editing / erasing part of 1 object in an array?

[emazur]

Hello,

First time poster here. I'm doing the exercises from the book "Discovering AutoCAD 2020" by Dix & Riley (I'm enrolled in Penn Foster and using this book but this is not a required exercise or project, just doing it for my own good). If you refer to the attached page below, it says to create the top half of an object, mirror it, and then create a polar array. After making the array, I'm to delete the bottom half of the object only on the extreme ends of the array. I know how to delete the the entire object(s) while leaving the rest of the array intact (ctrl + left click to select, then erase) but I don't know how to just erase part of an individual object and I've wasted too much time trying to figure it out. A workaround I found was to use the "explode" command (not yet introduced in the textbook) and then erase the bottom portion but this dismantles the array (and unless I'm mistaken, I can't "explode" just 1 object of an array). Another workaround I haven't tried but should work would be to delete the 2 extreme ends entirely and then redraw just the top half on each extreme end. But really what I'd like to do is what the book is telling me (3rd bullet point) I can do so I'm looking for some help

[Steven P]

So if I read this correctly, you have made an 'n' shape and mirrored it to get a brick shape? Doing this by the instructions will give you a top line, a bottom line and the end lines will actually be 2 lines? Each of these 4 lines will be from the top or bottom to the centre line / mirror line? ("draw half the brick only and mirror it")

 

So you should just be able to delete the 3 lower lines?

 

Can you post an example of the drawing you are working on - am sure that the solution is pretty simple - though like all these things, it is only simple when you see what you need to do.

 

 

This is how I read to make up the brick, made from 6 lines:

 

For the edges I draw them at the full length and then trim them to the temporary line - just saves me doing the sums in my head, though I think the correct way is to half the length of each and draw them from a temporary centre line at the correct length

 

 

Edited February 19, 2023 by Steven P

[emazur]

34 minutes ago, Steven P said:

So if I read this correctly, you have made an 'n' shape and mirrored it to get a brick shape? Doing this by the instructions will give you a top line, a bottom line and the end lines will actually be 2 lines? Each of these 4 lines will be from the top or bottom to the centre line / mirror line? ("draw half the brick only and mirror it")

 

So you should just be able to delete the 3 lower lines?

 

Can you post an example of the drawing you are working on - am sure that the solution is pretty simple - though like all these things, it is only simple when you see what you need to do.

 

 

This is how I read to make up the brick, made from 6 lines:

 

For the edges I draw them at the full length and then trim them to the temporary line - just saves me doing the sums in my head, though I think the correct way is to half the length of each and draw them from a temporary centre line at the correct length

 

 

 

You are correct (actually you helped me notice that I had not deleted the temporary line prior to the array, so I remade it). The drawing is attached. So now I'm at the point where the array is made and I'm ready to delete those 3 lower lines. The problem is I don't know how (my attempts lead me to erase the entire object)

chapter 5 drawing 5-1.WIP.dwg

[BIGAL]

When you array it can do 2 things make the objects as single objects or remember all the objects as if they were one item, if the latter then explode the array. pretty sure there is a variable you can set but I just hit explode.

[Steven P]

as BigAl, 'explode' the array tp get it back tot he components

 

 

 

If you get a group like this then often explode is a good start to get individual items

[Steven P]

Ahh I see my confusion here - I tend to use classicarray which doesn't group the objects but I prefer that interface