Control instance rotation along axis of curve tangent

Support Animation and Rigging
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I have instanced geometry perfectly pointing it’s Z axis down the tangent of the curve point it is instanced on - how do I stop it automatically spinning around the other two axis and actually follow the instance point’s tilt/twist?

(Deliberately using low poly tube & cube instance here to make the misalignment which I’d like to control obvious.)

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Align another axis to the curve normal/binormal or to an arbitrary axis

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How would I do this? I’ve tried doing another “align to vector” after the initial one that gets my instance z following the curve. This time aligning a single axis to the curve normal in the hope that it would serve as an “up vector” but it still spins around when manipulating the curve handle. (think the initial align rotation to vector, set to auto… keeps messing everything down the chain up … but I could be very wrong). Really appreciate the help.

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Two axes infer the third, and should be enough to stabilize an object, as long as they are more or less orthogonal. If they come close to colinear, there will be artifacts… Make sure your second align rotation to vector is set to align either X or Y with Z as the pivot

There’s also the new-ish axes to rotation node, haven’t really used it yet but should work for your purposes

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@Hadriscus - thought I’d share how well this little gem of a node worked for me: “Axes to Rotation”. Did exactly what you suggested, with 2 inputs in a single node - one primary axis that aligns the rotation of my instance to the curve, and a secondary axis to lock the “up vector”. Hope this works for you too & thanks again for your help.