Handrail to Spiral Stair

brian_pinder662

Good Morning, Could anyone give a little advice please. I have have completed a spiral stair to the point of adding the handrail and now wish to add the handrail. (Now the fun starts) The stair has two intermediate landings and a top landing. Sweeping round a helix is something I have in mind at the moment but yet to try. The biggest problem will be connecting to the horizontal sections of the landings which will need some careful manipulation. Is there anyone who may have done this and can give a little help.
Regards Brian.

konstantin_shiriazdanov

i suppose the problem you would get with builtin sweep feature is the control of profile orientation, and even Sweep normal FS doesn't provide full control. In Variable section sweep there is an option to take into account path tangent and reference normal simultaneously, but it only creates "sweeps" along a smooth paths, so it may not suit you.
Something like this:

after a little experiment i found that in this particular case Sweep normal gives the same result as Variable section sweep, the result of builtin sweep is not suiting. The only problem with Sweep normal is that it fails when you give it multy edge wire body instead of a number of individual edges

brian_pinder662

Thanks for your reply, I am about to do some experimenting now. I did this spiral back in 2016 with Inventor and had good results with the handrail using both helix and 3d XYZ coordinates to achieve this. At the moment I cannot see where this is possible in Onshape, though I am hoping someone can tell me otherwise. Brian.

konstantin_shiriazdanov

here is the document with different kinds of sweep features which are currently avaliable, you could take it as starting point
https://cad.onshape.com/documents/affea6ffe4df420f453419a7/w/e82e20fbea3d518ffaa26ce3/e/b115b786f0a5c6d579561451

brian_pinder662

Many thanks, will let you know how it goes. Brian