Parametric handles for pipe frames (eg. Hadley telescope)

SAFETY NOTICE: This grip is meant to offer a control point for a pipe frame (like the Hadley Telescope frame), it is NOT meant to lift anything or resist any force.

…With that out of the way… here is a practical and 100% 3d printed system to add a handle to a pipe frame.

The system is inspired and designed based on the 12 mm bars of the metric Hadley telescope, but it can be used on anything with a similar frame.

The system consists of a “U” shaped gripper with a split thread on either “prong”, a ring nut that closes the gripper on the pipe, and the handle itself that screws on the other side of the ring nut.

Tightening and releasing the ring nut it is possible to slide and rotate the handle (for example to fold/slide it out of the way when stowed).

The handle itself attaches to the ring nut via a slightly modified M22x3 thread, so you can design and attach other handle shapes (I know what you are thinking, please don't). 

The vertical walls of the thread are offset by 0.5 mm to make the thread more “squat” and easier on the printer, and there is a parametric tolerance added only on both the ring nut threads (rationale being that if the tolerance is off, you only have to reprint this one part).

For each component there are also some “special” versions.

Gripper and ring nut have added slots for TPU inserts giving a little more grip on the frame, while the special handle comes in the form of a top screw cap to access the hollow space within, if you want to load it with ballast and use the handle to further alter the balance of the final assembly.

In addition, the grippers also have “flat” variants to allow printing them on their side instead of vertically, this increases the amount of torque they can withstand if you really want to tighten them tight, or you have issues with them failing (credit for this idea goes to @Arc on the Hadley Discord). There is a flat sacrificial first layer to prevent adhesion issues with the thin and serrated U shape which would otherwise result.

All “special” parts are interchangeable with their basic versions so you can mix and match at will.

I am sharing the CAD file with a couple parameters for handle length, width and tolerance of the threads, going bigger should not be an issue, smaller may have problems with the cap thread on the open version.

Changing the diameter of the pipes is more complicated because changing that will make the “U” gripper wider, and making the parts wider will require to adjust the threads, and changing the threads means re-pointing the face offsets for the tolerance and for making them more printer-friendly… totally doable, just not as straightforward as changing one parameter.