components for electromechanically actuated robotic gripper.

[andradesilva]

Hi,

I need to print a gripper by FDM (3D printing). the problem is that we need components for the electromechanical actuation system.
-We are thinking of using a servo motor, its control unit.

-There is also a pressing cylinder, in which we are thinking of using a pneumatic cylinder.


However, I am not sure if we should couple the components stated above with any other component.
Any thoughts or experiences with this situation?

I thank you in advance,
Best regards,

 

[BrianE22]

A gripper is normally on/off. Why are you thinking servomotor?

 

[Jboggs]

"I am not sure if we should couple the components stated above with any other component."

Vague questions get vague answers.

 

[andradesilva]

The gripper is made of steel, to be actuated with a clampling motion (and force). If I want to build a prototype, which components do I need to create and control the motion of the fingers?. This is a two-finger gripper.

Best regards,

 

[Pud]

This example should be of interest:

https://www.emicorp.com/products/165/Sprue-Grippers/

Search for 'end of arm tooling' for many more.

Politicians like to panic, they need activity. It is their substitute for achievement.

 

[Jboggs]

"I want to build a prototype"
The answers to your main question will be found in your answer to this one: Why?
Why are you building a prototype instead of a real gripper? What is it that you don't know? What are you trying to learn from the prototype? Be specific.
What are your restrictions? Finances? Materials? Time? Tools? Weight? ...

Servos and their control systems are MUCH more expensive much more complex than simple pneumatic cylinders and valves, but also much more controllable. Does that make a difference to you?

Do you want a simple OPEN/CLOSE action, or do you want the gripper fingers to stop moving where you tell them to?

Do you want to be able to vary the force the fingers exert?

Are the fingers already defined? Is the geometry of their motion already defined? Is it rotary or linear?

Can you post some images? That will help.

More specific questions get better answers.

Step 1: Define your problem.

 

[andradesilva]

hi,

Answering your questions:

I want to build a prototype"
The answers to your main question will be found in your answer to this one: Why?
Why are you building a prototype instead of a real gripper? What is it that you don't know? What are you trying to learn from the prototype? Be specific.

Well, it's a real gripper, but it is the first one (new geometry)

What are your restrictions? Finances? Materials? Time? Tools? Weight? ...

Restrictions are mainly soft/flexible materials, with a weight of the samples going up to 5 kg. However, for scale testing, samples with 2kg should be ok.
Budget should be the lowest that allows us to test the gripper experimentally (fully functional gripper).

Servos and their control systems are MUCH more expensive much more complex than simple pneumatic cylinders and valves, but also much more controllable. Does that make a difference to you?

Well yes, because the load we apply (clamping force) varies in function of the thickness of the material and the material itself. This is to be tested in several materials.

Do you want a simple OPEN/CLOSE action, or do you want the gripper fingers to stop moving where you tell them to?

They need to be moving smoothly until they find resistance (material) and compress to a point where the material (sample) is well compressed but is not damaged in anyway.

Do you want to be able to vary the force the fingers exert?

Well yes, as it must be adaptive to the sample's properties and dimensions, namely thickness.

Are the fingers already defined? Is the geometry of their motion already defined? Is it rotary or linear?

Fingers are already defined. Yes, the motion is totally linear (1 translation DOF for the system).

Can you post some images? That will help.

That would not be ideal, as this is a new geometry.

More specific questions get better answers.

Step 1: Define your problem.

What are the (physical) components needed to have a fully functional 2-finger Gripper, whose geometry is printed by 3D.



Thank you for your help and I hope that I was clear enough.

 

[Jboggs]

"They need to be moving smoothly until they find resistance (material) and compress to a point where the material (sample) is well compressed but is not damaged in anyway."
That means you need some feedback, right? You need sensors to determine how much force the fingers are applying, right? Or do you already know exactly how much force they should apply? If so, maybe a simple air cylinder with a preset pressure regulator might do the trick. If you need to respond to some feedback to vary your force that is a very different animal.

"Well yes, as it must be adaptive to the sample's properties and dimensions, namely thickness."
The word "thickness" implies a physical dimension, which then implies control by distance traveled, as opposed to control by force exerted. Two different things. But they both are out of the typical scope of a simple air cylinder.

Do you have any experience with either technology?

 

[andradesilva]

thank you for your reply.

No, I do not have experience, that's why I need to know the components I need, so I can select them and order them.

In either case, which components are needed, to have a fully functional system?

Thank you!

 

[BrianE22]

Pneumatic seems like the way to go. Grip force would be proportional to regulated air pressure. You'd have to decide if you want both fingers to move the same amount or be independent of each other.

Is it 3D plastic? I doubt you'd get the strength you need for the parts.

 

[andradesilva]

Hi Brian

It is to be printed in metal.

In that case, what would the needed components be?

 

[BrianE22]

I think the easiest approach would be to find a 2 finger gripper on Ebay and take it apart. Schunk is a big name. The actuating mechanism would take the most thinking and parts - you go from air pressure to grip motion. Or Maybe Schunk has a cross sectional drawing of one of their 2 finger grippers.

 

[3DDave]

https://www.amazon.com/robot-gripper/s?k=robot+gripper

 

[IRstuff]

It's not like there's nothing on the web about

https://www.google.com/search?q=robot+gripper+projects&newwindow=1&sxsrf=APwXEdfyMB0mVkXEm3_0rhWgACbewn4LsQ%3A1681397987287&source=hp&ei=4xg4ZK-wD5bDkPIP38GkYA&iflsig=AOEireoAAAAAZDgm87G_pYDbxwRHEK5FDsMsj4pVkdsa&oq=robot+gripper+pro&gs_lcp=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&sclient=gws-wiz[/URL]]robot grippers

I would suggest doing some research. Nevertheless, your stated objective, i.e., components, seems to putting the cart before the horse. You need to concretely specify exactly what the gripper needs to do with numbers, actual rates, how the "squeezing" of the material needs to occur, how many different materials are to be held, how the robot will "know" what material it's trying to hold, etc., before doing component selection.

As with typical design projects, the system requirements development process comes before preliminary design.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Jboggs]

So, you're telling us that you work for a company that is willing to pay the BIG bucks for metal 3D printing, but at the same time they put an engineer with little or no experience in the required technologies in charge of designing a prototype?

I like the suggestion you have already been given - find some on the market and buy them. Try them out. What works? What doesn't? You would learn SO MUCH in the process! Surely if someone wants to pay for metal 3D printing, they can afford to buy a few operating samples for trials.

I guess I assumed that you had already done your market research and found nothing on the market that would work for you. I can't imagine any other reason to design a new style of gripper when there are already so many available.

 

[BEMPE16524]

I found a guy doing for 3D printing here:
'

https://grabcad.com/library/articulated-gripper-for-3d-printing-2'

R.Efendy