Bend using flow doesnt match maths of situation

see storyboard,
bend inner radii 0.04inch, draw circle and chop into quarters. one of these is 0.063 representing the bend
Thus the shelf at end of this bend needs to have that part of it 0.063 above the start of the bend.

place ‘shelf’ in this pre bend position accordingly and have a marker indicating where this end of bend is before and after bend.

bend it, it moves fwd more than it should have done.

why ?

Have I done maths wrong ?

bend doesnt match theory and maths.3dm (541.3 KB)



Hello - I don’t know how you’re getting there but I think this is what you are after?

matches theory and maths.3dm (108.7 KB)


Hi Pascal,
unable to open it, says created by a newer version.
I am V5

Hi @Steve1 ,
V5 version attached; I opened @pascal 's V6 file and saved it for you as V5.
matches theory and maths.3dm (115.1 KB)

Hi, Thanks Fred_C

Pascal, I see your start and end distances are the same though the bend rad and straight parts are different so I cant actually compare to mine.

You had 0.058 bend radius length, (rad of 0.037 ish), straight part 0.456, total 0.514
I had 0.063 bend radius length, (rad of 0.04) , straight part 0.474, total 0.537

I say 'ish as the rad varied as I moved the mouse.

My maths in this is perfect, I place the straight part starting 0.063 above the start of the bend, use flow and it ends up at E, further fwd than D where maths puts it.

How did you get yours to flow and remain same length ?

What is wrong with my maths, surely if a bend has rad 0.04, thats a circumference of 0.063, so the straight part that remains straight has to go 0.063 above the start of the bend curve ?

I use flow with curves straight and bent on the surface that remains unstretched with rad 0.04 and it stretches the item.

matches theory and maths pascal compare self con v5 fred_C.3dm (617.0 KB)

try your method on my item.
what was your method ?



Hello - if you want exact measurements, build it that way - the deformation tools are just not as accurate as that.


1 Like

2.1% error on a deformation :frowning:
I had hoped to do bends with flow, as it was shown by others to do so.
also its been suggested to draw 2D then bend,

Thats a promising tool gone for me as well as 2D then bend, unless the error is on solids only, and perhaps lost to other users, as its Rhino’s bend tool, v sad that deform flow is out that amount.

What was your method as it matched.

Is it same result on mine in V6 ?