topic Re: Best practice for parametric wood joints - sliding dovetails parts in Fusion Design, Validate & Document Forum

Best practice for parametric wood joints - sliding dovetails parts

Theoforus — Mon, 23 Oct 2023 09:43:33 GMT

I´m reaching out to you all amazing people here at the forum. I am trying to make a small stool with sliding dovetail joints. See attached file. I just wonder what would be the best practice for making it parametric so I can change material dimensions. Should every piece be a different component? How do I draw the boards and the joints so they align when I change the parametric dimensions?

Re: Best practice for parametric wood joints - sliding dovetails parts

davebYYPCU — Mon, 23 Oct 2023 11:00:22 GMT

Your model is currently broken on download with yellow icons.

These should be fixed when they pop up. Immediate Undo usually does that for you.

The model is symmetric in 2 directions, so you are working 4 times harder than you need to and giving Fusion 4 times as many ways to fail.

Changes to most of your parameters break the right end of the timeline. Some Extrudes just need opening and closing, not something you can fix, as it is likely a Fusion bug.

You are modelling as bodies in place, so unless you need Components later, this is acceptable,

and yes, one of each distinct part (make them Components now??,)

before duplication, is the better workflow.

Making sketches adaptable, takes practice, and planning for the early criteria being available in each set up that will be changing.

Now, that said, finding the breaking parameters will take longer than I have left tonight.

May I suggest that the wedge here is not going to hold the leg, without wider top opening, pic is exaggerated.

Also you will need sliding tolerances for the male and female dovetails, size for size is not practical.

Might help....

Re: Best practice for parametric wood joints - sliding dovetails parts

Theoforus — Mon, 23 Oct 2023 11:38:01 GMT

Thanks. I will look at it.

Re: Best practice for parametric wood joints - sliding dovetails parts

laughingcreek — Mon, 23 Oct 2023 15:48:24 GMT

what Dave said...mostly.

use skeleton sketches to drive the overall design. check periodically that they are reacting to dimension changes as expected.

me personally,

-I keep all the skeleton sketches AT THE BEGINNING OF THE TIME LINE with no other features in between them. I am careful to only reference projections from the skeleton sketches into other sketches, and not use bodies and components as references. ( I also use points on these sketches for extrude too so that changing dims means changing things in the sketches and not going into an extrude feature or the parameter table. it becomes a visual process, and one that is much easier for me to figure out when I go into my model a year from now and don't really remember what I did to model this thing)

-I generally pick the view direction for the first sketch to be the one that contains the most information for the project. this sketch will drive a lot of other dimensions in subsequent sketches. in your case that would be the view from the LEFT side of the view cube. that sketch in your model doesn't appear till the third sketch.

-I usually deal with tolerances at the end of the timeline, and not in the skeleton sketches (always exceptions). one reason is that you can keep your driving sketches cleaner, and easier to control. (another is that I use multiple process to prototype things over the coarse of the design cycle, and they all need different tolerances in different places. so I put those at the end)

-use components right from the start. when you extrude a body, set the dialog to "new component"

it will save you the step of creating the component by hand. also lets you use "display component colors" which I much prefer-

-and yeah, just model 1 quadrant of this, mirror the rest into being.

Re: Best practice for parametric wood joints - sliding dovetails parts

davebYYPCU — Tue, 24 Oct 2023 01:55:24 GMT

Yep, what Alex said he does.

Interested how you will cut into this corner.

Might help.....

Re: Best practice for parametric wood joints - sliding dovetails parts

Theoforus — Mon, 30 Oct 2023 08:36:02 GMT

I thought I had to cut it to object because it should be adjustable to the height of the side-piece. Can I cut it to a line in the sketch? If not, should I make a parameter for the cut that fits the height of the side panel without relying on either sketch nor object?

Re: Best practice for parametric wood joints - sliding dovetails parts

davebYYPCU — Mon, 30 Oct 2023 08:50:29 GMT

No, my question was not about how you do / did it in Fusion, no need to change anything in that regard.

In the workshop, how is it actually cut to a blind face? (Old school with chisel will work not many old schoolers around these days)

Might help.....

Re: Best practice for parametric wood joints - sliding dovetails parts

Theoforus — Mon, 30 Oct 2023 09:08:28 GMT

I understand. I have not tried it out yet, but I would try to use a router for the main part and than do the final work in the corner with hand tools. Maaaybe I could do it all by machine, but than I would have to angle the underside of the side piece at the same angle as the bit (would be some final hand tooling anyway I guess). Thanks for input.

Re: Best practice for parametric wood joints - sliding dovetails parts

Theoforus — Mon, 30 Oct 2023 13:00:04 GMT

"The model is symmetric in 2 directions, so you are working 4 times harder than you need to and giving Fusion 4 times as many ways to fail."

What would you suggest? I thought symmetry was great. Just make a half and mirror the other side. Have I missed something?

Re: Best practice for parametric wood joints - sliding dovetails parts

laughingcreek — Mon, 30 Oct 2023 13:09:47 GMT

@Theoforus wrote:
I thought I had to cut it to object because it should be adjustable to the height of the side-piece. Can I cut it to a line in the sketch?....

sorry, I'm going to go off on a tangent here...

first, recall my comment about how I organize my sketches at the beginning and make sure things that are projected are coming from those, and not the bodies created from those. with that in mind, yes, you can "extrude to" a POINT in a sketch. In my thinking it's usually desirable to instead of an object. the purpose is to avoid crating chains of projections that are each dependent on the previous geometry to remain functioning. chaining references (reference chains?) creates more opportunities for models to break AND makes it harder to trouble sho0t where the problem is when they do. also makes it harder to make wholesale changes to a model. when ever possible, when something needs to be referenced (such as for extrude to), try and go back to the original geometry. when I'm doing flat work modeling like your doing, I aim to be able to delete (not just remove) any component and not have other stuff break because some random thing was dependent on it.

Re: Best practice for parametric wood joints - sliding dovetails parts

davebYYPCU — Tue, 31 Oct 2023 01:33:12 GMT

Sketch symmetry not so great.

Step the timeline. Change parameters as you wish, within reason.

Might help....