What kind of hand do you add to your robots

[pkshima]

I mean I am sick of always ending up with just a moving vechicle that can do nothing because it has no hand.

I have been trying hard enough to have atleast a parallel jaw gripper on the bot. Results have always been unsatisfactory. They dont even end up being a size that macthes the bot or atleast looks cute and lovable.

Perhaps the reason is that I am no mechie and have no lathe or even a bench press drill. I just know a shop that can cut custom size plexi glass for me. I have tap and die set I use to make that special screw that has threads half cw and half ccw. and I have some gears.

So I am back to you great guys... What do you do about this issue ?
What is it that I am missing.

I dont want to just buy a hand from somewhere. I want to make it myself.
Size : something that mathces my 70 X 150 mm bot.

 

[dknguyen]

I usually don't build a hand until I can find a way for the robot to know how to use the hand on it's own. That's mainly because I build autonomous stuff and not remote-controlled stuff. THe other problem I face is also finding elbow and shoulder motors that has enough strength to do what I want- lift a 250-500g load at the end of a big long lever with a heavy hand at that end. But yeah, I usually just don't because I can't get the smarts behind the arm.

And who wants a cute loveable looking arm? I personally prefer to have a death claw.

 

[Krumlink]

If I were to use a robot gripper, I would use a parallel jaw robot gripper, because the jaws stay parallel to each other and it looks like what a robot would have

In the book "Robot Builders Bonanza" They have a few chapters dedicated to robot grippers.

 

[pkshima]

Thanks for replying.

I think I am more interested in the gripper style hand only. Too bad i dont have that book suggested by Krumlink which seems to address this.

Are there any links, snaps, videos you have seen anywhere. Anything simple enough to fabricate without a lathe/mill.

I am mad searching youtube and net in general.

 

[mashersmasher]

i found one on hackaday a while back that i want to try. it looks pretty promising and could be made out of trash

https://www.hackaday.com/2008/08/01/electric-screwdriver-robot-hand/

 

[dknguyen]

Thanks for replying.

I think I am more interested in the gripper style hand only. Too bad i dont have that book suggested by Krumlink which seems to address this.

Are there any links, snaps, videos you have seen anywhere. Anything simple enough to fabricate without a lathe/mill.

I am mad searching youtube and net in general.

Here are some examples. You can also just buy them if you feel like it:

https://www.crustcrawler.com/products/biggrip/index.php?prod=14
https://www.crustcrawler.com/products/gripper/index.php?prod=13
https://www.budgetrobotics.com/shop/?shop=1&cat=135

 

[mashersmasher]

what's the point in building something if you buy all the peaces ! might as well get lego

 

[dknguyen]

what's the point in building something if you buy all the peaces ! might as well get lego

I'm a EE not a mecE . Unfortunately, I don't have a basement wafer foundry so I still gotta buy premade EE parts.

 

[Krumlink]

@Mashersmasher

If you checked out my ARES1 thread you will discover that my attempts at a homemade robot base really put me back about 60 dollars. Premade parts up to a point are great, but I agree never go so low as lego.

 

[pkshima]

Attached are snaps of what I have built so far. not satisfactory :-(

 

[mashersmasher]

Attached are snaps of what I have built so far. not satisfactory :-(

what if you moved the motor around to give it reduce the stress on the motor? having it on it's side could be allot better since the motor has a more direct connection to the threaded bar. you can get all those parts from a floppy drive too!

edit: this will also allow it to completely close

 

[pkshima]

mashersmasher, I agree. that makes a lot of sense. I thought about it but rejected because I am crazy for symmetry . I want to somehow keep the motor at the center. that way i could also use it as the joint with an arm tomorrow such that this piece could rotate about it.

Anyway if symmetry IS the price, i guess I would have to pay it finally unless somone helps me with a better idea.

 

[mashersmasher]

hmm indeed that would be a problem. i posted a link to a grabber a while back that works wonders from my tries and works pretty efficiently on power that would suit your nitpickyness. OR if you wanted to salvage that one and had a couple extra motors you could have one linked to the other side and use both motors to power it.

 

[pkshima]

If only finding "face gears" was not so hard, I would have a simpler way of reducing stress on the motor.

 

[mashersmasher]

cd drives, vcr's, my friend there are endless supplies of gears of varying sizes. i personally stockpile them when i can. the good thing about cd drives is that there are 2 motors that are usually identical in many different brands of cd drives so you can get LOTS of matching sets

 

[pkshima]

I have plenty of matching gears myself.
But I dont have any 'face gears'. These are gears that have the gears on their face. This allows transfering rotary motion at 90 degree angle. see the link below for a photo
http://www.lighting-china-supplier.com/d-p2521455-Plastic_Gears/

These gears are not found on cd-drives etc.

 

[mashersmasher]

cheep wind up toys have those by the dozen. they arn't always durableb but they should do well for what you need