Dual 140 mm Fan to 150 mm Metric Duct Shroud

Description

Overview

The dual-140 answer to metric ducting: newer-generation miners moved to two 140 mm exhaust fans, and if your ducting is 150 mm European flex duct, an inch collar will not fit it. This shroud captures both 140 mm fans — 140.0 mm pitch, 134.0 mm bore per fan — and converges them into one 150 mm metric duct.

Single-piece PETG with a flex-over collar: the duct slips over the collar and clamps on the 148.0 mm sealing land under the 150.0 mm crest.

What it fits

Miners with two 140 mm exhaust fans on a 140.0 mm pitch, exhausting into 150 mm metric flex duct.

Measure before you order. Fit dimensions in this line are derived from published fan and chassis geometry and are not yet validated against measured production hardware. Check your flange size and clearances against the footprint below. If something does not fit, tell us — that is how the next revision gets better.

One more honest number: the collar’s sealing land sits at duct nominal minus 2.0 mm, while measured male metric hardware runs nominal minus 1 to minus 2 mm. Our land sits at or under that hardware and never over — which is a retention argument, not an exact-match claim. The metric ring coupon measurement that would settle it is still open.

A note on corroboration: the 150 mm sizing rests on manufacturer datasheet evidence only, so it has weaker backing than the 160 mm and 200 mm sizes in this line. Do not treat it as verified against physical spigots — it is not, yet.

How it is used

Mount the shroud over the two 140 mm exhaust fans using the fan screw pattern. The flange holes are 5.0 mm (with 5.424 mm slots); put a 9 mm or larger flat washer under each screw head, or reuse the miner’s own large-head fan screws. Then slip 150 mm metric flex duct over the collar, clamp it on the sealing land behind the crest, and route the duct to a window port, a plenum, or the space you want to heat.

Why it helps

• Built for the dual-140 fan generation — 140.0 mm pitch, 134.0 mm bore per fan.
• Metric-native: the collar is cut for 150 mm duct, not a 152.4 mm inch collar pretending.
• Single-piece PETG part: no seams, no glue joints, nothing to work loose over months of fan vibration.
• Every fan screw stays reachable: minimum measured tool radius 8.62 mm on this part, against a project target of 8.0 mm — all screws rate GOOD.

Specifications

Open source

This design is open source under CC BY-SA 4.0. The files are free at /3d-models/, and anyone may print, modify or sell them. Buying the finished part supports the work that produces these designs — you can also support it directly via the fund.

Works with

• Dual 140 mm to 6-inch duct shroud
• Dual 140 mm to 160 mm metric duct shroud

See the full D-Central shroud and ducting system.

Frequently asked questions