OS: Debian GNU/Linux bullseye/sid (LXQt/lightdm-xsession)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.20209 (Git) AppImage
Build type: Release
Python version: 3.8.2
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
For context see: "Wanting to 'pad' a part" earlier in this forum and the following quote from private correspondence.
I Am really trying to understand the hows and whys in the methodology and am hoping that going through your example (thank you very much for this by the way!!) will help me to at least understand what in the bleeping blazes is going on.Bance wrote:
Sat Mar 28, 2020 8:42 am
OK, I think that you should copy your PM to me and post it on the forum, Give it a title such as "new user analyzing forum provided sketch." I'll happily explain your queries and you 'll get the benefit of additional advice from members that are far more experienced than I.
I'm a little scared to because I had previously asked about what I see as inconsistencies between the different work benches. Basically got told that I needed to learn the 'freecad' way and/or ignored. I think that the developer crew might have a large tendency to see my questions as nuisance noise and would rather just code some more - - - - even though there are just very very few tutorials to help on figure out what to do. Its like I'm being told - - - - I had to figure it out - - - - you can too (that's where your assistance was so very useful!).
I am just finding that trying to model what I'm working on is really getting in the road of getting the job done, I have enough experience with paper and pencil so I can just quick and dirty get something down (trained where all too often its was a welding rod and dirt, great was a cigarette carton and a pen).
Had already altered your model to what I need for my work so grabbed another copy and stored that as an independent file.
Started by opening every aspect (in the tree view) of the doc.
List is as follows:
5. list of 3 axis and 3 planes
1. illogical numbering scheme - - - there are really 2 Sketch #1s
2. question as to why more than 1 pad needed
(I now understand that Pad can only be used on a max of 2 geometries at once but its really not clear why that is necessary.)
Next I will look at each of the sketches.
1. sketch is of 5 lines depicting 2 diameters, 1 radius and 2 thicknesses
5 degrees of freedom listed as an under-constrained sketch
1. sketch is of 2 coincident circles, 1 depicted by diameter and 1 by radius
sketch is fully constrained
1. sketch is of coincident circles, both depicted by diameter
sketch is fully constrained
(I hope the questions are not going to totally PO you but I'm trying to understand the work flow.)
1. both sketch001 and 002 are fully constrained yet I can't find a way to constrain sketch or any of its values - - why?
2. on the coincident circles was there a need to depict one sketch where a radius and a diameter are used and the
other uses 2 diameters - - - - is that necessary or ??????
3. it is possible to edit the values in sketch but not in either sketch001 or sketch002 - - - why?
4. how are the values in sketch linked to those in sketch001 and sketch002?
5. why is sketch done as 'lines'?
(Modeling the blade(s) for my project is only a very small part of the overall project. I have spent quite some time over a number of days trying to find a way to restrain (maybe better 'hold') a very long quite slender shaft containing a large number of these blades. As the shaft may be turning at greater than 10k rpm things are rather not straightforward so I've had to paper sketch and spec a seal/bearing/holding apparatus that is proving to be quite interesting in its engineering. This is a much more complex modeling exercise than that of a blade.)
What is really confusing me is that the process of using a 'Pad' seems illogical.
To me 'Pad' is adding the third dimension into a 2 dimensional figure.
That means that where there is thickness I 'Pad' the feature - - - where there is a hole or just nothing I could define the space as a hole (intrinsic to the part) or as nothing (extrinsic to the part).
Rather than being able to just attach values to the areas in the 2 dimensional structure it is necessary to break up the structure into pieces that only contain 2 geometries. As my next 'part' has at least 17 dimensions that means that I need to have at least 9 sketches - - - - the likelihood of error increases rapidly due to the very large increase in necessary connections.
I understand that you are (at least it would seem that you're not) not the originator of the 'logic' or the work flow - - - - I'm just boggled at how many extra steps and how many opportunities for error are created by using such an awkward shift from the 2 dimensional to the 3 dimensional model. )