Repair Micro Engineering turnout?

[nickelplate759]

Well, I broke a Micro Engineering turnout tonight.  Specifically, I snagged the throwbar and tore it loose from the points.  Then of course, the points fell out  .  I have all the parts, and sliding the points into place is easy, but the throwbar looks like it relies on pretty thin plastic to secure the points to it, and that plastic is distorted and it won't hold the points any longer.

I'm guessing I'm not the first person to do this - does anyone have a technique for repairing this?

[railnerd]

HO or N?  Just repaired an HO at my club one buy buying a pack of "spare parts."  The points are actually molded into the throwbar on the HO turnouts.

It is possible to rebuild the points with a PCB throwbar as well…  I'm sure @robert3985 can also provide some good advice.

-Dave

[Mark W]

Below is an Atlas turnout, but same concept applies.  Get a few PCB Ties. 
I prefer to replace the closure rails too, but that's optional. 
(And of course, gap the ties prior to installation as well)

[nkalanaga]

My only experience is with the original ME turnouts, from 20 years ago, and they may have changed since then.  I had a couple come apart, and replaced the throwbar with a PC tie, soldered in place.  If you've never built a turnout, the only trick is to gap the foil on the outside of both points, or you get a short, because the points are electrically connected.  This is the only way I know to fix it if the points are loose from each other.  It is also the easiest way to fix it without removing the turnout.  This is the method Mark and Dave used.

If the points are still connected by the metal throwbar, you can solder the entire piece to a PC tie, which will be a lot stronger.  This will also work without removing the turnout. 

Even better, if possible, and you can remove the turnout, put a brass rod through the hole in the middle of the metal piece, and solder it only to that metal piece.  Then the points can pivot on the PC tie, and there will be much less stress on the solder joints.  If you do that, though, you should gap both sides of the PC tie, because otherwise drilling a hole in one end to attach it to whatever you use to throw the switch can cause a short through the tie.  You'll also probably need to solder a washer or something on the underside to keep the PC tie from falling off.  An old trick was to put a piece of paper between the two pieces of metal before soldering the pin, then remove the paper, to keep from soldering everything solid. 

This can be done without removing the turnout, if you don't mind soldering everything solid, and will make for a stronger joint, but without the pivot feature.  In this case, drill the hole in the PC tie, and gap the underside, before installing the tie.

A third method, if you have a very small brass pin with a flat head, is to solder the pin to the underside of the tie, with the head holding the points in place.  That would be easier than trying to solder to the points without soldering to the tie, but you'll have to find that small pin.  This will obviously rewuire removing the turnout, so probably isn't an option in this case.

[robert3985]

After doing a bit of research online, it appears that "new" N-scale ME turnouts are built a bit differently than they used to be.  My experience is with the older ME's in C55, and mods had to be done to them to make them DCC "friendly", including modifying the throwbar, which was a brass bar with holes in it for the over-center spring and a wire from whatever mechanism you were going to use to throw it.

The new ones, from the photos I've been able to look at, appear to have a plastic throwbar, which insulates each closure point from the other so that they can be the same polarity as their adjacent stock rail, which is GOOD from an electrical standpoint.

If the plastic throwbar is kaput, then don't use it, but keep it so you can use it as a reference for making a replacement out of a PCB tie.  Find a PCB tie, and make sure the edges and corners are smooth (you can feel if there's a "wire edge" with your fingernail), and carefully file off the copper cladding where you'll drill a new hole for your actuating pin/rod from whatever mechanism you have to throw your turnouts.  If you're throwing your ME turnouts manually, taking advantage of the over-center spring, then drill a mounting hole in the PCB throwbar that corresponds to the mounting hole in the plastic throwbar that's broken.

I've found that when you replace the throwbars on ME turnouts, you need to not have the new PCB throwbar centered between the headblocks, but it should be just an RCH away from the furthest headblock tie from the point hinges.  This will act as a keeper to retain the soldered up switch so the point heels stay in ME's rail joiner hinges.

I don't trust solder joints alone to be strong enough where the point toes are attached to the PCB throwbar, so I cut teeny .003" thick brass squares (2 ea.), tin them, and solder them to the foot of the rail and the pcb throwbar.  This makes the joint MUCH stronger and more durable.  You don't need to, but you can put a very slight Z-bend in them if you like, but that complicates the process a bit and is more cosmetic than functional.

If the new PCB throwbar is rough, it won't operate smoothly and could cause problems, so I'll restate that it is ESSENTIAL that you make sure all the burrs and rough spots are off of the top surface of the new PCB throwbar where it goes under the stock rails.  Also, be careful to only take off the copper when you file it off when gapping the center of the PCB throwbar.  You don't want a notch in the fiberglass or Phenolic underneath the cladding because you want your throwbar to be as strong as possible, and a notch will seriously weaken it.  Soft pencil lead...applied by scribbling on the copper clad portions of the PCB throwbar that go under the stock rails acts as a wonderful lubricant.  Be aware that solder won't stick to any graphite markings on copper, so you should probably do that after you're done soldering.

OR, you can order (for $9.55 from ME, or about a buck less from your LHS or online hobby shop) the cast frog, two guard rails and a point assembly...which might be difficult to put on the turnout without dismounting it from your layout. I note that they're also backordered, so I think the PCB throwbar is probably the way to go.

I see no need whatsoever to replace anything on your busted turnout other than the throwbar.

Good luck!

Cheerio!
Bob Gilmore

[nickelplate759]

thanks all - the good(ish) news is that the turnout is not yet mounted on the layout, so I can fix it on the bench.  It's the new style ME turnout, with the plastic drawbar.
I could just pitch the whole thing, but that's wasteful and I wouldn't learn anything.  Looks like making a new drawbar from PCB is the way to go.

[Santa Fe Guy]

Yep I modified 84 of the very early ME code 55 turnouts the way described by Mark and Robert back in the early 20's. Make sure the surfaces of all that needs to be soldered are very clean and use a good grade of liquid solder flux to ensure you obtain a nice soldered joint that shines after it has cooled not one that looks dull as that will not last.
Rod.

[nkalanaga]

Bob:  Thank you!  It sounds like the new turnouts are MUCH easier to repair.  One insulating gap in the middle would do for me, since I use slide switches at the end of the throwbar.

I used the same type of thin brass reinforcement on my handlaid turnouts.  The only difference was that mine were not DCC-friendly (15 years ago...), so mine was a single piece of brass connecting the two points, and soldered to the PC tie.  It does make the joint much more durable.

[robert3985]

Yep I modified 84 of the very early ME code 55 turnouts the way described by Mark and Robert back in the early 20's. Make sure the surfaces of all that needs to be soldered are very clean and use a good grade of liquid solder flux to ensure you obtain a nice soldered joint that shines after it has cooled not one that looks dull as that will not last.
Rod.

FLUX???  Did someone mention FLUX????    Okay, once again, I'll recommend Superior No. 30 Supersafe liquid or gel flux, which you cannot buy at your local electronics, Lowes or Home Depot.  If anything will improve your soldering, this self-neutralizing, EXCELLENT flux will, and I've tried all of 'em, from beeswax to "Plumber's Honey".  Buy it here: https://www.hnflux.com/page36.html

This liquid/gel flux needs a precision applicator, and I buy mine here: https://www.hnflux.com/page30.html

In addition, you should think hard about solder that's a lot stronger than 60/40 Tin/Lead electrical stuff you use for soldering wires onto your LED's and decoders, since you need structural strength when soldering PCB ties to your rails, as well as electrical conductivity.  I prefer and use H & N Electronic's 96/4 Tin/Silver .031" coreless solder for ALL of my hand-made turnouts and mods on ME turnouts.  It's also available here: https://www.hnflux.com/page5.html

For fine applications, I squash the end about 1/4" and split the result with a sharp X-acto blade.  This works great for regulating the amount of solder you apply, and it also heats up and melts much quicker.

Although Superior No. 30 Supersafe flux is "self-neutralizing", on turnouts I build or modify on the bench, I rinse them in hot tap water.  On in-place track repairs, I don't worry about rinsing, and I have had zero problems, so it appears it really is "self-neutralizing", and I've been using the stuff for about 30 years now.

Cheerio!
Bob Gilmore

[nickelplate759]

The silver-solder suggestion is well taken.   
I just realized that I have an unusual advantage for this particular turnout - it isn't normally visible, so it doesn't have to look pretty.  I'm thinking that I will solder a brass tab to each point, then screw the tabs to a plastic throwbar.  It will look like heck, but only I will see it.

[nkalanaga]

The screws will also allow the points to pivot on the throwbar, which will eliminate almost all of the stress on the joints.

[OldEastRR]

Yeah, but what about the self-locking feature using the spring? Where did that go when you did these rebuilds?

[nickelplate759]

In my case, the turnout is controlled by a Tortoise, so the self-locking feature has been removed anyway.
Replacing the throwbar AND  keeping the self-locking spring would be a fine challenge indeed.   If that were important for me I think I'd just order the replacement points kit, although installing it would be a challenge - I think you'd have to pull off all the ties between the throwbar and the close end of the turnout, install the points and replace the ties.

[Santa Fe Guy]

Yeah, but what about the self-locking feature using the spring? Where did that go when you did these rebuilds?

I installed Tortoise motors to power my frogs on all turnouts and for signaling purposes in main line positions, my turnouts had no springs.
As I used ME Code 55 weathered track it is difficult to solder if not cleaned thoroughly.
I used a liquid flux from the UK (name escapes me that is quite good for this kind of work).
After adding flux and then soldering I sprayed all my soldered joints with Electronic Circuit Board Spray to clean the area and avoid any possible corrosion.
Rod.

[peteski]

I used a liquid flux from the UK (name escapes me that is quite good for this kind of work).
After adding flux and then soldering I sprayed all my soldered joints with Electronic Circuit Board Spray to clean the area and avoid any possible corrosion.
Rod.

Electronic Circuit Board cleaners are usually organic-solvent-based (possibly alcohol based) and are designed to wash away rosin-based fluxes used for electronic circuits.
If you used an acid-based flux (not used or recommended for electronic circuits) then the cleaner you used might not have rinsed all the acidic flux residues. Those type of fluxes might need aqueous cleaner (water-based).  In some cases the acid might also need to be neutralized.