Robot arm project

There have been a few short threads on this but none really suits the question so I’ll put it out there.

I’m in the thought process of a design for a project that would require a mechanized arm

Tool weight: 2 kg
Need to change tools - not currently
Tool tip accuracy - 1mm in all dimensions plus commensurate angular accuracy
Movement speed - fairly low maximum speed at a few cm/sec
Tool tip target area - around a one foot^3 spherical volume
Tool connections - a few cords that might present some issues with arm mobility but I imagine this could be worked out

The hardware I would need is a few steps above the hobby level. I’m just at the conceptual level now, but wondering what is available in terms of hardware and software. Are there standard protocols for ‘robot arm control’, a control language, more or less?

It might be good to know some basics about what is available and what software support might be common to the concept of mechanical arm manipulation.

Is any simulation software for robotic arm control? This would, I presume, have to be specific to a particular product or development environment.

DJ

i am working on retrofitting two industrial robot arms, they are big heavy high voltage systems…thats just what im in to but for you i would reccomend perhaps using one of the premade laser cut aluminium frames…i think they are called do bots or seven bots. Available on amazon. High torque (high voltage-12 volts lol) are available at extremely low prices from kpower rc-servo company. in terms of kinematics software, linux cnc seems to be what most people use. you can feed the program G-code which is coordinate based machine language use by most cnc machines, which can easily be generated from cad files…i also believe that there are various opensource cad cam robot arm programs, the simulator which you are refering to around on the internet.

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linux cnc http://linuxcnc.org/
k-power servo http://www.rc-kpower.com/en/
decent arm kit https://www.amazon.com/SainSmart-Control-Palletizing-Arduino-MEGA2560/dp/B00UMOSQCI/ref=sr_1_1_sspa?ie=UTF8&qid=1509129371&sr=8-1-spons&keywords=robot+arm&psc=1

Thanks, those are some good links.

Are you using the CNC linux resources? Where are you building your project?

i only recently heard of linux cnc, i havent gotten around to implementing it. one of my robots is in storage at my farm. my other unit the one with a controller is at a family members warehouse where they have three phase power, ive gotten it like 75% powered up but i havent quite gotten it to hello world, everything powers up but the user interface remains unresponsive im going to keep trying until it seems all hope is gone on its normal implementation. I am currently researching retrofitting either with a different control that simply hijacks the drivers or chucking drivers and controller all together and jerry rigging some second hand drivers, building open source ones, or being sensible lol and spending the money to use drivers that arent absurdly difficult to use, which wont include re-inventing the wheel.

Sounds like there are lots of layers to being able to perform a task. That’s sort of what I’m wondering about, whether there are layers to controlling the mechanics.

  • Hardware interface / drivers to steppers and position sensors / limit switches.
  • Move an axis (joint) to a given position at a given rate.
  • Move arm to position.
  • Move tool to position.

These would be the sort of layers of control I might imagine. There would have to be some intense real time calculation of geometry for something with many axes. While it would be interesting, I would not want to develop and trouble shoot something like that. Someone might have a utility that allows one to input the arm description and dimensions and let it do all the calculations.

It’s my understanding that Linux CNC breaks down kinematics in the way your describing, input coordinate s and it works out kinematics for you…with steppers you won’t need encoders only limit switches so it can zero. Then after zeroing it will know it’s position same way that a 3d printer or CNC machine works…you do have to run Linux CNC on a Linux machine though

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