Re: Linkage repair on a brass locomotive


Bryian Sones
 

Dan,

With all that said. I assume there might be better tools available than others. Do you have any suggestion on where to get the best tool for this and which to buy? 
Also, thank you to everyone for the input. There are really good suggestions and advice.


Thank you,

Bryian Sones
Union Pacific Prototype Modeler
Murrieta, CA


On Wednesday, January 30, 2019 12:03 PM, Daniel A. Mitchell <danmitch@...> wrote:


Good advice.

When setting such a rivet one wants to roll the hollow end over into a bead rather like a doubled-over sock. You do not want to just squash it flat. Flattening it may work, but will usually crack the rivet’s new head, and weaken the rivet. This is why rivet-set tools are made.


They form the new head with a smooth sort-of “rolling-over” action (no true rotary motion is involved). Lacking a rivet-set of the correct size, a reasonable alternative is to carefully expand the rivet just a bit with a countersink or other pointed / tapered tool, then work the edge outward and down with a small jeweler’s ball-peen hammer. It’s not as good as using a proper rivet-set, but can be quite satisfactory.

As an aside, this is the same idea as rolling in boiler tubes in a tube-sheet. Here the much larger tubes ARE actually rolled into form with a rotary-roller tool driven by a large air or electric drill. As the tool rotates inside the hollow tube it forces the metal outward then bends and stretches it back over itself forming a bead.


Such a tool would be great for hollow rivets too, but for HO valve gear the parts would be microscopic!

Dan Mitchell
==========
On Jan 30, 2019, at 11:09 AM, Edward <edb8391@...> wrote:

I would also like to add that when setting such a rivet to join moving parts, that it not be set too tight.
If set and too tight, the rivet should be removed and the job done over.
Trying to work a tight joint to free it up could damage the rivet 's upset.
Binding might also cause the moving parts to possibly fail at some point. 
Putting a thin piece of paper or similar removable material between the moving parts before riveting may help avoid the issue.

Ed Bommer
.



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