A wider marker changes the scale of a plot. This AxiDraw XL Pen Clip project is a two-piece, 3D-printed holder for round pen and marker barrels from 12 to 25.4 mm in diameter. The photographs show the printed clip mounted on the plotter with a large permanent marker, drawing broad black lines on cardboard.
A plate, a dovetail, and a removable arm
The mounting plate has two V-shaped saddles that support the barrel. A separate clamp arm slides into a dovetail on the plate and locks with an M3 screw. Captive M3 nuts provide the threads for the dovetail lock and the pen-clamping screw.
The plate is designed around two M3 carriage mounting holes spaced 31.75 mm center to center, with hole pairs for upright and 45-degree mounting. This version uses the sliding dovetail rather than the earlier keyed-arm design.
From the model to the machine
The close views show how the printed parts sit against the carriage and hold the marker. With the marker removed, the V-saddles, dovetail joint, and side-loaded nut slot are easier to see.
Plotting test
This short movie shows the holder in motion while the marker draws the repeating pattern on cardboard.
Printing and fit notes
The current design uses two printed parts, two standard M3 hex nuts, an M3 × 10 socket-head screw to lock the dovetail, and an M3 × 25 nylon thumbscrew to clamp the pen. The original M3 × 8 button-head screws mount the plate on the reference carriage. The photos show a metal screw used for the test; a nylon tip helps protect the pen barrel.
Print the plate on its flat carriage face and the arm on its broad side, with the nut slot facing up. A separate mounting gauge provides a quick check before printing and installing the full holder. The gauge fit has been confirmed on one carriage, so check your own machine rather than assuming an identical fit.
Before plotting, check the actual pen-tip position at Home, pen-up and pen-down clearance, and the full drawing area. A larger barrel, clip, or projecting screw can reduce usable travel. Keep pen-up moves and the return to Home inside the clearance you have checked.
The design was inspired by the factory AxiDraw XL pen clip. The AxiDraw setup guide is a useful reference for setting pen height and checking movement.
