Offset behaviour in dynamic block on 90-degree curve with straight edges

[andrealmeida1]

I need to create a 90-degree curve with an internal radius of 500 mm and 50 mm tips. The idea is to start with one lane and be able to increase it with stretch to six lanes, for example.
The problem is that the command does not allow me to create the tracks as if they were offset from the first track (Pitch 85mm).
I am attaching a file with a drawing of a 90-degree single-track curve and the same curve with six tracks, so you can see what I want.
It also contains a dynamic block and the behaviour I achieved, which does not satisfy my requirements in the slightest.

The block should be able to create any curve between 1 and 6 tracks.
Can anyone help me?

[j.palmeL29YX]

@Brock_Olly 

AutoCAD LT has some limitations in using constraints in Dynamic blocks. After testing I can confirm that the current problem seems (I think so) to be one of this limitations.

@andrealmeida1 

Which AutoCAD version do you use? (That would have been my next question anyway.)

For your both information: I designed and tested successfully the block in AutoCAD 2026.1 (W.122.0.0)

[andrealmeida1]

My version is S.51.0.0 AutoCAD 2022, but the previous blocks worked perfectly.

[j.palmeL29YX · Accepted solution]

Unfortunately, I have to confirm that the last block does not work in AutoCAD 2022 (tested in ACAD 2022.1.4, S.182.0.0).

Since I no longer have full access to this old version, I cannot perform a more detailed analysis.

If you are interested, you can delete all visibility states (for testing purposes) and check whether it now works. But even if you find the cause of the problem, it won't help you—unless you upgrade to a newer version of AutoCAD 😉

Sorry, more I can not do for you. 

[andrealmeida1]

Thank you very much, Jurgen, I’ve learned a lot with your help! Let’s stay in touch for any future complex developments 😁

[andrealmeida1]

Good morning, Jürgen Palme,
I tried to create a new block , similar to the ones we’ve been making, but I didn’t get a very good result. Could you please check the block I made? It’s a matter of constraints. Also, when I change the angle, the block becomes very slow, I don’t understand why... Thank you.

[j.palmeL29YX]

Can you please describe the expected functionality? Which dimensions should the user be able to change, and which dimensions should adjust accordingly?

[andrealmeida1]

I’m attaching a new version. I managed to get the block operational; however, it’s not fully defined in the constraints. I’ve already tried using Autoconstraints, but the problem is that it locks the block and prevents it from working. Could you help me with this? What I mean is the angle, incremental by 15° between 15 and 90°. If I apply autoconstraints, I can’t solve it manually—it locks the angle.

[andrealmeida1]

Another bad behavior of the block is the extendable tip on the right side of the curve. It is incremental, in 5 mm steps, from 0 to 50 mm. It works perfectly when the curve is at 90 degrees, or as long as I don’t set it to '0 mm'. When I set it to 0 mm and then rotate it, if I try to increase it, it extends in the opposite direction. I’m attaching a video showing this behavior...

You can see that bad behavior after time 40 seconds on the video

[j.palmeL29YX]

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@andrealmeida1 wrote:

Could you help me with this? .

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I am currently busy with other things. Please wait until tomorrow. 

BTW: Using autoconstrain is the worst idea (with your lack of experience). I'd suggest to set the needed constraints manually. 

[andrealmeida1]

No problem. I’ve been analyzing the blocks you made and I don’t understand how you manage to make a point coincident with a line, other than at the midpoint or endpoints.

[j.palmeL29YX]

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@andrealmeida1 wrote:

Another bad behavior

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After a quick look: 

I's suggest to avoid the value of LPontaDir to be 0 (Zero). 

If possible/allowed to cheat a little, in the properties window (Value Set) set the Min Distance to an (for you acceptable) very small value, e.g. 0.0001

[j.palmeL29YX · Accepted solution]

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@andrealmeida1 wrote:

 how ... manage to make a point coincident with a line, other than at the midpoint or endpoints.

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To restricted slide a point along a curve, select the point and the curve (as an object, choose the option "Object" in the command line).

The point may be an end point or the mid point of a line or an arc, also the center point of a circle or an arc and others. The object may be a line, a circle, an arc, a spline, a polyline segment and others.

Example: 

[andrealmeida1 · Accepted solution]

Thank you, I need to pay more attention to the command line, I was going in circles and couldn’t figure it out. It solved the issues from the previous requests, messages 25, 27, and 28.

[j.palmeL29YX · Accepted solution]

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@andrealmeida1 wrote:

I’m attaching a new version. 

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See attached video. 

Green rings = Left mouse button click

Blue rings = Reight mouse button click = Enter 

Is this what you are looking for?  

[EDIT]: Oops, just in this moment I'm ready creating the video, now I read the you solved your issue yourselfe. So I'm to late  ;-))

[2nd EDIT]: In the video I forgot to add a vertical constraint: 

[andrealmeida1]

Thank you very much, it’s always worth watching videos of others doing it. I’ve learned a lot these past few days and already made some good progress in my learning about dynamic blocks! 🙂

[andrealmeida1]

I found a bad behavior when we have areas with hatch. I show it in the video. There was a time when, even with the hatch, it allowed selecting the points of the rectangle outside the hatch, but now it’s not working. I already changed the order, placing the hatch in the background, etc., but it doesn’t work. I only managed by assigning a layer to the hatch and hiding it... the thing in the shape of a rectangle is a block.

Any other solution for this?

[j.palmeL29YX]

To disable the visibility of the hatches seems to be a good workaround for this strange behavior.

BTW: I have often problems with grabbing reference points or objects of inserted subblocks (also such without hatches) while adding constraints - and did not yet find what causes this behavior nor don't know a solution.