1.  Regardless of whether the switch is already installed in your trackwork, or new on the bench, first familiarize yourself with the parts we are going to modify - The moving switch blade assembly, the frog and the two guard rails.  Note that there are two small rivets retaining the metal connecting bars across the two point blades. Also, although they are not visible, there are solder joints between the guard rails and their respective stock rails as well as solder joints between the wing rails and the frog vee.

2. The first actual task is to prepare the frog area to receive the new, drop-in, Proto:87 frog, as above.  Note that if you are going to operate with a live, rather than insulated, frog, it is strongly recommended that you use/build the version of the frog with a power wire already attached. Despite a lot of marketing hype about having "DCC Safe" insulated frogs, DCC users can actually operate either way. But using a live frog is much better for running reliability. A simple and very inexpensive relay will switch the frog polarity automatically if there is not a spare set of contacts on your switch motor.

3. Visually position the new frog first beside the old one. The theoretically correct location of the new frog is with the point of the new vee in exactly the same place as the point of the old vee. Mark the closure rails lightly with a pen or pencil where the new frog ends are, for use as a reference later.

4. If you are doing this for the first time, preferably using a razor saw,  you may want to cut carefully well "inside" those marks ( in the direction towards the point of the vee)  to allow removal of the the center portion of the frog and wing rails. Hold the rails firmly in place while cutting, so that none of the fixed rails are pushed out of position. You can use a Dremel with a fine cutting disk for this, but unless the cutting disc is much larger than the Dremel Body, the cuts will be incorrectly sloping. Take quick, light, almost upright cuts and pause to let the cut edges cool back down. Be aware that heating the rail too much at one time may melt the plastic "spikes" and damage the switch beyond repair. Also, for the final cuts later, the body of the Dremel must be pointing away from the frog point. Why? Because otherwise the sloping cut will slope the wrong way and you will end up with too large a surface gap between the frog and the fixed rails.

5. Now we come to the violently destructive part. The old check rails, wing rails and finally frog vee need to be carefully removed. (in that order) This is achieved mainly by gripping each part with some needle nosed pliers and slightly but firmly trying to tip it over at an angle and back, over and over, until the solder joint becomes fatigued and breaks. Firmly hold any adjacent rail that should stay in place, so that it is not loosened or damaged. Each part should then come free, leaving the plastic base intact, with only slight cosmetic damage.

Sometimes the wing rails are so firmly attached to the vee, that sawing down along the frog flangeways may be necessary first to weaken the solder joint before trying to break it .

6. Here we see the base with the frog removed. Clean off up any plastic bumps and obstacles, that will  prevent the new parts sitting correctly on a flat surface, with a sharp craft knife. The solid plastic under the frog, which would show under a smaller scale sized frog has also been cut away until only the separate long ties remain. New scale length guard rails made from filed up strips of spare rail are being test fitted in this picture. Note for Proto:87's narrower flangeways, the back of the guard rail foot must be filed away.
 
 

7. The new frog must now be rechecked for exact alignment. This is done by placing the new frog on top of the gap and checking that the frog ends are the best possible fit with the remaining fixed rails. (inside railhead edge for the closure rails - outside rail head edge for the extended vee). The final, exact cutting marks are then made with the craft knife blade.

(This picture is showing how an experienced modeler can use a spare frog without a power wire to mark exactly at an earlier stage) .

If the frog power wire does not slip easily between the ties, during the alignment process, drill a small hole , 1/16th in. dia. or less, in the appropriate place so the power wire drops down out of the way.

8.  Now the fixed rail ends are cut and/or filed back with the saw and swiss files until the frog drops in and fits perfectly. There must be a small electrical isolation gap from at least the closure rails. This can be filled with expoxy cement after final assembly. Check all the frog and guard rail alignments are correct with an Ed McCamey gauge and glue all the new parts in place.
 
 

9. Moving now to the switch points. The first task, for improving the switch blades, is to remove the heads of these two rivets, without damaging the plastic tie base. The tops of the rivets should be removed by drilling. Use a much larger diameter drill bit, so that the drill bit does not merely jam into the inside of the rivet.  Often the rivets will try and spin rather that be cut. This must be avoided! Drill at various different angles off vertical,  or in extreme cases of difficulty, remove the switch to the bench and jam the other side of the rivet with a spike or small pliers.
 
 

10. Remove the blade assembly as above. Using a soldering iron, the switch blades should be removed from their metal bars and put to one side for use later.  The metal bars and the original plastic throw bar can be discarded.  Note the "C" shaped brass rubbing plate left behind. You may need to redrill the RH rivet more to fully separate it from the rubbing plate

11. Using a fine razor saw, or fine file,  cut the center section of the brass rubbing plate away, being careful not to damage the cosmetic surface of the ties. Do not permanently bend the plate! However, the plate is slightly springy and it is possible to slip some card under it's LH edge while cutting, to prevent cutting directly into the tie surface.  When completed, two flat small brass tongues, at least as wide as the size of the rail base width, should remain.

12. Now the unecessary supporting plastic can be removed from between the two ties as above. This is most easily done from underneath with a razor saw. The plastic webs under the stock rails should be left in place.  If the switch is already installed, remove the same material carefully from the top, using the very end of the razor saw and/or a craft knife.

13. Here is the finished appearance of this stage from below . . .
 
 

14.  . . . . and above.

15. Using pliers or metal clamps on the stock rail ends as heat sinks, very quickly tin the brass tongues with a hot soldering iron. Make sure this is done quickly to prevent any of the plastic close by from melting and causing cosmetic, or even worse, structural damage. Also be sure not to unsolder the tongues from the stock rail ends. The switch blades should also be retinned underneath at their matching ends.

Using some shim material, position the switch blades so that they are about twice as far open as they would normally be for Proto:87 operation.  (a gap of  ~ 0.070").  Then, with the stock rail heat sinks in place,  carefully and quickly resolder (sweat) the blades back onto the tongues, being sure to keep the rail ends properly aligned. Again, make sure this is done quickly to prevent any of the plastic close by from damage by melting.

16. The blades should now look as above and "spring back" if pushed against their adjacent stock rail.

17.  The final step of the blade reasssembly is adding a new switch rod, such as the "Stores" part # SWRD".  This can be assembled and inserted most easily from below if the switch is on the bench. Otherwise an unassembled SWRD plastic bar can be inserted (slid) into an installed switch.

18. Cut and add small plastic shims from the extra plastic strip provided. Glue these onto the SWRD plastic bar positioned hidden just under the stock rails to ensure the SWRD is pressed  flat against the roadbed in use. Sand them lightly on top if the movement is too stiff, until the bar slides freely. If not already inserted, press the etched rods pressed firmly into place in the SWRD plastic bar from above. Except for final wiring up, the basic conversion is now complete.
 
 

19. The finished switch can be detailed with joint bars and bolted plate detail around the sides of the frog. Matching ballast should be added to the indentation around the switch rod, to complete the illusion of near scale operting parts.
 

This WEB page last updated on 9/11/03. All illustrations, products and product designs are copyright of their respective owners, whether acknowledged or otherwise. All rights reserved.