Ball-arm constraints - Tutorial?

Ball-arm constraints - Tutorial?

Can someone possibly point me to a video or tutorial on IK constraints in C3D...? It has been (literally) over 20 years since I did *ANY* IK work, and that was in Lightwave. I just want to take a solid model of a ball-arm joint and apply constraints to the L-Rod... so that it can FREELY move 360° on its heading, but constrained on the other two axis by -42° to +42°.

I tried it on my own quickly and was getting frustrated. Any links would be appreciated... thanks.

This is the REAL object...

L_Arm1.jpg


And this is a low-effort approximation until I can figure-out the IK constraints...

L_Arm2.png
 
I'm not sure I'd use any constraints on it - just make sure the pivot-point (set via pivot-mode) is in the right spot.

Cheers
Frank
 

It seem like this is an orthopedic implant, so I guess you wouldn't
want the ball/rod to twist, so some constraint is helpful.

I used a parent constraint tag to constrain twisting.
The target of the tag is a folder.

 

Attachments

  • BallinSocket.zip
    32.8 KB · Views: 213
It’s actually a drum (tom) mount... and the reason I want to put constraints is because I want to use C3D to “virtually” setup a drum kit, but I want the L-Arm tom mounts to reflect what’s possible in the real world. Ultimately, I will also be adding a drum to each L-Rod, so the drum will be restricted to ONLY moving UP & DOWN the L-rod and rotating along the shaft... but the Ball will be free to allow me to position the drum wherever I need it while I LOCK the vertical mounting shaft in a plumb orientation.

Not sure if I said that right...
 
Similar to - but not exactly like - this drum mount...

ludwig_atlas_arch_rail-mounted_bass_drum_tom_holder.jpg


The VERTICAL post stays stationary... the L-Rod affixed at the ball-arm is free to rotate with SOME constraints... the drum can move UP AND DOWN the vertical bend of the l-arm as well as rotat around its circumference.
 

Boy was I on the wrong track.​
Glad you were - was thinking about the butterfly nut inside a body - made me nervous.
Similar to - but not exactly like - this drum mount...
The VERTICAL post stays stationary... the L-Rod affixed at the ball-arm is free to rotate with SOME constraints... the drum can move UP AND DOWN the vertical bend of the l-arm as well as rotat around its circumference.
I´d still skip the constraint tag. I´d add the drum to the pivoting rod (hierarchical) and got to go.

Cheers
Frank
 

This seems to work well.

 

Attachments

  • Drum Mount.jpg
    Drum Mount.jpg
    60.8 KB · Views: 229
  • BallinSocket02.zip
    71.6 KB · Views: 221
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