Re: rivet heresy/what's old is new


pullmanboss <tgmadden@...>
 

Manfred Lorenz wrote:
There was a decal manufacturer who made rivets, weld seams, hex
screws, latches etc. on dry transfer decals. These were mainly
intended for the military modeler but also for railroad models. He
has stopped making them due to the trouble they gave him in
production.

It appeared to me that this was/is a very clever method...
Wayne Long posted an excellent analysis of the Archer dry transfer
rivets to the Passenger Car list in December 1999, and I posted it to
this list in March 2001. Basically, he found them much too thin for
his purposes. But memories are short, so here's a repost of Wayne's
analysis:

BEGIN QUOTED MESSAGE
I measured the thickness of the items in the sample sheet I purchased
from ARCHER. They are 0.02 mm thick. I think that that is something
like 0.00075", which would be only 0.065" in HO.

The following is what I sent to ARCHER after I examined the samples:

I can't use your rivet detail because they, simply, are to thin. A
real rivet does not have a flat head. Instead, the head is rounded.
Let me share the formulas relating to size in most railroad rivets.

The "size" of the rivet (in inches) is the outside diameter of the
shaft which goes into the two or more holes in the metal pieces
being riveted together. The diameter of the rivet head, where it
bears on a metal surface is size x 1.5 + 1/8". The head at its
highest point off the same metal surface is:
size x 1.5 + 1/8" x 0.425.

Apply this information to a standard 1" rivet and you get:

Shaft = 1" O.D.

head = 1 5/8"

head thickness = 11/16" + which is 0.22 mm in HO scale

Your rivet would have to be at least 0.22 mm thick and dome shaped
to simulate the prototype.

Hope this helps. Of course, rivets are of various sizes. Most
often, the ones cast into plastic HO cars/tenders are oversize. If
they were of "correct" size, we would not be as aware of them as we
are.

Wayne R. Long
------
END QUOTED MESSAGE

Andy "Earnest Modeler" Carlson mentioned the rivets on the
forthcoming (finally!) Branchline passenger cars. When I submitted
the design drawings for those cars to Branchline I had assumed the
rivet head diameter was 2X the shaft diameter. According to Wayne's
formula my 3/8" and 1/2" shaft diameter rivets should have 11/16" and
7/8" head diameters respectively, instead of the 3/4" and 1" heads I
gave them. My bad!

As penance I will burn some incense and place a pair of calipers and
a jewelers loupe at my Byron Rose grotto.

Yes friends, Byron will be incensed.

Tom Madden

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