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# equations

#### toni1

##### New member
Hello!

i have one problem. When i use a curve from equations in 3d

that i also use Z cordinate it dosn't want to draw me a protrusion/sweep. When i use a 2d is all OK.

Does anyone now how to use a sweep in 3d traj?

Hello

Have you search for other ways to sketch a 3d curve ?

I think that the 2 projections curve option will solve your problem.

You must sketch two sections on non-parallel sketching planes.

The system extrudes (or projects) these sections until they intersect and it creates a datum curve at the intersection.

I suggest you to sketch to the one section of the curve from the x-y points you have and to the other section only the z-points curve in purpose to drive the curve to the z-plane

This type of curve is more efficient and it is acceptable from the system for 3d traj.

hope this helps

Hello!

I tray difrent way to sketch this but i need a ellipse in hellical sweep.

If this dosn't work when then i can use a curve whit equations.

I also tray with surface sweep and still dosn't work.

Ok

If you have problems finding the right equation to make your job, there is a way to make helical curves that is more efficient than curves by equations.

Draw a extruded surface (capped or not), this first feature has the dimensions of your ellipse,

then draw a helical sweep surface, be carefull to enter the right pitch (this will be the pitch for your curve).

Then use the Intr. Surfs option to create a curve. The system finds the intersection surfaces from the two above features you created before and created the desired curve. This curve is very efficient, you can change the dimensions more easily (is driven by simple features) and is valid for use in every feature you want.

To use the above method you must have the Pro/Surface module I think, because you use advanced features (helical sweep surfaces).

I have not had the need to use sweeps much but I do create pipes and conduits. I create these by offsetting points from the coordinate system with the first point at 0,0,0. This method is a fast way to create pipes and tubes.

Hi,

You can creat a sweep from a 3d traj by using advance

variable section sweep select you criteria....viz

Norm to traj,Normal to original traj,pivot dirn

with this options only can your requirement be fulfilled...

Bye

Shesha.

Create co-ordinate system. Then create datum curve using from equation option. The equation is as follows for creating an ellipse in a helical sweep:

n=’no. of turns’

x=x1*cos(t*360*n)

y=y1*sin(t*360*n)

z=t*’height’

where x1/y1=major/minor radius; height is the total height. If u want to specify the pitch then

z=t*'pitch'*n

Regards,

Rajesh S

Dear toni

Getting elliptical helix is quiet easy with the concept of datum curves from equations,exactly the way described by Rajesh.There may be many other ways,but this one is simple and efficient,if I am not wrong.

To have a look and feel,download the elliptical spring model posted by me from this very site.

regards

maurya

Try creating your x,y,z data on a spreadsheet and put it into ibl format. (search your help documentation on blend files).

Once you've got your data in this format you can then save it to a text file. Make sure you rename this file from *.txt to *.ibl.

You can then import a datum-curve from file to a desired coordinate system.

This file can be changed and updated at anytime after feature creation and is very robust.

Points can be added/deleted, cut & pasted and children tend to regenerate okay.

Dear Toni

Many people have replied your question. That means no further explanation is needed. I just add that go to files on Proecentral someone has uploaded elliptical spring

i think you can try to create a surface that is used the equation curve.

then you can create the feature (ex. sweep) by surface's boundaries......

You cannot use a sweep feature on a 3d curve by equation. However, you can use a swept blend.

Hi All,

I read something recently which stated that when you create a curve by equation and use *t you cannot use a sweep but if you put in *t*t it is converted to a spline and now a sketching plane and orientation plane can be set up. I have not tried this as I have not have access to pro for several months (travelling) but would be grateful to know if it worked.

Steve

hi toni

even i got the same props .if u get a good solution plz send it to my email id

slee

Try these 2 efficient ways to do it.

Create the curve from equation as before.

Use Var Sec Sweep and pivot direction. Use the plane z=0 as the pivot plane. This will work fine

Or try this, it is much powerful and covers a wide range of problems like this.

http://www.kinetivision.com/freevids/Generalized_helix.pdf

Enjoy. You can see it done in video if you have an account.

Hello friends,

I am unable to create a Hellical sweep which look like a telephone cord. i.e., spring along the non linear trajectories.please help me

thank you

yours

Harsha.t.

Create a datum curve representing the centerline of the cord.

Create a variable section sweep surface along this centerline that spirals around the trajectory by setting a relation in the sketch. Set up an angle dim in the sketch and use something like sd#=360*N*trajpar where N is number of coils and trajpar goes from 0 to 1. Now use the the edge of the surface as the trajectory for your sweep. Similar to that covered in http://www.kinetivision.com/freevids/twist_pair.htm