Asked — Edited

Jd Claw Foam Inserts

Just received my new JD and going through battery charging and calibration prior to assembly. Attached to the inner of JD's claws are some foam inserts, and they seem to be attached very firmly, perhaps even glued in? None of the assembly instructions depict the foam and leaving them there would seem to offer a degree of resistance against the grippers closing completely.

Just wanted to triple check before removing the inserts that this is the correct procedure? If the inserts weren't attached so securely I would have had no hesitation but I don't want to ruin the poor guy if they are not supposed to be removed.

Sorry if this is a repeat question, I searched the forum for 'claw' , foam' and 'insert' with the Revolution JD tag but couldn't find anything relevant although I vaguely remember seeing a similar question posted previously.

Thanks for the advice.



Upgrade to ARC Pro

Harnessing the power of ARC Pro, your robot can be more than just a simple automated machine.


The foam inserts are new, so not in the existing documentation, although there is a video somewhere of their use. They help the claw grip better. Just calibrate and fine tune the servos so they just close on the foam rather than with the tips of the claws.



Thanks Alan, you saved me from making a horrible mistake! :):):)



do you mean there comming new hands with foam in ?


Yes, DJ never announced it, but several people have reported that they now have foam in the claws similar to what DJ showed he had done in a video using foam cut from the shipping box. Helps with picking up objects that might slip out of the claw tips.



thats is great can i missed that.


The photos will be updated pretty soon. We're moving into the new facility this week, but there's still ongoing construction for the classroom, engineering department and boardroom. I think we are about a month away from being back up to full speed.

photo booth will be up soon


Hey guys, just got my JD about 2 weeks ago and at first I had the same question about the foam inserts but since they were firmly glued in place i resisted urge to pull them out. Luckily, this was the right choice because i quickly realized that the foam allowed JD to hold onto hard objects of any shape much easier. This just offers more variety and fun while testing or building routines instead of using only foam balls or similar. Not sure if this is what the EZ Team were thinking but if not its a great side effect ??


This is why we need a 3 fingered claw. Such an arrangement would allow the claw to close all the way down, grasping objects better. Especially narrow ones. You could still put narrow strips of foam on the fingers for softer contact if desired. Maybe even use those rubber finger tip things over the fingers for more friction to hold the object even better. Perhaps even some combination of the two. I may try cutting down an existing claw to make it 3 fingered and play with that. Or maybe someone could print something up? Nudge, nudge, wink wink. Say n' more, say n' more.


Lol:) if you draw it maybe I can whip something up.


Hmm. I have some spare claws and a dremel. Need to give this some thought.



I knocked this up this morning... Version... 1 Haven't printed them yet but I will later when I get home to see if they work.... When I have more time I can re-work (tweak) them so that they look and work much better. But for now they should close tighter than the original claw...

User-inserted image

User-inserted image

User-inserted image

User-inserted image


goodmorning averybody

i think these claws are way to finger for sure.


Way to jump into action guys!

@thetechguru Yes, that's the way I was thinking of doing it. Got all the Dremel bits and blades I need to try it. The required skills may be lacking however.

@Richard_R Excellent! That's exactly how I thought it could come out modifying an existing claw to make it 3-finger-like. Printing a set would save a lot of work trying to modify an existing claw. Might not work worth a darn after all.

@Nomad I don't think the strength of the plastic will be a factor since the servo is not all that powerful. I doubt it could break the fingers. But, again, who knows. Just have to try it and see. Modifying the existing claws, however, would probably make for a stronger claw since they are molded plastic.

For now though, I think I'll wait and see what Richard comes up with.


I like that 3 fingered design. Gives it a more of a hand look too. For now I have put the foam in my grippers for CY which I did a while back. I'm also still thinking of doing an IR/lever switch setup for a lil more sensitivity when closing on lite objects.


there is no guidens for the one finger go's perfect into the two fingered opening. you have to make the one fingered smaller and round up the edges. 3d printed parts breaks more rapidly cause its not all filled up,some 15 % or even 50% it can also burn up the mini servo if the one finger goes not, straight into the two fingered part.iqbot use this tree figered grippers. they use metal rods and metal spacers to guid the one fingered into the two fingerd.thats why you need to round up the side edges.


Nice Job Richard! You beat me to it actually, I was going to try to work on a 3 finger modification of the claw this weekend. :):D


@JustinRatliff LOL... Can't let you take all the design glory around here now can I... :) Anyway you're better at it than me so feel free to design your own... When I have more time I really want to start using OnShape to produce more complicated designs...