Do you like to carry a pocket comb? Do you also enjoy EDC and prefer a regular bottle opener instead of those tiny ones added to pocket tools nowadays?

Introducing the bottle comb! A compact pocket comb with a bottle opener using a penny inserted mid-print, no glue required. 

Dimensions: 102mm L x 36mm W x 6mm H

Opening bottle:

https://youtube.com/shorts/Vg4w3_Bytkw?feature=share

Inserting penny:

https://youtube.com/shorts/Z_DRMMoguUQ?feature=share

Print Instructions (condensed):

• Import, turn model 45 degrees so fan runs down length of teeth.
• 0.4mm nozzle, 0.2 layer height, 5 perimeters, 5-6 top/bottom layers, aligned seams, avoid crossing perimeters.
• 20% aligned rectilinear infill, turn 135 degrees or equivalent so infill runs length of the comb.
• Insert pause at the layer right before bridging over the penny area. Keep an eye on your print and snap in when it's ready, then continue the print. 
• Enjoy using your bottle comb! 

Print Instructions Background:

Turn the model 45 degrees on your build plate so you travel on 2 axes for the print. Also, make sure the fan is blowing down the length of teeth of the comb as shown in the gcode and penny insert video, it seems to help prevent the teeth from warping as much. Your filament may also be sensitive to this. If you run into issues with warping teeth, you could try drying your filament to see if that helps; otherwise it may just be some trial and error with more sensitive filament colors/blends/types.

PLA should be fine as it's quite stiff, this is what I used in prototyping to yield a strong design. If it does break it will most likely be on either side of the penny; if this is the case you could try increasing perimeters. PETG could be more durable but it will also be much more flexible. I haven't tried polycarbonate or nylon but I suspect both will be more than strong enough to prevent any failures over long use cases. 

Optimized for a 0.4mm nozzle and 0.2 layer height. May not print as well using other settings as the width of the comb teeth are set to the exact recommended thin wall thickness. 

5 perimeters minimum for strength, 5-6 top and bottom layers, aligned seams. Monotonic fill pattern is fine but I've found concentric also looks quite nice. Avoid crossing perimeters should help prevent any stringing from depositing on the comb teeth. 

20% aligned rectilinear infill, set fill angle to 135 degrees or equivalent to make the infill run the full length of the comb interior as shown the image and video. This will help with strength over other infill patterns. 

Last step before finishing slicing; use the slider and find the layer just before the bridging over the penny. Insert a pause at this layer and add a message if desired. The tolerances are set to be an exact fit for the penny so it should snap right in. If it's a bit tight, you can try printing at +0.5% scale.

Originally, I tried experimenting with supports so you could insert the penny after but ultimately decided to use a print-in part as it works best this way. This means if you want to use the penny again, you'll have to cut it out unfortunately. You may run into issues with bridging not connecting fully but it usually resolves itself with additional layers. If it's severe or causes your print to detach from the bed, you can try thick bridges, changing print temp, or warming up the penny some so it doesn't pull heat from the plastic as quickly. 

Thanks for reading. If you make any edits to the .stl, please share alike! Hope you enjoy, share your makes below and let me know if you have any issues!