add a simple sleeve for a hex spacer that isn't wide enough

I got a bag of spacers that are not as wide as what I normally use, so
they rattle around in the post hole and obviously don't help with the
fit of the completed stick. this sleeve seems to be right for them to
fill the hole. provided in case it is useful in the future, for myself
or anyone else

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

src/misc/m4-hex-spacer-sleeve.scad

@@ -0,0 +1,24 @@
+/* Wrap a smaller width hex spacer with plastic to get it to fit in our standard post hole.
+ *
+ * Since the hex spacers can vary in width, you may have to adjust the inner dimensions
+ * to make this work right for your piece, but this worked right for mine. YMMV.
+ *
+ * SPDX-FileCopyrightText: © 2025 Brian S. Stephan <bss@incorporeal.org>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+include <parameters.scad>
+include <components.scad>
+
+module small_m4_hole() {
+	scale([1, 1, 2]) cylinder(r=3.25, h=frame_z, $fn=6, center=true);
+}
+
+module m4_hex_spacer_sleeve() {
+	difference() {
+		resize([0, 0, 45]) frame_hex_bolt_hole();
+		small_m4_hole();
+	}
+}
+
+
+m4_hex_spacer_sleeve();