Compound shutter sizes

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

Ole, you best link to this thread in your signature. That way people can always refer to it :)

Good idea, Ash. :)

Nice idea Ole. Are those thread sizes 'really' t.p.i., or are they metric sizes translated into imperial units?

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... :)

Is it time to put this info up on the front page of this site as article? That would save peole searching for it.

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.

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

Quote:

---

Originally Posted by Ole Tjugen

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

---

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.

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.

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),

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...

So, the "tube" refers to an actual tube threaded on both sides: male into the shutter and female for the rear lens element, yes?

Quote:

---

Originally Posted by MAubrey

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.

Quote:

---

Originally Posted by Dan Fromm

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.

Quote:

---

Originally Posted by Christo.Stankulov

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.

Quote:

---

Originally Posted by Ole Tjugen

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..._centraux.html also supports this measurement.

Quote:

---

Originally Posted by Bemko

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..._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

Sorry to bring an old thread back to life, but I just received a lens in a Compound shutter. I'm assuming its a #3, the shutter speed goes to 100, and it seems approximately the right size. It didn't have a flange or retaining ring, so I measured it with a pair of cheap digital calipers and the outside of the thread is 63.5mm or exactly 2.5in. I compared that to the numbers listed on SK Grimes site here: https://skgrimes.com/products/mounting-flanges/

He lists two different sizes for Compound #3--M60x.9 and M62x.9 neither of which are close to what I need. Out of curiosity (and because I don't entirely trust my calipers for fine measurements) I took a retaining ring for a Copal #3, which should be 62mm, but with a .75 thread, and it wont even fit over the rear tube before reaching the threads. So I know its definitely larger than 62mm (I wouldn't think the calipers, no matter how cheap, would be off by over a millimeter.)

I've sent a message to SK Grimes, but I thought I'd ask here as well. Has anyone seen a Compound 3 with a 2.5in thread? Or do I have something customized? FYI, the shutter is labeled "C.P. Goerz New York" on the speed dial, and it houses a "GOERZ DAGOR F:6.8 FOCUS 12 IN."

My Compound 3 measured gives me: M0.9

See also the table in this post:
https://www.largeformatphotography.i...=1#post1565200

Hmm. B&L made Compound shutters under licence. Goerz American is more likely to have used B&L shutters than to have imported.

Abruzzi, just send your shutter to Grimes and pay their price for a retaining ring.

That’s what I was planning, but I was hoping to buy the retaining ring from him without having to ship shutter both ways.