Plane nrml to crv, thru pnt?

[james.lynch]

but shouldthe pnt you created not be at the intersection of the 2 lines (the shorter of which he is trying to create so he doesn't initally have) ??


thefinal plane you createdwhile it is normal to the curve, I dont thinnk that it contains the original point.. or am I misunderstanding again?

Edited by: james.lynch

 

[especial]

sure it does because everythingi start was from that point. check the family (parent/child) relation

 

[james.lynch]

View attachment 649


as you can see your datum (DTM 2) does not pass through the origiinal point..

 

[jeff4136]

Don't believe that's it, Especial. What I'm after is a plane normal to the curve with the point being coincident. DTM1 isn't normal and DTM2 misses the point (it contains your PNT0). Thanks anyway.

 

[especial]

"I'd like to create a plane normal to a (not planar) curve thur a given point near the curve or, at least, create a line from the point perpendicular to the curve."


your welcome. i guess i have never seen somethingthis easy and yetsohard to accomplish. anyway i gave it the good ole college try.i may be missing something some where.

 

[james.lynch]

save yourself a lot of bother.. buy the student version and measure the distance... if you have a lot of them to do then definatley worth it.. or hey, if your stuck send me the model and I'll do it for ya!


cant be much fairer than that..

sorry we couldn't get it worked out but maybe someone will be in tomorrow who can?
Edited by: james.lynch

 

[puppet]

my visualisation skills must have walked out the door 2day. anyone got a hand drawn sketch of what is needed? i

 

[james.lynch]

yup! but it on my desk and I've no scanner.. !


Anyway, picture a curve, any curve, and a point, again any point, now create a second curve which originates at the point and passes through the curve at right angles,


now depending on the curve shape, there could be more that 1 outcome so for simplicity think of an "almost" linear curve, as in something that doesn't turn back on itself like a circle..


hope it clears it up.. look at the iges geometry and delete the small curve and that's the problem..
Edited by: james.lynch

 

[james.lynch]

I take it puppet you didn't solve it either eh?


especial got it right when he said


"i guess i have never seen somethingthis easy and yetsohard to accomplish"

 

[puppet]

sketch it and scan it. then upload .

 

[puppet]

wouldnt that come up with a 2d parabola?

 

[james.lynch]

have no scanner.. View attachment 653


ok, so we have a curve, a we have a point, doesn't matter where it is, now i fyou go to create a new datum plane, you can select the curve and define "normal" to curve, but it need to know where alond the curve to create the plane..


wht we want to do it to create a plane that is normal to the curve andCONTAINS that point..


A little clearer?

 

[pedja666]

For this exercise BM must be used.<?:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" />


These are the steps:


1- Create a 3d datum curve by 2 projection


2-Create a 3D datum point (3 planes)


3-Create a Datum Axis using 2 of these 3 Datum Planes


4-Create a Datum Plane through this Axis and an angle so that it can intersect curve in different locations


5-Since Datum curve is 3D we will have to create a new Datum Plane rotating the previous one around an axis which goes through the point and lies in the Plane from 4.This is NORMAL plane.


6-Create a measure Analysis measuring the angle between Plane from 5 and 3D Datum curve. Parameter measuring this angle is automatically created


7- Create a feasibility study using this parameter as goal (let's call it "angle") angle=90 and two angled dimensions from 4 and 5 as design variables. Let BM calculate the angles and accept the values.


Now you can vary shape of the curve or/and position of the point and BM will always find the position. Run a feasibility study after changes and that is it.


Here is the file:2005-02-10_110653_plan_normal_to_curve.prt.zip

 

[james.lynch]

pedja, unfortunately Jeff hasn't access to bmx.. I suggessted something similar a while back.. nice work though.. very clean!


back to the drawing board!

 

[SW]

This thread just caught my eye, and unless I

 

[pedja666]

SW


Point and Curve come first and Datum Planenormal to the Curve and through the Point after

 

[SW]

The point and the curve do come first.





I first created a 3D curve, then a point in 3D space. Then followed the procedure outlined above, as you can see from the file.





Is that wrong?

 

[pedja666]

To automate the process create a optimization study at the end using the same design variables and goal. This way no matter how you change the Curve shape or Datum Point position after regeneration Datum Plane will always be normal to the modified curve.<?:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" />


BMX is really powerful modules and I am wondering is there a similar modules in other high end software such as CATIA 5 or NX ?





Here is the modified part:2005-02-10_124950_plan_normal_to_curve.prt.zip

 

[SW]

So does the sweep solution not work?

 

[jeff4136]

Thanks folks. I don't have BMX, but will try to get a look at the files when time allows. For the odd occasion when I need a solution I believe using a VSS will work well.

All along I'd have sworn that I had, at some time or other, been able to pick the curve and point to get the plane. It finally dawned on me that that I had been able to; in Rhino. 8~)