Barbed hose adapter, customizable: any two hose sizes

A one-piece barbed adapter that joins two hoses of different inner diameters, with a flange in the middle that both hoses butt against. At the defaults it joins a 19 mm and a 13 mm hose with 3 barbs per end, and it is 23 mm across the flange and 36.4 mm long. Set each hose's inner diameter (8 to 40 mm), how much the barbs oversize the hose (0.3 to 2.5 mm), the barb height, spacing and count, and the wall.

Customize Change it with AIFree STL, 3MF and STEP, no accountMeasured on the model

Parameters

Hose A inner diametermm

Hose B inner diametermm

Barb oversize over hose IDmm

Barb height (radial)mm

Barb spacingmm

Barbs per end

Wall thicknessmm

Flange lip beyond barbsmm

Flange straight lengthmm

Sliders and downloads are free. Changes by the AI designer use credits like any design; new accounts start with free ones.

It prints standing on its larger end with no supports: the steepest faces lean about 51 degrees from the bed. Hose stiffness varies, so print one adapter and try it on your hoses, and add hose clamps where it holds water under pressure. The bore is narrower than the hoses (14.4 and 8.4 mm at the defaults), which restricts flow. It has not been tested for any pressure or temperature.

Parameters

Every slider in the viewer above, with the range the model accepts. The model rebuilds valid at both ends of each range.

Parameter	Range	Default	What it changes
Hose A inner diameter	8 to 40 mm	19 mm	Inner diameter of the first hose. Whichever hose is larger always goes on the bottom end, the one that sits on the bed.
Hose B inner diameter	8 to 40 mm	13 mm	Inner diameter of the second hose. Set both hoses the same for a straight joiner.
Barb oversize over hose ID	0.3 to 2.5 mm	1 mm	How much wider than the hose's inner diameter the barbs are. Use less for stiff hose and more for soft hose.
Barb height (radial)	0.6 to 2 mm	1.2 mm	Radial height of each barb ridge above its root. It is reduced automatically when the barb spacing is too short for it.
Barb spacing	3.5 to 10 mm	5 mm	Distance from one barb to the next along the adapter.
Barbs per end	2 to 6	3	Number of barbs on each end. More barbs make each end longer and hold more hose.
Wall thickness	1.2 to 4 mm	1.6 mm	Wall thickness under the barbs. A thicker wall is stronger but narrows the bore.
Flange lip beyond barbs	1 to 5 mm	1.5 mm	How far the centre flange stands out beyond the larger barbs, as a stop for the hoses.
Flange straight length	2 to 10 mm	3 mm	Length of the straight part of the centre flange.

Proof: measured on the model

What the design must satisfy and what our CAD engine measured on the model at the default values. Only measured values are shown here; nothing on this page has been printed by us yet.

Requirement	Wanted	Measured
Centre flange diameter	23 mm (19 mm hose + 1 mm oversize + 1.5 mm lip each side)	23 mm
Overall length	36.4 mm	36.375 mm
Barb diameter on the 19 mm hose end	20 mm (1 mm over the hose)	20 mm
Barb diameter on the 13 mm hose end	14 mm (1 mm over the hose)	14 mm
Bore on the 19 mm end	14.4 mm	14.4 mm
Bore on the 13 mm end	8.4 mm	8.4 mm

valid solid, one body, 23 x 23 x 36.4 mm, fits a 256 x 256 x 256 mm printer; overhangs: 0.0% of surface would need support.

Print notes

Orientation: Standing upright on the larger hose end, axis vertical, as modelled.
Supports: None
Material: PETG or ABS; PLA can crack under hot water or clamping force
Layer height: 0.2 mm
Settings: At least 3 walls and close to 100% infill if it will hold water under pressure
Hardware: 2 x hose clamps sized for your hoses (optional, for a firm seal)
Time and filament: About 15 min and 5 g at the default size: a rough estimate from the model's volume and surface (PLA, 15% infill, about 1 mm of walls, 0.2 mm layers), not a slicer.

Print one adapter and push it into your hoses before you print more: the grip depends on how stiff the hose is. Change the barb oversize if it is too hard to fit or slips off.
Layer lines run across the barbs, which is the weaker direction. Keep the joint straight and do not use it where the hose is pulled hard.
It has not been pressure tested. Use clamps and check for leaks before you leave it running unattended.

How it was designed

Designed with buildcad's AI agent, checked by the buildcad team. This is the request it started from and an edited account of what it did (more on how text to CAD works).

The request
An adapter joining two hoses of different inner diameters, 19 mm and 13 mm by default, with barbs on both ends.

1
One revolved profile
The agent drew the adapter as one profile turned around its axis: barbs 1 mm over each hose's inner diameter (20 and 14 mm), and a flange 1.5 mm proud of the larger barbs as the hose stop. It wrote checks for the 23 mm flange, the overall length and one body.
2
First build: overhangs
The first build was valid and the sweep rebuilt all 18 slider extremes, but the overhang check failed: 6% of the surface (234 mm2), the 45 degree faces under the barbs and the flange, would need support.
3
It steepened the faces
The agent made those faces steeper, about 51 degrees from the bed, and the overhang dropped to 0 mm2. The taller flange cone made the adapter 36.4 mm long instead of 35.7 mm, so it updated the length check to match.
4
Final checks
The last build measured 23 mm across the flange, 36.4 mm long, with bores of 14.4 and 8.4 mm, and the sweep rebuilt all 18 extremes as one valid body each.
5
What it left to the maker
Its reply asks for a short test print because hose stiffness varies, a hose clamp for a firm seal, and PETG or ABS rather than PLA for hot water.

One run of the agent: 1 min 40 s, about $0.22 of model time at list price (claude-sonnet-5-5). The model code behind this page is the code it wrote, unchanged.

Change it with AI

Set the sliders, then press Change it with AI: a copy goes to your designs at those sizes and the designer opens with a suggested change you can edit. Its changes use credits like any design; new accounts start with free ones.

Change it with AI Describe your own part Use it from your own AI (MCP)