DIY Stereo Microscope

(There is an explanation in Japanese in the second half.) (後半に日本語の説明があります。) I made a stereo microscope by modifying a cheap pair of binoculars made in China. I use it by attaching them to a smartphone arm. After modifying the binoculars I used, the focal length from the front of the lens became 185mm, and the field of view became 12mm. If you can get hold of binoculars with the same structure as the ones I used, you should be able to do the same thing. However, the size and focal length of the lenses may differ, so they may not work as is. I'll also upload the Autodesk Fusion file, so please modify it as necessary. The printing material is PLA, and it was basically printed with supports. I wrote an overview on this blog (sorry, only in Japanese). https://minkara.carview.co.jp/userid/3336538/blog/48970902/ ■ArmJoint.stl This is the part that attaches the microscope to the smartphone arm. ■ArmJoint_Gear.stl This is the pinion gear that moves the telescope tube up and down to adjust the focus. It was printed with 100% infill. ■ArmJoint_Housing.stl This is the housing with space for the rack gear to slide up and down and a hole for the shaft. It has friction adjustment functionality. After printing, I recommend deburring the shaft holes with a 6mm drill. Considering the need to apply high-viscosity grease, the gears are designed to face inward to prevent contact with hands. ■ArmJoint_Knob.stl This is the knob for raising and lowering the telescope barrel. Two are required. ■ArmJoint_Rack.stl This is the rack gear for adjusting the focus by raising and lowering the telescope barrel. ■ArmJoint_Shaft.stl This is the shaft connecting the pinion gear and knob. Printed with 100% infill. Two are required. ■ArmJoint_Washer.stl This is the washer that is inserted between the knob and the housing. Two are required. ■EyeCup.stl Because the telescope barrel has a V-shaped layout, using the original binoculars' eyecups will result in light entering the eyepieces from the side. Therefore, I created teardrop-shaped eyecups. Print them with TPU filament. Two are required. ■LensExtender.stl This tube is used to position the binocular objective lens forward. The focal distance was 185mm when I looked through it with my naked eyes, as I am nearsighted. By adjusting the tube's mounting position on the holder, you can adjust the focal distance up to 185±12mm, but you may need to adjust the lens position depending on your naked eye vision. The farther the lens is positioned, the closer the focus will be. The closer you are to the object, the more magnified it appears, narrowing the field of view. With this setting, the field of view was approximately 12mm. To prevent diffuse reflections within the tube, you will need to use matte black filament. You will need two. ■LensInsert(A).stl The original binoculars' tubes are made of metal, but their interior surfaces are not matte-painted. This part reduces internal reflections. Therefore, you will need to use matte black filament. Select spiral mode in the slicer settings to print. You will need two. ■LensInsert(B).stl The objective lens of the original binoculars is glued to a plastic sub-tube. The inner surface of this tube is glossy, causing diffuse reflections and resulting in hazy images. This part reduces internal reflections. Matte black filament is required. The original binoculars' objective lens is large, with a diameter of 20mm, making it bright but with a shallow depth of field. To expand the in-focus range, an 8mm aperture is installed directly behind the objective lens. Select spiral mode in the slicer settings and print. Two are required. ■LightHolder.stl Since the viewing area is 12mm square, I thought there was no need for a ring light. So I decided to arrange two LED lights from Daiso in a V-shape. When deciding the position of the microscope, I found that it was easy to focus if I placed it where the centers of the light from the two lights intersected. In other words, it serves two purposes: as a task light and as a target light. Two are needed. ■LightHolderKnob.stl This is the head for manually turning the screw used to secure the light holder to the telescope tube. Use a threadlocker to tighten the M3/15mm screw and nut. Two pieces are required. ■ScopeHolder.stl This is the part used to attach the telescope tube. Since the focal length of my binoculars after this modification was approximately 185mm, this part is designed to move along a circle so that the two optical axes coincide at 185mm. The mounting position can be adjusted within a focal length range of 185±12mm. If it does not fit within this adjustment range, you will need to remake it. Printed with 100% infill. Two pieces are required. ■ScopeHolderBase.stl This is the part used to secure the holder. This part is designed to move along a circle so that the optical axes of the two telescope tubes attached to the holder coincide at 185mm from the tip of the lens. If it does not fit within the adjustment range of the holder, you will need to remake it. Features adjustable focal length and horizontal and vertical optical axis. For vertical adjustment, use only one of the two screw holes as needed. Printed with 100% infill. ■ScopeHolderCover.stl Although unrelated to functionality, I created a cover to prevent the screws from being visible and looking bad. ■PartsAll.f3d This is an Autodesk Fusion file with all parts arranged. Please modify as needed. ★ Overall The V-shaped groove on the inside of the cylinder ensures a smooth inner surface by placing seams in the valleys of the grooves during slicing. This is done automatically when using a BambuStudio slicer. Manual settings may be required for other slicers. I recommend applying high-viscosity grease (damping grease) to the shaft and gear parts. This makes it easier to focus. This is just my guess, but if you don't apply grease, static friction exceeds dynamic friction, resulting in a jerky focus adjustment. By applying grease, the shear force of the grease is added, which makes dynamic friction greater than static friction, making it easier to focus and also preventing wear on the shaft. The total weight, including the light, was 360 grams. Since the focal length is fixed, I realized there was no need for a free arm, so I created a dedicated arm. https://www.thingiverse.com/thing:7311355 双眼鏡を改造して実体顕微鏡を作る ・中国製の安価な双眼鏡を改造して実体顕微鏡を作りました。スマホ用アームに取り付けて使用します。 ・私の使った双眼鏡の場合、レンズ先端からの焦点距離は185mmとなりました。またこの時の視野範囲は12mmとなりました。 ・私が使ったのと同じ構造の双眼鏡が入手できれば、同じことができるかと思います。 ・ただしサイズやレンズの焦点距離が異なる可能性があるのでそのままでは使えないかもしれません。AUTODESK Fusionのファイルもアップするので適宜修正してください。 ・印刷のマテリアルはPLAで、基本的にはサポートありで行いました。 ・概要をこちらのブログに書きました。 https://minkara.carview.co.jp/userid/3336538/blog/48970902/ ★文字数が増えるとうまく表示できなくなるようなので、日本語の説明文は"SummaryJapanese.txt"に移動しました。