Solidworks

[adrian]

Trim all the lines so that you are left with a 90degree segment of the full skirt required. Ensure that these lines are properly connected to each other.

I think this maybe where I'm getting stuck - I have drawn the small radius at the top and the large radius at the side it's the loft bit that is complaining about the path.

Mirror this surface to go from 90degrees to 180degrees, then mirror all of that again to get the full 360degree wrap.

I will try that - again I think one of the problems I was making for myself was trying to loft the entire thing in one go. I like the idea of sorting out one quadrant first and then mirroring it.

 

[paratom]

Siemens Solid Edge Community Edition is free for life, and the only restriction is that you cannot share files to or from the paid-for versions. It is every bit as good as Solidworks and you get finite element analysis, full parametics etc. etc. It is the only 'professional' system were the free version is not a mugging into a paid for license. ... so far ... ...

OK there seems to be a few really good free CAD packages out there. In a vote I wonder which one would come tops. Haven't really looked into Solid Edge but what I have seen so far it looks like it would be a contender. My tick boxes would be, orthographic drawings that update when the model is changed, models that are easy to edit and the ability to export obj and stl files. Which ever packages we are using there are probably some tools we never use but I suppose it's better to have too many tools than not enough. With the combination of the latest 3D printers and available free CAD software scratch building is becoming more computer based and allowing people to create models that they would find impossible to scratch build.

 

[Brian McKenzie]

I think this maybe where I'm getting stuck - I have drawn the small radius at the top and the large radius at the side it's the loft bit that is complaining about the path.


I will try that - again I think one of the problems I was making for myself was trying to loft the entire thing in one go. I like the idea of sorting out one quadrant first and then mirroring it.

There are a couple of things I wrote that could do with correction or further explanation.
I don't know if FreeCAD makes use of 'surface' modelling tools, but that is what my suggestion amounts to.

For 'solid' modelling, both the loft sections, one on the front plane I.e. that with the small radius curve to the top of the boiler, and the second loft section - that incorporating the curve down the side of the boiler (on the right plane), will both need to have a line drawn down the centre axis of the dome, plus a horizontal line linking the lower end of the curved bits to join each axis line respectively.

A clumsy explanation, but do look back a few years in the CAD section where I did something similar (but not perfectly) for a loco chimney.
I'm a long way from home base presently, otherwise I'd put up some sketches.

-Brian McK.

 

[Chris Veitch]

I've been using FreeCAD to learn a little more on the 3D modelling side. So far I have managed with basic shapes and components reasonably okay where I've been adding and subtracting boxes and circles etc. However I've been struggling to get a satisfactory blend on the dome to the boiler from the tight radius at the top to a larger radius for the sides. I've tried some of the guides about lofting along a curve but can't seem to get a path defined for it to follow accurately. Any pointers to some useful guides would be appreciated.

I afraid I can't add any specific help, but I'm sure you're as familiar as I am with Darren Stone's MangoJelly video tutorials and it might be worth having a look at some of the v1.0 sessions if you're not up to date with them. It seems to have incorporated quite a few refinements compared to v0.2x, so is probably worth upgrading to if you haven't already. I moved to it a few weeks ago and haven't had many problems, although my subject matter is pretty simple. I have noticed that Darren's done a few ad hoc short sessions to answer specific queries, so it might be worth posing the question to him directly. He seems very well versed in the internals of FreeCAD and to be up to date with where the development process is heading.