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Unread 11-03-2020, 11:09 PM   #6
DonVoigt
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I wrote a post on these springs -somewhere and sometime ago- now I can't find it.

The Thickness of the flat springs governs the "strength".
The drawing in G&S shows the springs had two leaves of 0.88mm(this is hard to read it may in fact be 0.83mm!);
I believe these to be an interim specification.
I have measured many springs and find them from 0.7 to 0.9 with a max of 1.0 mm.

The springs were gradually "improved" for more certain operation.

As Ron wrote, the two leaves of the early springs were improved by changing one of these to a thicker spring.

I've satisfied myself that the original springs were 0.7 to 0.75 mm thick, they do taper slightly from top to bottom. Thus the 9mm spring would become one 0.7-75mm spring plus one of 0.95 to 1.0mm thickness.

I have rarely found springs with two 0.95 mm leaves.

Of course replacement and reproduction springs have been made now for over 100 years, and any measurements made may be confused by not knowing if a spring is original DWM mfg or from some other maker.

These leaf springs also suffer from fatigue, and some thicker leaved springs are actually by now weaker than newer or less used 0.7mm double springs.

Most recently, when my spring supply was quite low and I only had weak leaf mainsprings, I added a third spring leaf between the two "normal" leaves, creating a three leaf "reinforced" spring.
The third spring was from a spring with only one leaf left, the other broken before I obtained it.
This agglomeration works in my shooter 1900.

The 1902 carbine has the auxiliary spring in the forearm to assist in closing the toggle, as the long barrel and forearm weight creates too much inertia for the mainspring in the grip to close it
reliably.

Update:
I spent some time "finding" the pages in the Red Volumes of Pistole Parabellum by G&S, I sure wish those 3 volumes had a decent index!

See the spring story starting on p-221,222, and ref. carbine on 243.

Seems first springs had two leaves of 0.73mm, increased to two of 0.80, and then two of 0.85.
There are then springs noted that have one thicker leaf, but tapered from a thinner top to thicker at the bottom, these were 0.75->1.15mm and 0.85->1.15mm; these thicker tapered springs were combined with a second spring of either 0.75mm or 0.85mm.

So- how many spring varieties were made by DWM- at least 5!

Now you know more about leaf springs than anyone thought possible.
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