I have a Sunset K-36 that managed to throw and mangle one of its monkey motion valve gear linkages. It runs OK without it being there.The corresponding parts on the other side of the loco are chromed metal of some kind. I suspect these were stamped and the best I could probably do would be to cut some out of sheetmetal that may need to be thicker to be as strong.
Any suggestion on the best course here in respect to what metal I should use to make replacement parts? One is an L-shaped crank and the other is just a straight link. Both are sub-one-inch parts.
Mike Lehman
Urbana, IL
Your "Chromed metal" is most likely nickel silver, certainly trhe appropriate metal for the parts in question. Try to get a CAD drawing of the parts and have them 3D printed.
That happenned to me once. I managed to find a larger one in my parts box and adapted it by drilling a new hole and filing it down.
Simon
Sir Madog Your "Chromed metal" is most likely nickel silver, certainly trhe appropriate metal for the parts in question. Try to get a CAD drawing of the parts and have them 3D printed.
Ulrich,
Yeah, I suspect nickel-silver, too, based on what I've heard. Need ti see abut getting a small sheet of proper thickness and give it a try.
Don't think they can 3D nickel-silver yet, but perhaps you were suggesting try it in plastic? Dubt that would be tough or rigid enough. Also, no plans, so Id be stuck on that.
Simon,
Good idea, but my brass parts box isn't that deep. Will keep my eyes open for salvage maybe?
Mike - you´d be surprized what they can in 3D printing these days - brass, nickel silver, but I guess by the time you have prepared a CAD drawing, you will already have finished the part from sheet metal - not that I mean to say you´re slow at handling a CAD system
Make them from nickel silver. It is fairly easy to work with a file, it has the right silvery luster, and it won't rust. Take care to locate the holes correctly, an off center hole can confuse the rest of the valve gear. Since you have the parts from the undamaged side, all you need do is lay the good parts on the nickel silver, scribe around them, cut them out with a fine toothed saw, and then file them down to the scribed line. Measure the thickness of the undamaged parts and order a piece of nickel silver of the same thickness. You may have to go to McMasters-Carr to get it. I haven't seen anything but brass in hobby shops. Brass will work too, if you don't mind the yellow luster.
David Starr www.newsnorthwoods.blogspot.com
If you want to use nickel silver, use a mill file to reduce a length of rail to the thickness needed. Finish with needle files, of course, shaping it to match the intact part on the other side of the loco. Personally, I'd use brass, but I have a pretty good supply of it on hand, from about .003" thick up to 1/4"-or-so, and I generally paint valve gear and side rods.
I'm only guessing, but I doubt that the original ones are nickel silver - more likely, they're plated brass, perhaps with chrome, as they don't usually respond to blackening agents such as A-West's Blacken-It or even to gun blue. Nickel silver, however, can be blackened if it's cleaned of oil and grease.
The eccentric crank can be built-up using either nickel silver or brass - it's basically a piece of rod with a hole in the middle for the screw that holds it in place, with the "crank" portion shaped to match the remaining intact one, and soldered to the rod portion.
Wayne
Send an email to Scott Mann - sdmann@3rdrail.com
Chances are rather good that he'll have some suitable parts, or access to them, more good suggestions, or information for you.
I couldn't lodge the male part of the tether into its under-cab receptacle on my new T1-c 2-10-4 Selkirk. He asked me to ship it to him, and as far as I know, fixed it himself at no charge. Just shipping costs one way.
Amazon sells both nickel silver sheet and rod.
Ed
Thanks to everyone for your very helpful replies. I'll probably give it a try myself (freestyle, Ulrich, because I don't have a clue about CAD), so will see about getting some sheet material and filing it down after cutting a basic blank loose from it. Fortunately, ths part of the valve gear is "faked" on my Sunset, so merely has to flip back and forth realistically as it doesn't drive another part of the valve gear.
You can print in steel.