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Ole Tjugen
8-Mar-2007, 05:03
Since these come up quite often, I'll post what information I have here once and for all.

All data are taken from the Compur Repair Manual, so they should be correct.

There were five sizes of Compound shutter (late type, with X-sync):

Compound 3-X Tube 7
Compound 4-X Tube 9
Compound 4-X Tube 10/II
Compound 5-X Tube 12/I
Compound 5-X Tube 12/II

Dimensions are listed as:
A: Cell thread (all are the same front and rear), all are 40 t.p.i.
B: Flange thread
C: Largest aperture diameter
D: Body diameter
E: Length
F: Mount depth (flange to rear end of shutter).

Data - all dimensions in mm :

3-7 : A: 55.69 B: 60 x 29 1/13 t.p.i. C: 40 D: 87 E: 37 F: 15.7
4-9 : A: 62.20 B: 65.9 x 29 1/13 t.p.i. C: 52 D: 106 E: 50 F: 21.8
4-10/II : A: 67.92 B: 76.7 x 29 1/13 t.p.i. C: 52 D: 106 E: 45 F: 19.3
5-12/I : A: 82.77 B: M90 x 1mm C: 64.5 D: 125.5 E: 74 F: 33.2
5-12/II : A: 82.77 B: M90 x 1mm C: 64.5 D: 125.5 E: 60 F: 25.2

Fastest shutter speeds are: #3: 1/100 #4: 1/75 #5:1/50

Ash
8-Mar-2007, 05:11
Ole, you best link to this thread in your signature. That way people can always refer to it :)

Ole Tjugen
8-Mar-2007, 05:16
Good idea, Ash. :)

Struan Gray
8-Mar-2007, 05:40
Nice idea Ole. Are those thread sizes 'really' t.p.i., or are they metric sizes translated into imperial units?

Ole Tjugen
8-Mar-2007, 05:52
Those thread sizes are really t.p.i.

Those are the data taken directly from the book, and thus from the original specifications. The 29 1/13 tpi is very close to .75mm, which is what SK Grimes use.

The 40 t.p.i has a 64° pitch, the 29 1/13 t.p.i. has a 50° pitch. Don't ask me why... :)

Mark Sampson
8-Mar-2007, 06:59
Is it time to put this info up on the front page of this site as article? That would save peole searching for it.

Struan Gray
8-Mar-2007, 07:02
47.5° is the old BA standard for fine screws and bolts. The thread profile was used for wide-bore precision threads too, so I suspect the 50° comes from there.

64° seems odd, but then instrument makers are a funny bunch.

Ole Tjugen
8-Mar-2007, 09:35
I'll add the three types of "standard" Compur 2, too - same format as above:

Compur 2-X Tube 5/I
Compur 2-X Tube 5/II
Compur 2-X Tube 6/II


2-5/I : A: 45.8 x 40 t.p.i. B: 50 x 29 1/13 t.p.i. C: 35 D: 80.5 E: 35 F: 14.6
2-5/II: A: 45.8 x 40 t.p.i. B: 50 x 29 1/13 t.p.i. C: 35 D: 80.5 E: 25 F: 8.3
2-6/II: A: 49.65 x 40 t.p.i. B: 55.8 x 29 1/13 t.p.i. C: 35 D: 80.5 E: 30.8 F: 12.2

Efaron
8-Jul-2010, 15:38
Since these come up quite often, I'll post what information I have here once and for all.

All data are taken from the Compur Repair Manual, so they should be correct.

There were five sizes of Compound shutter (late type, with X-sync):

Compound 3-X Tube 7
Compound 4-X Tube 9
Compound 4-X Tube 10/II
Compound 5-X Tube 12/I
Compound 5-X Tube 12/II

Dimensions are listed as:
A: Cell thread (all are the same front and rear), all are 40 t.p.i.
B: Flange thread
C: Largest aperture diameter
D: Body diameter
E: Length
F: Mount depth (flange to rear end of shutter).

Data - all dimensions in mm :

3-7 : A: 55.69 B: 60 x 29 1/13 t.p.i. C: 40 D: 87 E: 37 F: 15.7
4-9 : A: 62.20 B: 65.9 x 29 1/13 t.p.i. C: 52 D: 106 E: 50 F: 21.8
4-10/II : A: 67.92 B: 76.7 x 29 1/13 t.p.i. C: 52 D: 106 E: 45 F: 19.3
5-12/I : A: 82.77 B: M90 x 1mm C: 64.5 D: 125.5 E: 74 F: 33.2
5-12/II : A: 82.77 B: M90 x 1mm C: 64.5 D: 125.5 E: 60 F: 25.2

Fastest shutter speeds are: #3: 1/100 #4: 1/75 #5:1/50

Paul Ewins
8-Jul-2010, 20:42
Ole, here are a few more Compurs and Compounds that I have discovered while researching the old Symmars:
II or II S (Xenar 165/4.5, Xenar 180/5.5, Angulon 165/6.8)
II 4/2 (Xenar 135/3.5, Tele-Xenar 270/5.5, Symmar 210/6.8)
II 6/1 (Symmar 240/6.8, Symmar 270/6.8)
III 8 (Symmar 300/6.8)

Those are all from the 1935 US catalog. Post war, the lenses had either disappeared or changed to one of the sizes you mention.

The only one of those above that I own is the 270/6.8 Symmar (actually a 27cm from 1928). Dimensions are the same as the 2-6/II except E=41.3 & F=19.

Christo.Stankulov
13-Sep-2012, 01:36
So, can be a Heliar 240/4.5 mounted on a Compound IV-10 II, to be mounted on a Compur 3 shutter?

Thank you.

Ole Tjugen
13-Sep-2012, 07:48
No, as the tables show clearly a 4 is bigger than a 3.
I can assure you that is cannot, at least not without some VERY expensive machine work (and in the case of a Heliar, even that won't help since the central lens element is larger than the opening of a #3 shutter),

Christo.Stankulov
13-Sep-2012, 16:11
Thank you Ole, I did not knew that Compound is made by Compur. My problem is that I have a very nice Heliar 240/4.5 on a original Compound, but I do not have the ring to attach the lens on the lens board. And I can not find nobody do make me this ring here in Paris. There was somebody the the atelier is closed 2-3 mount ago...

MAubrey
6-Dec-2016, 12:34
So, the "tube" refers to an actual tube threaded on both sides: male into the shutter and female for the rear lens element, yes?

Dan Fromm
6-Dec-2016, 12:43
So, the "tube" refers to an actual tube threaded on both sides: male into the shutter and female for the rear lens element, yes?

Sort of. Sort of because AFAIK the tubes don't unscrew from the shutter. Female at both ends to accept lens cells. Tube length is measured from the front of the front tube to the rear of the rear tube.

MAubrey
6-Dec-2016, 14:41
Sort of. Sort of because AFAIK the tubes don't unscrew from the shutter. Female at both ends to accept lens cells. Tube length is measured from the front of the front tube to the rear of the rear tube.

Thanks. I have a Compound 4 that didn't come with it's 10/II tube. I'll be heading to the machine shop.

seezee
7-Dec-2016, 12:01
Thank you Ole, I did not knew that Compound is made by Compur. My problem is that I have a very nice Heliar 240/4.5 on a original Compound, but I do not have the ring to attach the lens on the lens board. And I can not find nobody do make me this ring here in Paris. There was somebody the the atelier is closed 2-3 mount ago...

Christo, you might try an automotive machine shop. I had my retaining rings and other pieces made by a retired auto machinist here in my small university town — surely there are such folks in the big city of Paris.

Bemko
22-Apr-2018, 02:42
The 29 1/13 tpi is very close to .75mm, which is what SK Grimes use.

I believe that 29 1/3 TPI is actually closer to 0.9mm than 0.75mm. It can be easily calculated: 25.4mm/29.334=0.866mm

I can also confirm this by measuring the outer thread of my Compoud #3 shutter - it has 5 threads over ~4.5mm, which gives 0.9mm.

The table from this site http://www.suaudeau.eu/memo/pratique/Les_obturateurs_centraux.html also supports this measurement.

David Lindquist
22-Apr-2018, 18:46
I believe that 29 1/3 TPI is actually closer to 0.9mm than 0.75mm. It can be easily calculated: 25.4mm/29.334=0.866mm

I can also confirm this by measuring the outer thread of my Compoud #3 shutter - it has 5 threads over ~4.5mm, which gives 0.9mm.

The table from this site http://www.suaudeau.eu/memo/pratique/Les_obturateurs_centraux.html also supports this measurement.

Yes, the SK Grimes website shows a pitch of 0.9mm for the flange/retaining ring thread on those Compur and Compound shutters described elsewhere as having a pitch of 29 1/13 threads per inch. I expect Ole was mis-speaking. Incidentally it looks like his last activity here was just about two years ago.

I have no idea why such an odd pitch was used; years ago I asked Steve Grimes. He didn't know either.

David