Joint consideration

[tapir]

Super cool robot! I was wondering since the axis of your universal joints are actually offset, do you need to take that into account in your kinematics calculations?

I'm asking because I think this kind of universal joint is the best for a "printed" solution in terms of play (especially with an H7 pin) and life expectancy compared to ball-socket, magnet and traditional universal joints but I'm not sure I have the knowledge to modify my firmware (Klipper) to account for the offset if it makes a difference in kinematics.

[Scottapotamas]

Just to clarify, are you referring the to 'v1' joint design pictured in the slightly outdated readme image, or the 'v1.1' that since replaced it?

I don't take it into account with the solver in this project, but I did check the the mechanical setup used in this project matched the theoretical solve (Solidworks motion simulation used to compare motor angles against effector positions, compared to IK solves).

[tapir]

Both have the same offset I believe (just the pin is better) so talking about both actually. I'm using this https://www.marginallyclever.com/other/samples/fk-ik-test.html to calculate some dimensions and these kind of traditional delta robot solvers assumes the joints are ball joints which means the rotation point of both axis is same but it's close enough I guess