ILLUSTRATED INSTRUCTIONS FOR ASSEMBLING LAMINATED HO and PROTO:87 FROGS
(INTERIM 88-SAFE HO FROG KIT NOTES ADDED)

 

 

(Minimal tooling, solder method)

Please read these instructions all the way through first, before starting to build our frogs.



1. Place the frog kit on the bench the same way up and round as shown above. Familiarize yourself with the kit parts in place. A code 70 frog kit will have three long horizontal framed sections as above. A code 55 kit will just have (or just use) the lower two sections. Very occasionally, a code 83 kit may have an additional separate  top section. Two thinner metal tabs (seen between the large holes) hold each section to the next.

Each section has an alignment pad with an 1/8 in. hole at each end. The two outer thin strips of metal between the pads form a delicate, but fairly rigid, frame around each section and prevent the inner frog parts proper from becoming distorted during shipment and assembly. When handling, always hold the sections only by the alignment pads, to prevent any distortion or damage to the frame. The inner frog parts must not be removed from the frames until the assembly process is complete.
For 88-SAFE frogs be especially careful not to pull outward or twist the separate "vee" portion. It must be kept properly central before assembly

The lowest section  is the frog base. The underside of the base (with the writing on it) is actually upside down as supplied in the kit. This section will have to be turned over later during assembly.

The next section up is the frog top and is the correct way up as shown.

The third (and maybe fourth) sections, if provided, are shims and can be used either way up.

It is normal for the frog kit to be slightly bowed from left to right. This caused by the manufacturing process and not by shipping. However if any of the frames are significantly bent or otherwise damaged, contact us for advice BEFORE attempting to assemble the frog kit.



2. Clamp down the kit and using a firmly held Dremel with a thin ( 0.025 in. ) cut-off disc ( and proper eye protection! ) or a fine razor saw, carefully separate the kit horizontally into the individual separate sections, by cutting through the two tabs between the sections.



3. These are the sections after they have been separated. The base is still shown upside down.



4. Here are the tools you need to hold the sections aligned during assembly. Clamps to hold the frog sections firmly together and two 1/8 in. alignment dowels.  We are using the BLUNT ends of 1/8 in. drills for simplicity, but any accurate 1/8 th dia solid rod or bush will do. Do not use 1/8 in. screws, drawn or threaded rods, as the diameter will be way undersize.

You will also need some cored "electronic" solder wire, some paste or liquid "electronic" ROSIN flux and a fairly powerful electric soldering iron. but with a fine pointed tip, in the 25 to 40 W range. Do not use "plumbing" solder or fluxes, (containing Acid or Zinc Chloride) as these will cause corrosion of the frog in the long term.



5. Using a mild detergent in water, or a safe solvent, such as denatured alcohol, carefully rinse and dry the frog parts so they are clean and free of any dirt or oily residues. Make sure all the frames are in the correct Left to Right orientation as as above. Turn the frog base over so it is the correct way up (lettering on the bottom) and place the shim section(s) , if any, on top of it. Then place the top section right way up on the very top.

Now place the sticky label provided (not shown for clarity) over the top surface of the top of the frog. This will help protect the top of frog from excess scratching during clamping. Now apply just a thin film of FLUX over the INSIDE surfaces of the frog parts where they touch each other. This will ensure proper solder flow later.

Hold the sections together by the alignment pads and insert an alignment dowel carefully through each set of alignment holes. The fit should be tight initially, so a slow, but firm, twisting motion may be needed until the dowels slide into place. DO NOT DRILL THE HOLES OR USE THE CUTTING ENDS OF THE DRILLS



6. This is the way the frames should look like with the dowels in place.



7. Gently clamp the sections together as shown. Use small wooden blocks or similar (Not shown) to support the clamps so that the frog kit is approximately upside down as shown and perfectly flat. Then tighten the clamps just over finger tight.



8. Make a small sharp bend in the end of the OPTIONAL power connection wire provided so that it fits in the cutout in the middle of the frog base.  Tin that end of the wire



9. With soldering iron, heat the whole of the cutout  and melt a pool of solder sufficiently, until it runs and 2/3rds fills the cutout and touches all of the sections. Insert the wire bent end and do not remove the iron, until the pool is fully liquid again. This will not only fix the wire in place, but also solder the sections together by capillary action.  Add extra solder if necessary, but do not completely fill the slot. You do not want to have any solder proud of the frog bottom surface, or it will affect the frog height and you will have to file it off later.

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10. This is the correct appearance of the frog with withe cutout soldering completed. Note the 88-SAFE frogs have a slightly different shape center cutout



11. Now using the iron and a small amount of cored solder, carefully fully wet the INSIDE of all four of the tabs that attach the frog parts to the alignment pads. Again the soldering iron should held in place until the solder runs freely just into the ends of the frog rails. This will cause the end rails of the frog to be securely soldered together by capillary action also.

The 88-SAFE frogs require an extra soldering step here. Carefully also "wet" the two joint points where the (true) underside of the extra wing rail tabs extend out from the end tips of the wing rails. (The underside is of course facing up in the assembly clamps). This will capillary solder the otherwise unfixed ends of the wing rails to the main body of the frog. Only use a small amount of solder here, so that extra solder does not spill into the frog flangeway



12. Here we see the appearance after the tabs have been soldered. Note. It is important that the end rails be securely soldered. It better to use a little too much, rather than too little solder at this stage. Any excess can always be removed later with a small swiss file, or a wire brush in the Dremel.



13. With frog fully assembled, the outer frame can be removed. Clamp the frame securely in place and using either the firmly held Dremel with the thin cutoff wheel and eye protection, or the razor saw, CAREFULLY, cut across the end tabs as shown. The frame is no longer needed so it does not matter if that is also cut.  Note: Do NOT use excessive force, or use other than quick single dremel strokes at a time, as any longer than momentary friction will cause OVERHEATING while cutting. This may cause the end rails to bend or their solder joints to melt or break, or both.



14. Congratulations! You now have a completed frog. Remove the sticky label and carefully clean up any excess solder.  Please remember, even though assembled, this frog is still a delicate, precision, fine scale component and should always be handled with reasonable care to prevent damage or distortion.<

For finishing,  we recommend a chemical blackener such as "Blacken-it" if you wish to darken the inside of the flangeway. Painting the inside of the flangeway is not recommended and can affect both electrical and mechanical reliable operation. Painting and superdetailing the outside of the frog is, of course, no problem.