NURBS Spline?

[RStuart]

Can someone please help me. I generated a curve from a solid on one edge in order to create a 3D contour toolpath. Although when I actually machine the part the toolpath is made up of many lines instead of arcs. Does anyone know how I can smooth this out. It is a complete circle. I have tried modify convert to arcs but this does not work. Any help would be greatly appreciated. Thanks.

[EZ3PUTT]

Modify, convert to arcs.

[Rekd™]

jadkins is right, but I've not always been able to get splines converted. You could also try filtering the toolpath.

 

'Rekd teh Splineless worm

[RStuart]

I tried that as I have said above, I got that to work on a spline that was not closed but in this case it is closed and it will not work.

[RStuart]

I have also filtered the toolpath and this too does not work

[kccadcam]

Have you checked the arc settings in your post?

 

arcoutput : 1 #0 = IJK, 1 = R no sign, 2 = R signed neg. over 180

skp_lead_flgs : 1 #Do NOT use v9 style contour flags

arctype : 2 #Arc center 1=abs, 2=St-Ctr, 3=Ctr-St, 4=unsigned inc.

do_full_arc : 0 #Allow full circle output? 0=no, 1=yes

helix_arc : 1 #Support helix arc output, 0=no, 1=all planes, 2=XY plane only

arccheck : 1 #Check for small arcs, convert to linear

atol : .01 #Angularity tolerance for arccheck = 2

 

 

Also, make sure arcs are turned on in filter.

[RStuart]

I have the settings in the post the only way they can be and cut an arc without cutting across the face of the part. The toolpath is being generated so that is using the X-axis and the C-axis. I am machining this part on an Integrex.

[Philcott]

Would Modify, Break, Splines to arc work?

 

Phil

[RStuart]

That doesn't seem to be working Phil. It says it either does not lie in the construction plane or it ends up with a straight line.

[CAM-mando]

If it is "almost 2D" you could try squashing it first.

[TREV]

sometimes when splines will not convert to arcs it is because they may not all be at same z level. i will project splines to a flat surface then convert to arcs this works well for setting up geometry for simple 2-d contours and the like.

hth,

trevor

[pactec]

Are you doing a replace Y type of move? If so, then unroll the 3-D curve into the centre of rotation. This will allow you to create arcs from splines or filter the toolpath so you get arcs. Any time you run a 3-D contour it can be unrolled and then the Rotary Axis button used to re-wrap the shape onto the cylinder. If this isn't the case I am sorry for wasting your time, perhaps describe the movement more and we'll have anothere crack.

 

Take care...

[Dan Bedore]

i would creat an arc circle 3 point with my c-plane in 3-d and then select three end points about the same distance away from each other. or i would losen my tolerance in the convert to arcs.

[foolsh]

try break splines into half,then modify convert into arcs,if it doesn't convert,break it into half again until all your splines are converted.although it will be better then modify break splines to arcs,where you tend to have many small arcs.

[markb52]

If your having this much trouble creating a single arc and all your getting is a bunch of small arcs that replace the lines of the spline, create a spline with even more control points that the original. Then you will not see the lines on the piece you are cutting. Of course you would not use the arc filter then.

[Jody]

Take a look at what Glenn wrote. It should be put in the tech tips I think.

 

http://www.emastercam.com/ubb/ultimatebb.p...t=004928#000001

 

 

After reading your question again this may not be what you want but is still a good tip.

 

Jody

[Eric S.]

hi

 

Have you tried cranking up the filter? This usually works for me.

[mikhael gutman]

Well, I would not use filter, could violate into the part.

What I usually do : Create arc 3 points from the spline

Or Modify – brake – spl to arc

It might helps.

Good luck

 

[ 05-28-2003, 04:18 PM: Message edited by: mikhael gutman ]