topic Re: Bisecting angles in woodshop not matching sketch dimensions in Fusion Design, Validate & Document Forum

Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 02:44:43 GMT

I've sketched out a "tree" style shelf and dimensioned everything out. I've now taken that to my woodshop and would like to start making my cuts. My simple method of bisecting the shown angles isn't working. Take for instance the small tree to the left in the file I've attached.

First angle is 105 so I cut that at 52.5

Second long angle is 166, so I go to cut that at 83 and that is not the right angle.

Did I sketch this out wrong, or what needs to be done to get these angles to translate directly for bisecting them?

Thank you!

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 03:09:28 GMT

The dimension shown as (90.3 Degrees) (the brackets mean something important here) is a driven dimension and all those Blue lines are unconstrained (which is a problem). Can you share your Fusion 360 file?

Re: Bisecting angles in woodshop not matching sketch dimensions

davebYYPCU — Mon, 04 Sep 2023 03:10:48 GMT

Will depend on which side of the board you measure, you are right 105 / 2 is 52.5, but there are other angles to play with. You didn't say what angle you ended up with.

Might help....

Re: Bisecting angles in woodshop not matching sketch dimensions

davebYYPCU — Mon, 04 Sep 2023 03:28:48 GMT

Your 90.3 dimension is not driving anything, you have to make it 97 deg, and the line will grow a bit, because the 166 degree angle is below the 2 lines, not above.

Might help....

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 11:51:34 GMT

Thank you, with the design of the shelf, each blue line is a piece of wood, all coming off of each other as it moves on.

I've attached the stp below, let me know if you need another format.

So the lines that I've drawn here are how the design should be, and I was hoping fusion would give me the true angle that I can then simply bisect and assemble.

Thanks to you all for the help.

Re: Bisecting angles in woodshop not matching sketch dimensions

TheCADWhisperer — Mon, 04 Sep 2023 12:21:58 GMT

@boasist

First thing I notice is that your sketch is not fully defined.

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply? (Not step file.)

@boasist wrote:
...each blue line...

Should keep you awake at night. No blue lines or white dots.

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 13:11:16 GMT

You got it, thanks for defining the process.

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 17:42:04 GMT

This is a great point, and I didn't even think that fusion had, or the ability to map this out. Every angle should be listed as we're looking at the shelf from the front. So that the planed (wall) side of the wood is always away from me as I cut.

Great point.....now how do I do that!?

Re: Bisecting angles in woodshop not matching sketch dimensions

davebYYPCU — Mon, 04 Sep 2023 18:00:20 GMT

How do you do ... what?

If it were me, I would Offset the lines, by thickness of the material,

then you can join across the relative endpoints. Add the dimension you require and Fusion does the hard yards.

I don’t think I would be using bisection angles, rather,

top above bottom plates. Still need to know the angles.

Might help....

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 18:33:35 GMT

Can you tell us what you're trying to build? Is it a tree bookcase or shelf similar to this? (Sorry I cant locate a photo of the actual build.)

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 18:36:12 GMT

and based on your sketch lines:

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 18:37:41 GMT

A shelf, or a series thereof. The entire unit is mounted directly to the wall and each shelf/cut becomes a shelf. The end risers hold certain items in place.

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 18:43:55 GMT

Here's one I did a while back:

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 18:50:21 GMT

and a new sketch projected off the solid body will give you a way to measure your cut angles:

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 18:53:38 GMT

My rough adaptation. Note this is very much unconstrained and simply a WIP!

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 20:02:16 GMT

Wow, you cranked that out fast!

Your design is really great looking, how did you achieve the tapered trunks/branches?

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 20:27:28 GMT

Every angle referenced here is the exact same as in my sketch, so I'm out there floating on a resolution once again.

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 20:42:32 GMT

Hi again. What are you trying to progress here? If you're happy with your overall design both style and dimension I assume you simply want to extract lengths and angles of cut to achieve a simple mitre cut? Not that it matters but what thickness board and depth of shelf are you thinking? 5/8" and 8" Wide board?

Re: Bisecting angles in woodshop not matching sketch dimensions

Warmingup1953 — Mon, 04 Sep 2023 21:09:00 GMT

Let's concentrate on just one joint that you believe yields incorrect angles. Can you post a zoomed-in?

Re: Bisecting angles in woodshop not matching sketch dimensions

boasist — Mon, 04 Sep 2023 22:19:41 GMT

Take the first two on the small tree.

As I read it, I’d miter a 52.5 and then an 83. The 52.5 turns out, but the 83 is not.

So that’s where I’m at.

Thank you