Hi Everyone,

For the past couple of days I have been trying to experiment with Rail Sweeps on varying shapes.
When testing on some Cassini Ovals I have come across an issue that I can't figure out, in this case with a Cassini Dog Bone shape.

I will attach a file which has an Oval & a Dog Bone shape, each with a rail sweep on the outer perimeter so when Subtracted they will give a small concave around the perimeter.

I can't seem to get the 3D Subtract to work on the Dog Bone Shape or variations of it even though it works fine on the Oval shape, I was just wondering if someone could try it in Deluxe & see if they have any luck, my version is Deluxe 21.2.

Also, why does the Rail Sweep become misaligned & have an Angle with the Dog Bone Shape?

I have tried different templates etc with no luck on this one?

If Deluxe cannot do this, can the Pro version do it as I need it for some things?

Cheers
David

The Dog Bone polyline contains a great many vertices, which might be the cause of the problem. I traced it with a new Polyline (heavy line in the attached screenshot) and also had to experiment with the orientation of the "D" profile to make the Sweep align correctly (a minor chore in Pro but a much bigger chore in Deluxe). Your drawing, modified and renamed, is attached.

Henry H

Hi Henry,

Thank you very much for that, it does work now with no issue's.

I tried many times with a small number of vertices with no luck, I find that when using a small number of vertices the rendering looks like some cheap machining

No problem with the D profile orientation, I was just wondering why it actually does change orientation?

Only if you have time, why the use of the heavier Polyline, I would like to know to understand better!

Thanks Henry.

Cheers
David

"I tried many times with a small number of vertices with no luck, I find that when using a small number of vertices the rendering looks like some cheap machining "

My polyline is smooth, with few vertices, because it's comprised of just four circular arcs.

"No problem with the D profile orientation, I was just wondering why it actually does change orientation?"

Just one of the program's maddening little quirks, I guess.

"why the use of the heavier Polyline"

The only reason was to make it easier to see in the attachment. It has no effect at all upon the 3D modeling tools.

 Henry H

Hi Henry,

Ahh Polyline Vertices, I misunderstood about that, if I am correct now I was thinking facets not vertices & it explains why it doesn't work in the original file.

Thanks for the help once again.

Cheers
David

Hi Everybody,

I just wanted to add this for people with Deluxe like myself.
As Henry has kindly mentioned that the number of Polyline Vertices has an influence on the final outcome of what has been mentioned above.

I just tried a complex shaped component that I need to design properly & the Polyline for it had over 2600 Vertices & obviously the 3D Subtract would not work subtracting the rail sweep from the perimeter of the component.

I used the Convert To Arcs Polyline tool & this reduced the Polyline Vertices to 129 but still to many for the 3D Subtract to work?

I then used the Convert To Curve tool & it changed it to a Bezier which still would not work in a Metric Template but works very good in an Imperial Template so job done!

May be of help to someone?

Cheers
David

That was an inventive series of experiments to get what you needed.  I wonder if I would have figured it out.


Jeff

Hi Jeff,

From what I have read from your posts you would have come up with a more practical method to do things like this instead of fumbling around like myself being a newbie.

With what I have mentioned I found if another Boolean operation is performed on the object before using what I suggested above the outcome of the accuracy of the rail sweep is not so good sometimes.
It appears to work better before any other Boolean operations are performed, well on what I have tried it has been the case, maybe the particular shape also influences the final outcome.

A couple of questions I guess everyone knew was coming next:

How do you keep the number of Polyline Vertices down to a minimum when drawing complex shapes, it seems as though everything I draw has far to many vertices before & or after any modification to perform certain tasks?

Is the problem of having to many Polyline Vertices only an issue in the Deluxe version, does this apply to the Pro version as well?

How to overcome this issue?

Cheers
David

You would have the same problem in the Pro version if you were dealing with Surface objects.

You would have essentially none of the problems you are seeing here if you were using the ACIS Solids that are available in the Pro versions, but you could have other problems (for instance, Boolean operations on ACIS Solids generate problems - or just outright fail - if the vertices overlap).

That being said, I use ACIS Solids as much as possible because I deal with curves and I want them to remain accurate.

I started out with TurboCAD Deluxe V14.  That lasted a few months and I upgraded to Pro Platinum V14.


Jeff

Hi Jeff,

Thanks for the reply.

I see, so it's an issue because of using surfaces, interesting!
Much to learn!

I can see the Pro version on my computer in the near future.

I would still be interested in any answers on how to minimize Polyline Vertices, maybe with drafting technique?

Thanks Jeff

Cheers
David

I would still be interested in any answers on how to minimize Polyline Vertices, maybe with drafting technique?

In the Pro version, there is the TC Surface Simplification tool.

In Deluxe, the only thing I can think of is to select the object and go into Properties.  Once there, click on the TC Surface Options tab to see what you can do.


Jeff

Post Deleted as Alvin's Post went missing?

Alvin, Please see attachment!

Cheers
David

Hi Jeff,

The version of Deluxe I have has got the Surface Simplification tool, I have not used it yet not knowing what it actually does, I will have a look into it & see what I can do.

Thanks Jeff

Cheers
David

Hi Jeff,

I just tried the Surface Simplification tool but it doesn't seem to select Polylines, after reading a bit it appears it is for meshes.
Still worth a go, thanks!

Cheers
David

Post Deleted as Alvin's Post went missing?

Alvin, Please see attachment!

Cheers
David

Hi David.  I was curious to see the object.  Since I don't have 2016, I'd have to rely on a screen-capture.

I just can't imagine how one would create a 2600+vertice object in a short time.  An object that was created in an optimal-- or close-to-optimal-- way.

With a perimeter of 312mm and an area of 5.44sq.in., and 2624 vertices, that's quite an object!

Hi Alvin,

I was glad to see your post gone as I deleted my reply which was a bit rough

Sometimes it's how things get interpreted or written!

After finding out that my problems were due to having to many Polyline Vertices which I didn't know about & was the reason for attempting the rail sweep on various shaped objects to find out why it would not work.

After Henry mentioning the Polyline Vertices I returned to a drawing that was near completion that I was having trouble with & I found that the number of Polyline Vertices (over 2600) was the reason why the rail sweep was not working.

Hence the questions now about how to minimize Polyline Vertices when drafting something.

Cheers
David

David, how did you create the complex Polyline in the first place? Did you calculate a bunch of points and then connect them with a Polyline? If so, try connecting them with a Spline by Fit Points instead.

Henry H

Hi Henry,

Normally with the Spline By Control Points tool & then use the Edit Tool to maneuver things around. I have now change this & am using a more conventional method using lines & arcs etc.

I have just found a way to manually remove the number of Vertices & it works really well, I use the above method first to reduce the number of vertices with the Convert To Arcs Polyline tool only.
Then select the Polyline with the Edit tool, hold the Ctrl key down when hovering over the Nodes & a small Trash Can appears, Left click mouse & the Node disappears & reduces the Vertices by one each time you do it.

It's a slow method but it works fine!

Cheers
David

Hi Henry,

Normally with the Spline By Control Points tool & then use the Edit Tool to maneuver things around. I have now change this & am using a more conventional method using lines & arcs etc.

I have just found a way to manually remove the number of Vertices & it works really well, I use the above method first to reduce the number of vertices with the Convert To Arcs Polyline tool only.
Then select the Polyline with the Edit tool, hold the Ctrl key down when hovering over the Nodes & a small Trash Can appears, Left click mouse & the Node disappears & reduces the Vertices by one each time you do it.

It's a slow method but it works fine!

Cheers
David

Spline by Fit Points is usually right the first time; doesn't require editing to make it fit the points and it's just as fast as tracing the points with a Polyline.

Henry H

Hi Henry,

Thanks for that, I will try the Spline by Fit Points as you suggest.

Thanks Again!

Cheers
David

David,
In Deluxe you need to experiment with when to use "smooth", most of the 3D operations have it.
I know that these are simple objects but the principle is the same when creating a more complex part.
I rail sweeped on polylines.

Hi Dean,
Thanks for mentioning the smooth option once again.

I am the first one to admit that I have a lot to learn & to experiment with, I think that is the beauty of a program like this.

Anything that keeps the brain thinking is healthy although mine is half dead now most of the time?

I don't know much about using CAD programs & this is a first for me but I am enjoying it immensely hence all the basic questions.

I'll keep at it.

Thanks Dean

Cheers
David

The more you use it (TurboCAD or your brain), the better you get.   


Jeff