failed somehow sketching rotating mast

[jadory]

I'm a newb trying to figure out Freecad and used an image to create a sketch of the mast section of my sailboat roughly (doesn't have to be perfect) using a combination of b-splines, arcs, and straight lines. The section has varying thicknesses and some flat (straight line) sections as well as the curves. The computer I'm using is a desktop but rather old (Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz) with 16 Gb ram.

This drawing about locks up my computer. When I load it, it takes about a minute before it loads the sketch. So I've probably made several mistakes. I was working on constraining it and used the Constrain Block for the b-splines. Then several other various methods on the other pieces. Obvious I don't know what I'm doing. It is difficult to work back on the sketch as each action takes forever. I actually created it using the latest version .19, but acts similarly in .20.

I'm curious if it also loads slowly on a modern computer, and I'm curious what mistakes I've made - perhaps how I could have handled it in a better manner. Thanks for looking!

Code: Select all

OS: Gentoo Linux (KDE//usr/share/xsessions/plasma)
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.20)
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.9.13, Qt 5.12.9, Coin 4.0.0, Vtk 9.1.0, OCC 7.5.3
Locale: English/United States (en_US)

[adrianinsaval]

the sketch may be too complex, for starters the profile seems symmetric, try modelling only half of it then doing a mirror outside of the sketch, consider replacing some of the bsplines with arcs instead as they are likely less resource intensive, if it's still too slow consider breaking down in more than one sketch, for example the outer bounds in one sketch and the inner bounds in another, or the upper quarter in one and the lower quarter in another.

[jadory]

the sketch may be too complex, for starters the profile seems symmetric, try modelling only half of it then doing a mirror outside of the sketch, consider replacing some of the bsplines with arcs instead as they are likely less resource intensive, if it's still too slow consider breaking down in more than one sketch, for example the outer bounds in one sketch and the inner bounds in another, or the upper quarter in one and the lower quarter in another.

Thanks - good idea. I did do a symmetry from the left side to the right side, rather than mirror. But otherwise will try your suggestions. I'll have to figure out how to join sketches if I do inner and outer, but should be in the youtubes. /jd

[hammax]

... trying to do it with a single and variable BSpline.
That must be an extruded Al-profile with a lot of fillets.

Mast.PNG (51.27 KiB) Viewed 615 times

[jadory]

... trying to do it with a single and variable BSpline.
That must be an extruded Al-profile with a lot of fillets.

I'm going to take a look at what you did but I have a suspicion I won't have the foggiest idea of how you did that. But looks great! I've just redrawn it using no b-splines, but haven't constrained it yet as I have to research how to do that, if necessary to bring into Part Design or whatever.
Thanks!

[jadory]

Ultimately I'm hoping to learn enough to model how to design my mast step sheaves which, in one image are imagined with the wooden disks. The mast piece is just a stub until I affix the rotating base to the actual mast of same section. I'm probably asking too much. The base has a place to mount a stainless trailer hitch ball to rotate on, not shown.

[adrianinsaval]

personally I think I would model the general shape of the profile then use a 2d offset (or 3d offset if it works) to make it thick, then model those little protuberances in a different sketch.

[papyblaise]

a little patience and skill, with arcs of circles

[jadory]

a little patience and skill, with arcs of circles

I need a good how-to source to follow these. I'm unfamiliar with fusion and fillet, I guess. I can google it. One source I looked at had me using Sketcher, then import that into a body under Part Design for padding and stuff. I'm coming from Autocad so this is a new way of working, for sure. I have recreated my sketch using just lines and arcs on the left side, then a mirror for other half. So I have ImagePlane - Sketch - MirroredSketch and will try working from there. Thanks for the examples!

[Shalmeneser]

SheetMetal_AddBase