K-Line/Lionel SD70MAC Legacy Conversion

Here it is!

The ditch lights, and front and rear headlights are LEDs. I need help though, are the outputs on the old legacy board DCfor LEDs or AC? I am assuming the old legacy motherboard has ac out and converts it to dc in the old legacy headlight board. Attached it a picture of the new light board.

Nice work!

Those KLine/Lionel SD70MACs are good looking engines

Pretty certain Legacy R4LCs have the same outputs as TMCC R2LCs except for serial data. That means around 12v AC for the lights. The light boards must do the conversion for the LEDs.

Pete

Not much progress. A lot of test fitting and taking apart. I either had to move the capacitors on the motherboard or start cutting the body. I moved the capacitors..... I did get power to the board, and got the ditch lights hooked up. Here is a test of sounds and ditch lights. I still have a long way to go. The smoke unit lines up perfectly, but the board has too much overhang on one side, so I need to find another smoke unit. I am not too worried about smoke currently, but I would like to have it functional. If anyone knows of a unit that is the same as this one, but with the plugs at the end please post a part number!

All lights work, mother board is mounted, encoder installed, and electrocouplers are installed. I need a mounting tray for the motor driver, and flywheel and encoder. I think the flywheel pictured is the one I need. 

Well, I managed to find the flywheel from the donor engine, I just need the encoder ring.  On the smoke unit, Inam going to cut the fan driver and ac input off and just relocate it after wrapping it in heat shrink. I will need a ac regulator as the donor one was starting to act funny. I had thought about just putting in a 27 ohm element and running to the associated pin under the R4LC to delete the regulator. 

Great job with the conversion. This type of tinkering is my favorite part of the hobby. Keep the updates coming - I look forward to the final product. 

Smoke unit has been modified and still functions. I need an AC regulator for it though. Time to order an AC regulator and an encoder ring. Other than that, tidy up the wiring and mount the motor driver. The shell fits as it should. I put heat shrink over the part I removed and ran wires up to the traces on the smoke unit to power the element. I will have to make a smoke stack extension and offset to get it in alignment. 

Got the encoder ring today, it wasn’t quite the right size so I had to make another tooth for it. I didn’t hook the smoke up with the new regulator as I can’t remember where a couple of the wires went, so I will have to find the diagram. I do have it making laps and hauling loads now!

If anyone has the schematic on how thins AC regulator (691ACRG104) should be wired in it would be greatly appreciated! My attempt was a failure, but luckily I didn’t fry anything. 

An update after some run time, the engine gets a minor surge (speed up and slow down) and the motors whine a touch. I am going to get a long shaft motor from a friend and a new flywheel with encoder ring and see if that cures my issues. The filler I made isn’t exactly the same as the other pieces and the set screw engagement on the motor shaft isn’t what I would like to see.

In a lash up, the engine is off by 1-2 speed steps. I don’t know if that is enough to hurt either engine in a lash up, so advise would be greatly appreciated. Can you put legacy engines into a nudge mode like you can with ERR boards?

*Update on the lash up. I got the train up to the speed I wanted, addressed the faster engine and backed it off a couple speed steps and then acknowledged the train again and it seems to maintain the matched speed. 

Here is a clip of it operating independently and in a lash up.

Well done!!!!!!!!  I just got the same set and am looking into either having someone add the TMCC/sounds or getting some of the ERR commanders and sound boards and doing it myself.  When I got it, it does not have any sounds.  Did you add the speakers or were they in there and not hooked up?  Any and all info would be appreciated.

Have a great day,

Randy