Model Locomotive frames

Nope. My frames are all brass bar.  If you would like to consider brass, see my articles on 0-6-0s in OGR of about eighteen years ago.

I agree with Bob.  Brass bar stock works very well and seems to be the standard.  Unless I'm starting with a cast frame......oh wait, I use brass for that also.

Jay

Sunset has cast frames on their engines. They also have detail and are well constructed. Some of the boilers are .032 (AC-7, 12 cab forwards). I think KTM had .025 boilers. If you can find a Lobaugh, you can't go wrong.  They had very thick brass boilers made of brass.  I sympathize with you, alot of high end stuff has alot of detail but flimsy construction, particularly thin frames. The cheaper brass engines such as Williams Crown series, and Weaver are fairly well constructed.  They don't have alot of detail, but you can add that on.  When I see a brass engine on ebay, the first picture I look at is underneath the frames to determine their thickness.

Wisco2r,

If you don't like the answers maybe you shouldn't ask the question.  I see no advantage to cast iron over brass bar stock.  The difference in weight is minimal and brass is far easier to machine.  Oh yeah, you better check your weights......brass is heavier than iron.

Jay

If you can get a piece of 1"square meehanite, annealed, and have a good end mill, you can do what you are proposing.  I have machined a frame out of 1" x 1" brass, and it worked out ok.  I would not do it again - too much waste, and too many ways to make a mistake.

let us know how itmworks out.

Thank you for the advice, Bob. I will give that a shot. The endmill won't be a problem.

Once I get my mind made up, I have a tech school machine tool instructor who spent 30 years at Eck Machine in Manitowoc and a bunch of Haas CNCs to make this happen. 

And I will make sure I get this project documented, so that anyone who's interested might be able to recreate it and hopefully save a few bucks in the process.

John Dill (rip) had a bunch of Hudson frames CNC'd out of 1" brass bar.  One side was slightly narrower than the other.  Hard to believe he would go in to production with a flawed program.  Also hard to believe that he thought he would make a profit.  I have one, but do not know where the rest went.  I think I would do the first one in aluminum, and then inspect very carefully.

Again, good luck.  I am willing to bet that you will go for built- up after your first attempt, and that you will select brass for subsequent models.  Brass is the material of choice  for O Scale, in limited quantities.  It is a lousy bearing material, but for axle bearings, it seems to work just fine.

Absolutely no reason why a frame can't be made in cast iron, especially when you have access to CNC (I'd be in heaven to have that!) but I can think of a good reason why you shouldn't - rust.  Maybe you can surface treat it such that it lasts for many years, but having put the time and effort in, I would be happier knowing it's going to last so I think alli-bronze would be far more sensible.  I speak from many years spent designing machinery for marine environments, and first rule is; if it's going to be a major to get at something to maintain it - i.e. treat rust - then make it from something that won't rust.  I think that stripping down an engine to get at any patches of rust will get old real fast.  Regards, Paul.

Do it the "hard" way... use a hard metal; how many real locomotives have soft metal frames? Brass might make nice trophy tops; but, steel and iron make machines!

Take advantage of the metals ability to rust; real motive power rusts!

Rick