Mainly an issue of size. To get joint bars in HO PLUS drill holes small enough not to destroy all physical integrity in the rail, AND get nuts and bolts small enough to fit that actually hold and don’t simply strip when trying to tighten them down - those would be some really tiny nuts and bolts. Rail joiners and solder are plenty strong enough to ensure the integrity of a joint for HO and smaller scales. Large scale locos can be quite heavy plus especially in an outdoor layout you can have significant stress on the rails. Soldering the huge cross section without melting the plastic ties can be tough, plus some large scale rail is not easily solderable - it’s made of materials other than brass or nickle silver.
I am curious. You say you want invisible feeder connections for your HO rail. And I have described how I do it. And I do not drill holes in the rail. I wonder why you negate/ignore what I see as a valid approach.
I also wonder just where you have drilled your holes. For a truly invisible connection, it would have to be in the base, and up into the web. THAT is a truly tiny hole. Is that what you did?
In my experience, my soldered joints do not fail. And they are invisible. I do admit to a slight concern about feeders soldered to point rails, however. I could concede that a drilled hole MIGHT be appropriate in this case.
I will mention that I use resistance soldering for these connections. I reccommend it highly.
The only soldering task I have been unable to perform consistently is soldering feeders to rail - even the visible type. Depending on how many I have to do at once, my failure rate varies between 20% and 50%. If I have a hole to hold the wire, it always works. So I guess you could say I’m using the hole as a crutch.
I am drilling a 1/32" hole through the base of the rail. I feed the 22 ga. solid copper wire up through the hole, solder, then flush cut and file smooth. The process leaves behind a copper dot that will be hidden when the rail is painted. On track that will be hidden, I feed the wire down through the hole and skip the cut and file steps.
An interesting feature of this approach is that I can put the feeder through either side of the rail which helps in situations where it is difficult to reach the outside of the rail away from me.
This works for me every time, it’s faster (for me at least), and achieves the desired result.
edit: Just to be clear, I am using Atlas flextrack with plastic ties that is already glued down to the roadbed. Rereading the description of your process sounds like you may be ataching feeders to rail before it is installed on ties.
I see. And I can also see the utility. Especially if the track is already installed. In fact, I think I’ll file the concept away for possible later use. I do wonder about getting a file down in there. Perhaps a riffler file? If so, I’ve got some tucked away, never used. Yet.
So far, all my feeder soldering has been to the bottoms of Walthers Code 83 track, using resistance soldering. I do it upside down, so that the probe is pressing downward to hold the wire to the rail. And the rail is supported by a worksurface. And there is no need for a hole.
Thanks! I was trying to remember the name for those so I could order a set. I’ve been using a flat sided needle file that is just flexible enough so I can get in there with the bottom of the smile.
What is the failure mode for these wire connection? With solid feeder wire, you should be able to bend it to maintain a slight tension pushing it against the rail (unless you have a prehensile tail or somethign to hold the wire while you have the soldering iron in oen hand and the solder in the other). Two prep steps - file or use a Dremel abrasive of some sort (those brass scratch brushes Micro Mark sells also would work) to clean the rail at the spot of attachment - drilling a hole also does this, so that may be why the hole method works better, and also a dab of flux on the rail at the point of attachment. Bend the wire in contact witht he rail, apply a CLEAN hot iron tip, apply solder to the joint (NOT the iron tip) and presto, it should eb soldered. 40-60 watts of soldering iron power should be plenty, my soldering station is 60 watts. The tip needs to be clean and shiny and properly tinned - this to speed the heat conduction so you don;t have to linger so long that you melt the plastic ties.
Here’s the first one. I got a little heavy handed with the file and knocked off some spike heads (riflers haven’t come yet) but I think I can do better. You can see the wire coming up from under the rail and the copper dot where it comes through.
On trick I remember from an old MR, if you are using solid feeder wire, zig-zag it so when you push it up the hole, it grips the sides. This will hold the wire tightly in contact with the underside of the rail so it can be securely soldered without any sort of holes. The solid physical contact is the key to making the solder joint solid and reliable.
The other option for an “invisible” feeder is to drill through the tie and flatten the end of the wire like a spike head.
The gap between the ties. rail and roadbed is about .08" high and .12" wide. If you can get a hot iron and solder into that space to attach a wire to the underside of the rail and not melt a tie, you must be some kind of soldering savant. There is no way I could pull that off.
It just seems like a whole lot of work when there are other ways. It’s probbaly just fine, since a drill that small will snap before it ruins any track if it gets seized up. I’m not sure I could get the wire to line up in the hole even with my magnifier headset but then I am starting to develop vision issues.
It appears you are drilling in to the slanted bottom web of the rail - while you think it would take almost superhuman power to solder a wire under the rail, with the extended very thin tip in my soldering station it wouldn;t be too much trouble, while I feel almost the same about trying to start a tiny drill on a slanted surface and not have it wander all over the place. I’m fairly steady if a rest my forearms on something, but there reamisn the issue of seeing what I’m doing.
Pretty much anything short of running an inch of wire along the visible side of the rail is darn near invisible after the rail is painted. ANd model rail joiners ruin any effect anyway, painted or not. Unless you are not using joiners, which IS possible, and adding some joint bars.
Now there’s a product idea - instead of both sides of the rail joiner crimped over, one side could be punched to resemble a prototype joint bar. Just one side, which you place facing out, so there is nothing to interfere with flanges. Or if carefully made, the “joint bar” part of the detail wouldn’t stick out past the railhead. These would have to be track brand specific since the dimensions of the web vary from track brand to track brand, even when it’s the same overall height. Boom, every track joint has proper detail.
My previous method of powering via the rail joiners also made invisible feeders, although of course they had to be installed when laying the track. I am probbaly not going ot use that method on the next layout since I will have many isolated sections for signaling and detection.