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Newton Gripper Jaw Modifications

Hi everyone,

Looking at creating some 3D prints, and wanted to see what work was already done in the space. I would like to be able to either attach to, or substitute the jaws on the Newton Gripper with 3D prints, thinking perhaps an extended claw, a claw with two flat surfaces meeting rather than interlocking, perhaps something like a digger bucket which could increase the volume of area grabbed? Another idea would be an addition which allows an amount of flex in the jaws, perhaps something with room for a spring attachment which would allow for sensitive objects to be gripped.

Application for reference - looking to sample coralline algae on pebbles, and medium sized invertebrates. I think the current jaws may be too “precise”, and would prefer something that grabs from a bigger area.

Would love to see some peoples designs for inspiration or CAD models!
-Jack

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Hi @Marruger,
Check this:

Hope this help.

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Hi @Marruger, sounds like a fun project! :slight_smile:

@slensgra posted recently about a project with a modified gripper - there’s some more information in the manipulator section of their linked blog post.

There’s also:

Note the gripper mechanical properties, and drawings and 3D models we provide in the technical details tab of the gripper product page, which will be useful for designing custom jaws or an extension to the existing ones :slight_smile:

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Thanks very much Eliot and Ender!

Finding my way through CAD and building onto the (very helpful) technical drawings provided by Eliot - this should be a breeze. Will post again once finished!

-Jack

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Morning all,

As promised, here are two iterations of my alternate jaws for the Newton Gripper.

Testing, design ect is still underway, but keen to hear peoples thoughts / experiences

Sediment sampler / Cup Gripper
https://grabcad.com/library/bluerov-round-cup-gripper-1

30% Longer, face meeting gripper
https://grabcad.com/library/bluerov-v3-gripper-1

Feel free to edit / improve these, if you do - post back your adjustments for all to learn from!

Cheers!
Jack

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Cool designs!

I’m intrigued by the small pyramids along the bottom edge of the face-meeting gripper. Are they offset so they would effectively slot into each other when the gripper is closed, or is the idea that the points will meet?

Have you had a chance to try them out yet? :slight_smile:

Thanks Eliot,
The outer teeth are made to meet, then the face has a slight concave through the middle to add some angle to the contacting face. This design has been quite good for picking up individual small objects off of the bottom, the big increase in its grip being right up at the end, where the existing jaws tended to be a little awkward. This set of jaws is certainly aimed for smaller scale object manipulation!
-Jack

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That’s really excellent! Thank you! I will certainly print the cup gripper and let your know :+1:

Hey,
I have finally made printed a gripper based on your 30% Longer, face meeting gripper. I have added two cups to be able to catch things on the floor. Objective is to collect waste underwater. On my ROV, the bottom of the gripper is at 3mm from the ground.

Here is the Gripper Ender Left_2.stl (219.4 KB) model. We used PLA+ to print it and resist to sea water. It weights 162g (2 x 81g).

Tests are in process…

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OK, I have mounted the gripper on the ROV.

But I have encountered a problem, while trying to opening it for the first time ; too much friction ! The basis of the gripper has broken but it still works…

short

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Looking great @enderocean! :slight_smile:

Avoiding excess play in a mechanism while also keeping things smooth is definitely a challenging problem. It may be worth sanding/filing the holes a bit before mounting, adding some silicone grease, or possibly making them slightly larger before printing.

Also keep in mind that all printers will have slightly different tolerances, and slicing settings play a big role in the finished product, so it’s possible this base design works well for the combination of printer + material + print profile @Marruger is/was using :slight_smile:

Hey Ender / Eliot
Awesome stuff!
I am currently in Antarctica using the jaws we settled on - I will post up a full write up in about a week and a targeted one here pertaining to the grippers for you both - thanks for your continued involvement!

I had the exact same problem with printing the full jaws- as well as meeting the issue that the entire force applied to the jaws is transferred to the area where it is mounted to the gripper - this is hard to print with enough strength for good use - we ended up creating a metal “backbone” which the gripper hinge and pusher connect to, then we mount 3d printed jaws onto this backbone - Strength and shape flexibility. The two hinge holes on this backbone were made larger than the mounting bolts, and we printed a nylon sleeve to help with the friction issue. The most useful of the jaws was a round cup for picking up benthic samples (I think about half the size of yours) , but the flat faced gripper was also super useful!

I will get back to this post when I land back on home soil and upload pictures of the jaws we used for the project - all in all I have been thoroughly impressed by the Newton gripper - We had a lumen disagree with the cold and flood at 20m, which has thrown our rangefinder into a tizz and need to be disconnected, but the gripper was the vital element for our sample collection and it has been absolutely incredible!

Very pleased with the BlueROV heavy!

-Marruger

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Sounds awesome - keen for both updates! :slight_smile:

Out of interest, which material were you using, and how much force is “good use” (assuming you have some kind of estimate)? :slight_smile:

Great to hear both of these! :slight_smile:

Less great - sorry to hear it.

Not sure if Antarctic waters are within our operating specifications, but I’d recommend you contact support@bluerobotics.com and let them know what happened. Worst result for you is that we just log the failure, but if we determine that your use-case is within the design conditions and the product has failed to perform as expected then we should be able to sort you out with a replacement/refund :slight_smile:

Hey Ender,
See our final setup below with original jaws for size reference. The 3d printed faces were held on by two bolts and changing them was a matter of minutes. We had zero strength issues, and the gripper performed admirably!

The faces pictured in the first two images were intended to have a strip of foam mounted along them for soft grabbing, but the cup jaws pictured in the final image ended up doing such a good job that these were not necessary. Our second preference came in a flat face meeting gripper which took my original design and made it double high

Jaw B L.stl (392.3 KB)

(I will post an image when I have it in hand, it is being shipped currently)

Original jaws, 3D printed jaw face with backbone (middle), and trial printed jaws

Working jaws for reference. Note printed sleeve to reduce friction at hinge point.

Cup jaws mounted to BlueROV

Thanks Eliot - I have sent through an email and my full write up will be posted shortly. I cant put a number on the force applied, but can say that when the gripper was told to grip on a solid object, the fail point was at the “pusher rod” section on the fully printed jaws. I beleive this was with PLA - nylon may give a better result but we couldnt afford to have a break on this job so we went for the sure thing which was the metal backbone.

These mounted on the Heavy configuration allowed us to sample up to 200 individual benthic individuals in a 5 hour period from multiple sites, and our job was a full success! Watch the forum for the write up which goes more in to depth about how I operated the unit for grabs, as well as the benefits that button mapping gave me.

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