Frag mount STL generator
A frag rack keeps frags in one place. A frag mount puts one exactly where you want it: on a ledge, in a crevice, out on the sand bed or up on the glass, wherever it gets the light and flow it wants.
Free to design · 1 credit per new design · Watertight STL + 3MF
How it works
Your numbers, not ours.
Pick how it attaches and the socket stays the same. The pad glues to rock, the spike wedges into a crevice or a hole you drilled, the sand stand lifts the frag on a post, and the magnet shelf holds to the glass. Tilt the socket up to 45° and set how many copies you want on the plate.
What you can tweak
- Socket depth 8–30 mm and wall 1.6–5 mm, closed or open at the bottom
- 1–3 sockets side by side, for a small cluster
- Tilt 0–45°, so the coral faces the light or the flow
- Glue pad 12–60 mm: flat, curved for a rounded rock, or with a grip texture
- Taper or peg spike, 10–80 mm long, with grip ribs and a stop collar
- Sand stand with a post up to 100 mm tall and an optional sand anchor
- Magnet shelf with 1 or 2 magnets and a set standoff from the glass
- 1–24 copies on one print plate
Print tips
Print it right the first time.
Measure your plugs
Plug sizes vary. Measure the stem with calipers, type that size in and print the Fit-Test Coupon once: every socket after that gets your fit offset, so plugs seat without forcing them.
Dark or rock-colored filament
Print in PETG or ASA, in a dark or rock-colored filament, so the mount blends in until coralline covers it.
Reef-safe glue
Use a reef-safe gel super glue or epoxy putty to fix a pad or a spike to rock. A peg comes out a little smaller than your drill bit, so it slides in with glue around it.
Read before you print
Frag plug hole sizes, and why fit matters
Plug stems vary by brand, and printers print holes a little small. Here’s how to find the hole that holds your plugs snug, without guessing.
Choosing filament for saltwater tanks
What each common filament handles, what to keep out of a reef tank, and the print settings that matter more than the brand on the spool.
FAQ
Frag Mount questions.
Plug sizes vary, so measure yours with calipers and print the free Fit-Test Coupon first. It finds the offset your printer needs, and every socket gets it from then on.
Glue pad for a flat or rounded spot on a rock, spike for a crevice or a hole you drilled, sand stand to lift a frag off the sand bed, magnet shelf to hold it on the glass.
Yes. The pad, stand and magnet styles print base down. The spike prints standing on the socket rim with the spike pointing up, and ends in a blunt 2 mm tip. A curved pad’s underside prints as a shallow dome over the bed, so that side comes out rough, and it’s the side that gets glued. The sand anchor is its own small piece that pushes into the base.
Yes. Set the copies and ReefCAD lays them out in a grid for your printer’s bed, all in one export. Changing the number of copies isn’t a new design.
PETG for most tanks, or ASA under strong lights. Skip PLA for anything that lives in saltwater.
More parts
Same fit, different job.
- Water Test StationOne home for your reef test kits.Reef water test station STL generator
Stop buying racks that almost fit.
Your tank, your plugs, your printer. Design it in a minute, print it tonight.