Modifying a replacement Seuthe Smoke unit to fit the AF Mikado and Pacific

Click on images for larger view.

The unmodified Firma 5 Seuthe Smoke Unit 
 (4-6 volts.)

 These are the units unmodified dimensions in mm.

The Lionel AF Mikado and Pacific's replacement Seuthe smoke unit is no longer available from Lionel.
The Firma 5 Seuthe smoke unit can be made to fit as a replacement with some modification.
The Firma 5 is 3/8" too long but it can be cut down.
I use my Micro lathe and a diamond cutting wheel to remove 3/8" from the unit's case. The added temporary brass tube is there to prevent damage to the element when the cut off happens. The element is VERY FRAGILE! It can be bent or destroyed easily.
Remove a bit of the plastic after shortening the casing so the new ring can be soldered on.

The ring is made from 20 gauge copper wire bent to fit the casing

Solder the ring to the casing. Use the solder and heat quickly and sparingly. This unit has not had the flux removed yet. You may want to trim  the inside a bit with an Exacto knife to clean up any extra solder..
The unit needs a piece of 3/8" heat shrink tubing added.

Shrink so the end has a lip covering the brass.
This is so the brass case does no touch the loco shell. It needs to be electrically isolated.
Here is the old original and the new replacement.
Note that it is a bit shorter than the original.
This makes wiring a bit easier too with more room.
Here is the replacement sitting in the collar that holds the unit to the loco's shell.

The Firma 5 Seuthe Smoke Unit is available from and probably others. Be sure to only use smoke fluid deigned for Seuthe. Using others will shorten the life on the unit

I recommend LGB or Williams smoke fluid