One possible source for unique standard, quality and really not expensive rods is IKEA curtain rods.
IKEA is almost everywhere and most of the time they have unique identifiers for items.
HUGAD Curtain Road. : Price 6.99USD or 6EUR (in FRANCE)
item: 502.171.39 (black)
item: 702.171.38 (silver)
item: 302.171.40 (white)
It’s telescopic, has a total of more than 385cm = one inner rod approx: L>170cm OD=25mm and one outer road approx:L>200cm OD=28mm
Rod: Steel, Epoxy/polyester powder coating
Plug/ Sleeve: Polypropylene
Min. length: 210 cm
Max. length: 385 cm
Diameter: 28 mm
Max. load: 10 kg
A stiff base for the CNC could be the solid wood kitchen cart like BEKVAM 59.99USD (or 49 euro)
Length: 22 7/8 ”
Width: 19 5/8 ”
Height: 33 1/2 ”
Length: 58 cm
Width: 50 cm
Height: 85 cm
Starting from these basic two items (and some other IKEA items we might find would fit in) with some clear documentation (like IKEA doc 🙂 I think more people will step into this very interesting project.