Tripod Socket Size

[T.G.]

Tripod socket size; is having 3/8" a requirement? I'm making a camera and am wondering about doing just 1/4" on camera bottom or should I do the 3/8" since I will be having these done by a machine shop.

Thanks

[BrianShaw]

Why not both, like Hasselblad does? Tripod heads and quick-mount plates come in both of those sizes.

[BrianShaw]

... but if you do 3/8 only you can always use a bush adapter for 3/8-to-1/4.

[BrianShaw]

p.s. Mea culpa for the mention of a medium format camera brand on this forum. :)

[Jim Jones]

Since you are having the tripod socket machined, doing both sizes would be better than using an adaptor with a 3/8" socket. The depth of the 1/4" socket should be at least 3/8" to allow for tripods, like some B&J models, with a long screw.

[Steve Smith]

How big is the camera? If it's small, just 1/4 will do.


Steve.

[T.G.]

I can't really do both, as the piece will surely be done via a lathe. I reckon I should go with the 3/8" and a bushing to avoid any issues at all. Concept wise, it will be very similar to the base on the deardorffs. Those seem very solid and "trustworthy."

Jim says, "... The depth of the 1/4" socket should be at least 3/8"...".
Thanks, I have taken note of that and will plan it in.

[Leigh]

The threaded hole should be in a flange that supports the camera and distributes the weight.

That flange should be as large as possible/convenient. I would think 2" diameter would be reasonable.

The 3/8" size is fine. You can always buy a bushing if needed.

BTW, you'll get better threads in this size range using a tap and tapping head on a vertical mill (e.g. Bridgeport) than cutting on a lathe.
The outer profile of the flange is appropriately lathe work.

- Leigh

[Alan Gales]

Why not both, like Hasselblad does?

I second this idea.

I own a couple Ries tripods that I use with multiple cameras. It's easy to change the screw on a Ries head but it's just that much faster if you don't have to.

[Leigh]

There are problems with putting two threaded holes in the flange.

1) They must be separated by some minimum distance to ensure that the strength of the flange is not compromised.
2) Given that they must go through the entire flange, which goes through the bottom of the camera, a larger hole is required in the wood, thus weakening it.

The Hasselblad holes are 1" apart on center, with the support spanning 2". That's a huge hole in the bottom of a wood camera.

Using a 3/8" hole with a 1/4" bushing when needed is much more sound from an engineering standpoint in this situation.

- Leigh

[BrianShaw]

How big is the bottom of the camera, or the flange? :confused:

[T.G.]

Bottom of camera will be 15" x 14". The flange will be about 5 1/4" diameter. Yes, I imagine the lathe will do the shaping of the flange and extending post that will be then be tapped to 3/8" x 16. The only hole that will be drilled though camera base will be the 5/8" for the post to extend in, the rest of the flange will just surface mount. Think Deardorff.
Thanks all for the help and thoughts. Ty

[Leigh]

The only hole that will be drilled though camera base will be the 5/8" for the post to extend in...
That 5/8" post is WAY too small for a camera that size. It only gives you a 1/8" wall around the major diameter of the threaded hole.

I would go at least 1" through for the post.

What material are you using for the flange?
Try alloy 954 aluminum-bronze. It's a beautiful bright yellow. It won't tarnish like brass will. Surface finish with standard tooling is gorgeous.
And it's extremely strong. It's bearing-grade bronze used for high-strength high-wear applications. Available from McMaster-Carr www.mcmaster.com

If I sound like a cheerleader for 954, it's because I am. It's the only 'yellow' metal I stock and use; no brass and no other bronze.

- Leigh

[T.G.]

Ok, thanks, I'll increase that measurement. Bringing to the machinist tomorrow. Could I meet in the middle and do 3/4"? The Deardorff example I have in front of me has a 1/2" post for the 1/4" threaded hole.
Material is most likely going to be just basic aluminum (6061), same as all the other parts. The other parts will be anodized. My Deardorff one here is aluminum as well.

[Leigh]

Yeah, 3/4" would probably be strong enough. That's a large camera, so it doesn't hurt to make the support on the robust side.

The 6061 aluminum will work, but it might be better to use alloy 7075 for the flange (I don't know the thickness). It's much stronger.
For that matter you might consider 7075 for the whole camera. 6061 is pretty weak, particularly for a camera this big.

Is your Deardorff a 20x24 format?
The torque on the tripod socket is very much a function of format size. I think yours is at least three times larger than the Deardorff.

- Leigh

[T.G.]

Nope, an 8x10. And it looks just the same size as the ones they are selling as replacements on their site now.

[Peter Spangenberg]

Why not just use the Deardorff solution? Here's a link to a Barry Cochran Deardorff converter (I have no affiliation with the seller).
http://www.ebay.com/itm/Deardorff-3-8-inch-European-to-1-4-20-Tripod-Adapter-/330527589515?pt=LH_DefaultDomain_0&hash=item4cf4fac48b#ht_500wt_1162