Hornet's Needle - Collapsible Sword - Hollow Knight: SilkSong

***Edit*** - added a flattened point version for anyone who doesn't want a sharp point. It is approximately 20mm width flat.

This is a collapsing version of Hornet's Needle from Hollow Knight: SilkSong

This build will allow anyone with a half decent printer to own a fairly accurate cosplay prop that's easy to store and fits on a 220 Z-height bed.

The sword extends to approximately 1200mm when printed properly (450 Handle, 735 Blade). If you wanted to attempt a full 2 metre version and have a tall printer, you could try scaling it up by 1.6x but this is untested by me.

Like many collapsing swords, this print is not easy. Due to the many concentric moving parts, and giant thin towers, there are a few settings and preparations you will need to make to ensure your sword releases after printing.

BOM

• Super glue (or very strong prop glue equivalent)
• Approx 270g Filament PETG preffered (PLA can work fine, just treat it nicely as it will be less durable).

Print Settings

To ensure that your telescopes release, you need to have a very carefully tuned printer - especially things like seams, blobs and stringing.

Preparations:

• Calibrate your Pressure Advance - Having very clean corners, line ends and seam bumps will help to prevent issues as the tall towers build
• Dry your filament - To prevent strings from gunking up gaps between telescope and preventing release.
• Calibrate your retraction - you need to ensure minimal to zero stringing to prevent the telescopes from fusing.
• Flatten your Z-seam - Either increase the seam gap% to flatten it out, or maybe look into scarfe seams (this increases printing time though).
• Clean your build plate - You will need perfect adhesion to prevent the tall wobbling towers from releasing off the plate.

Settings:

• For quality's sake, please consider printing in 0.2mm layer height. You can increase your line extrusion width to 0.7mm to reduce printing time (this is fine even for a 0.4mm nozzle). The walls are mostly 1.4mm thick, so having 0.7mm lines will reduce your wall count from 3 to 2 while still giving you a nice sturdy wall.
• Use a large outer Brim - 8mm or more to keep the towers stuck to your plate (ESPECIALLY if you're using a bedslinger). Sword towers can be printed individually, but not the handle unless you remove the top ring.
• No supports needed. The top ring is designed to be printed without supports, but if you're concerned about poor overhangs, add a Normal - Snug support for the ring only (example below):

• Check your towers for coinciding seam bump lines - where the towers walls touch, check to see that you don't have long lines of aligned seams printing next to eachother (example of this below). These lines tend to protrude a little, and when they're next to eachother the tiny protrusions will multiply, rub against eachother and potentially disrupt the telescoping ability of your print. It may also lead to more stringing as your printer will make short hops from one line to the next without breaking off the filament.

• If you're using a bedslinger with a moving Y-axis bed, orient your prints to have the longest parts along the Y axis (pictured below). This is to help prevent wobble, although I can not guarantee that it will prevent it.

Assembly

The sword base needs to be superglued (or strong glue equivalent) to the hilt. There is not a lot of surface area to work with for the outer wall of the sword, so make sure it's a powerful adhesive and that you are not fusing your telescopes together during the curing phase. I could not find another way to design this piece without making major sacrifices.

I just used the cheapest super glue I could find. You just apply it and press the parts together for a minute, and it will hold. Then I ran over the seam a second time with more glue and wiped off the excess, let it cure for 30 mins then it's good to go.

Good luck, Hunters.