Inconsistencies with the arc tool
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I use the arc tool a lot, in conjunction with pipe-along-path.
However there seems to be either an inconsistency or, I'm doing something wrong.
When I make an arc between two joined lines, usually at 90 deg, I use the tape tool to create guide points on both lines equidistant from the apex in order to form a smooth curved join. Then with the arc tool, I will create an arc between the 2 guides and (try to) form a tangential arc. Then I delete the 2 line stubs and face formed by that arc and run P-A-P on the formed line.
Here's the problem. Sometimes, maybe 1 in 20 tries, the arc tool will show a magenta tangential arc. Most times it will not. When it does not, P-A-P will leave a join line between the curved and straight "pipes" which have to be softened and smoothed.
When the magenta line does not appear, the arc tool seems to first snap (on edge) at a point that causes an excess bulge, and is not tangential. I then have to eye the curve to what seems tangential to me, and that always leaves a join line in the pipe.
It does not matter if I do the arc on a temp face at the apex, or just the 2 lines alone. But I do seem to get a better quality first snap on lines that are not perpendicular.
The only times I can get a consistent tangential snap is when I do the arc between one or both of the mid-points of each line, which is no use if the line is 10 feet long and I want a 3 inch arc.
I get the tangential snap (but tangent to only 1 line) if I do NOT use guide points to place the arc. If I use guide points, I don't even get the snap at 45 deg.
Still on V6.4.112
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Hi Joel,
The magenta inference will only show when the two P1A and AP2 lines are of equal length. Magenta means that your arc is tangential to both lines. In other cases, there is only a cyan inference meaning your arc is only tangential to one of the lines (you most likely will get it first with the longer one).
Your problem is that with the arc tool, you can only draw symmetrical arcs. So a workaround solution would be to draw the arc with a magenta inference - no matter where it will end - and then scale it non uniformly to match the point you want it to end. Note that I grouped the original arc first so that what I am scaling, will not "stick" and distort other geometry.
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Nice explanation Gai, but sadly does not address my problem.
First off I have dozens to do in this model (heavy cable electrical runs), almost all at the same symmetrical arc radius of 3 inches, so drawing "any" arc then scaling it back is not practical. That's way more fiddly work than cleaning up the join lines after the P-A-P runs.
The problem is that I do not get even a magenta 45 deg line if I start from a 3 inch guide point on 1 or both lines. I only get it from a midpoint or intersection or from any unmarked point on the line(s).
And I am testing every statement here as I write.
I have 2 lines perp to each other on the blue/red axis, each about 100 inches long, but not equal.
From midpoint to midpoint I get the 2 cyan tangent cues.
From any point on 1 line to the magenta inference on the other I get a magenta tangent cue.But if I make a guide point on 1 line at say 30 in, I do NOT get a magenta inference. And if I click on the midpoint on the second line, I only get the cyan tangent cue tangent to the midpoint line only, but NOT the tangent to the guide pointed line.
2 guide points at any equal or different distances and I get NO cues for tangent at all.
I also played with a rect. tool created face, and got very similar results. 2 guide points = no tangent cue.
Me thinks there may be a bug in SU here (don't tell Gully
) Again, this is SU V6.In order to reduce my labor in most of these arc generations, and considering almost all my arcs are same size and between 2 perp. lines, I create 1 arc as best I can, and copy it to other intersections oriented in the same plane (flipping as required) and repeat the same for the other 2 orientations. Then I clean up all the corners, select the whole line, P-A-P and finally soften/smooth each join.
Having the arc tool perform with proper tangent cues from a single guide point would reduce that workload considerably.
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@cmd said:
jgb,
yes... it looks like the Arc tool does not analyze the edges when you are going from Construction Point to Construction Point .... or when creating edge tick marks (my personal habit)
[attachment=1:2ph543wi]<!-- ia1 -->Arc Tangents_1.jpg<!-- ia1 -->[/attachment:2ph543wi]
Is it by design that you get no inference when you go edge tick to edge tick. That is a scenario I often encounter and it'd be very nice to have inference there as well.
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@cmd said:
jgb,
yes... it looks like the Arc tool does not analyze the edges when you are going from Construction Point to Construction Point .... or when creating edge tick marks (my personal habit)
jgb... perhaps line segments or construction LINES instead of POINTS may help in your work.
CMD
Yes, construction LINES do work, Thanks. I too tried tick marks and I was surprised they do not work when a crossed line intersection does work. But ticks are work to create, as you have to measure where they go first, so it's a double step, unless you need the tick to make a line break or it is needed after you delete guides.
I noticed that with only a single guide line, I sometimes do not get the magenta cue at 45 deg, unless I trace the arc tool from the guide line intersection to the apex and then to its' diagonal inference. And even that does not work when you do a second arc on the same pair of lines.
So, lines work, points don't. that is an easy workaround, and Pipe-along-path happily makes seamless joins. But, as Thomthom said, it would be nice if the arc tool was consistent with construction points as are the other tools.
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And quarter-circle snap would be nice.
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jgb,
yes... it looks like the Arc tool does not analyze the edges when you are going from Construction Point to Construction Point .... or when creating edge tick marks (my personal habit)
For those who may not know, I have included some examples of where you will get the cyan/magenta hints.
jgb... perhaps line segments or construction LINES instead of POINTS may help in your work.
CMD
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@thomthom said:
And quarter-circle snap would be nice.
Agree.
But better yet, arcs at a defined radius (and segments) between 2 selected intersecting lines and a tangential arc forms.
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@jgb said:
.......almost all at the same symmetrical arc radius of 3 inches, so drawing "any" arc then scaling it back is not practical. .....
The problem is that I do not get even a magenta 45 deg line if I start from a 3 inch guide point on 1 or both lines. I only get it from a midpoint or intersection or from any unmarked point on the line(s).
.....Do not start at any midpoint or endpoint. Stay away from any inferencing.
Just find some clean spot on one edge to click the first point.
Hover over the second edge to find the magenta 'On Edge' straight connection. Click right then and there on the second edge. Now hover in between to get the magenta arc and popup 'Tangent to Edge'. (*see note)
Midpoints and other inferencing just interfere finding the magenta arc. Once you get it click the third time to finish.The arc you just made is tangent but not yet the right size.
The nice thing is you can adjust its radius in entity info, still letting it stay tangent to both edges.Note that there must not be anything between first (and second) point and intersection of both edges. Not even a coinciding guide.
*Note: you just let my find a real bug in SU. You can get a totally wrong magenta tangent arc. But it's obvious that it's the wrong one. so no real problem. The right one is easy to find too.
Wo3Dan
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@wo3dan said:
The arc you just made is tangent but not yet the right size.
The nice thing is you can adjust its radius in entity info, still letting it stay tangent to both edges.
Wo3DanYes, that is a neat way to lay down a tangential arc of a defined radius, without guides or inference points. However, it is too many tool changes, clicks and a keyboard when I have a few dozen to do at one time.
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you might want to try a fillet ruby for this..
download the one called 2D Fillet here:
http://www.ohyeahcad.com/downloadselect all the intersecting lines you'd like to fillet then run the ruby.. enter a radius and all the intersecting lines will be rounded..
there's another fillet tool included in the 1001 bit kit ($30) and you'll like TIG's TrueTangents if you need to fillet an arc-to-line or arc-to-arc
using fillet.rb, this is possible in one simple operation:
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@jgb said:
@wo3dan said:
The arc you just made is tangent but not yet the right size.
The nice thing is you can adjust its radius in entity info, still letting it stay tangent to both edges.
Wo3DanYes, that is a neat way to lay down a tangential arc of a defined radius, without guides or inference points. However, it is too many tool changes, clicks and a keyboard when I have a few dozen to do at one time.
ok, skip the 'Entity Info' part. Right after creating just a tangent arc you type its new radius like 450mm[Enter] and if necessary, its new number of segments like 8s[Enter]. This brings down the tools needed to just the 'Arc' tool. Nothing else.
Wo3Dan
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There's also my 2D Tools - 'Fillet Tool' - which Fillets or Chamfers any 2 picked intersecting lines - works in 2D or 3D, you can control the fillet's radius, number of segments etc - remembered that session once set until they are next changed [or chamfers size or sizes etc]: it places a guide-point at the center of the arc too... When set with a 0 radius it trims/extends the lines instead. It also tidies the end of any lines that are not needed for say other faces etc...
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That's better Wo3Dan, I will keep it in mind.
But, TIG's fillet tool looks more like what I want, but hey TIG!! Where's it at?
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@jgb said:
That's better Wo3Dan, I will keep it in mind.
But, TIG's fillet tool looks more like what I want, but hey TIG!! Where's it at?A simple Advanced Search on the forum for '2D Tools', author 'TIG' returns this http://forums.sketchucation.com/viewtopic.php?p=185760#p185760 as the third item...
As is common the script is downloadable from the first post in that thread...
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Got it, thanks, TIG.
I'll Try it on Wed as I gotta take the Mrs out for a quick dinner (she was too lazy to cook) and tomorrow I am out most of the day.
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