Kinematic model for a 5axis mill with universal (nutating) head

Do I have to use decimal numbers or is there any other solutions?

I would first try using the exact algebraic expression (ie sin(50°), cos(50°)) and see what the rotation matrix looks like.

This is what I came up with 

If you manage to get the correct forward and inverse kinematic model using pen and paper then my hat is definitely going to be off to you. I started out that way ...
I attach my jupyter notebook (remove the '.txt') which contains all the ipython symbolic math to automatically derive all the formulas in the documentation. Using jupyter and ipython will save you a LOT of paper and headache.
You will need to adjust some of the matrices and order of the matrix multiplications though.

Hi Arciera,

Nice work ! Impressive.

Hi Arciera,

Thank you for sharing your work with us. It's very impressive. And I have found it invaluable for setting up my own CNC machine.

I've worked through all the files except the remap.py file for the TWP functionality. Everything else seems to be working fine so far and I have a decent understanding of it all, but some help with the remap file would be much appreciated. I'm a little stuck on the opening section where it returns the A/B joint positions for a given tool-orientation vector. I don't fully understand the calculations and how they would need to be modified to suit my particular setup (A/B will become A/C).

As a bit of a background on my machine, I have a fixed table with a rotary B axis, and a moving gantry with an A,C head where the A axis is 55° nutating (similar to the Hiteco head shown here on page 1). I can provide more information if needed.

Basically I'm just looking for a bit of guidance for modifying the remap.py file other than the basics like updating the matrices and changing the values to match my kinematic model. Thanks again.