C30-7 Sound Install!

[AKNscale]

So recently I did a sound install on one of my SD50s using a 9X16MM speaker and a friend of mine wanted to hear the difference between that speaker and the 8X12mm in my B30s. I changed the file in it to match the 30s and had him compare them. He was very happy with the difference and asked if I could do an install for him in one of his C30s so he'd have sound for a coal train. I agreed and a week later(I think) he handed me a non-dcc ready Kato C30-7 and told me to have at.

Upon opening it up I found this fantastic surprise:

Those of you that have been around a lot longer than me(I got back into MR and "found" N scale back in 2009) probably know of this but I've never seen a decoder in the fuel tank before. I'm quite happy as it has made this much easier and taught me something new. However I'm not too surprised as the guys I model with are all way above my pay grade in the knowledge bank and continue to teach me a lot all the time. Apparently, when older/early generation decoders were installed in the back, eliminating the back light, or in the tank.

Here's the original setup/powertrain:


Here's the tank after I stripped everything out and after I'd been milling here and there. The new decoder fit well with some minor trimming:


Then I started on mounting the speaker. Since I didn't need to mount the decoder in the back I decided the speaker should go back there. Here's where I filed the frame in the back so it's fit:



Hopefully tomorrow I will be wiring and programming

[jdcolombo]

Ah, this brings back memories.  One of my very first decoder installations was a Lenz silver mini in the fuel tank area of an Arnold S-2 back in the late-1990's (1997, maybe?).  I still have those units, but there's no practical way to get sound in them.

The only thing that would concern me about a fuel tank install for a sound decoder is wrapping all the wires around the motor housing.  In addition to the seven wires normally needed for a non-sound install, you have the two speaker wires and if you are using a keep alive of some kind, at least one more wire for that (assuming that you can connect the positive of the keep alive to a blue wire at either end of the loco where the LEDs are).  That's 10 wires.  I guess if you divide them and put 5 on one side of the motor and 5 on the other side, that would be doable.  But that's a LOT of wires.  Will be interested to see how this all goes.

John C.

[AKNscale]

So, got some work done today. With all of the necessary milling done, I started doing the wiring. So far I have the motor hooked up and the wires laid out in their proper spots, so here's how it's set up:

This is the rear of the loco.

The two brown wires are for the speaker, the yellow is for the rear headlight, and the blue is the positive used for the lighting/aux functions. It may be trimmed to the middle of the loco along with the lights' power wires for ease of shell removal.

Here's the front of the loco.

The purple and green wires are for the capacitor(s) that will be installed, the white is for the headlight, and the black and red are for power. All of this will fit in the front quite easily. All of the wires need to be trimmed back to their proper spots once I start installing all of the components, they're curled/taped up to test shell fitment.

Just for you JD: Here's how the wires made it to the top of the frame from the decoder.

All of the wires come up right there. While there are many more wires than the previous decoder, the wires are much smaller allowing them to be run in this manner without issues.

Here's the fitment of the fuel tank and shell with the decoder installed w/ wires ran.


Hopefully I'll continue tomorrow evening.

[SSW7771]

How are you doing your milling? I have a bunch of sound decoders to install in my future.

[AKNscale]

For this install I used a file and a dremel. I use a dremel for the big cutting and milling out the corners, and I used a file to do the final smoothing/bit of milling. On my SD50 I basically did everything with a file.

[jdcolombo]

That's working out very nicely - and the upside of the fuel tank decoder install is that you don't have to worry about fitting the shell over the width of the decoder.  You do probably lose a bit more weight from the frame this way, but for an engine the size of the C30, it won't matter.  And it leaves a lot of room for the 9x16 speaker (plus, you could probably add some lead sheet to one of the "shelves" on the frame to get back some of the lost weight).

Very interesting - I'll have to keep this idea in mind . . .

John C.

[MK]

John, where would one buy lead sheets?

[jdcolombo]

John, where would one buy lead sheets?

https://rotometals.com/lead-sheet/

You could also use tungsten, if you can find a way to cut and shape it to what is needed:

http://www.espimetals.com/index.php/online-catalog/467-Tungsten

Lead is generally a lot cheaper (though a much more hazardous material if you don't handle it carefully) and easier to cut.  I've tried tungsten putty in the past, but the overall density of tungsten putty is often less than pure lead sheet, so I've migrated back to lead (plus the tungsten putty I've used has an oily binder than can get messy).  Pure tungsten (or nearly pure tungsten) is considerably more dense than pure lead, though: 19.3g/cc vs. 11.3g/cc).  If you can find a way to cut it (maybe a diamond wheel in a Dremel?), tungsten would be superior.  With lead sheet, I just use a pair of old scissors to cut it.  That won't work with tungsten . . .

John C.

PS - you can try to use pre-cut tungsten cubes or discs made for pinewood derby cars, but I've found that they never fit the space perfectly, and hence you end up getting more weight out of lead sheet, which you can cut and shape to fit the space available.  Still, this may be a viable path for people who are concerned about handling lead.

[Burlington Bob]

A diamond cutting wheel will cut tungsten very nicely.  I don't know where you buy or what shape, size and price you you pay for tungsten but I would suggest a welding supply or an online supplier like Cyberweld.com.  http://store.cyberweld.com/tunpur040dia.html, shows 1/16" diameter tungsten for $6.25 plus shipping for 10 pieces that are 7 inches long.  You can get it in different diameters and it can be cut to the length you want.

[MK]

Thanks John.  Sounds like lead sheets are the way to go for ease for workability.

[RBrodzinsky]

For very easy (and cheap) to use lead sheet/strips, go to your local golf pro shop! They normally have lead tape, which has one side with an adhesive backing. Used for weighting club heads.

[peteski]

I bought some lead flashing at Home Depot few years ago. They had a roll of it and sold it by length. I cut  off about a foot of it.  IIRC, it is 0.040" (or 1mm) thick.

[AKNscale]

I had a little time to work on it tonight. I was hoping to get a lot farther with it, but oh well, I'd much rather get it done right the first time than rush through it and see magic smoke or run into any other frustrating situations. What I did was setup the pick up for the decoder:

I'm quite happy with the end result.

After drilling and tapping the holes I checked the screw depth as I knew it would be close to the drivetrain. Sadly, the screws ended up being too deep. I tried to think what I could use as a shim for the screws and just couldn't come up with a good plan. I started mocking up new locations for the p/u screws until I randomly glanced at my coupler parts box. I realized I have tons of MTL bolster washers and wondered if they would work, and they sure did. That's what is between the screw head and the contacts.

Hopefully on Thursday I'll get some time to work on it...

[peteski]

Why not just cut the screws down?  For 00-90 and  0-80 brass screws I use rail nippers to cut them slightly longer than needed, then I dress the cut end with a mill file or sometimes using a Dremel running on slow speed and a cutoff disk (used as grinding wheel because it has a fine abrasive).

[MK]

For very easy (and cheap) to use lead sheet/strips, go to your local golf pro shop! They normally have lead tape, which has one side with an adhesive backing. Used for weighting club heads.

Not being a golfer I never knew that.  Just checked on Amazon and under $5 for a role.  Cheap enough for me!