Z-Series Expanded Helping Hands / Flex Clamps

Updates

• 17-05-2025: I've added a “Large” version of each of the top jaws, which have a more prominent grip ledge to grasp when actuating the jaws. (Shoutout to @Charly_Brown for this one)
• 25-04-2025: I added a few variants of the base. “Deep” takes 3 magnets instead of 2 for a better grip. M5Bolt takes a hex-head M5 bolt that I've been using with the E-series Fixture Plate. There are also knurled versions of each base, if you prefer to have some gripiness.

Starting Materials

you will need:

• M3 Bolt of whatever head shape you'd like. I recommend Furniture Bolt style flat head (not countersunk). The length of this bolt will impact the length of spring that you use, and the height that the jaws can open to.
• A compression spring, 5mm in diameter. The length of this spring will depend on the length of your M3 Bolt. A good number is about 10mm less than said bolt (as such, I've found a 20mm spring is a good bet).
• an M3 Nut (You can use a hex nut, but if you want to be fancy: a knurled nut works really well). This nut will let you adjust tension on that spring and set the openable depth. (if you don't care about adjusting the tension or anything, you can use a washer instead - you still need something to have the spring push against).
• One of or both:
  • M4-threaded Ball (Magnetic Joint, I think is the proper term) - useful for being able to angle your stands
  • M4 Knurled Thumb Nut (a blind-hole thumb nut is best) - this is useful if you want to have the stands be vertical rather than swivelable.
• optional, but recommended: 11mm OD, 8mm ID, 1.5mm Width O-Ring. this is useful for having a bit more friction around the ball joint. (Someone smarter than me probably could put together a base that uses TPU instead, but I can't be bothered.)
• optional, just for fanciness: M4x10mm Standoff with one female end and one male end.
• optional: some heat-shrink tubing

There are some additional materials depending on what jaw attachment styles you use - see below.

What filament?

really it's up to you. I decided to go somewhat out and used ABS-GF for some amount of thermal tolerance. You probably could get away with ABS, PETG or even PLA depending on your use-case.

The Jaws

There are three shapes: Finger, Standard, and Wide, in ascending order of width.

Each upper and lower jaw comes in three attachment styles. For the upper jaw: “Insert”, “Press”, and “Locknut” - for the lower: “Insert”, “Tap”, “Locknut”

Top Jaws

“Press” style

additional materials:

• M4 Bolt of the DIN912 spec. I would not go shorter than 50mm, or longer than 70mm.

Slide the bolt through the top of the Top Jaw - the head should press into the recess you find on the model.

I, personally, recommend this, even if the DIN912 bolts are a bit harder to come by. The unthreaded part of the bolt makes for a smoother sliding action when opening and closing the jaw.

“Locknut" Jaw

additional materials:

• M4 Bolt of pretty much whatever type you want (except countersink) at whatever length you want - again: I would not go shorter than 50mm nor longer than 70mm
• M4 Nylon Lock Nut

Press the Lock Nut into the bottom of the jaw, into the hexagonal cutout. Thread the bolt through the top of the jaw and screw it into the lock nut until you've completely bottomed the screw through.

“Insert” Jaw

additional materials:

• M4 Bolt of pretty much whatever type you want (except countersink) at whatever length you want - again: I would not go shorter than 50mm nor longer than 70mm
• M4x6mm Heat set Insert

Set the insert into the centermost hole of the jaw, and thread the bolt into it until it bottoms out.

Bottom Jaws

“Locknut” Jaw

additional materials:

• M3 nylon lock nut

“Insert” Jaw

additional materials:

• M3x6mm heat set insert

“Tap” Jaw

additional materials: none

Assembly

• after assembling the top jaw, you may need to widen the smaller hole a bit - the M3 bolt should slide through it smoothly. 
• slide the bottom jaw onto the bolt through the centermost hole.
• Thread the M3 nut onto the M3 bolt until its near the head.
• Slide the spring onto the M3 bolt. That M3 nut will serve to add a bit more clamping force while also narrowing the jaw opening.
• Run the M3 bolt through the smaller hole on the top jaw. 
• If you're using the Locknut or Insert variant of the bottom jaw, simply screw that M3 bolt into that insert/locknut.
• If you're using the “tap” version of the bottom jaw, you can just screw it directly into the plastic (it's really “Self-Tapping” I guess).
• If you want the extra fanciness, screw the Standoff onto the bolt, and then Screw the Ball or Thumbnut onto the standoff - otherwise just screw the ball or thumbnut onto the bolt directly.
• if you want, you can put some heat-shrink tubing around the jaw fingers/mouth for some extra gription.

The Base

• glue the magnets into the base - that's really it.

A Note

this should be compatible with omnifixo, but I don't promise anything.