How to connect Nikon measurement scope base to camera

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

zzffnn
Posts: 1896
Joined: Thu May 22, 2014 1:25 pm
Location: Houston, Texas, USA
Contact:

Post by zzffnn »

Thank you very much, Enrico!

zzffnn
Posts: 1896
Joined: Thu May 22, 2014 1:25 pm
Location: Houston, Texas, USA
Contact:

Post by zzffnn »

Gents,

I am guessing we can use nuts to hold those 4 screws that connect the camera adapter to focus block (so those 4 screw holes can be smooth without threads), correct? Assuming we have enough space to apply 4 nuts.

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

The screw specification is as I posted, 3/8-16 UNC. There's no need to use Whitworth unless you can't get UNC.

Fan, for someone with even basic machining facilities, it wouldn't much matter what clamp you use. Existing holes, other than a central one, are likely to be a nuisance rather than a benefit, if they interfere with where you need them.

Choice of clamp depends whether you're going to use an intermediate plate between the focus block and the arca clamp. You may dicide it's better to use an IP, to give spacing fromthe focus block. You can use a slab of aluminium an inch thick if you want to, it's not expensive or hard to work with simple equipment.
If you don't use an intermediate plate then you will need to be careful as I suggested, about clearances, a lever-type clamp may be better because there's zero projection of the lever below the bottom of the clamp, unlike a knob. At the moment however I can't see a suitable lever-type arca clamp. Many also have knobs which may be in the way.

Assuming you do have some adjustment of the angle of alignment, then a longer distance between fixing centers, with some movement available at one/both ends, makes it easier to control. SOme "play" inthe hole where the screw (heads) are would be necessary. Also the length would make it more resistant to being knocked out of alignment.

If you use a clamp similar to the one I pictured (which by the way, has a 3/8 to 1/4 adapter in it) then you have enough length, free of holes, for your machinist to work with.

There are advantages to having an intermediate plate, but you COULD do it like this, where the spacer only has plain untapped holes. For alignment the holes in the part marked Nikon need sufficient clearance.:

Image
Not to scale, the screws would be M4 Hi tensile hex socket headed, so quite small.
Chris R

zzffnn
Posts: 1896
Joined: Thu May 22, 2014 1:25 pm
Location: Houston, Texas, USA
Contact:

Post by zzffnn »

Thank you very much, ChrisR, especially for spelling out and explaining things in language that a mechanical dummy like me can understand.

I like your idea, as illustrated in the drawing, very much.

My "Nikon" part offers some 1mm of extra circumference in the 4 screw holes, so around 1.5mm of play room in any direction is there.

In your drawing, it looks like center hole of the Arca clamp is not even used/needed, since the 4 red Nikon screws do the holing job?

If that is the case, assuming I can find an Arca clamp of the right size, then I can make that "spacer" myself with aluminum or polywood. Really we only need a perfectly flat piece there; since no threads (and related screwing/unscrewing action) are needed, good durability is not needed either.

I will try to find a bigger Arca clamp.
Selling my Canon FD 200mm F/2.8 lens

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Correct, the spacer doesn't need any screw holes.

One easily available, hard and stable material, is laminate flooring. There are always offcuts.

You still need to get the Clamp drilled and tapped, though.
If you mark and center punch it carefully, you could do that by hand quite easily with a 3.4mm drill. Tapping is done by hand, though you need a tap holder.
Chris R

zzffnn
Posts: 1896
Joined: Thu May 22, 2014 1:25 pm
Location: Houston, Texas, USA
Contact:

Post by zzffnn »

I found some big Arca clamps that may work with ChrisR 's idea, please kindly correct me if I am wrong:

50mmx80mm
https://www.ebay.com/itm/Universal-Arca ... SwbYZXVSQ9

48mmx78mm
https://www.ebay.com/itm/78x48mm-Clamp- ... xyKh5SC6jv

50mmx120mm
https://www.ebay.com/itm/QR-120-Clamp-A ... SwHIlZwIey

Which one do you like best?

Thank you very much!
Selling my Canon FD 200mm F/2.8 lens

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

I don't see anything wrong with any of them :).

Between the various clamps I have, the expensive ones have mote nicely rounded corners and better anodizing. Not all plates and clamps are exactly alike, so some plates won't go into clamps except by sliding them in from the end because the clamp won't open wide enough. Unless you use a single brand, you don't find out until you get it!
Whether RRS 80mm clamp such as B2-LLR-II is worth its $132,.. depends...
Chris R

Post Reply Previous topicNext topic