$5, No Tool, Bamboo Sunglasses

I have wanted a pair of wooden sunglasses for a while now but haven't been able to justify the fairly exorbitant price tag associated with them. After recently getting a new pair of prescription sunglasses I decided to try my hand at making some wooden frames for as little as possible. I ended up spending only about 5 dollars and not having to invest in any tools or supplies.

The caveat was that I already had the lenses, the consumables (sand paper, wood glue, ect) and I skipped any finishing steps (varnish and sealing). This was my own personal introduction to wooden glasses so I wanted to make it as approachable and cost effective for myself as possible. I also managed to cash in on a coupon that reduced the laser cutting costs from ~$25 to ~$5 which further reduced the cost of this project.

The items required for the design portion of the project were minimal. You really just need the lenses you are planning to work with and some other odds and ends. I used Solidworks and AutoCad for this project because I am farmiliar with both but any 2D or 3D program would work fine.

Note I used ponoko.com for the laser cutting of the frames. They have a really good site with lots of helpful design guides. When I used them they had a promotion for $20 off your first project with them. Two things to note about Ponoko, it was hard to find the design guides and helpful information until you created an account with them and secondly the $20 had to be used within 48 hours of creating an account with them.

Design Bill of Materials

• 1 Set of Lenses
• Paper
• Optional
  • 1 Set of Frames

Design Tools Required

• Ruler
• Pencil
• 3D Cad Software Capable of importing jpg
• 2D software for dxf generation
• camera or smartphone
• Ponoko Membership

Build Bill of Materials

• Laser cut frames
• Lenses
• Paperclip
• Wood glue
• Sandpaper

Build Tools Required

• Wood clamp, butterfly clips or heavy object
• Sandpaper
• Razor Blade

I had just bought a pair of Ray-Ban sunglasses which can be found here: http://www.ray-ban.com/usa/sunglasses/RB4165%20MAL...

As they were prescription I got to keep the lenses that came along with the glasses. The problem with these high quality lenses is that they were very rigid, they don't really flex at all when handled. I didn't want to risk damaging them by heating them up. This lead me to designing a set of frames that would sandwich the lenses in the middle layer so that they wouldn't fall out.

As many noteworthy Instructables on this subject have mentioned the easiest way to get the lenses from real life into the digital world is by taking pictures and tracing out the lenses on paper. The cad file can then be printed out 1:1 and compared back to the actual lenses. I repeated this until I was confident that I had accurately portrayed the lenses.

Since I liked the look of the Ray-Ban's that I bought I tried to stay true to that overall frame design as well. So I also took pictures of the frames and tried to convert them to the digital world as well. My plan was to make the front frames from 3 laser cut pieces of wood. The middle slice would be just bigger then the lenses and the outer slices would be just smaller than the lenses so that when glued together they would encase the lenses. I would also laser cut the arms and hinges of the glasses.

This approach meant that I wouldn't have to machine out anything and wouldn't have to heat up my frames or lenses to get a good fit. The downside of this is that if I ever want my lenses back I would have to destroy my frames.

Frame Design

1. Import picture of frames, trying to be as square as possible when taking the picture of them
2. Draw outline of frames
3. Extrude outline of Frames
4. Import picture of lenses
5. Draw outline of lenses
6. Offset outline of lenses either slightly bigger (middle slice) or slightly smaller (outer two slices)
7. Extrude-cut outline of lenses from frames extrusion
8. Back Frame only added cutouts for hinge attachment

Arm Design

1. Import picture of arm, again trying to be as square as possible
2. Draw and extrude outline of arm
3. Add cutouts for hinge attachment

Hinge Design

1. Honestly I just kinda designed a hinge that looked right
2. See Detailed Hinge Design in next step

All of the references that I looked at when setting out on this adventure either bought individual glasses hinges or tore apart cheap frames to get them. I considered this route but it didn't appeal to me for several reasons. One, it involved either purchasing something or destroying something that I wasn't planning to do on this project, that means either extra cost or extra destruction. Two, it just felt wrong to do all this work to get wooden lenses then slap on some plastic or metallic hinge. I really wanted to try to make some wooden hinges because how hard could it be right? It's not like every other homemade and store bought frames don't use wooden hinges.

This was also a learning/entry into what I hope was a few different variations of this project, so I wanted to learn as much from this first pair as possible.

The idea was to have a cut out in the back frame of the sandwich to fit in the middle piece of the hinge and on the arms have the top and bottom pieces. These pieces would be cut out separately then wood glued into there respective cavity. After they were assembled a pin would be dropped into place to hold them together.

This is probably a good time to talk about wood thicknesses. I originally intended to get the frames and arms laser cut out of 1 mm plywood. This would mean that the total frame thickness would be ~3mm and the arms would be either 1mm or 2mm depending on if I wanted to double them up or not. Unfortunately I saw that Ponoko had bamboo plywood as well as regular plywood. This proved too tempting to ignore, bamboo wooden sunglasses... for $5, unheard of. The catch was that the bamboo was 3mm thick, which means that the front frames are 9mm thick.

The upside of the larger material thickness is that it made the hinges simpler. If I would have gone with a 1-2mm ply I would have had to double up the hinge pieces so that they would be strong enough. As it was I had two identical pieces set into the arm and one piece set into the back frame. It was a simple design that ended up working quite well.

I created drawings in SolidWorks and saved them to dxf files. I then opened the Ponoko template and saved it as a new file name. After I copied all of the SolidWorks dxf's into the template I was good to go...

Ok so it wasn't quite that easy but almost. After manually arranging all of the shapes I tried adding some test to the arms, note make sure you mirror the two arms, not simply copying them. I made this oversight and ended up with one arm with the "logo" on the inside, kinda embarrassing. Another small alteration was that I drew a "spur" to connect all of the small parts. Ponoko warns that small parts can blow away during the cutting process

I was very impressed with the laser cut pieces that I received. And plan on using Ponoko again.

This part was really easy and quick. After dry fitting everything to ensure my CAD skills were up to snuff I determined that no additional sanding was needed, silent fist pump. I put the back frame down, liberally applied wood glue, then put the middle frame on top ensuring it was aligned on all sides. Next I set the lenses in and aligned them where I wanted. More wood glue, trying not to cover the lenses with it, then pushed the top frame on and aligned it. After cleaning away the excess wood glue I clamped it all together with butterfly clips.

As the plywood wasn't finished I didn't sand between the layers. This was mostly because I don't like sanding. The end result was a very strong joint and I don't think that sanding would have changed anything, results may vary.

After the frames have dried the hinges can be glued in. Unfortunately I had to sand off the remaining spur to get them to fit. These where then glued into the respective cavities and held together with more butterfly clips.

After everything was dried I dropped a bent paperclip through into the hinge and I was good to go.

In the end I was really happy with the sunglasses, more for what I learned during the way but also for how well everything turned out. I really liked the fit, they were very snug and didn't require any alterations. I will be make several changes when I get around to making the R02. But I will pass along what I learned now so that everyone can benefit from it, and so I don't forget.

Lessons Learned

1. 3mm ply is thick.

The frames are very thick and although you don't really notice when you put them on. I would aim for a 1mm ply with my maximum being around 1.5mm in all future products. 3mm arms are quite good though and if I was using 1mm ply I would at the very least plan to double up the arms. This would also allow for covering up the wooden hinges.

2. Larger Hinges

The 1mm hole for my hinges worked well but the ~.5mm wall thickness was too small. I fell into the age old trap where it looked big enough on the screen. Once these thin walls are accounted for I think that the wooden hinges will work great.

3. Hinge Pin

I'll admit the paperclip is pretty hack but I didn't have time to find anything better. I think that on the next iteration I will oversize the middle hinge hole and purchase a pin to press fit into the top and bottom.

4. Nose Pieces

I had nose pieces cut out when I laser cut my design but didn't end up needing them because the sunglasses fit so well. I think that if I went with a thinner ply thickness then I would be forced to have nose pieces. I would notch out a hole in the back frame and slide the nose piece into it.