Quick release plate adapter to mount a "red dot" (reflector/reflex) sight to a spotting scope (1 Viewer)

[Hauksen]

Hi everyone,

After designing a couple of different solutions for mounting a reflex sight on a (Kowa 883) spotting scope, I've tried something new now and decided to create a mount that is part of the quick release plate rather than mounted directly to the scope.

The challenge with designing a reflex sight mounting for the Kowa is to find a feature that allows the sight to be locked stable directionally without interfering with the stay-on case.

The foot of the Kowa provides such a reference feature, so here is the new solution:





The main design ideas:

• The recess in the top plate accurately matches the forward/rear edges of the Kowa foot to asure directional alignment. (I felt this was more reliable and more robust than video-camera style aligning pins.)
• Dividing the quick release plate into an upper and lower part allows changing of the lower part for a different style, for example an Arca-Swiss type plate.
• The separate arm can fold over 90 degrees for easier transportation of the adapter when carried separate of the scope. However, the main purpose of the folding hinge is to allow the sight to fold away and rest on the stay-on case when the scope is stowed away and squeezed in tight, as otherwise the long lever arm of the mounting will potentially cause it to crack and fail. (It also allows easy mounting of differently sized arms so I can experiment with the ergonomics of the solution.)
• I've not managed to design a perfectly symmetric adapter, which is sort of difficult because the Kowa's tripod thread is not centered in the foot, so simply flipping it around is not going to work. Accepting this, I've moved the arm fairly far forward to make it easier to reach the Kowa's clamp arresting screw (or whatever it's called),which is located on the right hand side close to the scope's foot. (Most people are right-eye dominant, so that's why I decided on a right hand mount. It would only take a few minutes to derive a left-hand mount, though.)
• The arm is not held in the open position by a spring, but by friction. I think this is going to be entirely practical, but I've yet to try it in the field.

Regards,

Henning

 

[JerryLogan]

Well that is very clever indeed Henning! I’m sure you’ve noticed that the upper plate can be customized for a variety of scopes (and even binocular mounts). A very good generalization from the Kowa focus with applications in astronomy as well as birding. Very nicely done.

Very best,
Jerry

 

[Hauksen]

Hi Jerry,

Well that is very clever indeed Henning! I’m sure you’ve noticed that the upper plate can be customized for a variety of scopes (and even binocular mounts). A very good generalization from the Kowa focus with applications in astronomy as well as birding. Very nicely done.

Thanks a lot!

You're in fact entirely correct that different scopes can be acommodated with different upper plates, but my impression is that the dimensions of the various scopes' feet are not usually published (because normally, people aren't too interested in these). So, to design a different upper plate, I'd probably have to get my hands on that scope, or ask someone owning that scope for a sketch at least.

Your post inspired me to consider mounting my Nikon ED50 to the same plate, though - if the Nikon's foot is all-around smaller than the Kowa's foot, it should be possible to design an insert for the "Kowa" upper plate that locks the Nikon into aligment

By the way, did you already give my older adapter design a try? If not, maybe you'll like the newer on better ... I'm planning on publishing it on Thingiverse as soon as I've got it tested and the bugs worked out.

Regards,

Henning

 

[KLucas]

I like your design. I am left eye dominant. A half-dozen years ago I made a simple clip-on mount for my Zeiss scope with the reflex on the right. That works great for me. I advise not to get hung-up on sidedness. I secured it with high quality zip ties. The gray clip is a 1" section of 2" PVC with a small portion cut out to fashion a spring clip. I mounted a section of Picatinny rail to it, then the sight to the rail. I leave it on all the time. I do not have a scope cover. I purchased the less than $30 sight from the huge online retailer. It's been perfect. The battery lasts phenomenally, even when unintentionally left on in storage. I edited my photo, digitally scribbling out my email address and phone number label on the eyepiece.

 

[billb9430]

Hello Lucas,

I just came across your recent addition to Henning's excellent thread. I've been using a somewhat similar "low tech" mounting, but attach to the scope and use it over the stay-on case that protects my scope. Since my scope is a Pentax, I posted this in the seldom visited Pentax thread. This simple "hose clamp" method is adaptable to any scope brand, so I'll just add a link here for those who might not have seen it in the Pentax forum:

Attaching a Red Dot Finder OVER a stay-on spotting scope case

The thumbscrew hose clamp is easy to remove and reattach for use on several scopes. The attaching thumb screw hose clamp ring can also be partially padded inside with thin adhesive-backed felt strips and heat shrink tubing for use on scopes without stay-on cases. I'll attach three photos of that.
-Bill

 

[KLucas]

Well done. Thanks for sharing.
Instead of vertical over the scope body, I mounted mine in the 1 o'clock to 2 o'clock position, to keep it low profile, and not be blocked by my angle eyepiece.

 

[KLucas]

Thank you also for your link showing how you made and mounted it.