Customizable Magnetic Phone Adapter for Spotting Scopes (Digiscoping)

Documentation Updates

Overview

This customizable phone adapter for spotting scopes uses an integrated Magsafe magnet to secure the phone to the spotting scope.  It depends on a Magsafe-compatible steel plate to either be integrated into the phone (as with iPhones), phone case, or a sticker Magsafe steel place attached to non-iPhone phone, such as Android phones.  By entering phone and scope dimensions in a parametric Autodesk Fusion file, you can create a model that fits your phone and scope precisely - no 3d modeling experience necessary.

With this design, there's no more fussing with clamps to line the camera up with the scope lens and no guessing at the proper distance between the camera and the scope lens for the best image - the model parameters automatically calculate this with the correct measurements input to give you a printable design.  This documentation walks you through the measurements and parameters that you need to edit.

Disclaimer:  The number of different phone, cases, and spotting scopes in the world is too large for me to have anticipated every possible combination and design consideration.  If you find an issue, please leave a comment and I'd do my best to help guide you and/or adapt the models.  You use this design at your own risk - I'm not responsible for any damage to your phone or scopes.  The phones and spotting scopes I've tested have been very securely attached, but your mileage may vary based on the accuracy of your measurements, a design consideration I missed, or any user error in generating the model and printing it, among other reasons.  Use caution when using this adapter for the safety of your phone and spotting scope.

Please read the following documentation in full and carefully before reaching out for help.  This is my first 3d model and first time creating a parametric design so I welcome constructive feedback and remixes to improve on it and further customize to meet your or others' needs.

I hope you enjoy this design! 

-Michelle

p.s.  If you have binoculars, check out my Customizable Binoculars Adapter, based on this same design.

p.p.s.  A dust cover model is now available for this design.  Helps keep dust off your lens when your phone is not on the adapter.

Materials

1. 1 M3x16 socket or button head + washer or knurled thumb screw.
2. 1 M3 nut
3. 1 56 x 46 x 2.5mm Magsafe-style magnet.  The 2.5 mm thick version is very secure; I have not tested with a phone case, but I believe there is enough margin in the strength for adding a thin case or one that is magsafe compatible or with a steel plate.  You can adapt the model to other magnet dimensions in the same circular shape through the “Magnet” parameters.
4. Optional:  a Magsafe steel plate to attach to the back of your phone or inside your case if it isn't an iPhone or Magsafe case.   See Phone Dimensions Note below.

Print Material and Settings (tested on Prusa i3MK3S):

• Material:  PETG
• Nozzle Diameter:  0.4mm
• Layer Height:  0.20mm Quality
• Infill:  15%
• Support on build plate only
• I recommend using opaque, dark colored, filament.  Any light bleeding through the material may cause your phone to select the wrong camera (like the macro lens.)  Often you can work around this, but you don't want it to switch cameras on you at the wrong time.
• IMPORTANT:  In your slicer, insert a Pause in the print in the layer just before the layer that encloses the magnet.  When your print pauses, place the magnet in with the steel plate side up; magnet side down.  If you use Octoprint with Prusa, please see Octoprint note below.
• Let the build plate cool before removing your print to avoid the adapter warping.
• Print with the eyecup holders pointing up and the phone-side of the adapter pointing down on the printer plate.

Optional - you can use PLA for the design if you're careful to not expose the adapter to high heat (leave in a hot car) and the elements.  Same settings apply.

Customizing Your Adapter

The parameters you need to change are in the Favorites list in the Parameters table in Autodesk Fusion.  I added a table and diagrams documenting the Parameters in the appendix of this documentation.  I also attached pdfs of the diagrams in case you would like to annotate them with your measurements.

To view and edit the parameters:

1. Open the CustomizableMagneticPhoneAdapterforScopesv1.02.f3d file in Autodesk Fusion (free for personal use.)
2. Navigate to “MODIFY” → “Change Parameters”
3. Change the parameters in the Favorites list to match your phone and spotting scope.  Follow carefully the instructions in the comments for setting the dimension of each parameter.  See the appendix for a helpful visual of how the parameters map to the back of the phone. Tip:  Click the header of the “Name” column to sort the parameters alphabetically.
4. If you need further customization, feel free to explore the other User Parameters, but do so at your own risk.  If you're a Fusion wiz, have at it.  :)  

Phone Dimensions Notes and Disclaimers:  

• For iPhones, you can use the Apple Accessory Design Guidelines pdf to get the precise measurements for your phone - this assumes you don't use a phone case.  Whether you use a case or not, you'll need this guide to set the Magsafe magnet location and the “Keep Out Cone” measurement to ensure the camera is positioned the optimal distance from your scope (see Eye Relief Notes below.)
• If you use a phone case, you need to take the measurements with the case on.  I haven't tested compatibility with cases, but if the case is not too thick or with weird protrusions, I believe you should be able to configure the parameters to work.  
• Android phones generally do not have an integrated steel plate to mount magnetically like iPhone does with Magsafe.  You can purchase a Magsafe steel plate and adjust the location you want the magnet to line up in the parameters.  I recommend waiting until your print is done to attach the steel plate to the phone to make sure you can line it up correctly.  Post-print, I place the steel plate on the adapter where it will be held in place by the integrated magnet, take the sticker backing off, line up the phone along the edges such that the camera is positioned correctly, and press the phone firmly against the sticky side of the steel plate to attach it to the phone in the right place.  Note - this is not compatible with any other steel plates attached to your phone/case.  
• Most modern phones have multiple cameras.  I find using the 1x lens to be the best for photos and videos.  Test which lens is 1x by using a paper cutout to block other lenses to find the one that works in 1x mode.

Tip:  Before committing to an entire print, you can optionally cancel your print after the first handful of layers are printed to check the fit on the phone, placement of the camera cutout and holes and magnet.

Eyecup Diameter and Height Notes:  

• The fit of the eyecup holder should be very close and have some slight friction on the eyecup, but not get stuck.  I found that a good diameter starting point is 0.5mm more than my caliper measurement at the widest part of the eyecup.
• For the eyecup holder diameter, you can use the included EyecupFitTest_v1.f3d Fusion model for testing your diameter before commiting to a full print.    Modify the EyecupDiameter parameter in the EyecupFitTest model as you do in the “edit parameters” instructions above and print the ring to check the fit.
• I haven't tested this design on foldable eyecups.  The adapter depends on firm eyecups to grab onto - this should work with the eyecups folded down, but this isn't yet tested.

Eye Relief Notes:

• A very good video explaining Eye Relief, sometimes called “Exit Pupil Distance” (not to be confused with “Exit Pupil”) is in this YouTube video. 
• I use this Eye Relief distance to create standoffs within the adapter eyecup holders to position your phone camera at precisely the correct distance for the best image.  Note that the position the image needs to hit your camera is not at the camera glass - it's at the aperature iris of your camera lens.  The Apple  Accessory Design Guidelines specifies this location in the “Keepout Cone Distance” measurement - you can enter this number in the CameraKeepoutConeDist parameter.  For other phones, if you can't find the distance in any specification, you can guesstimate where it lies within the phone.
• Eye Relief is typically found in your scope specs.  In my experience, this is measured from the scope lens and not the top of the eye cup.  The EyeRelief also varies based on magnification.  The spec typcially gives the distance at the lowest magnification (the longest distance.)  Often you can find the “effective” Eye Relief in product reviews and you can use that as a guide and I use a middle number in the range.   You'll find an example chart of Eye Relief varying with magnification here.
• The EyeRelief parameter assumes your eye cups are fully tightened or folded over.  If you want to keep your eyecups unscrewed to a certain distance, subtrace this distance they are unscrewed from the EyeRelief parameter.
• You need to factor in any phone case and/or magnet steel plate depth that adds distance between your aperature iris and the lens of the scope.  You can adjust for this by adding this depth to EyeRelief.  Be sure to do this to get the best result.
• If your phone case is very thick, you may need to widen CameraDiameter so that it doesn't interfere with the FOV of the camera.  If you suspect you have interference, you can test by putting your camera on the adapter without the scope and check if any of the camera view is blocked by the adapter.
• Please see the appendix for the profile diagram that visualizes Eye Relief and how it relates to the other parameters.

Magnet notes:

• The magnetic hold on your phone should be very firm.  
• With the magnet linked in the materials and an iPhone OR a non-iPhone phone with the steel plate linked stuck to the surface of the phone (without a case) as close to the middle of the phone as you can get, you will achieve this strong hold.  
• Any other variation (different magnet used, steel plate location, steel plate alignment with magnet, or depth steel plate depth from the adapter plate) may result in a weaker hold.
• Steel plates on your phone or case that are not in the Magsafe shape may interfere with the magnetic positioning of the phone on the adapter plate.  
• If you are using a case, you may need to play around with the steel plate placement and/or plate thickness to get the best result.  There are Magsafe compatible cases - these may give the most straightforward solution.
• Since the magnet hold is strong, it's best to twist the phone off the adapter to release it, rather than pull straight up as this motion may pull the adapter off of the scope.

Print Your Design

1. To print your design, you need to export the design to an .stl file for your slicer.  (The Make Utility in Fusion doesn't work with this design.)  To save, select “File” → “Export” and save in the .stl format.
2. Open the .stl in your slicer, orient as needed so the phone-side of the adapter is on the build plate, and use the print settings listed above.  
3. Don't forget to add the Pause for inserting the magnet.
4. Important:  Make sure your magnet is oriented the right way when you insert it!  The magnet side is down and the steel plate (smooth) side is up.  
5. When done printing, carefully break off the supports and add the M3 screw and nut to the clamp.  It's important to clean the supports off thoroughly from the camera cutout to ensure a good fit. You can glue in the nut for added security so you don't lose it.

Good luck with your print and I hope you enjoy this adapter as much as I do!  If you have binoculars, check out my binoculars adapter!  :)

Appendix

Parameter Description

Notes: 

• X parameters are distances from the left side of the phone as you look at the back of the phone and Y parameters are distances from the top of the phone.  
• All numbers are expressed as positive numbers.  See diagrams below.
• You may get extrusion errors as you update the parameters - these should sort out when you have all your measurements entered.
• The fillets for the phone and camera plate cutout need to be non-zero.  If you have a cutout that spans the width of the phone you won't want a fillet at the corners.  In this case, you can set your cutout X values beyond the edges of the phone (e.g. (-6mm, PhoneWidth+6mm)) so that the fillets don't interfere.  Or you can make the fillet small enough to effectively be zero in your print (e.g. 0.001mm)
• If you want to save your parameter settings into a CSV and import them later, check out the ParameterIO plugin for Fusion in the Autodesk app store.

Parameter Diagrams

Ignore BinoInterPupilaryDist - not used in this design.

Tested Phones and Spotting Scopes

As of the writing of this documentation, here's the list of phones and scopes that have been modeled to test the parametric design.

Phones

• iPhone 12 Pro - no case.  The 1x camera is upper left as seen from the back.
• iPhone 12 Pro Max - no case
• iPhone 13 Pro - no case
• iPhone 14 Pro Max - no case
• iPhone 15 Pro - no case
• iPhone 16 Pro - no case
• iPhone 16 Pro Max - no case
• Android Pixel 2 - no case, with 0.4mm Magsafe magnet attached

Scopes

• Swarovski ATX 25-60x85 - ATX eyepiece purchased 2015
• Swarovski ATX 30-70x115 – ATX eyepiece purchased 2024 – different eyecup dimensions than 2015 ATX eyepiece.
• Vortex Razor HD (Angled)
• It's also been tested on several binocular eyepieces, listed in the bino version of this design.

Model Errata

V1

1. I've evaluated a Samsung phone + case that had an integrated Magsafe magnet to determine whether the camera placements would work with this parametric design.  This phone has the rear cameras lined up in a way such that the cutout to avoid interfering with them would expose some of the magnet on the phone side of the adapter, which I believe should still work, if not look a little ugly.  I'll be testing this theory soon.
2. I've evaluated compatibility with phone cases but am still testing my guidance on how to adapt the measurements to cases and looking for edge cases (pun intended :) I missed.

Octoprint + Prusa/PrusaSlicer Users:

Note for Octoprint + Prusa/PrusaSlicer users to make sure the Pause/Resume is correct:

To turn the nozzle heat back on after the Pause, the Octoprint profile needs to be updated with the following G-codes (in the GCODE Scripts section) .

• After print job is cancelled: M604
• After print job is paused: M601
• Before print job is resumed: M602

If you start the job from Octoprint, you need to Resume from Octoprint - the Prusa LCD doesn't give you an option to resume.

Starting and Resuming from Prusa LCD screen works for the Pause with no modification.  If you're unsure about the Octoprint control, this is the safe way to do it.

Acknowledgements

Special thank you goes to my boyfriend, MattG, for inspiration, design input, and testing the fit and function of the prints.   Thank you to the awesome community members like @BikeCyclist for their feedback comments.

This is a spotting scope version of the bino adapter design I created.  I designed the scope first, in fact, but published the binocular design on Printables, first.