FilletEdge sees mismatch on SIMPLE shape how to solve?

Rhino Rhino for Windows
1

Hi,
V5
this SIMPLE shape which I was looking fwd to a simple 30 sec filet on sees a mismatch, I try filletSrf no better.

How do I get the end to be a continous fillet everything matching up uniformly ?

surely 0.02 would be such coming at the corner from both sides ?

What is the method to achieve a decent corner ?

FilletEdge mismatch
FilletEdge mismatch600×1836 158 KB

FilletEdge mismatch how to solve.3dm (1.4 MB)

The cutter was a D shape extruded and the norman arch end was made from the D and two more.
all joined then boolean differenced.

Looked ok to me.

Sweep2 made a mess of the D’s.

I dont see it as being responsible but is it ?

Cheers

Steve

1 Like
2

Hello- there is no reason to expect the two fillets to match up at the hard corner unless the input is symmetrical.

-Pascal

2 Likes
3

Hi, ok.
how do I get a matching pair as such at that corner and the approach to it, I presume I need to alter the radii of the LHS as I dont want to go less than 0.02 at the right or on the uprights at all.

Its one of those things where the machinist 80 years ago just did it by hand , certainly no CAD and minutae and gaps to worry about.

How does one calculate what is needed to then add some fillet radii to the left arch lessening the rafii and getting an actual match, in the option that occurs when all is done filleting. (so Jerememy says)

and am I right to avoid FilletSrf on this occasion as the fillets didnt follow on but left gaps.

I am finding Rhino Filleting a nightmare.

Steve

1 Like
4

you could use the FilletEdge option Distance between rails:

image
image1286×895 109 KB

1 Like
5

You could do something like this:
FilletEdge_mismatchx.3dm (157.5 KB)

6

Hi,
V5.
@Gijs
Gijs, I dont see that option of DistanceBetweenRails in FilletEdge, would that be V7 ?

@jim
Jim, good idea and I tried that with FilletEdge and it worked, I then went better and added a 0.02 handle and adjusted the last one to 0.024 the size of the LHS fillet, and got this.

FilletEdge above arch mismatch fix
FilletEdge above arch mismatch fix1100×3147 190 KB

Then to get it to the other side I exploded surface and mirrored it across, trimmed the surfaces with it, and joined all surfaces, and ran ZoomNaked, and it shows 10 naked edges.

Why ?
FilletEdge mismatch how to solve.3dm (2.9 MB)

I seem to have lost a surface or two in my trimming !

Maybe easier to slice the object mirror it across and join then mergeFaces.

Steve

1 Like
7

I’m not sure why you have naked edges, but I did see that your tolerances are lower than what I would recommend for small parts like these. I use 0.0003". You might not want to change tolerances in the middle of a project, but maybe consider that for the future.

1 Like
8

Hi,

I see my absolute tollerance is .001 and if if was to go to 0.0003 would that get more or less fussy on me.

would it complain and fail if something was 0.0002 on fitment ?

I want forgiving, not extra days spent trying to solve something that only needs to be 0.001 accurate, in fact more like 0.02 accurate.

My naked edges wre because I managed to trim a rear surface away when trying to pick the surfaces to be trimmed from the filletEdge result.

Is there a command to atack only surfaces abutting a chosen surface, so we pick the cutting surfaces then it only allows surfaces touched by such to be trimmed ?

Steve

1 Like
9

If you’re building fillets that are .02" radius, you need a much higher tolerance than .02. If you only need your model to be accurate to .02", then you wouldn’t bother building those .02" fillets at all, right?

But I don’t know what will work best for you. My personal experience is that .0003" works well for things at this scale.

2 Likes
10

DistanceBetweenRails is and allways has been an option in version 5 in FilletEdge and BlendEdge as well as in VariableFilletSrf and VariableBlendSrf.

1 Like