded that I could just barely fit a LokSound 5 micro wired version if I (1) milled about 1.5mm off the top of the frame; (2) flipped the decoder over so that the Next18 adapter fit over the front "shelf"; and (3) milled a channel in the front part of the frame for the wires to fit in. 

My first attempt was a disaster.  Because of the fragility of the frame, as I was milling it, the mill put too much side force on the top of the frame near the motor mounts, and the frame broke in half.  Lesson learned: I'd need to better support the top of the frame if I was going to make this work, or else use a hand file the next time.

To the Atlas N-scale parts site I went, and ordered new frame halves (actually, I ordered two of each half, figuring that I'd probably screw it up again before I got it to work).  The parts came in yesterday, and this morning I clamped up each frame half individually in my mill, supported the frame on each side with some 1/8" masonite that I could mill right through if need be, and fired up the mill.

Lo and behold, this time I managed to mill the top of the frame without breaking it (I should note that one of the frame halves I got from Atlas was slightly bent; I used the other one, but the fact that one was bent shows how fragile this frame really is).

Then it was time to think of how to mount the components and find a way to add some weight to this thing.  So I did two things.  First, I made a custom enclosure for the speaker out of .75mm lead sheet.  I don't normally do this because lead is toxic and I have to cut it, handle it, even sand it lightly to rough up the surface for CA cement, but it really was necessary this time.  Latex gloves, N95 mask for this part.  (I looked ready to head for the grocery store in this COVID-19 world!).  I also added some lead sheet to the ends of the "shelves" of the engine.  The frame had a sort of "dimple" at the ends to accommodate a 3mm LED for the headlight and rear light, because Atlas decided to get cute and light up the marker lights with another 3mm bicolor LED that sat on top of the headlight LED.  In order to make the install work, and provide some room for extra weight, my friend approved ditching the marker light cuteness.  I replaced the 3mm LEDs with 604 smd LED's, one mounted to the end of the speaker enclosure, the other mounted to the edge of the lead sheet "insert" I made for the frame.

Then I faced one last problem - the decoder was just a hair too wide to fit in the front part of the shell.  The center of the shell was plenty wide, but Atlas made the two ends of the shell thicker.  So, back to something I hadn't done since installing LokSound Selects in my old Atlas GP9's: thinning the shell around the cab area to make it as wide as the center portion.  More than once I wondered if I would end up needing to order a new shell, too, if I made a mistake with my 1/4" Dremel sanding drum.  But this turned out fine.

So . . . here are the results.

The first photo is a top-down view of the installation.  The speaker is mounted on the rear shelf; next to the speaker are 2 tantalum chip caps for keep alive; for power pickup for the decoder, I used some tiny pieces of 1/32" single-sided circuit board wedged in the "fingers" for the original circuit board.  It's nearly impossible to see these in the photo, but they are right next to the caps.  Then comes the decoder, with the Next18 adapter facing down.  I cut off the original plastic wrap, and used some thinner kapton tape for insulation purposes.  At the very far right end you can see a tiny piece of circuit board with two 1K surface-mount resistors for the front and rear headlights.

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This next photo is a side view of the install, showing how the decoder fit in the milled space (I actually milled about 1/8" too far to the left; but the amount of metal I removed was tiny, so I didn't fret much about this - I more than made up for this "mistake" with all the lead sheet I added).

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And finally, here are "head on" front and back views showing where I mounted the new LEDs for the front and rear lights.  If you look closely, you can see where I added the sheet lead in the frame "dimple" in the front and back.
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I'll add a video of the engine in operation later.  Right now, I'm too tired to mess with my video camera!

And I'm not doing another one of these any time soon!

EDIT: OK, here's the video:

John C.

[mmagliaro]

At the risk of derailing this thread...
I am curious about how you are milling this.  Is it in an actual milling machine, and if so, what kind of end mill and what cutting speed are you using to cut the frame?   It seems to me that with a decent sharp end mill, and if you only take, say, .010" or even .020",  off per pass, it should be putting almost no stress at all on that frame when it cuts.    I'm really surprised the frame broke on the first attempt, even though more support is always better.

[jdcolombo]

Hi Max.

It's a Proxxon MF70 mini-mill.  Used a 1/8" coated dual-flute mill from McMaster Carr - almost new, so it should have been pretty sharp.
8000 rpm on the mill, which is the same speed (and same mill type) I've used on at least 50 other frames with no ill effects.

The problem, I think, was a combination of thin metal around the motor mount, lack of support (the portion of the frame I was milling stuck up 1/2" above my milling vise) and perhaps getting a bit too aggressive with the cut depth the first time around (.5mm). This time I went 1/10th mm (.1mm) at a time.  It could also be that the first frame was slightly defective - perhaps not formed well around the rear motor mount, where there is very, very little metal.

These frames, though . . . you can push on one end with moderate force while holding the other end and it will bend.   One of the frame halves I got from Atlas had a slight bend.  I bent it back using not much pressure.  I also had the full frame mounted in the vise the first time around, instead of trying to do each half separately.   The frames halves themselves are $4.85 each from Atlas, so how much metal could there be???

John C.

[RBrodzinsky]

Nice, John. Always interesting to see some of these “too small to do” locos work out.

[Nick Lorusso]

John,
Why didn't you use a direct board? I've done one in the past no issues.

[jdcolombo]

Mostly because of the space (or lack thereof) left for a speaker, and the desire to add weight.  I could have done a board, and mounted a speaker below the end of the board on one of the shelves, but then to get a decent amount of enclosure volume, I'd have needed to mill off the ends of the shelf flat with the phosphor-bronze worm holding "fingers".   And then I would have needed to find space for the keep alive caps, probably in the front shelf, which would have negated using that space for additional weight (I put some additional sheet lead on the front shelf after I took these photos - about an additional 2mm of thickness, raising the front LED and the board with the resistors to the same height as the frame top).  Weight with this engine is an issue, so I wanted to find a way to put in a decoder and ADD weight.  I felt that using the wired decoder with the layout I ended up with gave me the maximum possibility for adding weight via lead sheet everywhere.   

And . . . there are certain things about the LokSound 5 that I find to be worthwhile improvements over the Select.  But it was mostly about preserving as much open space as possible for additional weight.

John C.

[OldEastRR]

We should also note the reversing-color running lights -- which were the "gimmick" that was I guess supposed to make this product popular -- had to be eliminated to get the electronics in.

Personally I think this loco was a big dud for Atlas. Pretty green-red light shifts weren't enough to make up for its many flaws.

[jdcolombo]

On the plus side, I added enough weight that the engine now will pull 25 of my weighted 40' boxcars.  That's 10 better than my VO-1000, which will only do 15.  And it does sound good - the start-up sequence is particularly a hoot.  It sounds like the whole thing is going to blow apart until you finally get a more-or-less even diesel cadence from it.

If one were truly adventurous, I suppose you could install bi-color 402 smd LEDs on each of the marker lights and wire them to the auxiliary outputs of the decoder.  But I'm not capable of adding magnet wire to stock 402 LEDs - hands just aren't steady enough anymore.  And you'd have a LOT of wires going from the shell to the decoder, although I think Rick has done this with some passenger power in the past.

John C.

[RBrodzinsky]

Yeah, soldering to 0402s is a job I always find a reason to put off to another day  LOL.   And I can only do 5-10 in a day, without driving myself nuts.  Doesn't take too long, but after that many, my eyes and back require significant rest.  If I have to do both 0402s and 0603s, I always do the smaller first.  Then the 0603s feel "easy"

[wazzou]

You usaually post videos.   

[jdcolombo]

You usaually post videos.   

OK, you shamed me into it.  Video added to top post.

John C.