O Scale Weaver SD40-2

[ron045]

I thought I would start documenting my install process.

I have a older Weaver SD40-2 which I stripped of everything except the motors.

My LM-3S-G and HC-2b were not delivered yet, so I decided to install LED Lights in the shell.  This is a simple engine, so there is only a headlight and a rear light.  I might add class lights and marker lights.  Still deciding.

[ron045]

I stopped by GScaleInstallations in York.  The owner Bob Buck has helped me in the past with some equipment for battery dead rail.  This engine will also be deadrail, so a stop to see Bob was a must.  He is also online at 
https://gscaleinstallations.net/

I purchased batteries, switches and speakers.  I'm also going to test these exciters.  When mounted in the shell, the shell is supposed to become the spearer.  Sounds cool.  I have a second engine to upgrade which is why you see two of everything.

[ron045]

I made some progress yesterday installing the charge port and the switch.  Bob Buck at GScaleinstalations recommended using these Futaba RC wires for charging.  Being an RC guy, I have plenty of these lying around.  I made a little cutout in the fuel tank and the charge port fit nicely.  It should be concealed well.  Especially  after I paint it blue.

Next was the switch.  Bob also sold me this nice push button switch.  In my last battery projects I was using toggle switches.  These button switches are easy and conceal very well.  Once might even think it really is part of the engine.  I was going to try and put in the the end of the fuel tank, but these Weaver tanks are two pieces and the shoulder and screw were in the way.  So I decided to find an area of the frame that would work best and not interfere with the trucks or the shell.  This was the spot.

You'll see in the test fit below they conceal fairly well.  I did not screw it together because I still have to install the speaker.  That is why you see a gap on the left side.  I should have easy access from the track without having to lift up the engine or remove it from the layout for charging.

[ron045]

Yippi...  My RailPro system arrived early.

I could not wait to play with it, so I just did a quick mock hookup and when through the quick start guide and fired it up.  Don't worry... my final install will not look like this.   Man that little TB 1925 speaker can put out some sound.

I was also able to use my Sons computer and played with the RailPro softwares.  That little CI-1 usb device really comes in handy.  No need to use the controller while at the computer.

[CPRail]

Looking good!

I've always wanted an O Scale loco. It wouldn't run anywhere as I'm a full fledged HO modeller, but it sure would be nice to have something that big to drool over.

I'm curious, are there any O Scale SD40-2s with body mounted pilots and couplers? It looks like both the Atlas and Weaver ones have truck mounted pilots and couplers, no doubt to accommodate the 3-rail curves.

Ian Lisakowski
Winnipeg, MB

[ron045]

Looking good!

I'm curious, are there any O Scale SD40-2s with body mounted pilots and couplers? It looks like both the Atlas and Weaver ones have truck mounted pilots and couplers, no doubt to accommodate the 3-rail curves.

Ian Lisakowski
Winnipeg, MB

You are correct, this has truck mounted pilots.  You can buy 2 rail engines that have fixed pilots.  I have some MTH F7's with fixed pilots and kadee couplers.  Sometimes those can be troublesome even on my O-72 curves.

Ron

[ron045]

Anyone see a problem with this spacing? 
The black part that says, "May be hot" is 3/16" away from the battery.

The width of the engine is such that I really do not see a mounting alternative.

Thanks in advance for your thoughts and ideas.

Ron

[G8B4Life]

It going to be a "depends" situation. From the LM-3S-G instructions...

Step 2 – Mount the LM-3S-G in your locomotive.
IMPORTANT: Module must be mounted level with the RailPro logo pointing straight up in order for it to have proper heat dissipation. You need to be sure there is 1/8" of space on the four sides of module and a 1/2 inch of space above the module for proper cooling.  The module can be attached with double face tape to the bottom of the LM-3S-G module.
TIP: If the auto set for the Motor Full Load current is set up to less than 1500mA you can mount the module in any orientation.

If the loco doesn't draw much power you might be ok but until you know what it draws it's hard to say. I'm guessing that the free space in the shell to the right side of the pictures is is not usable for the LM due to it's size? One possible solution could be to channel the heat away to an area with more air space (eg, to the right side of the LM in the pics). You could "glue" some formed copper sheet with heatsink compound to the heatsink of the LM. Then you could put a thermal insulator between the copper sheet and the battery.

I do not know how well if this would work, if at all (they do this sort of thing inside laptops though so it has some merit) but it's an idea.

- Tim

[ron045]

Thank you for the reply.

Unfortunately the space to the right and the left are mostly used up by the can motors.

When I ran the motor current test is read over 2100ma.

I was fiddling with it last night.  The battery either has to be mounted on its side or sit at a 45% angle.  It's just too wide to go in flat.  That was the best battery configuration available.  Others were too big or too bulky.  I even cut out two mounting posts just to get this to fit.

I can mount the module as written, but I would not be able to achieve 1/8 inch spacing on the sides.  It's a perfect (loose) fit.

I remember reading those instructions you posted before.  Why does the orientation of the module matter based on the full motor load current?  What bad things could happen with a sideways mount and motor current over 1500 ma?


Thanks
Ron

[G8B4Life]

Having less than 1/8" clearance on the sides (for the flat mount method) would possibly be ok, there would be far less heat radiating from the sides than the top.

The mounting orientation is all to do with heat dissipation. I'll let someone smarter than me get into the specifics of why (I know other things like power supplies also have different ratings depending on the orientation they are mounted) but in your case 1500mA generates less heat than 2100mA.

I don't know what the bad thing that could happen with a vertical orientation and more than 1500mA of current being consumed LM wise is; again someone smarter than me will have to get into that but what I can see as the bad thing that could happen with how it set up in your pictures currently is that the heat generated could melt the battery casing. This is why I suggested a heat pipe as a possible solution.

Another possible solution, though far fetched it may seem would be a miniature fan that blows down the length of the body installed near the hot end of the LM.

- Tim

[CPRail]

I'm not sure how much work you want to do, or if the appropriate parts are even available in O scale (I'm sure they are), but why not drill out the various fan housings on the top of the model and replace the grills with etched grills? HO guys do it, mostly for looks and/or sound quality.

Open grill fans will give you extra heat dissipation openings, especially if you include a micro-fan or something to move the air.

Ian Lisakowski
Winnipeg, MB
Great White North

[ron045]

I'm not sure how much work you want to do, or if the appropriate parts are even available in O scale (I'm sure they are), but why not drill out the various fan housings on the top of the model and replace the grills with etched grills? HO guys do it, mostly for looks and/or sound quality.

Open grill fans will give you extra heat dissipation openings, especially if you include a micro-fan or something to move the air.

Ian Lisakowski
Winnipeg, MB
Great White North

That would be cool (pun intended).  This Weaver model does not have open fans.  My next model upgrade is an MTH GP38.  That model does have three openings with fans.

Live and learn for upgrade choices.  Where can I start searching for such parts Ian?

Ron

[ron045]

I may have a solution.

I can mount the battery on the frame.  Using some foam cut on one side, I can angle the battery so that the shell will fit.

On the shell roof there are some ceiling bulkheads.  I cut the center posts out.  Still have 6 screws holding the shell on.  I never understood why manufacturers thought 8 screws where needed to hold a shell on.

If I mount the board on those bulkheads then I can orient the module flat with Blue Logo forward.  I can achieve all spacing needs, top, bottom front and rear.  Boths sides will be very close.  It's still a loose fit.  If I don't tape it in it will fall out.

See Pics.
Ron

[CPRail]

Ron

Precision Scale has a catalog of Diesel detail parts for O Scale: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjisOn5_87xAhVCVc0KHdHmC0AQFjACegQIBBAD&url=https%3A%2F%2Fwww.precisionscaleco.com%2Fwp-content%2Fuploads%2F2018%2F04%2FO-Diesel-WOP.pdf&usg=AOvVaw1GyTzaRsol8gXsBWRmL9rJ

Page 23 list the fans. #5680 is the Dynamic Brake Fan, #5688 is the Radiator Fan. #5633 are the Fan Blades. FYI: Those are the Brass P/Ns, but they also have Plastic versions. I presume you can get these PSC O Scale items from Walthers just like you can get PSC HO stuff.

A quick gander at the Atlas web site shows that they have parts for the SD40s as well, including Fan Bases and Grills.

Ian Lisakowski
Winnipeg, MB
Great White North

[ron045]

Ran some sound tests today.  Maybe the exciter would have done better in an empty shell.  But in this case the speaker in the fuel tank was much better than the exciter in the shell.  I even moved the exciter to the fuel tank, but that made it worse.

Time to put the finishing touches on this project.
Ron