Fully Compliant Pliers

by BYU_CMR Mar 12, 2019
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this seems to have a great deal of promise if certain materials are used. life of part can be extended and material portfolio increased by controlled constrained stress relief springs. supports constrain how much an area can bend, and several parts within have several week points that only bend a little.

this is awesome, I just saw this on Veritasium. thanks for making this available.

This was made, and posted in 2014, .... https://www.thingiverse.com/thing:334435

I'm new to Thingiverse, but this seems wrong?

...It's literally the exact same model? Are Duplicate posts not against the rules?... Shouldn't they at least delete the old one?

Fully compliant pliers

BYU developed these, so they get full credit, otherwise, don't ever repost anything without giving permission.

We gave permission to Polymakr to use this model to demonstrate the ability to print compliant mechanisms with their flexible filament. If you look on their description, they give credit to us (BYU CMR). We decided to upload this model to our own account rather than directing traffic to another profile.

One way to obtain an adjustable opening is with w pipe clamp style mechanism. That would give you an adjustable jaw opening.

Can the size of the opening between the jaws be adjustable? Like vice grips. Even better, I can imagine a set of jaws that remain parallel and apply a constant force over a range of separation. So as you apply pressure the jaws close until they reach an object. At this point, the jaws stop moving and as the handles continue the jaws apply constant pressure. Eventually, the handles engage a bi-stable mechanism and lock shut.

I want to combine this with the Bi-Stable model to make a locking clamp. Any thoughts?

I love these mechanisms! I want to print them all. Just found you thanks to Veritasium :) I love your work and design!

me too xD
i honestly wasnt expecting too see this one here =D
So happy to see this awesome files open for us...

i also saw them there, on yt xD

I have a mp select mini v2, will tpu filament extrude normally on the default nozzle for it? I've heard you need a special extruder for flexible filaments.

useless on PLA :(
on the first bend it didn't come back to its shape.

I have a set in PLA that are doing great after a few days of playing with them.

I had to scale this up 155mm and situate it so it had multiple walls on all the hinges. Slic3r wanted to make the layer start where the item was thinnest, causing the thin hinge near the jaws to just be a series of blobs that would break immediately. Setting seam to be random, rather than aligned helped keep the hinges from becoming weak spots. It took some trial and error.
Bad, not enough walls:
bad hinge

Good, multiple walls:
good hinge

Scale up so the hinges will be bigger than nozzle hole diameter

Did you try to scale it up when you printed?

maybe you overextrude it or print it so thick that you end up breaking the pla instead (?

Nope, it was a standard 0.4mm nozzle and no overextrusion. I think maybe I should scale it even bigger, like 25x or something.

Prints well in PETG, minus a bit of stringing still very strong

I printed mine in PETG. Stringing is normal for PETG

Hey, any chance of an stl for the Wyrd Elephant compliant mechanism?
Really appreciate your work! Cheers!

"Wyrd" Elephant Compliant Mechanism

I assume these are using units in inches or something? They come out realllllly tiny if you assume mm (they're 7mm wide)

I had to scale up to 1000% to get to something similar to the one in the picture, but the front hinge is still 1 wall width and pretty fragile (at least in PLA).
Probably more robust scaled to 2540 as per inches made files

I just did something similar, and yes the front hinge doesn't seem like it'll last too long, I went for 1540% as 2540% seemed like it would take a while.

Greetings from your rival to the North! ;) Your website is awesome! I believe read somewhere on it that polypropylene lasted the most cycles. Is that correct? I haven't tried printing that yet. How does PETG fair?

Your fatigue testing rig in the Veritasium video led me to believe that you've probably tested a lot of these files with different materials. Could you pretty please point me in the right direction to check out your juicy data?

Awesome work, I had no idea the Y had such cool stuff going on.

P.S. from the perspective of someone that cheers for your defeat every year in the holy war, I think you should have uploaded the version with the cool BYU logo embossed in it. It's super cool knowing that such a cool thing came from you guys.

PETG should work great. For compliant members, polypropylene typically has the longest fatigue life before failure compared to other plastics. This is due to its high yield strength to Young's modulus ratio (Sy/E). Thanks for your support! We're glad to see such a positive reaction from the video and our work!

I printed in PETG, it is very strong

Can you print this with pla or does it need to be flexible/semi flexible material?

you can print with PLA just fine! However, a more flexible material like TPU will last longer.

What are the required settings for printing with TPU?
U3+ tpu95A