[skippy]

Can anyone help me with this two part AutoCAD question please? I have attached a drawing that has a couple of straight lines, a radiused corner and a spline.
(A) I would like to outline or inline it (offset) in one go. If I understand correctly, AutoCAD must recognise the shape as being a closed shape before it can do an outline or inline. I used the PEDIT command and all is joined except the spline. What do I do now so that AutoCAD recognises it as one closed shape.
(B) Now that it's closed and inlined or outlined, I want to cover the whole thing (along the line) with multiple copies of the 3mm circle and with +/-1mm gap between all circles. Can AutoCAD do that? If so how? (pretend it's a garden path (aerial view) and I want to place potplants around the perimeter)
Thanks for your help in advance

[skippy]

Sorry, here's with the circle in it.

[ger21]

Something like this?

[ger21]

First, you don't need a closed shape to use the offset command. The problem, though, is that you can't join a spline to other entities. Just offset the two seperate objects. You can do both during 1 command.

Autocad can place objects along a line, spline, or other object. But, it's a bit tricky, a litlle more so in your case (because you have 2 objects).

You use the divide command, with the block option, to place blocks along the object. So, first, you have to make your circle a block. Type "block", and choose the center of the circle as the basepoint. Name the block something you'll remenber when asked for it later. Now, you need to know how long your line and spline are. You can use the properties window, look for length. Or, type "list", select the object, hit F2 to open the command window, and you'll see the length somewhere among all the info listed. hit F2 again to close the command window.

Once you have the length, divide it by 7 (6mmD +1mm space). round it down, and this is the number of circles.

Now, type "divide", and choose the line. type "b" for block. Enter the name of the block (you remember, right?) , choose yes for align (it doesn't matter for circles, though, but you'll usually want them aligned), and enter the number of circles you want. Repeat for the spline.

I had to add two circles at the polyline and spline junctions. If your shape was a polyline, it would work a little better. Depending on how important the spline is, there is a spline to polyline lisp program available for download from http://new.cadalyst.com/code/browsey...?fullyear=2003, December download. That wouls let you convert the whole thing into one polyline.

[ynneb]

Nice garden design Skip

(He He, I know what it realy is. Its a.............................(bummer, I am sworn to secrecy)

[skippy]

Gerry, that's exactly what I meant. (A) "Just offset the two seperate objects. You can do both during 1 command" How do you select the polyline and the spline in one move to do the offset? I can select one or the other but not both. (just curious as I prefer your polyline solution below)

(B) It seems like the "length" doesn't get shown in properties for polylines unless I'm doing something wrong.

(C) "If your shape was a polyline, it would work a little better. Depending on how important the spline is" No, it's not important.

(D) "there is a spline to polyline lisp program available for download from....." That sounds like my best bet however, before I do that let me confirm that I'm on the right track. If you were drawing similar shapes from scratch, would you end up with the same polyline and spline that I ended up with and then convert all to a polyline or is there another method. The other day you were talking about arcs, elipses, circles and splines and of those, only the spline seems relevant to this drawing. Is that correct?

(E) regarding the dividing operation, I'm still having problems with that too. Each time I try, it places the circles somewhere else but not along the line. Strange thing is that if I select one of the circles it then highlights a small square along the line in the corresponding position. Any idea what I might be doing wrong? Here's my input:
Command: divide
Select object to divide: (I selected vertical line)
Enter the number of segments or [Block]: b
Enter name of block to insert: testblock
Align block with object? [Yes/No] <Y>:
Enter the number of segments: 10
Thanks

[ger21]

A) I wasn't very clear. What I meant, was, that when you use the offset command, it remains active, letting you offset as many objects as you like without having to restart the command. You still have to click on both lines and offset them seperately, but it is very quick and easy.

B) You're right. Use "list" like I explained above. (The length does show up in the properties dialog in ACAD 2006 )

C) If I wasn't clear, what I meant was would a series of short, straight segments be acceptable.

D)I'd have to see what you we're tracing to say for sure, but for free flowing curves, using splines is very fast for tracing images. and they are very easy to edit; by moving the grips around, you can fine tune the splines after they are drawn. Just don't skimp on the points while tracing, or you may be limited. If you didn't know it, while drawing splines (or polylines), if you place a point you aren't happy with, just type "u" and enter, and the last point will be removed, but the command will still be active. This works in other commands, too. If you're trimming lines with "trim", and you accidentally trim something you didn't want to, just "u" enter.

If I'm tracing something that I'll be routing, I try to use arcs whenever possible, to minimize all the short, straight segments. But in reality, it really doesn't make a lot of difference.

If you haven't already, download the spline to polyline lisp, that's the easiest way to go. If you don't know how to use it, or would like to know how to use it without having to load each time, let me know.

E) In my previous reply, you missed a very important piece of info. "Choose the center of your circle for the baasepoint". When making a block, there is a set of coordinates labeled basepoint. Click on the "pick" button and choose the center of your circle. This is the location relative to the circle that is placed along the line. It is called the insertion point of the block. The small square you see is the grip for the block when it is selected.

You did the command correctly, you just didn't set the basepoint in the right place when you created the block.

[mxtras]

I have rarely had ANY luck using Splines for machining/programming - what's the fixation with Splines?

I stay away from them because they aren't compatible with code generators (at least in the past). I prefer creating filleted polylines or lines and arcs.

Am I missing something? Of what use is a Spline that can't be duplicated with a polyline?

Scott

[skippy]

Scott, unless I'm missing something, the example above using free flowing curves (testblock.dwg) could only be drawn with splines and then for the purpose of machining, it would have to be converted to a polyline with the spline to polyline lisp Gerry mentions above. However in saying that, I must state that I'm a relative novice at this.
Phil

[mxtras]

Skippy -

I guess what I am saying is that I would generate the shape using the fundamental entities that you end up having to convert to. I guess it's just a different philosophy. That shape CAN be drawn very precisely using basic entities. You are not forced to use a spline.

Every code processor I have used craps out on splines, so I quit using splines many, many years ago to generate math data.

It looks like this converter might take that constraint away.

It's hard to teach an old dog new tricks!

Scott

[mxtras]

Of what use is a Spline that can't be duplicated with a polyline?

That doesn't sound quite the way I meant it - let me re-word that a bit:

Of what use is a Spline when the shape can be duplicated with a polyline?

That's better.....I think!

Sorry, guys!

:withstupi

Scott

[ger21]

I guess what I am saying is that I would generate the shape using the fundamental entities that you end up having to convert to. I guess it's just a different philosophy. That shape CAN be drawn very precisely using basic entities. You are not forced to use a spline.

You can draw (and edit) a spline far faster than you could duplicate it using lines and arcs. Actually, it would really have to be with arcs alone. And it would be very difficult to make sure all the arcs are tangent to each other, so you don't get corners. In AutoCAD, you CAN use the arc command to draw consecutive tangent arcs, but it can still be quite difficult to get the shape you want. Especially when hand tracing images, splines can take a fraction of the time. And with the lisp to convert them to ploylines, they can be a viable option. Depending on what you're trying to do.

Splines are not always the answer though, as converting them to short straight segments might leave an unacceptable edge finish.

[mxtras]

The projects I worked on were for the Automotive community and the data generated was valuable to create tooling, so it had to be smooth and accurate - choppy and fauceted data was absolutely not acceptable.

I hear ya on the speed issue - splines are faster than my methods - I agree - but I got so tired of the complaints from the pre-processor and the customers (and the machine tools), I found ways around it that would generate acceptable data - like using series of tangent arcs as you mentioned. Once PE'd and joined they aren't all that difficult to manipulate - you learn how many control points to position and where to place them and the data is readily accepted by other packages. I think this method creates very useable, exchangable data and when it's used to create code it doesn't turn the machine into a chatter box.

I always wished that you could explode a Spline into basic entities - but then this thread would not exist!

I was just offering my experience - I am always looking for better ways to get things accomplished!

Scott

[ger21]

You're right, Scott. For mechanical type parts, splines would really not be a good choice. But for artistic type stuff, they can be really helpful.

I always wished that you could explode a Spline into basic entities

You could always turn a spline into a polyline. Just save it as a V12 .dxf and then open it back up. V12 dxf's don't support splines, so they are converted when saved.

[mxtras]

You could always turn a spline into a polyline. Just save it as a V12 .dxf and then open it back up. V12 dxf's don't support splines, so they are converted when saved.

Thanks for the information! Excellent!

Scott