Motoman K6SB Retrofit

You know that will be around 102 volts once converted to DC?
Those motors are gunna sing!

Yeah should be pretty good at those voltages. I need to get my other projects finished so I can play with the Ethercat drives.

Does anyone have any advice on the type of grease I should use to replace the old?
I have done a bit of looking and cant find a definitive answer.

depends on the joint and gearbox , joints S L U , or 1, 2 , 3 take a MOLY WHITE 00(for the joints with cyclodial gearboxes) , joints R B T , 4, 5, 6, take harmonic SK-1 grease(for the harmonic joints), and the pivot joints not connected to gearbox take EP2, some of the names have been updated since, but thats what it says on my robot, i have an old SK-6.check if your gearboxes/joints are different. spent a lot of time learning about the yasnacMRC controller, so if you any questions, i might be able to help. my goal was also a linuxcnc retrofit, but im a bit hesitant about it. are your newer ones using the the yasnac XRC controller?

Thanks for the grease advice. This robot had the ERC controller, even older than the MRC.

My newer robots have a NX100 controller.

I wont be going back to proprietary controllers when I get the LinuxCNC based controller set up.

You would not believe how difficult it was trying to get the recommended grease here in Australia!. I contacted the Australian Yaskawa dealer and they wanted $800 for a 18KG drum of Moly White 00 and $900 for a 2.5 kg can of SK-1.

The only company offering tubes of the stuff was Robotworx in the USA. They were selling the tubes for $22 USD each but wanted $330 AUD just for shipping.

I spoke to my local bearing supplier and he put me onto a guy from Shell who recommended Gadus S2 V220 0, but I had to buy a 18kg drum. It only cost me $240AUD for the drum, much more than I need but at least I wont run out!

Hello,
your project look very interesting. I´m doing something similar with
a Motoman K10S. Almost the same Robot, just bigger.
I´m using the original Servos without a problem but i have a problem with the Joints. The motors for the first and second arm have an interesting behavior. motor 2 moves only joint 2, but motor 1 moves joint 1 and 2 because of the linkage. Should be the same with your robot. Do you have a solution to the kinematic problem to control it?

Hi xcp92,

I have not gotten to the point of actually controlling the arm with LCNC yet, my project has stalled due to other commitments.

I think you will need to implement some custom kinematics. I have not looked into it yet so I am not much help.

How are you controlling the original motors? Using the original drives? What control signal do they take? I went away from the original drives due to lack of information that I could find at the time.

At first i wanted to change the drives and servos, but it was way to expensive. Luckily i found some information about the servopacks online after some intensive searching. Now im using the original drives. Its relatively simple. Analog signal for Speed and direction with a 7i77 Mesa card. And some controlsignals for the drive, like enable and so on. I made a small pcb adapter to use the original wiringharness of the servopack to connect to the mesa card.

This is the webpage with the informations i found. There might be infos about the K6s:

spaz.org/~jake/robot/

@thefabricator03 - I have the exact same arm! I linuxcnc’d a unimate puma arm a couple years ago, and it works remarkably well in Cartesian mode with the arm simulator too. I’m using Mesa real-time Ethernet devices.

Unfortunately, I lucked out on the puma- all the linuxcnc inverse kinematics examples came setup for my arm with DH parameters and everything. I have not been able to find anything at all for DH or kinematic params for the K6SB. That’s my biggest sticking point right now. 

Please let me know if you find them / get your arm working in Cartesian coords!

Were you able to find the kinematics params to run in Cartesian mode? I can share my linuxcnc config if you want to show how the inverse kinematics are set up, but I need to find the DH parameters for my yaskawa arm somehow :-/

EDIT: this is meant as a reply to @xcp92