Best Materials for Lightweight Robotic Arm Design?

[Jane Will]

Hi, I’m a research student working on a lightweight robotic arm. I’m looking for materials that balance strength, weight, and cost. Are carbon fibre composites worth the expense compared to aluminium or titanium? Any suggestions or experiences would be helpful. Thanks

[studiot]

Hi Jane and welcome.

 

This is presumably a project ?

 

I suggest you haven't given us enough information.

 

You should sit down with your tutor and draft a detailed specification of what you want to this arm to do.

Lift - how much ?

Transport  how far ?

environmental conditons of working  - temp range -humidity - hazardous atmousphere ?

and so on.

 

Having a target objective is the way to a splendid project.

[Callipygous]

I don't know about robot design, but it seems like this would depend entirely on your project's limitations. Mountain bikers will tell me that carbon wheels are totally worth it, but they are not in my budget and I don't ride hard enough to care about the difference. Its worth it for them, but not for me.
Does your budget support the difference in cost? Can your robot tolerate slower arms, or bigger motors to move heavier arms?

[Jane Will]

22 hours ago, studiot said:

Hi Jane and welcome.

 

This is presumably a project ?

 

I suggest you haven't given us enough information.

 

You should sit down with your tutor and draft a detailed specification of what you want to this arm to do.

Lift - how much ?

Transport  how far ?

environmental conditons of working  - temp range -humidity - hazardous atmousphere ?

and so on.

 

Having a target objective is the way to a splendid project.

Hi, thanks for the welcome and your valuable input!

Yes, this is indeed a project as part of my research work. You’re right—I should have provided more details. Here’s a more detailed specification of the robotic arm I’m working on:

• Primary Purpose: The arm is designed for precise pick-and-place operations in a controlled laboratory environment.
• Load Capacity: It should be able to lift loads of up to 2 kg at full extension.
• Reach: The arm’s reach is approximately 0.8 meters.
• Environmental Conditions: The arm will operate in a standard indoor lab environment with temperatures ranging from 20°C to 25°C and low humidity. No hazardous conditions are involved.
• Weight Constraint: A lightweight design is crucial, as the arm will be mounted on a mobile platform with a limited payload capacity of 10 kg (including the arm, motors, and electronics).
• Cost Considerations: While budget constraints are present, performance and efficiency are top priorities. I’m looking for an optimal balance rather than simply the cheapest solution.
• Other Factors: The arm should maintain structural rigidity during operation to ensure accuracy and minimize vibrations.

Based on these specifications, do you think the added cost of carbon fibre composites is justified over aluminium or titanium? I’m particularly interested in long-term durability and ease of manufacturing.

Thanks again for your guidance—I appreciate any further suggestions or experiences you can share!

22 hours ago, Callipygous said:

I don't know about robot design, but it seems like this would depend entirely on your project's limitations. Mountain bikers will tell me that carbon wheels are totally worth it, but they are not in my budget and I don't ride hard enough to care about the difference. Its worth it for them, but not for me.
Does your budget support the difference in cost? Can your robot tolerate slower arms, or bigger motors to move heavier arms?

You’re right—it all comes down to balancing project needs and budget. While carbon fibre offers significant weight savings and rigidity, which could allow for smaller motors and better efficiency, it’s more expensive and harder to work with. Aluminium is cheaper, easier to machine, and may be sufficient if I can manage the added weight with stronger motors, though that affects overall payload and power consumption. Titanium is strong but heavier and costly. I’m weighing whether the performance benefits of carbon fibre justify the expense given my project’s weight, speed, and precision requirements.

[studiot]

Just now, Jane Will said:

Yes, this is indeed a project as part of my research work. You’re right—I should have provided more details. Here’s a more detailed specification of the robotic arm I’m working on:

etc

Good reply +1.

Robots are the subject of electromechanical engineering. Is your laboratory some other discipline and you need a robot arm for say moving test tubes ?

Or is this an academic electromechanical project ?

I ask because if this enquiry is part of a coursework or project work we are only allowed to advise.

 

My thoughts here are that the arm should be hollow, with a sectional material as far as practicable from the holow centre, and preferably longitudinally fluted or ribbed.

This will ensure the necessary rigidity as far as possible.

The mobile platform should be counterweighted to avoid and tipping when the arm is extended extended past the edge of the platform.

A carbon fibre fishing rod will hold 2kg but bend excessively and not be controllable for precise placement.

I would suggest that ease of manufacture should be considered, depending upon what you have available.

Titanium requires special machines methods.

Aluminium is subject to fatigue, depending upon the alloyand is extremely difficult to weld reliably so consider riveted joints.

Carbon (or glass) fibre should be laid in mats with the weave laid criss cross to form the hollow tube. The whole process requires curing time etc for the resins so a single arm would take longer to manufacture that metal. This is an important factor in a production line.

[npts2020]

Have you looked at other robotic arms already being made? Here is a pretty good discussion of the various types and their uses >  https://howtorobot.com/expert-insight/robotic-arms . Admittedly, it is a commercial site selling robotics but the explanation of the different kinds might be of use and you can see how they look after being built.

[Callipygous]

Id probably prototype with aluminum and 3d prints, and if you find you really need the lighter weight switch to carbon fiber once you've ironed out the kinks.