6-Inch Flex Duct Adapter — Rigid Socket to Flex Collar

Description

6-inch flex duct adapter — rigid fitting to flex collar

This 6-inch flex duct adapter is the part that lets a rigid duct fitting end in flex duct. One end is a 152.4 mm outside-diameter plug that seats in any 6-inch duct-fitting socket in the D-Central catalogue — sockets bored 153.0 mm and up. The other end is a male flex-over collar, clamp land 150.4 mm, retention bead crest 152.4 mm, 145.6 mm through-bore, that 6-inch flex duct slides straight over.

Most home mining runs are not all rigid or all flex. A coupler here, an elbow there, then two metres of flex to get around a joist and out to the window. The joint between those two worlds is normally tape, and tape on a hot exhaust run is a maintenance appointment waiting to happen. This is that joint, shaped as one part with a clamp land on it.

The plug is also deliberately sized not to fit a shroud collar. Shroud collars bore 152.36 to 152.39 mm against this 152.4 mm plug — a designed 0.041 mm radial interference. Every D-Central shroud already carries its own flex-over collar, so a shroud never needs this adapter, and the geometry makes sure you cannot spend money finding that out. Slip flex over the shroud directly; use this adapter on the rigid fittings downstream.

What it fits — 6-inch rigid sockets and 6-inch flex duct

• Any 6-inch duct-fitting socket in the line, bore 153.0 mm or larger: couplers, elbows, reducers, window ports and wyes.
• 6-inch flex duct, slipped over the collar end and clamped on the 150.4 mm land.
• Not shroud collars — those are an interference fit by design, because shrouds already have a flex collar of their own.

Working in 8-inch duct instead? The 8-Inch Flex Duct Adapter — Rigid Socket to Flex Collar does the identical job at the larger size, and the 8″ to 6″ Duct Reducer is where a full-size trunk steps down to a 6-inch drop.

How it installs

1. Pick the fitting you want to convert — an elbow that has to continue in flex, a window port fed by a flex run, a coupler joining flex to rigid pipe.
2. Push the plug end into that fitting’s socket until it bottoms.
3. Slide the flex duct core over the collar end, past the retention bead.
4. Seat a worm clamp on the 150.4 mm land, behind the bead, and tighten. One part, one clamp, no tape.

Why the geometry does the work

Flex duct and rigid duct do not connect the same way round. A rigid pipe end goes into a socket; a flex core goes over a male spigot, because its wire helix will not sit square inside anything. Any part that joins the two has to be male on one side and male on the other in opposite senses — which is exactly what this is, with the transition length to keep the airstream straight through the change instead of stepping it. The retention bead sits proud of the clamp land so the clamp cannot walk off the end when the duct is pulled, and the through-bore stays open at 145.6 mm rather than necking down at the joint.

• Convert any 6-inch rigid fitting in the line to flex with one part.
• Replace tape-and-hope transitions with a clamp land and a retention bead.
• Keep the same collar geometry as every other 6-inch flex interface, so clamps and duct stock interchange.
• Seat positively in sockets bored 153.0 mm and up, without shims or sealant.
• Stay out of your shroud collars by design, so parts cannot be assembled the wrong way.
• Hold shape in PETG at ASIC exhaust temperatures, where PLA goes soft.

Specifications

Open source — print it yourself, or buy it finished

Transitions like this one are exactly what a home miner needs at 9 pm on a Sunday, which is why D-Central Technologies designed one and published it instead of sitting on it. The plug, the collar, the bead and the 0.041 mm interference are ours — drawn here, not adapted from anyone else’s model — and the file goes out under CC BY-SA 4.0 through the 3D models download center, free to download, modify, remix, print and sell. Its card is the 6-inch flex adapter model.

Take the file itself as duct_flex_adapter_6.zip: the STL, the CC BY-SA 4.0 licence and the installation and safety guide in one download. Buying here gets you the finished part in PETG instead, black or orange, made to order in Montreal, Quebec, with the collar and plug dimensions matched to the rest of the fitting family. The file stays free either way; the printed part and D-Central’s fund page are what pay for the next design in the line.

Works with

• 6″ Duct Coupler
• 6″ 45° Duct Elbow
• 6″ 90° Duct Elbow (Compact)
• 6″ Window Exhaust Port
• 6″ to Dual 4″ Y-Splitter

See how the pieces chain together in the D-Central shroud and ducting system.

Frequently asked questions