Re: [Emc-developers] Homing robot arm differential joint [ was robot arm, free to a good home]
On Tue, 26 Mar 2019 at 08:05, Frank Tkalcevic wrote: > > Thanks for the suggestion, but I don't think that will work. I need to move > both motors in the same direction to home the hinge part of the wrist. Then > I need to move the same motors in opposing directions to home the rotation of > the wrist. Only after both joints are homed can the motors be considered > homed. Maybe you can get round this with dummy joints. Make the motor positions the sum of two joints in HAL. Home Joint1 + Dummy2 then Dummy1 + Joint 2. Let the dummy joints hold a home offset but otherwise leave them unconnected to axes. (ie not mentioned in the kinematics) -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
Re: [Emc-developers] Homing robot arm differential joint [ was robot arm, free to a good home]
Thanks for the suggestion, but I don't think that will work. I need to move both motors in the same direction to home the hinge part of the wrist. Then I need to move the same motors in opposing directions to home the rotation of the wrist. Only after both joints are homed can the motors be considered homed. I may be able to home the rotary part by sending the motors off in opposite directions, then I'll have to find another solution for hinge part. -Original Message- From: andy pugh [mailto:bodge...@gmail.com] Sent: Tuesday, 26 March 2019 8:18 AM To: EMC developers Subject: Re: [Emc-developers] Homing robot arm differential joint [ was robot arm, free to a good home] On Mon, 25 Mar 2019 at 21:10, Frank Tkalcevic wrote: > I'm not sure how to home these joints. To find the 2 home positions (bend > and rotate) requires moving both motors at the same time. That doesn't work > in joint mode homing as each motor/axis homes independently. If you give both motors the same homing sequence number then they will home at the same time. With v2.8 / Master if you give them the same _negative_ homing sequence number then each axis will "wait" for the other like is best for a gantry. That might suit your requirements. -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." � George Fitch, Atlanta Constitution Newspaper, 1916 ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
Re: [Emc-developers] Homing robot arm differential joint [ was robot arm, free to a good home]
On Mon, 25 Mar 2019 at 21:10, Frank Tkalcevic wrote: > I'm not sure how to home these joints. To find the 2 home positions (bend > and rotate) requires moving both motors at the same time. That doesn't work > in joint mode homing as each motor/axis homes independently. If you give both motors the same homing sequence number then they will home at the same time. With v2.8 / Master if you give them the same _negative_ homing sequence number then each axis will "wait" for the other like is best for a gantry. That might suit your requirements. -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ___ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
