True threads in PartDesign-Hole, how to give users the best experience?

[davidosterberg]

In my opinion the default value should be fully threaded (It is possible to machine it, though seldom worth the trouble), this is also the case in other software I've used. If not fully threaded would be default, which value would?

I asked around a bit at work. He informed me that best practice is 3-5 x Pitch less than the hole depth, but it is possible to get Depth - 2 x P with a bottoming tap (an additional machining operation).

Default now is Depth - 3.5 P. But I agree with others that there needs to be a way of specifying the thread depth. Although that is a general problem with the Hole dialog.

[davidosterberg]

And different clearance in the 3D model will disturb 2D derivatives (or in CAM (Path)).

I don't expect any negative interaction. If you enable 'Model thread' then you can choose if you want to also enable "Custom thread clearance". If you don't have Model thread enabled it will work just like usual. I.e it will make the hole with diameter = minor diameter of thread .

And perhaps there needs to be a way to specify the thread length.

+1, yes this is an essential feature, which is missing.

Just in case, here suggestion how a thread should be represented in 3D for a simplified view, like in the mechanical engineering. I think that can be used also for 2D derivatives. Do not be forced to do something in this direction, this is just information.
https://forum.freecadweb.org/viewtopic. ... 6&start=10

That is looking very nice. I think this should be made in a separate PR. The thread modeling implemented in this PR will be trivial to adapt once the thread depth parameter becomes available in the UI.

[chrisb]

That would be neat. I have not seen expression aware "true/false" properties. Do you know of a feature that has one?

They are usually not really expression aware, but they could well be. Toggle the "Reversed" flag of Pad001 and see the other pad going in the opposite direction. So it works, but should be made more official and user friendly.

[davidosterberg]

That would be neat. I have not seen expression aware "true/false" properties. Do you know of a feature that has one?

They are usually not really expression aware, but they could well be. Toggle the "Reversed" flag of Pad001 and see the other pad going in the opposite direction. So it works, but should be made more official and user friendly.

How did you do that? Some kind of python trickery?

[chrisb]

How did you do that? Some kind of python trickery?

No Python, I forced an expression as shown e.g. on the Placement wiki page. And apparently 0 is interpreted as false and 1 as true. I wasn't able to set true or false directly in an expression.

[davidosterberg]

I am still struggling a bit with how the dialog should be organized.
Is it good or bad if different checkboxes and settings become visible only when it makes sense. Like this:

user_interaction.gif (199.48 KiB) Viewed 209 times

Alternatively the settings could be disabled (grayed out) and only become enabled as you check the Model Threads option etc.

[chrisb]

I prefer disabling for two reasons. I don't like flipping dialogs; editing very quickly you can get the wrong entries, because they have changed their position. The other reason is, that showing them tells the user that they exist in some circumstances.

[bleber]

that showing them tells the user that they exist in some circumstances.

I'm agree with these.

To clarify options it would be interesting to put an image to better interpret the terms for uninitiated people.

[davidosterberg]

No Python, I forced an expression as shown e.g. on the Placement wiki page. And apparently 0 is interpreted as false and 1 as true. I wasn't able to set true or false directly in an expression.

Aha, so right click on property and choose Expression in context menu. Thanks, that is neat.

[davidosterberg]

that showing them tells the user that they exist in some circumstances.

I'm agree with these.

To clarify options it would be interesting to put an image to better interpret the terms for uninitiated people.

Yes, there seems to be consensus that hiding and showing stuff conditionally is not the way to go in FreeCAD. Fine with me.
I agree that pictures would be good. It would be nice with a popup tool-tip with a little drawing showing exactly the meaning.