Ask HN: What’s the best commodity robot arm?
I want to play around with some robotics what’s a good robot arm I can buy?
Alas, in my opinion, such an arm does not exist for the hobbyist. Why? Mainly, I think, leverage sucks (in this case). At 16 inches there is quite a lot of torque required at the base to move the arm (with the mass of the arm plus what it is grasping). And liability may be (probably is with most would-be suppliers) an issue.
I have built a few arms myself with various hobby servos. High torque motors where needed and smaller, light weight ones towards the wrist. * Some * of the motions are smooth and neat. Others are simply jerky. Then there is the problem of backlash.
There is a company (Trossen Robotics, I think) whose arms are ..., well, I don't know what to say. Certainly, it seems, they offer cool motors that are seemingly designed for what we want. But the videos are always disappointing. Maybe its just me.
I assume you want something for a couple of $K. In my opinion, it does not exist. The demand/application is not there to bring the cost down.
And, again, there is the liability issue.
Maybe some day, soon.
(I hope someone responds with something that will work for ya. I would like to see that.)
Have you considered going "old-school"?
That is, picking up a used Microbotics Teachmover can be easily done - though you'll probably have to hack up a controller for it. Similarly, there are old Rhino Robotics arms that can be bought fairly cheaply (though I warn you - they are very heavy). There are several other robot arms from the 1980s that you can find if you look, but all of them will require more than a bit of "hacking" to get working with modern computer systems.
Have you considered building an arm using Lego or some other similar building kit (Meccano, Fischertechnik, KNex)? Or maybe parts from Servo City, or 80/20 extrusions?
What about hacking a conversion? Like converting an old Armatron to be computer controlled (not easy to do, but it is possible - it was done more than once back in the 1980s, and those articles on how to do it are still able to be found). Note that it is easier to convert the Radio Shack Armatron that has a wheeled base, than it is to convert the joystick controlled Armatron (the latter requires a bit of mechanical skill and knowledge, on top of the electronics to interface it).
Another possibility (though fraught with even greater issues) would be to find a second-hand laboratory industrial robot arm, and get that interfaced. There are more than a few out there which were electric powered (mostly - some have pneumatic end-effector attachments), and are small enough to play with in a "home" setting. The downsides are lack of inexpensive replacement components if you need them, among other issues.
most of them are super expensive, I would consider building one from scratch by following https://www.youtube.com/watch?v=Citiq6Zfdu4