Bike rack support for Veteran Patton EUC

WHAT IS IT

A snap-on mount for attaching a bicycle rack (luggage carrier) to a Veteran Patton EUC. It is two C-shaped clamps, one for a 30 mm rod and one for a 10 mm rod, rotated 90 degrees to each other and joined by a bridge. Press it onto the rods, no screws or tools. The rubbery TPU grips well and dampens vibration from the wheel.

A smooth S-shaped gusset runs along the top, from the flat part of the bridge up to the top of the small clip, so the small clip is supported instead of hanging off the edge. All edges are rounded.

Two files are included, so you can build a rack with a mount on each side:

- cross_clip.stl: standard version

- cross_clip_mirrored.stl: mirrored version

In both, the small clip's slot faces outward, away from the bridge. The text "SPY" is engraved on one side wall.

FIT ON THE PATTON

I designed it around rod diameters of 30 mm and 10 mm. Before printing, measure the tubes on your own wheel and rack and check that they match. The bores are 0.3 mm undersized (29.7 mm and 9.7 mm) for a tight press fit. If your tubes differ, change d1 and d2 in the OpenSCAD file (included).

DIMENSIONS

- Overall size: 40 x 63 x 53.5 mm

- Large clip bore: 29.7 mm (for a 30 mm rod, 0.3 mm interference)

- Large clip slot: 25.5 mm

- Small clip bore: 9.7 mm (for a 10 mm rod, 0.3 mm interference)

- Small clip slot: 7.5 mm

- Wall thickness: 5 mm

- Clip width: 40 mm

- Small clip axis height above large clip axis: 30.7 mm

- Gap under the small clip: 1 mm

- Edge fillets: 1.5 mm

- Engraving: "SPY", 0.8 mm deep

The parametric OpenSCAD source (cross_clip.scad) is included. You can change the wall, slot, clearance, gap and gusset (gusset = false removes it).

SAFETY

This is a DIY, community-made part, not an official Veteran accessory. It is printed in flexible TPU, and layer adhesion and fit depend on your printer and settings. Print a test piece first, check it for cracks, and do not rely on it alone for a heavy or valuable load. Inspect it regularly, because a rack that comes loose at speed is dangerous. You use it at your own risk.

MATERIAL

TPU 95A (Shore 95A). A softer TPU (85A) will grip more but may feel floppy with a 5 mm wall. A harder one (98A or TPE/PETG) will be much harder to press on.

RECOMMENDED PRINT SETTINGS

- Nozzle: 0.4 mm

- Layer height: 0.2 mm (0.25 mm is fine)

- Perimeters/walls: 5-6 (the part is almost solid at 5 mm walls)

- Infill: 20-30%, gyroid

- Print speed: 20-30 mm/s

- Nozzle temperature: 220-235 C (follow your filament's spec)

- Bed temperature: 40-60 C

- Retraction: off or minimal

- Cooling fan: 50-100%

- Supports: only if needed (see below)

- Brim/raft: not needed

ORIENTATION

Print with the 30 mm clip's axis vertical, so the layers follow the arc of the clip. Layer lines then run around the C-shape rather than across it, so the clip flexes without splitting along layers. The small clip's round opening may need light supports (tree supports work well). Remove them carefully and clean the bore, but do not sand or enlarge it.

TIPS FOR TPU

- Dry the filament (about 50 C for 4-6 h). Wet TPU gives stringing and weak layers.

- Feed from an external spool, not an AMS, and keep the filament path short and straight.

- Print slowly. Fast TPU prints are the main cause of jams and under-extrusion.

- If the part bonds too strongly to a smooth PEI plate, use a thin layer of glue stick as a release agent.

FIT AND TUNING

The press-in force is about 4 kgf by calculation (assuming a TPU modulus around 26 MPa and the 25.5 mm slot). This is an estimate, not a measurement. Real force depends on your filament and print settings.

- Too tight to press on: widen the slot (open2 in the SCAD file) or reduce the wall (w2, try 4 mm).

- Too loose: narrow the slot, thicken the wall (w2, try 6 mm), or reduce clr to 0.2.

- Print a 10 mm slice of the large clip first to check the fit before printing the full part.

TEST RESULTS

(Add your own here: filament brand, settings, how the fit turned out.)