Finger shape

For discussion of hand designs.
Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Finger shape

Postby Jason M Bryant » Fri Mar 27, 2015 6:15 am

Whenever I make a new hand, I spend a little time trying to use it. It's generally a frustrating experience. Holding on to things isn't nearly as hard as getting them into the hand in the first place. Upright cylindrical objects, like water bottles, are the easiest. Flat objects, like a cell phone, are the hardest.

I believe one issue is the shape of the fingers. My fingers are fairly wedge shaped. This is a pretty good shape for sliding under an object. However, eNable fingers basically have a ball on the ends. I've attached a picture to show the difference in the shapes, plus another picture to show how useful a scooping shape is for getting under my TV remote.

Finger shapes.jpg
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scooping fingers.jpg
scooping fingers.jpg (55.5 KiB) Viewed 2629 times


What do you all think would b he advantages and disadvantages of a more natural finger shape?

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Tue Mar 31, 2015 6:37 am

I decided to test a more natural finger shape. I loaded the Raptor Reloaded finger into Blender 3D and did a quick scaling on the fingertip to try to get a natural wedge shape. It actually turned out a lot better than I expected.

Old vs new.JPG
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After wiring up the hand, I strapped it onto my fingers and tried picking a few things up. Picking up my cell phone was extremely hard. That's actually an improvement over the standard fingers. With the standard fingers, it was nearly impossible.

Picking up the TV remote and the air conditioner remote is significantly easier. It's not easy, but it is easier. The fingers are able to push under the object and scoop it up.

Picking up.JPG
Picking up.JPG (51.79 KiB) Viewed 2618 times


I don't feel like holding onto things has gotten harder. Even without the ball shape on the end, the last digit seems to do a pretty good job of wrapping around objects and locking them in the grip.

I feel like our hands are currently better at holding things than at picking them up. This finger shape feels like it helps that a little. I think we should consider a more natural shape to the fingers.

Plus, the hand is just nicer looking. I was actually a bit surprised by how much of an aesthetic improvement it was. They look more like human fingers.

Ew Chee Guan
Posts: 21
Joined: Tue Feb 17, 2015 2:23 am

Re: Finger shape

Postby Ew Chee Guan » Tue Mar 31, 2015 6:57 am

Hi Jason,
Good idea on the fingers shape. I saw this design on today's R&D hangout.
Might not suitable for Lee Tippi but I think I will try to make a silicone mould for this design.

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Tue Mar 31, 2015 7:31 am

Actually, the Lee Tippi fingers have a pretty natural shape. I put them on my test hand, but the shape is only 100%, so it's too small for them to fit well. I'll print a bigger fingertip and see how they work.

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Tue Mar 31, 2015 8:56 am

Okay, I can now say that the Lee Tippi fingertip covers work great with the modified fingertip. I think they actually fit much better than they have on the regular Raptor Reloaded fingers that I've put them on.

Finger shape comparison.JPG
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Fits like a tiny, one finger glove.JPG
Fits like a tiny, one finger glove.JPG (47.45 KiB) Viewed 2609 times


If anything, the Lee Tippis are more wedge shaped than my experimental finger.

Peregrine Hawthorn
Posts: 64
Joined: Mon Feb 16, 2015 5:49 am

Re: Finger shape

Postby Peregrine Hawthorn » Fri Apr 03, 2015 4:32 am

I'd be happy to give these a shot. That could be pretty useful.
Heavy duty hand user, and co-designer of the Talon.

I break hands and then tell you how I did it.

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Fri Apr 03, 2015 7:37 am

Here's a link to the file.

https://www.dropbox.com/sh/4czgh09iy0js ... Hv07a?dl=0

Keep in mind, this is only an experiment that I did very quickly. I think the next step is someone creating a finger from scratch that is even closer to the natural shape of a human finger.

I'm also planning to make a more natural thumb. I'm going to make it wider than the other fingers, mainly because I think it would look better than the skinny thumbs we put on our fingers. I also want the edges to be more rounded on that. Since the fingers tend to push things against the thumb at an angle, it seems like that might provide a better surface. This will require making it from scratch. However, right now I'm a little behind on my project list. I'm not sure when I'll get to the thumb.

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Tue Apr 07, 2015 12:18 pm

Now with a thumb!

Despite me not being an artist, this turned out pretty good. I had a few false starts, but then I figured out a good way to model them. I one point I hit a button and said, "Wow, that looks like a thumb!"

These are wider than the standard finger, about 1.5 times as wide. I probably should have looked up up thumb/finger ratios on the web, but I just roughly measured my own, and it looks decently close.

It's also more round than the standard finger. I feel like the fingers should be rounder, *especially* the thumb. The flat bottom of the thumb almost never touches anything when I pick something up, it's always an edge. I think this provides a better surface. I tried it in the Lee Tippi gel, and it works great with that.

At the very least, I think it looks more natural. Thumbs are just supposed to be wider.

If anyone would like to try it out, it's in the same dropbox folder as the finger experiment.
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joecross
Posts: 80
Joined: Fri Mar 13, 2015 11:03 am

Re: Finger shape

Postby joecross » Tue Apr 07, 2015 12:27 pm

So awesome!!!

Jason M Bryant
Posts: 198
Joined: Mon Feb 16, 2015 1:59 am

Re: Finger shape

Postby Jason M Bryant » Sat Apr 11, 2015 10:27 am

Round 2

DSCF3258.JPG
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This is RR only right now. You will need a longer snap pin for the thumb, which I have provided.

https://www.dropbox.com/sh/7in9qjh599rc ... Hk2Ya?dl=0


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