Light engineering procurement question.

[ollypenrice]

We want to use a bar or plate to bridge between one scope on a dual rig and the other.  The physical tubes are not necessarily perfectly parallel (optical axes, drawtubes etc may introduce slight tube misalignment) and they are offset relative to the saddle plate because one rides on a tilt pan adjuster.

What we need are self aligning joints (some kind of ball section in a cup section) which would allow the tubes to be aligned before these joints were tightened. I can visualize the blessèd things and am pretty sure I've had hands on them at some time. I remember two thick washers, if you like, one machined into a cup shape and the other into a segment of a ball. They sat between the two items to be aligned and tightened.

Does anyone know what they are called or where they might be ordered?

Thanks,

Olly

[Dr_Ju_ju]

Could you produce some sort of diagram, of what you require, as it may need multiple parts to cater for all eventualities.

As a first step, it may well be possible to 3D print something, before a metal is created...

[ollypenrice]

11 minutes ago, Dr_Ju_ju said:

Could you produce some sort of diagram, of what you require, as it may need multiple parts to cater for all eventualities.

As a first step, it may well be possible to 3D print something, before a metal is created...

Something like this.

I think it's quite often necessary to attach two items without the attachment interfering with their alignment but I don't know what term to use in a search.

Olly

PS @DaveS  I dare say Dave might know.

Edited August 25, 2021 by ollypenrice

[markse68]

Hi Olly, not sure anything like that is going to be particularly rigid but what is it you’re trying to achieve? If you have the pan/tilt adjuster for alignment, why do you need these braces? Is it just to more rigidly couple the scopes? Could you just use a linking plate with fixed scope rings on one side and adjustable (like for finders) on the other scope?

Otherwise maybe magic arms (noga make excellent ones) could be used to damp inter-scope vibrations?

Mark

Edited August 25, 2021 by markse68

[Dr_Ju_ju]

These will probably be way over the top, but have a look here http://www.offroad-engineering.com/sway-bars.html   it may give you an idea of something that can be cobbled together,,,,,

[Swoop1]

I think you need something from the film/ photography industry such as light bars or reflector mounts but I cant find anything to match your requirements at he moment.

[ollypenrice]

8 minutes ago, markse68 said:

Hi Olly, not sure anything like that is going to be particularly rigid but what is it you’re trying to achieve? If you have the pan/tilt adjuster for alignment, why do you need these braces? Is it just to more rigidly couple the scopes? Could you just use a linking plate with fixed scope rings on one side and adjustable (like for finders) on the other scope?

Otherwise maybe magic arms (noga make excellent ones) could be used to damp inter-scope vibrations?

Mark

If the balls and cups were made of aluminium with a high coefficient of friction I think they would help. The idea is to link the scopes together with additional fixings after the tilt pan adjuster has aligned them. The tilt pan is a short device, a fraction of the length of a long OTA, so the advantage of the braces we envisage is that they could go at the ends of the OTAs, so gaining mechanical advantage. Tomato and bro are using something like this to good effect but without the tilt adustable joints it takes a lot of setting up.  High res dual rigs are well known to be hard to keep parallel with trailing showing up on the unguided scope side.

Olly

[markse68]

something like this could be very rigid and yet light weight and cheap- maybe big jubilee clips could be used instead of scope rings with 3d printed saddles

Mark

[markse68]

33 minutes ago, Swoop1 said:

I think you need something from the film/ photography industry such as light bars or reflector mounts but I cant find anything to match your requirements at he moment.

maybe something like a double ball joint? 

https://cvp.com/product/smallrig_sr1135_dbl_ballhead

or heavier duty

https://www.uwcamerastore.com/sealife-kit-11-flex-connect-ball-arm-kit-with-sl995-sl99907

Edited August 25, 2021 by markse68

[ollypenrice]

33 minutes ago, markse68 said:

something like this could be very rigid and yet light weight and cheap- maybe big jubilee clips could be used instead of scope rings with 3d printed saddles

Mark

Thanks, but this won't allow the scope tubes to be slightly misaligned, which in reality they need to be for the optical axes to be aligned.

Olly

[markse68]

Just now, ollypenrice said:

Thanks, but this won't allow the scope tubes to be slightly misaligned, which in reality they need to be for the optical axes to be aligned.

Olly

why won’t it? it’s flexible in all directions/orientations until you tighten the bolts.

Mark

[ollypenrice]

1 minute ago, markse68 said:

why won’t it? it’s flexible in all directions/orientations until you tighten the bolts.

Mark

Maybe I'm missing something. What's the item marked 'Slob' above the rail?

Olly

[markse68]

slots.

But i’m not sure if this will accommodate vertical twist actually so you are probably right

but maybe you could add these for that

https://www.berger-tools.co.uk/Screws_Nuts_Washers_Clamping__Supporting_Elements/Din6319_Spherical_Washers_Steel_Male_Or_Female/?gclid=CjwKCAjw1JeJBhB9EiwAV612yz0jd8ieI1JsFxwdZL_YNGkCqBkbZTJGze4m-L5OvCc-sZzvRTF97BoC2kkQAvD_BwE

Edited August 25, 2021 by markse68

[ollypenrice]

4 minutes ago, markse68 said:

slots.

But i’m not sure if this will accommodate vertical twist actually so you are probably right

but maybe you could add these for that

https://www.cromwell.co.uk/shop/spindle-nose-and-workholding/fixing-components/fc25-17mm-bore-2pc-spherical-washer-set/p/IND4252860G?gclid=CjwKCAjw1JeJBhB9EiwAV612ywuGB3-wUoFeLSvyLeIvLvuv9H-fFkqIHwGNrCVVmAzJX7PMlg6tmxoC6NgQAvD_BwE

Well done that man! That's the thing to try. Many thanks.

Olly

[StevieDvd]

Something like this do?

Flexible coupling - Amazon

No toilet jokes please.

[Alien 13]

Though I would mention tripod "bowl" heads as an option, the large diameter of the cup and ball ensures a strong clamping action... I have one for my tripod to ensure its level for pano shots.

 

The downside is that the cheap ones are only rated at 15 Kg and tend to have a 1/4 camera thread on the top rather than 3/8..

Alan

[ollypenrice]

5 hours ago, Alien 13 said:

Though I would mention tripod "bowl" heads as an option, the large diameter of the cup and ball ensures a strong clamping action... I have one for my tripod to ensure its level for pano shots.

 

The downside is that the cheap ones are only rated at 15 Kg and tend to have a 1/4 camera thread on the top rather than 3/8..

Alan

Is that in effect a ball head with limited range?

Olly

[Alien 13]

21 minutes ago, ollypenrice said:

Is that in effect a ball head with limited range?

Olly

Sort of, its based on the tripods that have a bowl rather than a flat plate. The low profile and large bowl (around 70mm on mine) gives far more stability than a ball head but yes the range is limited.. For photography these are a far better method of leveling the tripod head than fiddling with the tripod legs, especially if the tripod is fully loaded with the camera etc.

Alan

Edited August 25, 2021 by Alien 13