Fairly New To FreeCAD, Not Sure What To Ask...

[dahopkins]

I have tried searching through multiple tutorials on the net, and can not find how to do what I am trying to do. So either I am searching for the wrong terms, or the way I am trying to do this is wrong.

I have attached an FCStd of my sketch. I have four rectangles arranged in a square and separated by 1mm, that I extrude to 5mm thick using the Part WB (Work Bench) since Part Design WB will not Pad multiple parts. I then switch to Part Design, and try to use Subtractive Cylinder to create a hole of 1mm radius through the side and bottom (X-Axis) parts at 2.5mm Z offset by 2.5mm Y offset and 278mm height. I have to rotate the cylinder 90 degrees, related to the X-Axis, of course. When I click on OK, however, all of the other parts disappear and only the bottom part is left. It does have the hole in it.

So, am I going about this all wrong?

Environment:
OS: Ubuntu Core 20 (ubuntu:GNOME/ubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24276 (Git)
Build type: Unknown
Branch: releases/FreeCAD-0-19
Hash: a88db11e0a908f6e38f92bfc5187b13ebe470438
Python version: 3.8.5
Qt version: 5.12.8
Coin version: 4.0.0
OCC version: 7.5.0
Locale: English/United States (en_US)

[chrisb]

Hi and welcome to the forum!

I don't see the Extrude you describe, so I guess you want to Pad this sketch? It's not possible, because sketches cannot be padded if they have crossing lines or T-joins.

[heda]

hi,

as you have correctly noted part design wb will not pad a sketch that will result in multiple solids, whereas part wb extrude will.
another way to put it is that a body in part design wb has to be a single continuous solid/volume, i.e. one solid volume per body.

so when you switch to part design wb to make a hole through an extrude that is a multi-solid, is it not so that you are violating the same rule that did not allow you to pad the sketch with gaps in it?

you need to stay in part wb, then it will work just fine. so make a cylinder, and then use a cut.

a general example attached,
the rectangles are made with draft/rectangle and pattern array instead of using sketch.
not that it is better that way, just a different way to do it, you could as well pattern the extrude rather than the rectangle.
many different ways to get to the same end state.

or if you want to do everything in part design wb, that works as well as long as you stick to the rule of making one solid volume per body.

[chrisb]

I may add that you should work on your sketching. It is preferred to minimize the number of dimensional constraints and using geometric constraints instead, because it reveals the intrinsic relationsships in most cases much better. Furthermore the screen is less polluted.

Your sketch contains 12 dimensions:

SnipScreenshot-dace70.png (81.11 KiB) Viewed 460 times

after rework, it contains only 5 and is still fully constrained. I have added two construction lines which helped to reduce this number so far.

SnipScreenshot-b8bc32.png (69.54 KiB) Viewed 460 times

Another point: don't use the Length constraint, if you can use vertical or horizontal distance.

[dahopkins]

you need to stay in part wb, then it will work just fine. so make a cylinder, and then use a cut.

Heda, thank you! Wonder why I did not think of that...

I may add that you should work on your sketching. It is preferred to minimize the number of dimensional constraints and using geometric constraints instead, because it reveals the intrinsic relationsships in most cases much better. Furthermore the screen is less polluted... Another point: don't use the Length constraint, if you can use vertical or horizontal distance.

Chrisb, thank you for the tips and reference. I am always wanting to improve my methods.

I noted I forgot to include my FreeCAD and system info, I will edit the original post.

[dahopkins]

...after rework, it contains only 5 and is still fully constrained. I have added two construction lines which helped to reduce this number so far.

I missed your note about the construction lines. I have not seen a tutorial that explains them yet, the tutor just adds it and quickly moves on. I have bought a pretty good book I think, I just need to find the time to read it...

[chrisb]

I missed your note about the construction lines. I have not seen a tutorial that explains them yet, the tutor just adds it and quickly moves on.

Have a look at section 15 in my sketcher lecture linked below.