Making a replacement case for a Verner's Pattern Mk vii Compass

[Djumpster]

Hi all,

I've recently come into possession of a beautiful 1915 Verner's Pattern Mk vii, by Ed Koehn in Geneva. 
It's needed some love to get it back in working order (don't worry, I took all the precautions - I'm aware of the radiation risk!), but now that I've put it back together, I'm absolutely over the moon with it

Unfortunately it didn't come with a case. Now as I'm also a bit of a leathercraft enthusiast, I figured I'd try my hand at making a new case for it myself. 
I was wondering if anyone out here could provide me with some good quality photos of an original case, preferably with dimensions? 
Any help would be most appreciated!

Here's some pics of the compass: 

[MikB]

Here's the case that came with my 1916 Cruchon & Emons - case was made by LF&Co.

The long axis of the oval piece is 79mm, the short 56 - that's just the leather insert, excluding the 'rind'. The oval inserts are 5mm thick, the rind about 4. Strap's 11.4 (probably 7/16") wide and forms a loop about 430 mm long. Internal depth to fit the compass is a little tight at 22 mm, and there's a thin dark red baize lining. The rind continues to form the hinge and outer rim of the lid, but the inserts for that sewn to the edge of the rind, not the inner side.

I've only done minor leather restorations, but my guess is this is a long and difficult job! Good luck! :-D

 

Edited 5 February , 2023 by MikB

[Spaceman]

I've repaired quite a few WW1 leather cases of one description or another and the most challenging  technique for me is stitching two pieces of leather back together at right-angles as in the compass case. I assume the trick is to glue them together before stitching and to mark the holes beforehand but making the new holes accurately from scratch would definitely be beyond my capability.

[17107BM]

I'm liking this thread already.

Any chance of keeping us updated?

Gary.

[MikB]

Last time I made a barrel cover for a hand telescope, I used a domestic sewing machine with a stout needle and worked slowly by hand to pre-punch the holes at a suitable pitch.

But the edges to be sewn together there were parallel - for right angles I think I'd need glue as suggested above and a 1.0 - 1.3 mm drill in a Dremel or suchlike to prep the holes. I'm just speculating here.

Sooner thee than me... (!) 

Edited 3 February , 2023 by MikB

[Chasemuseum]

There is a leather workers hand tool, which has a small studded wheel. This is run along the leather and marks the position to make all the holes so that they are uniformly spaced. You then use an awl to make all the holes.

[Spaceman]

That's exactly the way it is normally done. For stitching two pieces of leather together at right angles, I guess you would only need to mark the holes on one piece but the real challenge would be using the awl to make the holes at 45 degrees that came out accurately in the other piece of leather. I recently repaired the stitching in the leather case of a Mk V Heliograph and that was quite challenging lining up the pre-existing holes to get the needles through at 45 degs!

[Djumpster]

23 hours ago, MikB said:

Here's the case that came with my 1916 Cruchon & Emons - case was made by LF&Co.

The long axis of the oval piece is 79mm, the short 39 - that's just the leather insert, excluding the 'rind'. The oval inserts are 5mm thick, the rind about 4. Strap's 11.4 (probably 7/16") wide and forms a loop about 430 mm long. Internal depth to fit the compass is a little tight at 22 mm, and there's a thin dark red baize lining. The rind continues to form the hinge and outer rim of the lid, but the inserts for that sewn to the edge of the rind, not the inner side.

I've only done minor leather restorations, but my guess is this is a long and difficult job! Good luck! :-D

Thanks so much for the excellent description, this really clarifies a lot! I found a bunch of good pictures of cases online, but somehow none of them showed how the lid actually attaches to the body. That's perfectly clear now.

I think I'm with you on this being a challenging project, but let's see how it turns out😎

 

Edited 4 February , 2023 by Djumpster

[Djumpster]

20 hours ago, 17107BM said:

I'm liking this thread already.

Any chance of keeping us updated?

Gary.

Absolutely! I don't really have a timeline in mind so it may be awhile before I can post something, but I'll be sure to share it here once I have something worth showing

[Djumpster]

9 hours ago, Spaceman said:

That's exactly the way it is normally done. For stitching two pieces of leather together at right angles, I guess you would only need to mark the holes on one piece but the real challenge would be using the awl to make the holes at 45 degrees that came out accurately in the other piece of leather. I recently repaired the stitching in the leather case of a Mk V Heliograph and that was quite challenging lining up the pre-existing holes to get the needles through at 45 degs!

I don't think one of those wheel things will work here, because the stitches will need to be of different sizes. The stitches on the 'faces' need to be closer together than the ones on the 'rind' because those are on the outer diameter. I think I should be able to calculate that somehow though. 
I usually take a pair of... well, compasses, to mark the stitches at the exact spacing I want, then use the awl to punch them through. 

Anyway all of this looks good on paper, but we'll have to see how it turns out. I think I'll do a bit of prototyping with some thick cardboard first, I'll post some pictures!


 

[Chasemuseum]

1 hour ago, Djumpster said:

I don't think one of those wheel things will work here, because the stitches will need to be of different sizes.

The marking tools are (used to be) made with interchangeable wheels with different spacing of the barbs to allow the leather worker to space the pitch of the stitching to their needs.

Here in Oz leather working was a popular hobby many years ago but has largely gone out of fashion and the supply shops have disappeared. Those that remain are more general "craft" shops and only have a very limited supply of leather working tools.  

[MrEd]

11 hours ago, Spaceman said:

That's exactly the way it is normally done. For stitching two pieces of leather together at right angles, I guess you would only need to mark the holes on one piece but the real challenge would be using the awl to make the holes at 45 degrees that came out accurately in the other piece of leather. I recently repaired the stitching in the leather case of a Mk V Heliograph and that was quite challenging lining up the pre-existing holes to get the needles through at 45 degs!

I have done some box sewing of leather - I have pricked the stitch marks n both pieces then use a pricking iron to hammer the stitch holes through at 45degrees on each piece - it mostly lines up, and certainly well enough to hand sew with an easiawl

[MikB]

SORRY, Djumpster! 

I just realised one of the dimensions in my first post on here with the photo of my compass case was utter b0110x!!

The short axis of the oval is 56mm. I've edited my earlier post to correct.

 

[Djumpster]

Yeah, I was actually sketching it out this morning and came to the conclusion you had to be about 2cm off 😅 

I had a question about the lid though: when it's shut with the compass in it, does the lid rest on the ring of the compass, or does it fit snugly on top of the case?

[MikB]

3 hours ago, Djumpster said:

Yeah, I was actually sketching it out this morning and came to the conclusion you had to be about 2cm off 😅 

I had a question about the lid though: when it's shut with the compass in it, does the lid rest on the ring of the compass, or does it fit snugly on top of the case?

I fold the ring under the compass body and have the prism case and cover at the peak of the oval - it's a tight fit:-

Edited 5 February , 2023 by MikB

[MikB]

Note there should probably be a rubber donut in the undersurface recess, with a moulded cutout to fit the ring:-

There's also an arrangement of crossed linen threads across the inside bit of the rind that forms the hinge - probably strengthening but I don't really know what it's about - you can just see one end of it in the previous pic.  I'll photograph it later.

Edited 5 February , 2023 by MikB

[Andrew Upton]

20 hours ago, MikB said:

Note there should probably be a rubber donut in the undersurface recess, with a moulded cutout to fit the ring:-

 

When these were brand new there was no moulded cut-out - they simply go that way after decades of being stored in the case with the ring pressed against the rubber.

[MikB]

4 minutes ago, Andrew Upton said:

When these were brand new there was no moulded cut-out - they simply go that way after decades of being stored in the case with the ring pressed against the rubber.

Ah, thanks - I had wondered whether the behaviour of the earlier red rubbers might have produced this, but haven't seen its like in more modern formulations. In the trough of the depression the stuff's really only as thick as the depth of the turned recess. I have worked in neoprene moulding, and wouldn't expect that to compress like this even after extended periods.  I concluded it was probably made like that, but happy to stand corrected. 

[Chasemuseum]

I have often wondered whether it was made like that, by fitting a partially cured rubber ring to the compas body then pressing the thumb ring into the rubber before it fully cured or whether years of storage did that. Every compass I have handled has had the rubber compressed like that.  

[MikB]

18 minutes ago, Chasemuseum said:

I have often wondered whether it was made like that, by fitting a partially cured rubber ring to the compas body then pressing the thumb ring into the rubber before it fully cured or whether years of storage did that. Every compass I have handled has had the rubber compressed like that.  

That would require a type of rubber that continues curing after extraction from the mould. If such a type exists and was used, presumably that would mean it was seated in the recess whilst still hot and then had the ring folded against it while it completed curing.

The neoprene I was working with wasn't demoulded until fully cured, so AFAIK couldn't have been used that way. But that stuff was a long way from the old sort of red rubber.

[Chasemuseum]

Natural rubber is cooked in an autoclave (under pressure and with limited free oxygen) to "Vulcanize" it. Back in WW1 a lot of the use of rubber was with only a partial/incomplete vulcanizing process for various technical reasons. This produced a product that has not survived well across the century. The rubber coating inside the face mask of a small box respirator often peels off the fabric and virtually turns to dust. The same with the rubber flutter valve of a PH helmet. Again with the PH helmet, the metal tube that goes in your mouth has a short length of rubber tube around it. This has often degenerated into a mass of blobs of hard rubber stuck to the metal.

 

This also applies to a lot of WW2 Japanese rubber products. Many years ago I left a WW2 rubberized canvas bayonet frog on a shelf where it was in direct sunlight for a few hours a day. The rubber melted and leaked out of the canvas fabric on each side of the frog. 

Edited 7 February , 2023 by Chasemuseum
speliing errors

[Djumpster]

What exactly was that ring for? I know they are called 'friction rings', so I assume they are there to prevent the compass flom sliding off of things, but I haven't used a compass often enough to tell for sure.

I would like to find or create a replacement for it though. I assume it's just a kind of latex?

[MikB]

1 minute ago, Djumpster said:

What exactly was that ring for? I know they are called 'friction rings', so I assume they are there to prevent the compass flom sliding off of things, but I haven't used a compass often enough to tell for sure.

I would like to find or create a replacement for it though. I assume it's just a kind of latex?

I think especially to stop them sliding on maps. The brass ring is a thumb ring to hold by when taking bearings through the prism. If used skilfully  these compasses can be good within 1/2 a degree.

I've never tried it, but I don't think the rubber ring can have any magnetic isolation value if the compass is placed on a metal surface.

[Chasemuseum]

With a prismatic compass you put your thumb through the "thumb ring" and hold the compas up to your eye so that you can look through the prism. You can look through the compas and the fine vertical wire in the lid of the compass and read the "card" (the rotating disk they use instead of a needle) at the same time. In this way you can take a very accurate bearing on a distant object.

 

For a compass in degrees rather mills, you can take a bearing to half a degree. 

[Djumpster]

I see... I didn't know you were supposed to stick your thumb through the ring, I always thought that was just for attaching a lanyard or something. Today I learned!

The sighting wire I've had to remove because it had come off at one end and there was no way I could put it back tautly again. Will try to replace it with something. I think that was an actual (pig?) hair btw :-)