topic Re: Changing thickness of RC airplane rudder. Help! in Fusion Design, Validate & Document Forum

Changing thickness of RC airplane rudder. Help!

awsmits — Tue, 07 Oct 2025 17:21:20 GMT

Hi, I'm making a rudder for a Corsair RC airplane (that is only missing the rudder). I have a drawing of all the dimensions, and I've created a sketch in Fusion that matches the side profile of the rudder with lines and arcs, and I can extrude it, but here's the issue. The leading edge of the rudder needs to be full extrusion width (20mm), then taper gradually to 2 mm at the trailing edge. How do I make this gradually change of thickness in Fusion?

Re: Changing thickness of RC airplane rudder. Help!

TheCADWhisperer — Tue, 07 Oct 2025 18:10:58 GMT

@awsmits

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

Re: Changing thickness of RC airplane rudder. Help!

Drewpan — Wed, 08 Oct 2025 01:28:20 GMT

Hi,

We can help you a great deal more with your fusion file and images of what

you want to achieve.

There are a number of Aircraft and Boat modelers in the forum who can probably

help you, but from what you have described, an extruded side profile that is

simply rounded and tapered at each end is not as aerodynamically efficient as a

well constructed airfoil.

You would be much better off going to www.airfoiltools.com and downloading the

actual airfoil used on the tail of the aircraft that can be found with a little research.

There are several fusion plugins that enable you to create airfoils directly with the

data files. Once you have the correct airfoil you can trim it and shape it as needed.

I don't know what size your model will be when complete but @wersy is an Expert

with smaller aircraft, and @davebYYPCU is excellent with larger designs and both

these guys and @TheCADWhisperer should be able to help you model what you

actually need.

Cheers

Andrew

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 03:43:41 GMT

20mm circle and 2mm circle, joined with straight and tangent lines.

Sweep with Guide Rail, up the hinge pin and guide rail is the TE curves.

Might help....

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 11:44:48 GMT

Thank you all for the quick responses. I will assemble a .f3d file and pictures of the plane tail section and attach them soon.

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 12:56:43 GMT

Here are the files. The .f3d is a sketch in Fusion that is pretty close to the outside dimensions of the rudder. I learned that just extruding this and trying to filet or chamfer doesn't really work well. I like the idea of starting with an airfoil, and I downloaded and installed one of the airfoil apps in Fusion (not sure it was the best one), and was able to create a sketch and body by extruding the airfoil, then scaled it, and I guess I could trim that extruded airfoil to get the curve of the top and back of the rudder.

For clarity, I'm just a beginner in Fusion, but willing to learn if you point me in the right direction.

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 13:02:13 GMT

Wow, Dave, that looks good. But I have no idea how you did this...

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 14:44:45 GMT

Was a guess, but basically a profile that you told me to use, and then a side view for Trailing edge, and hinge pin position.

Sweep with Path and Guide Rail.

I could not get Fusion to behave with your sketch, was it a "3d sketch" at some point?

Should / doesn't look like the photo. Had to copy it.

You will have to confirm how I sorted out the hinging of the rudder to the Fin clearance cuts. (Normally a Thin Extrude.)

This time I Sweep the profile up the straight section of the LE, and TE section.

Split the Body in half,

Surface Lofted a Tip portion, and it needed some clean up with ellipses as rails.

Boundary Fill the surface Loft > joined, and Combined to one body, then

Thin Extrude for the Fin cut and then some Fillets.

If you want to change to a more pointy fin, we can change that, I just followed your sketch for the Fin.

As you are new, research the tools I mentioned, (you will learn to read the timeline icons)

use Edit Feature to see my settings and

Happy to answer questions.

Might help...

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 16:01:57 GMT

Thanks so much...it looks really good, but I think I'll print a fast copy to see how it fits and measures up. Yes, that sketch had been a 3D object at one time, so that's likely why you couldn't use it...sorry. If it doesn't fit, I'll try to make a more accurate sketch.

I'll study your file in Fusion to learn how you did this...very elegant result!

Re: Changing thickness of RC airplane rudder. Help!

johnsonshiue — Wed, 08 Oct 2025 16:53:55 GMT

Hi! Here is another approach by using Non-Uniform Scale. You may revolve the profile around the shorter axis to create a rounded shape. Then use Scale -> Non-Uniform Scale to flatten the body. Split the body in half and create the rectangular cut.

Many thanks!

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 19:24:23 GMT

Dave, your Fusion file is almost perfect! Just small dimension changes in Sketch1 are needed. Can I make those dimension changes in your Sketch1, or just send them to you for adjustments?

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 19:25:18 GMT

Thank you! I'll check out your file. Always interested in new tricks!

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 19:38:48 GMT

Edit your sketch for dimensions, (there were none) mine (copied by projection)will update.

File should not break, and will update with no other changes.

Might help….

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 19:43:41 GMT

Sorry, do you mean I should edit YOUR sketch (RudderDB) that you sent me? OK, newbie question...aren't those line lengths constrained, and how do I unconstrain them?

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 20:01:11 GMT

My file, still uses some of the first sketch you made, edit that first sketch, because my first sketch is tied to yours, with Projections.

If you are changing the shape of my second sketch, (base profile) then edit it, and unfix the green lines, to turn them blue.

Might help…..

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 20:11:29 GMT

No luck...when I changed the length of lines in your Sketch1, I got numerous warnings/errors.

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 20:20:21 GMT

Write a list of changes you need, will check what is going on.

I use a lot of Project tools to sketch later in the timeline, they should not break, if your changes are done in the sketch 1, and 3 in the timeline.

might help….

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Wed, 08 Oct 2025 20:33:42 GMT

Thanks...I suck at this.

1. No changes to the Rudder Post (your Body6)

2. Rudder base needs to decrease from 110mm to 100mm

3. Add 5mm to the bottom of Rudder (to increase vertical height)

4. The "cutout" in the Rudder needs to be 3mm deeper (change from 29.119mm to 32mm)

Re: Changing thickness of RC airplane rudder. Help!

davebYYPCU — Wed, 08 Oct 2025 22:08:30 GMT

Sorry for delay, Fusion is not playing nice today.

Because there are a few splines involved, not as easy as first stated. Somethings had to be replaced.

Might help...

Re: Changing thickness of RC airplane rudder. Help!

awsmits — Thu, 09 Oct 2025 01:03:48 GMT

No problem...thanks so much for creating this...wish I could have developed this myself, but I can see I have so much more of Fusion to learn.