Inside a Standard Gauge wheel

Holy cow! When we mold (plastic) parts, we X-ray them to detect voids in the castings like this. I've got a box of old warped Std ga wheels, and an atlas 4800 lathe. I should cut a few open and look inside.

CJ Meyers posted:

Holy cow! When we mold (plastic) parts, we X-ray them to detect voids in the castings like this. I've got a box of old warped Std ga wheels, and an atlas 4800 lathe. I should cut a few open and look inside.

Quite the voids there, aren't they? I chucked it in a three-jaw and had a live centre up against the axle-hole to hold it. All worked out ok. I made a couple of small saw cuts on the "tire" and pried it off. I have three more old wheels if this one goes south, but I suppose I should work fast. Removing metal might cause more warping. 

Porous pot metal castings - whoda thunk? Maybe this is where the zinc pest resides!  LOL!

Is it really a surprise that castings for what were once considered toys did not have the precision of say a NASA product?

Tinplate Art posted:

Is it really a surprise that castings for what were once considered toys did not have the precision of say a NASA product?

LMAO!  

Henning's Trains has those wheels if you wreck yours.

GRJ: Nice segue.

Tinplate Art posted:

GRJ: Nice segue.

Well, I figured it was a good time to mention it.

I'm with GRJ on this. Not worth my time to mess with bad standard gauge wheels. Zinc rot in these is well known, and replacements readily available.

Chris

LVHR

And the replacements, especially from Henning's, are well crafted in the quality tradition of MEW!

For the younger folks on the OGR Forum, Model Engineering Works (MEW) was a quality pioneer supplier of prewar replacement diecast drive wheels, as well as other parts, such as headlights and loco pilots for many years. 

gunrunnerjohn posted:

Henning's Trains has those wheels if you wreck yours.

Aha! I no so stoopid I look! I bought replacements before I carved up the old ones. 

Henning's bought the MEW line and produces them right in downtown Lansdale.

Model Engineering Wheels at Henning's Trains

Firewood posted:

gunrunnerjohn posted:

Henning's Trains has those wheels if you wreck yours.

 Aha! I no so stoopid I look! I bought replacements before I carved up the old ones. [] []

Good thinking.

I wish they would do a set for Marx too; more chips than Pringle's has.

Adriatic posted:

I wish they would do a set for Marx too; more chips than Pringle's has.

The prewar spoked drivers can be rotted, but very seldom on the postwar Baldwin style.  At least they are interchangeable except the ones from later DR motors. Spare used motors/engines are cheaper than a set of Repro wheels would be.

Steve

  I'm usually not hesitant to go with used, but I've had every pair of Marx I've pulled crack or be loose on the splines.

  They still work, but take care to pick up, do fall off at times, or are unsightly. I think it's their weak point and wouldn't mind the sure thing vs a risk. I can put up with beat up and rusty beyond the norm on the topside, but only if I like the mechanicals.

 Maybe give me a holler when you dump that old junk box upside down Papa Steve.

(and thanks for pointing that out too btw)

 

It is more likely that many original wheels are damaged by the use of an inappropriate wheel puller tool, or by misusing a proper one. Older castings are probably more brittle by nature, and should be handled with great care by using the proper tool, and by exercising gradual force. The careful use of a drift pin punch on a driver axle might be a safer choice than a wheel puller. Even with these precautions, there will unfortunately be some breakage. RE: MARX  replacement parts: The Robert Grossman Company out of Mentor, Ohio, has been the long time reliable supplier of parts for MARX trains, including tools.

I'm by no means a novice with pullers large and small; I used to help build custom temp. & pressure gauges.  It's a very brittle metal and reminds me of old magnesium/aluminum alloys.  I'll have to find a totally ruined one and see if it will ingnite 😈  (outside & eyes protected as it is akin to welding and once started to self-comubustion, hard to stop...Very very bright green, it will make your yard look like aliens have landed. "the biggest welding arc you've ever witnessed")

I can tell you with certainty that the old magnesium/aluminum stuff from aircraft will ignite!  We decided to try to fire up one, I believe it was in the summer of 1959.  Hit it with a oxy-acetylene torch and away it went!  As you stated, once it's burning, very difficult to put out.  We heaped about 6" of sand on it, but that was just making glass, didn't even slow the combustion!  It finally burned the roughly three foot rod and then it went out.  Left a nice big burn line in the asphalt of the hanger apron, we disguised it as good as we could so my father wouldn't notice it!  Never did get questioned about it, but I had a new respect for magnesium after that.

Your looking at the root cause of Zinc Pest. Those voids represent where the impurities were in the metal.

Tin