Back fin: an add-on for the back of the head
The Back fin add-on goes on the back of the head: a swept fin up the back, like a shark. It adds 3 g of PETG. On a bot built by 3D3D it adds $0.33, and it fits 7 of the 8 heads, the Gem head included.
- 3 gPETG added
- +$0.33on the built price
- 7 of 8heads it fits
- Fins and tailsgroup
How it is priced
It sits on the back of the head. The price above is worked out on the Gem head on the Mini v2's body, from the same cost sheet as every bot: $0.11 a gram in PETG, 1 extra piece, so it is a few cents, not a new part to buy.
Finishing: 1 pinned kit piece to cut pins for and fix on. 3D3D charges $25.00 an hour for that, counted by the minute when it slices the job, so it is not in the figure above.
Which heads it fits
| Head | Result |
|---|---|
| Gem head | Fits |
| Mini head | Fits |
| Dome head | Fits |
| Visor head | Fits |
| Cyclops head | Fits |
| Twin-lens head | Fits |
| Antenna head | Does not fit. Head shell: A wall is only 0.42 mm thick; the printer needs at least 1.2 mm. Make the wall thicker. |
| Pod head | Fits |
Not together with
- Hex plates: The Hex plate 1 runs into the Back fin. (and 2 more)
- Tail: Head shell: A wall is only 1.06 mm thick; the printer needs at least 1.2 mm. Make the wall thicker. (and 1 more)
See every add-on or the questions people ask.
All prices are in Canadian dollars before tax and shipping. Bought parts are priced from amazon.ca listings (seen 2026-11-04), plus 15% when 3D3D buys them. Printing, the build and test fee and finishing are 3D3D's own rates, listed on the prices page.