topic Re: Fusion360 Spline Adjustment Issue in Fusion Design, Validate & Document Forum

Fusion360 Spline Adjustment Issue

sfg18 — Sun, 25 Jan 2026 20:12:38 GMT

Hi! Somewhat new to Fusion and CAD as a whole so apologies ahead of time if my terminology is unclear.

I'm trying to connect one curve to another smoothly (both splines; one is projected from a separate sketch). However, the handle associated with the endpoint coincident to the projected spline can't be adjusted—only translated. My goal is to adjust the handle so that it is close-to tangent to the projected spline so that a "smooth" transition is achieved.

What's going on/why is this happening? Is there a workaround? Thank you!

Re: Fusion360 Spline Adjustment Issue

TheCADWhisperer — Sun, 25 Jan 2026 20:21:57 GMT

@sfg18

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: Fusion360 Spline Adjustment Issue

sfg18 — Sun, 25 Jan 2026 20:24:18 GMT

Here it is!

Re: Fusion360 Spline Adjustment Issue

TheCADWhisperer — Sun, 25 Jan 2026 21:11:50 GMT

@sfg18

What is the function of the feature to be created from Splines?

I would use the simplest geometry possible to achieve the function.

Arcs and lines, if possible, rather than Splines.

I would consider Splines to be mostly limited to freeform organic art. If you need splines, use splines, but I question if more basic geometry would suffice in this case.

Also, I observed that many of your dimensions appear to not have a logical basis.

Re: Fusion360 Spline Adjustment Issue

TheCADWhisperer — Mon, 26 Jan 2026 06:05:25 GMT

@sfg18

I remodeled your assembly from scratch. (see attached)

I think you will have to come up with an alternate for the problem splines using arcs and lines.

Re: Fusion360 Spline Adjustment Issue

sfg18 — Mon, 26 Jan 2026 06:12:59 GMT

I just wanted to widen the curved path at its end to accommodate some thicker wiring (connected to components inside the shelled area). To be honest, this is more of a very rough prototype so there are indeed a lot of dimensions not fully thought out—I was just really confused why the control handle at the coincident end of the spline couldn't be manipulated while the other one could.

Will definitely just remodel the curve with new splines.

Re: Fusion360 Spline Adjustment Issue

sfg18 — Mon, 26 Jan 2026 06:18:41 GMT

Wow! This is amazing, thank you so much!

Your workflow is really refined and clear to follow; I haven't even had the chance to go through each step carefully yet and am already learning new things. I'll try to use arcs+lines and see what I can come up with.