The New Hotness

The instructions for the Photo Backdrop frame (upon which we hang Mary’s quilts for photos) suggest the crossbar fits on like this:

Photo Backdrop - OEM crossbar installation — Photo Backdrop – OEM crossbar installation

The slot in the bottom is wider than the M10 stud, so the crossbar tends to flop around while assembling it overhead. I immediately replaced the wingnut with a chunky knob for better griptitude, but was never happy with how poorly the whole thing fit together.

This is dramatically better:

Photo Backdrop - fitting installed — Photo Backdrop – fitting installed

The crossbar is upside-down from the OEM instructions, but the bottom of the gray plug holds the tube firmly to the tripod while the nut seats firmly on the plug’s flat top:

Photo Backdrop - fitting top view — Photo Backdrop – fitting top view

A snippet of 3M 300LSE adhesive sheet holds the plug in place, so that’s one less thing to fiddle with on each end.

The solid model holds no surprises:

Photo Backdrop Fittings - solid model — Photo Backdrop Fittings – solid model

Of course, it builds with the flat end downward.

The OpenSCAD source code as a GitHub Gist:

	// Photo backdrop fitting
	// Ed Nisley – KE4ZNU
	// 2026-07-01

	include <BOSL2/std.scad>

	Layout = "Show"; // [Build,Show]

	/* [Hidden] */

	ID = 0;
	OD = 1;
	LENGTH = 2;

	HoleWindage = 0.2;
	Protrusion = 0.01;
	NumSides = 324;

	Clearance = 0.3;

	$fn=NumSides;

	Tube = [23.0 – HoleWindage,1*INCH,100.0]; // arbitrary length

	Aperture = [24.0,15.0,100.0]; // oblong nut hole, arbitrary Z

	Washer = [10.5,20.0,1.5]; // M10


	//—–
	// Define things

	module Fitting() {

	difference() {
	union() {
	intersection() {
	xcyl(Tube[LENGTH],d=Tube[ID]);
	cuboid(Aperture,rounding=Aperture.y/2,edges="Z");
	}
	cuboid([Aperture.x,Aperture.y,Tube[OD]/2],rounding=Aperture.y/2,edges="Z",anchor=BOTTOM);
	}
	cyl(Aperture.z,d=Washer[ID]);
	}
	}




	//—–
	// Build things


	if (Layout == "Show") {
	Fitting();
	}

	if (Layout == "Build") {
	up(Tube[OD]/2)
	xrot(180)
	Fitting();
	}

view raw Photo Backdrop Fittings.scad hosted with ❤ by GitHub

The New Hotness

Photo Backdrop: Crossbar Improvement