subtract solid copy without losing subtraction

[sdc]

Good evening to all,

I have a problem with a solid to which I extracted an internal shape, I explain better:
we take for example a tube made with a circle to which I subtract a circle of smaller diameter then extrude it and get a tube.
my problem is that when I try to copy the tube, autocad copies only the part formed by the outer circle and the result is that the copied tube becomes a cylinder. How can I copy the tube so that it remains such?
Obviously it is a more complex form of the tube.

Thank you all for your help.

 

[doking]

then you create two cylinders of two different and concentric diameters to which you will subtract to the larger cylinder the smaller cylinder so as to get a hollow cylinder or tube, obviously from this moment the smaller cylinder disappears and will remain only the hollow cylinder or tube, there is no more way to recall the small subtracted cylinder
If you need the smaller cylinder, you can copy a second, move it to a known size, subtract and move the cylinder previously copied to the same size so that it returns to the same position as the "mother" cylinder

 

[Cristallo]

Well... I just think you didn't take anything from anything before extrusion, so you just have 2 solids inside each other, but always 2 solids full.

How did you get the inside out before the extrusion? If you tell me the procedure, I can give you lumens on where the error is. because what you say can be done, but only under precise conditions.

 

[sdc]

then you create two cylinders of two different and concentric diameters to which you will subtract to the larger cylinder the smaller cylinder so as to get a hollow cylinder or tube, obviously from this moment the smaller cylinder disappears and will remain only the hollow cylinder or tube, there is no more way to recall the small subtracted cylinder
If you need the smaller cylinder, you can copy a second, move it to a known size, subtract and move the cylinder previously copied to the same size so that it returns to the same position as the "mother" cylinder

thanks for the prompt response.
so there is no way to copy a solid to which another solid was removed without changing shape?

 

[doking]

solid subtracted to another solid means that it has already changed shape, so if you copy it, you will still copy the solid resulting from the subtraction! There is no way to copy a solid and make it change shape at the same time.

 

[doking]

Well... I just think you didn't take anything from anything before extrusion, so you just have 2 solids inside each other, but always 2 solids full.

How did you get the inside out before the extrusion? If you tell me the procedure, I can give you lumens on where the error is. because what you say can be done, but only under precise conditions.

is an act to be interpreted

 

[Cristallo]

Doking... The friend didn't take anything, but he didn't notice.
are 2 solids inside each other, so when copying, copy only the outside.
There is only one way to subtract a flat figure (which is constituted by its alone on board) from another flat figure (with the same conditions). You have to turn them into regions. Afterwards you will subtract the small region from the great and you will get a moth region of "ciambella". then extrude the region.
but without passing through the regions, you cannot get a solid cable.

 

[doking]

Doking... The friend didn't take anything, but he didn't notice.
are 2 solids inside each other, so when copying, copy only the outside.
There is only one way to subtract a flat figure (which is constituted by its alone on board) from another flat figure (with the same conditions). You have to turn them into regions. Afterwards you will subtract the small region from the great and you will get a moth region of "ciambella". then extrude the region.
but without passing through the regions, you cannot get a solid cable.

in fact it is not that it is explained very well....... .

 

[GP.]

with premtrasc (_presspull) and clicking "between" the two circles you get the solid immediately.

 

[sdc]

are 2 solids one inside the other, so when copying, copy only the outside.rasform them in regions.

thanks for the answer
That's what happens. probably the mistake lies in the passage in which I extrude from how you explained to me why I first extrude the inner figure (the little one) then extrude the external figure (the big one), finally subraggo to the big solid the small one but when I go to copy this solid, fruit of the subtraction, I copy only the external one that returns to the conditions of origin that is to what it was before the subtraction (in a few words becomes full again). I hope I've explained a little better and apologize if I haven't explained very well in previous posts.
I'll try to post a photo tonight
thank you all very kind and helpful as always.

 

[doking]

I would say that it is better than to explain step by step the steps you do in the subtraction, ie I would do, button subtract, I click with the left key before the solid in this case the big cylinder, then right button that allows me to access a new selection and trifle with the left the small cylinder so as to get the big cylinder with a hole in the center of the same size of the small cylinder

 

[numero1]

If I remember well, I am very tired, there is a variable that allows to maintain the starting solids......... No matter what you did on him.
What does that have to do with anything? :
greetings

 

[sdc]

that is I would, button you will subtract, click with the left key before the solid in this case the big cylinder, then right button that allows me to access a new selection and trimming with the left small cylinder so as to get the big cylinder with a hole in the center of the same size of the small cylinder

is exactly what I do too..after the steps you listed select the solid (cylinder with a hole in the center) and I make copy..the result of the copy is a cylinder without hole because I probably cover only the external cylinder..how do I copy also the inner cylinder?
ps if I have understood correctly the inner cylinder disappears after subtraction and therefore I can no longer select it

Thank you for your help and apologize for all the time I'm taking you:redface: