Fillet This?

[Bruce Kieffer]

How would I round over the edges of this frame as if I were using a woodworking router with a 1/2" rad. bullnose router bit? The results should be rounded over transitions between the rail ends and stiles, and the joint lines need to be visible. I know I can add the six pieces together as a solid and round over, but the joint lines will disappear, and they need to be seen.

[Pat Stanford]

Another way to do this would be to actually simulate how a router works.

 

Let's just talk about the interior openings. In a plan view, draw a rectangle to simulate the path of the pilot bearing. So this rectangle will be inset from the edges by the radius of the pilot bearing. Now filet the corners to the radius of the pilot bearing. So you should now have a rectangle (polyline) with rounded corners that matches the path the the center of the pilot bearing will follow when you make the actual piece.

 

Now draw the profile of the router bit. Select the profile and the path rectangle and do Extrude Along Path. Edit the Profile and move it from the 0,0 point to match the radius of the pilot bearing. You may also need to adjust the Y value up or down depending on where in space you want to put the path object. For me, putting the path at 0 and then aligning it to the "top" of the part to be routed makes the most sense, but if you prefer to put the path lower so it is where the pilot bearing will actually run that is fine, but you will have to adjust the location of the "bit"

 

Select the Extrude Along Path object and the frame and Subtract Solids. You should now get a piece with the proper 3D "fillets" to match what the router would actually do.

 

If you follow JimW's original advice and add all of the solids before the Subtract, you only have to do a single subtraction. When you split along the edges each piece will have the proper profile. 

 

If you prefer to not Add Solids on the frame, make sure the Retain Subtracting Object check box  is selected so you can reuse the Extrude Along Path to repeat the Subtract Solids on the other parts.

 

 

[PVA - Admin]

I suggest adding the pieces together with Add Solids, perform the fillet so that you get the desired filleted corners. Then use the Split tool to slice the single solid back into pieces along the lines that used to exist so you get the fillet edges as well as the joint lines.

[markdd]

Try this setting on the fillet edge (and also chamfer) tool and set the radius to ½". Then pick each timber individually. Use the shift key in the usual way to add to the selection.

 

Mark

Edited July 18, 2017 by markdd

[mike m oz]

Round all the edges using the Fillet tool and then use Add Solid to add back in the timber that would not have been removed where the cross pieces intersect with the rails.

[AlanW]

Followed Jims suggestion and but used subtract solid to do the work. Just another way.

 

 

Edited July 18, 2017 by Alan Woodwell

[AlanW]

Bruce_fillet.vwx

[mike m oz]

A better way to do it:

- model the rails and round the edges

- model a cross pieces 1'" longer than is required.

- model a piece to subtract from each end and round two of its edges.

- Solid Subtract these two pieces from the rail.

- duplicate for the other rails.

 

See attached Vw 2017 file.

 

Rails rounded solution.vwx

[Bruce Kieffer]

2 hours ago, mike m oz said:

A better way to do it:

- model the rails and round the edges

- model a cross pieces 1'" longer than is required.

- model a piece to subtract from each end and round two of its edges.

- Solid Subtract these two pieces from the rail.

- duplicate for the other rails.

 

See attached Vw 2017 file.

 

Rails rounded solution.vwx

Interesting, but not how it would be built in the shop.

[Bruce Kieffer]

So far Jim's way of using the split tool is the easiest, but the filet edge results are not what would happen in the real world when a bearing piloted round over router bit routs an inside corner (photo attached). I see ways to adjust this, but they are far too complex for any value added to my drawing.

[Bruce Kieffer]

OK, I found a solution that matches the way the router would cut the wood in the shop. Sure it's a lot of work to do in VW, more work than routing it for real! I'd still be interested if someone has a simpler solution. Here's what I did:

 

First off I used a 1/4" rad. fillet because I needed to change my design. I rounded the top faces of the stile and rails.

 

Then I drew a 1/4" rectangle with a 1/4" rad. circle at each end.

 

I clipped the circles away from the rectangle. Then I drew a 1/4" rad. sweep and placed one at each end of the rectangle.

 

I extruded the rectangle to 1/4" and I added the sweeps to make one solid object.

 

I added that object to the stile. A bit more work and it looks correct. Just like if I had done the work in my shop.

Edited July 18, 2017 by Bruce Kieffer

[Kevin McAllister]

Nice solution Bruce.

 

Here's one other one that gets you very close. The steps are in the file. The key is the step where you create a small fillet in each inside corner before extruding. I've only gone as small as 1/32" in my right hand example but I suspect you could go smaller. Its just about changing the geometry at the corners so the 3d fillet behaves the way you would like.

 

Kevin

 

 

Fillet_This?_KM.vwx

[Bruce Kieffer]

Kevin, now that's interesting. Certainly less work than what I did. I wonder why VW needs the small inside rad. to do this close to the way I want.

[mike m oz]

Another way to do it using Nurbs.  You could build up a 'Blue' Symbol library of these for different radii (Blue Symbols convert to a Group on insertion).

 

This corner fillet object is 1/2".  You could create the other corner fillet objects by duplicating it and then using Scale object to change its size.  Once you have your required range of corner fillet objects create Blue Symbols of them by choosing the Insertion option to Convert to Group.

 

Fillet nurbs solution v2017.vwx

[mike m oz]

Pat's solution would be the best way to go with more complex routing.

[Bruce Kieffer]

Pat's suggestion is a good one. Mike's method is similar to what I came up with. I attached a simple version of my file here for others to deconstruct. Double click multiple times to drill down in history mode.

Fillet This.vwx

[markdd]

Hi all

 

I'm struggling to understand why doing a simple solid addition to all the rails and styles, filleting the top face by ¼" and then using the split till to separate them to give the joint lines is not the simplest way to do this. I did just that and got the results shown below....

[Pat Stanford]

Take a close look at the joints. When you filet the joints, the filet runs all the way to the edge of the object.

 

Using a real world router there is usually a pilot bearing the is used to ensure smooth movement. This offsets the actual actual path of the router by with radius of the bearing, typically 1/2" (12mm). That means that at the intersection of the rail and stiles, the filet will not be smooth all the ay to the joint, but will actually be curved based on how close the bearing cad get into the corner.

 

With a real router you get a compound curve in the corners. With a VW Filet you don't.

[markdd]

I see the distinction now. Very good.

[Bruce Kieffer]

All of this discussion has me thinking there may be ways for VW to help in the future. Possibly fillet edges of grouped objects so the individual objects are maintained, and maybe this is tied to fillet edges being part of history mode, wouldn't that be nice! Also, a checkbox in the fillet edges settings to ignore inside corners (no addition of a fillet there).

Edited July 19, 2017 by Bruce Kieffer

[Kevin McAllister]

1 hour ago, Bruce Kieffer said:

All of this discussion has me thinking there may be ways for VW to help in the future. Possibly fillet edges of grouped objects so the individual objects are maintained, and maybe this is tied to fillet edges being part of history mode, wouldn't that be nice! Also, a checkbox in the fillet edges settings to ignore inside corners (no addition of a fillet there).

These are all good wishlist items.

Kevin