Southern Digital Frames

[Mike Madonna]

[This is a merged set of two parallel threads. -gfh]

Good evening all,

I am about to perform an install using the above replacement frame(s) from Southern Digital (Sodigi). The instructions state to solder the Red & Black wires directly to each frame half. My question would be this; does one literally solder to some point on the frame? I was contemplating drilling and tapping a spot on the frame, inserting a small screw and soldering to that. As anyone performed one of these conversions? It is for a Kato F unit (not DCC friendly chassis) "blue label". Thanks in advance!

[Mike Madonna]

Good evening all,
Just posted this on the "DCC/Electronics" page, thought I'd post here as well....


I am about to perform an install using the above replacement frame(s) from Southern Digital (Sodigi). The instructions state to solder the Red & Black wires directly to each frame half. My question would be this; does one literally solder to some point on the frame? I was contemplating drilling and tapping a spot on the frame, inserting a small screw and soldering to that. As anyone performed one of these conversions? It is for a Kato F unit (not DCC friendly chassis) "blue label". Thanks in advance!

[ChristianJDavis1]

I've never heard of the outfit you speak of, but in my experience, solder doesn't like to stick to the frame halves of most diesels, so adding a screw and soldering to that seems like the best choice to ensure a good connection.

[Jim Starbuck]

What I have done in similar installs is to drill ( I think it’s a #63) hole and tap it for a 00-90 brass screw. The ones that come with 905 Z couplers work nicely.
I strip back about a quarter inch of the wires and make one wrap around a toothpick then twist the wire creating an eye. Adding  flux and tinning the wire creates a nice  little rigid loop for the screw to hold down to the frame half.

Jim

[peteski]

Yes, same experience here. Solder does not stick to whatever Zinc alloy is used for frames. Plus it woudl take some really powerful soldering iron to get that large chunk of metal hot enough.

I have in the past drilled/tapped holes in the frames for brass 00-90 screws and solder the wires to those screws.   Or take it one step further and make small terminals from piece of thin brass sheet, solder the wire to that terminal, then screw the terminal to the frame with a screw.  That last method is preferred because the wires can then be easily removed without needing to unsolder them.

[rodsup9000]

 Mike  I solder the black and red to the light board. If it a "B" unit, I find a old light board from another loco and cut to make work.

[DiggerDownUnder]

I saw these last year and bought 6 for the Bachmann Dash8s from the first run that I had to use on Australian locos plus 3 for the Life-Like Erie Builts. I have have used two frames so far and used a 30 watt iron to heat a small spot on the frame, drop on some solder and soldered pick up wires for TCS Z2s. Have not yet had any problems so far.  Not sure of the material composition though.

[peteski]

I saw these last year and bought 6 for the Bachmann Dash8s from the first run that I had to use on Australian locos plus 3 for the Life-Like Erie Builts. I have have used two frames so far and used a 30 watt iron to heat a small spot on the frame, drop on some solder and soldered pick up wires for TCS Z2s. Have not yet had any problems so far.  Not sure of the material composition though.

Are you actually making a joint where the solder wets the chassis material, or is the solder adhering to the frame strictly by mechanical means (like a cold solder joint)?

[drgw0579]

> I was contemplating drilling and tapping a spot on the frame, inserting a small screw and soldering to that.

That's my preferred method.   If there are close clearances, I might grind the head off the screw.  All you need is something that gives you good connectivity.

But you'll get 1001 good suggestions. Maybe they'll be one I think is better than mine!

Bill Kepner

[superchief]

Mike, on the many hard wire decoder installs I have done on the early "F" units I removed the the brush cap holder so I can solder to it for the orange and grey wire. I remove the copper tabs from under the brush holder and install then on either side of the insulating washer and that gives you two great places to solder the red and black wire. Just do not forget to put some kapton tape between them. Easy to take apart for maintenance and cleaning!!!!
                                                                                Gordon Bliss-Santa Fe/ All the way

[Drgwspup]

I do it the SuperChief/Peteski way.  Learn it from an old thread by Carl Sowell I believe.

[Mike Madonna]

Greetings all,
A lot of great feedback, appreciate all your time and assistance!

[Roger Holmes]

The best way to deal with the old Southern Digital frames is to sell off them like I did 

[mmyers]

The best way to deal with the old Southern Digital frames is to sell off them like I did 

I did the same with mine. That was back in the mid to late 90's. I found them slightly smaller than the original frames which caused the shells to just fall off. They were castings from molds that were made from original frames. Trouble is the metal shrinks as it cools so that they wind up just a bit smaller. I also could not get the original light boards to fit the slots on my F units. I wound up just cutting the stock frames. Took a bit longer but they worked quite well.
I don't see just soldering a wire to the metal. I would attempt to tin a spot on each half first to see if that will work. Tinning if possible would let you get in and out quick when soldering the decoder wire.

Martin Myers

[Mike Madonna]

Gordon,
Did you use the original Kato frames and modify to accept a decoder OR did you use the Southern Digital frames? Great idea for track pick via the copper strips from the brush holders!

Martin,
I noticed once I "mocked up" the new frames and assembled them, they did seem to slide in the shell a bit too easily. Will have to see how this goes. When you "cut the stock frames", did you use a Dremel with a cutting bit or ??

Again, thanks...