6″ 90° Duct Elbow — Airflow Variant (R/D 0.94)

Description

Overview

The right angle you use when you actually care about the airflow. Instead of turning as tightly as the fitting can be made, this one carries a centreline bend radius of 0.94 times the duct diameter — a sweeping turn rather than a corner.

What it fits

Standard 6-inch collars on both ends, fully interchangeable with the compact 90 and the rest of the 6-inch line. It occupies a larger envelope than the compact version; check your clearance.

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 the clearance around your machine against the footprint in the specifications below. If something does not fit, tell us — that is how the next revision gets better.

How it is used

Substitute it wherever you were going to fit a compact 90 and have a few extra centimetres to spare. It matters most early in the run, close to the machine, where the air is moving fastest and the losses are therefore largest.

Why it helps

Bend loss in ducting is governed largely by the ratio of bend radius to duct diameter. Standard engineering loss tables put a sharp, short-radius turn at several times the loss coefficient of a sweeping one, and at R/D 0.94 this fitting sits firmly in the sweeping category. The geometry is a measured fact of the part; the airflow benefit is what those published loss relationships predict, not something we have put on a flow bench ourselves. We would rather tell you which of those two it is.

• Centreline bend radius of 0.94 × duct diameter — a sweep, not a corner
• Direct swap for the compact 90 where clearance allows
• Best deployed early in the run, nearest the machine
• Single continuous body, no assembly

Specifications

Open source — print it yourself, or buy it finished

Every shroud D-Central designs is released as an open file. The geometry for this part is free to download from our 3D models download center: use it, modify it, remix it, run it in your own shop, sell what you make from it. There is no licence to buy and no design gated behind a purchase. Shared knowledge is the whole reason this industry has open hardware at all, and we are not going to be the ones who stop passing it on.

This listing is for the finished part: made to order in PETG and shipped from Montreal, Quebec. If you would rather have it in your hands than spend an evening making one, buy it here — that is what pays for the next design in the line. You can also support the open-source work directly through D-Central’s fund page.

Works with

• 6″ 90° Duct Elbow (Compact)
• 6″ 45° Duct Elbow
• 6″ Duct Coupler
• Antminer S19 / S21 Venturi Shroud — Dual 120 mm to 6″

See the full D-Central shroud and ducting system for the compatibility matrix and sizing guide.

Frequently asked questions