I have had this K-Line Mikado for some time. I use it to pull my semi scale Western Pacific feather boxcars. My collection has grown to well over 20 cars and the engine was nearing its limit. A big part of the problem is the piston type smoke unit driven directly from the motor. These create a lot of drag and rob a lot of power from the motor. I finally got around to replacing the smoke unit with a fan unit. That of course required a new chuff switch to provide the 4 chuffs.

The gear that drives the piston gave me an idea. Its the same gear as the one on the axle so turns the same speed. Rather than install an axle cam I just had to drill and tap 3 more holes for screws to act as cams on a mechanical switch.

Here is before showing the piston attached to the gear.

After the gear mod.

And the result.




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Original Post

Excellent idea, great job.

     Dennis L. Schlossman

  Denver, NC

  TCA, LCCA      

     Yadkin & Catawba Model Railroad Club


      SE Shortline and Narrow Gauge Museum

Newton, NC

     E-5, United States Marine Corp 



Thanks guys. Its been so long since I ran this engine I forgot I had already put a Cruise M in it. Must have been when Jon first made them. Anyway I replaced the first video I posted here with one with the engine in 100 step mode. The gearing is pretty high as it is and 100 steps calms it down some.

I hope to check pulling power in a few weeks when the club sets up a big layout at the Syracuse show. I am aiming for 30 cars and if it does that I will be happy.


It's great to get rid of that big smoke unit.  Even though they're among the best smokers for mechanical smoke units, they really do present a lit of drag and make the locomotive stagger at slow speeds.

That would be the Chuff-Generator-M, nice job.  I'm not sure what Pete uses for the smoke control, but he has all the elements, smoke at idle and chuffing smoke, so whatever it is, it works.

No sophistication here John. The interface is just a 5v regulator and a double pole reed relay. The switch sends 5v to the relay. One set of contacts goes to the chuff input of the R2LC and the other feeds 5v to the fan motor. If the cam stops on the micro switch the relay is closed and the fan is on.

On this engine there is no wire from the power triac to the smoke unit in the tether. The only control is a switch under the cab. The resistor is a 24 ohm, 5 watt piece connected to the track. Even at 16v its puts out a ton of smoke. This was a quick afternoon project and I didn't really want to get into installing a new tether.

Most of the time smoke will be off. Probably just get turned on for demonstrations. Even at shows I have discovered most people find the excessive smoke objectionble.

I am sorry I didn't order more of these smoke units though as I see it and all of its substitutes are NLA at Lionel. This narrow rectangular unit is the only one I had that would fit is this narrow opening. I will have to check out the MTH units at York.





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FWIW, I've put the MTH smoke unit in the semi-scale K-Line locomotives.  It's a pretty tight fit, but it does go in there.

I'm curious, if you are feeding the chuff from one side of the switch and the motor from the other side, are the chuffs in sync with the smoke?  I found it interesting that it always stopped with smoke at idle, nice trick.

FWIW, this one is still listed as available at Lionel, looks like the same mechanical fit as yours.  You seem to have one of the "smart" smoke units with the 5-pin connector.  I use the "dumb" ones like below for my conversions, I already have the board for the "smarts".


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Its the relay that is feeding both the R2LC and fan using separate poles which close at the same time so no problem with syncing.

I will have to check my other Lionel units. I may have one of those. The one I used is a semi smart one with all the smarts bypassed.

Still fine tuning. I may turn down the screw heads so micro switch on time is shorter.


They're the same size, so I suspect it would work just fine for how you're using it.  I get the relay now, I was thinking SPDT, not DPST.

Trainlover9943 posted:
gunrunnerjohn posted:

The Lionel doesn't have the same nifty gear that Pete used for his chuff switch, so that option doesn't exist.


Matt, you can use the smoke unit John pictured. You just have to come up with another chuff switch. John can provide you with another option.


There are no problems, only solutions.

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