How to Upgrade an 1999 Atlas SW-8 Switcher to Command??

An upgrade of a similar model. Click on the underlined phrase to link.  Done with an Atlas/TAS, used, split board that I acquired from this forum. Other parts, including the articulated electro-couplers were from Atlas.  Part of the metal frame was dremeled away, to allow for the electro-coupler.  I also installed 18 volt lamps, command voltage is usually higher than conventional.  Modification, to the fuel tank, for the speaker, was done, with a dremel cutting tool, and small hand file.  There were also slight modifications, to the inside of the hood, to accommodate the boards.   Original board, and speaker were quite different.   A time consuming project.  

ERR board should be smaller.  Use the full boards, not the lite/smaller board if possible, these Atlas models have a motor that draws a lot of amps.  IMO.  Mike CT.  

Interesting Mike; thanks! I just checked out the link to your build pictures. Very nice and very informative. Gives me lots of ideas. Earlier I was looking at the blowup drawing that came with my SW-8 and noted that it uses a single horizontal motor exactly like that setup in yours. I right away figured there was not much chance of getting any boards that would fit, so I am happy to see that you have managed the upgrade using those boards. I will have to check out the ERR boards and see what sizes they are. I have a full set of used TMCC boards out of an Atlas diesel around somewhere, bought here off the forum. Will have to dig them out and check what they are exactly.  I like your buildings in the background by the way.

I wonder if a set of PS-2 or PS-3 boards might fit inside that hood?

Rod

These were the best drives Atlas ever put into their O scale locomotives.  Definitely worth the upgrade.  I have a similar challenge with my AEM7 and ALP44 which have similar drive systems.

That may have been the best drives, but they're a royal PITA to try to upgrade to command!

Well here are the TMCC boards that I have. About 133 x 33 x 40mm high, overall. The big heat sink plate on the bottom makes them stand higher than they would otherwise.

I have not measured the space available in the SW-8, but I am pretty sure these are going to be way too big. Guess I'll take a look at what sizes the ERR offerings are.

Rod

Not even close Rod, that old TAS setup is WAY too big!

The problem with that horizontal motor version is it also sucks quite a bit of power, so the Mini Commander II may not have enough capacity to run it, that's the only thing that pops into mind.

My thought would be a custom tiny motherboard for an R2LC, the Cruise Commander M, and the new RailSounds Commander single board.  Those three can be spread around to fit in the available space.  In order to make the CC-M lower profile, you can do a custom heatsink and even replace the FET's with low profile FET parts.

When the Cruise Commander Lite was discontinued, I embarked on a project to create a replacement.  Although the board is longer than the CC-Lite, I got the profile down by replacing the FET's with a different package.  My intent was to use thermal epoxy to do a small heatsink that just wraps over the top of each pair and maintains the same profile as the top of the R2LC.

I recently got the thermal epoxy, I guess I should complete this project.  It works fine, I just want a little more power handling for the FET drivers.

That's quite nice and compact John. It even looks slightly narrower than the R4LC piggybacked on top, but that might be camera parallax. Do you have any numbers for overall dimensions of the package? I'd be very interested in seeing the final FET heat sink . It looks like the overall height is somewhat dictated by the large blue cap on the main board? But again that may just be the way it looks to my eye.

Would it be possible to use standard FET's (TO-220?) and bend the tabs over at 90 degrees so that they are on top of the bridge? Then they could perhaps be sinked directly to the engine chassis by mounting the board upside down?

Is there a serial data output to drive the sound board?

Rod

Weren’t some of these built TMCC-ready? If so, how’d they do it?

Mainliner posted:

Weren’t some of these built TMCC-ready? If so, how’d they do it?

Early 2000's, TAS (Train America Studios, Youngstown, Ohio, Mike Reagan)  Designed, and had built, the mother boards pictured.  A hot item at the time.  Many early (Dallee electronic drive), Atlas SW8/9 models were upgraded, Youngstown, OH.   There were models sold as TMCC ready, not the SW model.   20 years a very long time in the electronics industry.  I purchased the model, for spare parts, found it too nice to scrap.  Model has 1998, bottom of the fuel tank.    

Even before TAS there were Digital Dynamics boards, ??Ed Bender??   Similar board, to the one John pictured, with a wrap-around heat sink.  Early designs had three modular boards.  ERR design is two boards or less ??   Lower center of picture.  Split boards allowed for a tight fit, Weaver A5, 0-4-0 tender.   Note:  Scotch 88 tape was used on the inside of the brass shell to insulate, and isolate the shell, as the TMCC antenna. 

Similar installation Weaver G5 tender.  Slightly large, still a difficult fit. 

Again note the electrical tape used to insulate the back of the boards from the metal shell.  

What board fits inside the MTH O scale switchers? Is it a special board?

I'm guessing the vertical motors allows for a bigger board?

I'm wondering how big a motor the MTH S scale board could drive? (this model??) and if it would fit here?

Rod Stewart posted:

That's quite nice and compact John. It even looks slightly narrower than the R4LC piggybacked on top, but that might be camera parallax. Do you have any numbers for overall dimensions of the package? I'd be very interested in seeing the final FET heat sink . It looks like the overall height is somewhat dictated by the large blue cap on the main board? But again that may just be the way it looks to my eye.

The height is governed by the components on the main board.  The heatsink would have to be two, the pairs of FETs have to be insulated from the other pair as they're not the insulated types.

Would it be possible to use standard FET's (TO-220?) and bend the tabs over at 90 degrees so that they are on top of the bridge? Then they could perhaps be sinked directly to the engine chassis by mounting the board upside down?

The TO-220 tabs on the FETs are not the bendable type, that won't work.

Is there a serial data output to drive the sound board?

The hacked version has all the outputs and capabilities of the standard Cruise Commander.

Rod

Comparison of sizes between the CC-Lite and my hacked CC.  As you can see, the CC-Lite is 2.25" long and my creation is 2.75" long.  Obviously, the width is the same, 1.25".  The height of the CC-Lite is about 3/16" shorter than my hacked CC.

Engineer-Joe posted:

What board fits inside the MTH O scale switchers? Is it a special board?

I'm guessing the vertical motors allows for a bigger board?

I'm wondering how big a motor the MTH S scale board could drive? (this model??) and if it would fit here?

The MTH switches have standard PS/2 or PS/3 boards, sometimes it's a tight fit between the motors, but they manage.  The horizontal motor takes a LOT more space in the shell.

I upgraded an Atlas SW-9 using a Cruise Commander Lite and new RailSounds board from the original Electric RR Co.  Sadly, the CC Lite has yet to be included in 3rd Rail's ERR offerings.

That's why I've been saving my remaining stock of CC-Lite boards for future projects, I don't know that it's ever going to make it back into the lineup.

You could make an EMD TR4 cow/calf by purchasing an MTH dummy calf unit. Put a Cruise Commander and sound in the calf and tether the two units together. Of course you would have to match the paint scheme on the calf with the cow unit and change engine numbers.

Ken

Does that make John the go-to on for this type of project? Sounds good to me. I have been looking for an Atlas UP SW w/TMCC.

I wonder what the CC-Lite board can safely handle for motor current? For that matter I wonder what the Atlas SW-8 draws for current with say 6-8 cars in tow? May have to put the old girl on the tracks and check that out. Wow, conventional running; that will be a novel experience! Hard to mess it up though I guess.

John, when can I send my SW-8 to you for upgrade?

Rod

I wondered the same thing, the CC-Lite is pretty sensitive to overload, and that horizontal motor sucks some juice when it's running.

I don't really want to see one of those Atlas horizontal motors, I don't know if I could fit the stuff for upgrade.  It would also not be one I'd quote at a fixed price, so it could get expensive.   Those are projects best left to the owner who doesn't charge for his time.

CC lite board failed in my small, Rich Yoder, GE 44 tonner.  My guess the Atlas horizontal motor application is probably a bit much.  IMO  Mike CT.  

All my CC-Lite installs include a PTC in the motor circuit to avoid overload taking out the driver FETs.

OK so I stuck the old Atlas on the track with 6 fairly light tank cars just for fun. A somewhat typical load for a switcher. The current draw was from 1.9 to 2.3 amps, all at realistic speeds, probably not more than 25 smph tops, up and down grades. Not too bad really. For comparison I then attached my PS-2 S-2 switcher to the same consist, and it pulled 1.6-1.9 amps max. So the Atlas might pull about 1/2 amp more. Is that a realistic current to expect the CC Lite to handle?

As an aside, it was a hoot to briefly run conventional again. Warp 1 takeoffs, rocket sled cruising speeds. And then just let the train cruise around the track for a few laps unattended. I didn't know what to do with my hands! Slower up hills and faster down hills of course. Anemic sounds, and the worst sounding horn ever. The reversing relay was a bit balky at first, but eventually settled down. I also was reminded about the stiff Atlas coupler centering springs, that means you need a weighted 12 pound car immediately behind the engine to prevent derailments on almost every corner. Ahhh the joys.

Rod

Do you have a CC-Lite?  The real issue is if you ever have a motor stall.  When I had some of these to beta test before they actually got released, I smoked one when my engine snagged a switch, it only took three or four seconds!  The husky motor in the Atlas will certainly have stall currents way more than the K-Line motor in the Interurban that I smoked it in.

I really don't think I'd put a CC- lite into that unit.

Right' I hadn't thought of the stall currents. Sounds like your idea of putting in a PTC is a good one. No. I don't have any CC-Lite's on hand. (Bud Lite's yes; no CC Lite's)

Sounds like time for plan B; whatever that is going to be! I would potentially be interested in one of your clone CC-Lite's, if you wind up with any for sale. First thing I have to do though is pull the Atlas apart and measure up the available space.

Rod

Reminds me I need to check my inventory of CC Lite's.  Haven't needed to use them any in a while.

Jim

So in keeping with social distancing I hid in the basement most of the afternoon, haha. Wasn't even missed I guess.

I took the Atlas SW-8 apart and had a good look around inside. It looks like the space inside the hood and above the can motor (the highest part) is about 130mmL x 39mmW x 21mmH. The hood is of course curved and in the middle there is about 3mm more. So John it looks like it will easily fit your cloned CC-Lite board length and width wise. But I am not sure about height wise. Looks to me like your board is more than 21mm high. And of course we still need to add a sound board.    Follows an elevation view with the main items shown:

The motor and the curved heat sink at the front are the highest items, but the sink can be easily removed or cut down if needed. So the clone CC Lite might actually fit in the front, inverted, with the FET's heat sinked to the curved existing sink after cutting it down a little.

A set of PS-2 boards looks like it will also fit, less the black plastic mounting frame, though it is tight for sure. Again the board set would have to be inverted with the bridge rectifier heat sinked to the curved sink. after cutting it down a little. The PS-2 boards with plastic mount measure 85mmL x 30mmW x 34mmH with the plastic mount frame; about 5 mm lower without.  The highest item on these boards is the bridge rectifier, by several mm. I could gain some more clearance by mounting the bridge separately to the engine frame, and wiring it to the PS-2 board set. A nice feature of the PS-2 pack is it already has sound. No extra sound board required.

I also discovered that the hood on this engine is cast metal, did not know that before. Here is another strange thing:

There is a GOW bulb illuminating some holes in a small panel that is between the engineer and fireman, down low on the floor of the cab. What the heck is this supposed to be?? Certainly not a firebox door, though that's sure what it looks like. Cripes there better NOT be a fire in there!

Anyway I have not concluded which would be the better way to go just yet. Research continues.

Rod

The "doctored" Cruise Commander is 23mm high, the stock CC-Lite is 21mm high.  Of course, a little clearance from metallic objects is good for electronic boards as well...

Removing the heatsink and mounting it externally is the only hope for the PS/2 boards it appears.  I'd think PS/2 would be the better option, as you say, you have sound built in.

I remember that bulb at floor level, and I marveled at why they put it there when I had one of these apart.  I thought it might have been intended to be a cab light, but it sure didn't light the cab!

Bulb at floor level, lights the instrument panel.  Kind-of like a fire box glow, for an SW diesel.    

For a while, Atlas had available replacement frames for the early SW with Dallee equiment to convert to Lionel TMCC equipment. After business start opening again you may want to drop Bill there and ask if any of the TMCC conversion frames are available.

Mike, thanks for that clarification for the lights. So its to simulate lit up gauges I guess? Funny I never ever noticed them until I had the shell off!

Chuck, thanks for that information. I have sent Atlas an email just in case they still have those frames. I don't expect an answer anytime soon.

Rod

Atlas had used ERR electronic drives the last time they produce the SW offering.  It would be interesting to know which boards they used.  

They might have had a custom package.  Too bad we can't get parts and a schematic for the Cruise Commander, we could create a distributed package that would fit into stuff like this.

Now that would be sweet! But most likely an impossibility.......

If someone comes up with a decent back-EMF motor driver for TMCC, I'll do the PCB work to make it happen.

I wonder if Atlas went to two vertical can motors in the later command SW offering?

Rod

All of the Atlas SW's have the single horizontal motor drive.

Good to know Bob. So there must be a way to fit the full TMCC or ERR compliment inside.

Rod

We've kicked around this issue here before, here's the TAS Bottleneck board discussions from the past.  Obviously, no cruise, but TMCC and sound.

TAS board for EMD Diesels??

Train America Studios Bottleneck board manual.

TMCC in an Atlas SW9 switcher