Wimberley Knob Replacement

This is a replacement knob for the Wimberley Shapeshifter M-4 and F-2 macro photography bracket.

Requires a 7/16” hex nut and the original capture sleeve+set screw from the failed knob.

Print Settings

Printer Brand:

Prusa

Printer:

i3 MK3

Rafts:

No

Supports:

No

Resolution:

150

Infill:

40

Filament: Prusament PLA Galaxy Black Notes:

This is a replacement knob for the Wimberley Shapeshifter M-4 and F-2 macro photography bracket.

Macro photography enthusiasts (and photographers in general) probably know the Wimberley line of products. Most are black metal parts designed for mounting camera gear, often with precision clamping. The Shapeshifter is a unique, double-ball adjustable arm used to arbitrarily position flash lighting for extreme close-up macro photography. Most Wimberley equipment is gorgeous, smooth and precise. The knobs for the friction ball adjustment brackets on the Shapeshifter, however, have proven to be too weak over time. As you can see in my photo, they crack along the side which opens around inset bronze threads and they start to twist. This effectively ruins the knob.

The concept here is similar to “Ram” branded components using 1/4-20 standard tripod mounting hardware. What makes these knobs unique is the capturing sleeve on the outside end of the knob. Wimberley has used this design to keep the knob from loosening too far. When you are shooting photos and adjusting your flash rig, the last thing you want is for the knobs to open too far so they fall off—or even just far enough to allow the hard rubber ball ends to slip free of the clamping mechanism. The capturing set screw holds a sleeve onto the end of the bolt, so this object needed to accommodate that design.

Printed on a Prusa Mini+ (not selectable) Printed with 4 shell perimeters for strength, honeycomb infill at 40%. Maybe this is overkill, but I can repeatedly crank down on this knob and I don’t feel any give.

Orient the handle upside-down to print so the levered handles are on the print bed and the round end faces up to avoid overhang. No supports needed.

Be sure to print both parts. Because I am using a standard 7/16” 1/4-20 hex nut instead of the original embedded bronze thread insert, the nut needs to sit up inside the knob at the right height to match the height of the original and allow the set screw endcap sleeve to function as originally designed.

Had I simply included the “plug” material in the knob model, it would have introduced bridging which may have worked, but in order to avoid overhang, we are printing the knob upside down, and adding the plug later works nicely.

Post-Printing

Assembly

You will need to print both parts to make this work.

You also need a 7/16” hex nut for 1/4-20 threads.

Insert the hex plug you printed into the round end of the knob. Put the knob on a flat surface and push it down over the hex plug so it is flush. This may be a tight fit which is good. You don’t want this spacer sliding out. If it loose, add some glue? Probably not even necessary.

Hex plug sits flush with the bottom of the knob.

Insert the hex nut on the opposite end of the knob (the outside end of the knob with the lever handles). Push the nut down until it sits against the hex plug you inserted from the other end above. If the fit is tight, you can screw the knob onto the Shapeshifter bracket and tighten. The nut will be pulled into position.

Hex nut sits down inside on top of printed hex plug.

Attach the end sleeve (original hardware) to the bolt over the nut and position it how you want, then tighten the set screw with the appropriate allen wrench.

Thread the capturing sleeve onto the bolt after the knob and tighten the set screw at desired height.

How I Designed This

Built the model in TinkerCAD on an iPad after measuring the original and working out how to replace it using a regular hex nut

Category: Camera