Where can I find a die cast/metal chassis that can be inserted into HO scale locomotive frames?
The thread title and the text ask 2 different questions. And I assume we are talking diesel models, not steam.
Hobbytown of Boston used to make heavy mechanism/chassis kits for a decent variety of diesel plastic and metal shells. They were reknown for their pulling power. Bear Locomotive Works took over the product line, but only lasted a few years. I believe the remaining parts stock was bought by Micro-Mark - at least the universals were.
The Hobbytown kits were pretty much driven out of business by the improved stock diesel mechanisms that started being produced in 1980s, and have pretty much taken over almost all the diesel model production.
Athearn used to have large block weights to fill all the space in their “super” line of F-7s and some other models. Most plastic production diesel models today fill most of the space with weight, so again this generally isn’t an issue with modern production.
my thoughts
Fred W
But suppose you wanted to find a lead (or metal) weight of certain dimensions. You could turn the locomotive shell upside down and just pour hot lead into it. No wait, I think I can see a problem with that.
OK, let us line the shell with plastic wrap and force some of that florists foam into the cavity. Then you can lift that out and make a mold around the outside of it, and then pour your lead into that. Then of course you would need to machine the rough spots and cut out the cavity for the motor and other stuff in there.
There are just simply too many locomotives out there, you will just have to find what will do.
Maybe the LION would take the shell off and simply glue printers slugs to the inside of the shell. (Yes, printers slugs have gone the way of buggy whips, but maybe you can find some.) Put the shell back on. If it fits take it off again and try another slug. Keep doing this until it does not fit, and then take that last slug back out again.
But you need not pour lead at all. Maybe a clear plastic resin will be enough weight. Maybe you can fill some of the shell with that.
roar
Lot of us use stick on wheel weights stuck to the inside of the shell and or on top of the chassis.
Cuda Ken
I have used fishing weights. Just pounded and cut them to the shape I needed.
I bought a sheet of lead online a few years ago. Here is the source I believe I used:
http://www.rotometals.com/Lead-Sheet-s/31.htm
The sheet I purchased is 1/16" thick. I have used it to add weight to a variety of rolling stock. It can be cut and formed into whatever shape you need. I use either double sided tape or epoxy to hold it in place. I have also used it to model flat car loads (but getting it perfectly smooth is a bit of a challenge).
There are obviously some concerns about working with real lead. I use gloves to handle it and I do not cut it, sand it or otherwise work with it in any manner which would create dust.
I bought a 1 foot by 2 foot sheet and I think it will last me throughout my entire modeling career.
Dave
I work often with my own custom blended ultra low melting point metals. Rotometals, already noted above, offers some lower melting point metal aloys. These are all very dense as the bulk of the metal is bismuth and lead. With the addition of Tin, Cadmium and Indium, a 117 degree F melting point metal is the result. It is expensive due to the indium content, but can be cast directly into plastic!
Many of these metal alloys are called “blocking metal”, used by machinists to hold parts at odd angles for milling or turning.
I would practice on something non-critical though, if casting in plastic. The 117 degree alloy is not very conductive of its heat and neither is plastic. As room temp is often in the 70’s, the differential is low and such castings take a while to cool if thick or volumetrically large. This means that you should melt this metal very slowly until it just melts and quickly remove all heat from the melt and cast quickly also. Do not blast heat with a torch or a stove or hot plate set on high. 117 degrees is not all that hot. You don’t want to overheat and have the plastic soften on you.
Richard