Where do I start with a bookshelf?

[Philip Rayment]

I'm a new user trying to come to grips with FreeCAD. I want to design a bookshelf, which will basically consist of various panels joined together. I tried the Part workbench, and it almost allowed me to do what I wanted, but I was frustrated that each panel had a length, width, and height, whereas with real panels I would normally say that the have a length, width or height, and thickness. A horizontal panel like a shelf has a thickness in the vertical dimension and a length horizontally, but a vertical panel like the side has a thickness in the horizontal dimension and a length vertically. The back could have a length vertically and a width horizontally, unless it's quite wide, in which case it could have a length horizontally and a height vertically. (I did eventually discover how to rotate the panels).

The bookshelf will stand on the floor, so that is the zero point in the Z dimension. It will be against a wall, so that is another zero point. I fairly-arbitrarily chose the left end to be the zero point in the third dimension, although I'm not fussed about that one. However, if I make the wall parallel to the Y axis (so distances from the wall, such as to the front of the shelves are on the X axis), then showing the front of the model actually shows me the left-hand end! If I do it the other way (the wall parallel to the X dimension), then showing the front of the model does the right thing, but distances from the wall towards the front of the bookshelves have to be negative!

All of that I could just about live with, but my shelves are large, and have six lots of shelves side by side, so positioning each panel individually is a nightmare. (I really like that you can link the dimensions and placement values to a spreadsheet, although the spreadsheet itself is very basic and tedious to use.) Then I found that if I make a union/fusion (consistent terminology seems to be an issue) of some parts, I can position each component relative to the whole fusion, and then position the whole fusion in one go. (I did end up with three fusions themselves fusioned into one.) So then I copied and pasted that outer fusion five times for each of the other five sections, but when I went to alter some dimensions on just the last one, I found that I was altering four of them in the process! (I must have done a couple of them differently, so the other two weren't linked in that way.)

This all became so frustrating that I explored a bit more, and decided to try the Arch workbench, and created a FreeCAD panel in that. Great—here the panels have a thickness. However, the placement of them is based on the centres of the panels! I couldn't find how to change that.

And so I'm now at the point that I'm asking, what is the best way for me to do this, without as many of those issues as possible. I have to redesign it, so I'm happy to start again, but should I be using a different approach altogether, or are there solutions to the issues if I stick with one of those two work benches?

(Actually, the whole workbench thing is confusing. In some ways it seems that they are simply different sets of tools to work on the same models/drawing, but then I read that things created in some work benches are incompatible with some other work benches.)

[Bance]

Perhaps you could attach a file, for further help?

Steve.

[bejant]

Hi Philip, and welcome! An example of a bookshelf is in this post:
https://forum.freecadweb.org/viewtopic. ... 20#p257437
and there is a link to the document that contains the drawing at the beginning of the topic.

[Philip Rayment]

Perhaps you could attach a file, for further help?

Steve.

A file containing what?

[Philip Rayment]

Hi Philip, and welcome! An example of a bookshelf is in this post:
https://forum.freecadweb.org/viewtopic. ... 20#p257437
and there is a link to the document that contains the drawing at the beginning of the topic.

I thought you meant for me to look at the book, but that simply gives you an exercise without explaining how to do it (in any CAD system, let alone FreeCAD). Then I realised that you might be referring to the drawing that the poster created for that exercise, so I downloaded that and looked at it. But that doesn't address my concerns, as far as I can tell. For one (minor) one, clicking Front still shows the left end, not the front.
More seriously, I don't understand how that is built, but it appears as though it is just a drawing of the whole, comprising shapes but not parts representing the individual panels of wood that it would be built of.

[Bance]

I wanted to see what you had already achieved, and to get an idea of what you are aiming for, (a picture is worth a thousand words.)

An idea of the purpose of the model would also be helpful, do you intend to create working drawings for yourself from which you can extract a cut list,etc. Or do you need a dimensioned idea of what is required for someone else to fabricate?

The first part of your original post is rather pedantic, it doesn't really matter what the dimensions are called, they are simply dimensions, however you can name dimensions individually if you use part design WB.

As to positioning with regards to the origin it depends on how you intend to construct the model, I quite often set the origin in the dead centre of my model, this allows for planes and axes to be used as construction geometry for operations like mirror or revolve.

If you wish to examine someone else's model, you can use the space bar to make operations invisible/visible in effect exposing how the model was constructed step by step.

Steve.

[Philip Rayment]

I wanted to see what you had already achieved, and to get an idea of what you are aiming for, (a picture is worth a thousand words.)

Is there somewhere here to add images, or do I have to find my own place to put it on the Internet?

An idea of the purpose of the model would also be helpful, do you intend to create working drawings for yourself from which you can extract a cut list,etc. Or do you need a dimensioned idea of what is required for someone else to fabricate?

Yes and no. It will be the main working drawing, but I'll probably draw up a list of what size boards etc. I need manually, from the dimensions that I put into the drawing (or the spreadsheet). I will be building it myself.

The first part of your original post is rather pedantic, it doesn't really matter what the dimensions are called, they are simply dimensions, however you can name dimensions individually if you use part design WB.

As I said, I could live with that if I had to, but it makes the whole process that much more confusing and therefore harder. It's not user-friendly.
As for the Part Design workbench, I've discussed that a bit in another thread (Switching between workbenches using Part) where someone said that "Part Design uses a Body, and there can only be one solid thing per Body.", which suggested to me that that was not a good workbench to use for my task.

As to positioning with regards to the origin it depends on how you intend to construct the model, I quite often set the origin in the dead centre of my model, this allows for planes and axes to be used as construction geometry for operations like mirror or revolve.

It's more practicable for me (in this case) to set the origin to be the floor and the wall against which the bookshelf will sit when built. And for a similar reason, it's also more practicable for the third origin to be at one end or the other, not in the middle.

If you wish to examine someone else's model, you can use the space bar to make operations invisible/visible in effect exposing how the model was constructed step by step.

Yes, I had discovered that, thanks.

[openBrain]

Is there somewhere here to add images, or do I have to find my own place to put it on the Internet?

How-to is described in the (aptly named) 'IMPORTANT : read this first' link in the red banner on top of the page.

[fmluizao]

What about design every panel in PartDesign, then assembly them with a2plus (install from Tools > Add-on Manager)?

Something like this:

Screenshot from 2020-01-16 10-06-06.png (28.37 KiB) Viewed 1762 times

Note that I designed only 3 pieces, and just added the amount I wanted of every piece in assembly.

[Philip Rayment]

Is there somewhere here to add images, or do I have to find my own place to put it on the Internet?

How-to is described in the (aptly named) 'IMPORTANT : read this first' link in the red banner on top of the page.

I DID read that, you know. Before I made my first post, when I wasn't looking to add a picture.

Here's an image of my first attempt:

Bookshelf image.png (22.23 KiB) Viewed 1748 times

(It will have adjustable shelves, not fixed ones, so I've not drawn them in.)

What about design every panel in PartDesign, then assembly them with a2plus (install from Tools > Add-on Manager)?

Thanks. I'll have a look at that.