Trimming 3D Objects AutoCAD 2010

Firstly, I am pretty new to CAD and feel out of my depth and stupid. Secondly, I have tried the search function but have obviously not found the right answer for me.

Drawing up a bracket for a car (see attached). There is a rectangular box that passes through the middle of a hollow cylinder. I am trying to delete that part of the box that is inside the hole of that cylinder. Further, I am also trying to delete that part of the box which is on the outside of the cylinder (refer to attached drawing....I think it will make sense then!!!!).

Tried everything and just cannot work it out.

Please bear in mind that I am new to AutoCAD and very very new to 3D modeling so simple answers please???

Alternator Bracketv2.dwg

If I understand well, you need to retain only the common parts between cylinder and box – in this case INTERSECT command is your answer.

Regards,

I do not agree with the above posted answer.

I suggest a two step approach using an extruded circle to trim away most of the square tube from the circle followed by slice what little remains on the exterior of the circle using the surface option.

The end result looks something like this.

ReMark that is the result I am ultimately after. I did try slice with a surface but it did not recognise the surfaces as being such. Will take another look. Cheers

Sorry ReMark. Tried to do what you said but just cannot work it out. Can I have more detail (me stuoopid remember!!)? Cheers

It might be easiest to create the profile with simple geometry, turn it into a "closed" polyline and extrude.

I do not agree with the above posted answer.

@ReMark, you are right!

I usually don’t open drawings/files from unknown sources, so I based my recommendation only on OP's description; therefore wrongly supposed that he/she want to preserve only the common part(s). Seeing your sketch helped me to understand the real requirement. Sorry for inconvenience.

Regards,

msasu: There is no need to apologize. I've misunderstood a few posts myself.

Mk1_Oz: I'll see what I can do to clear up any confusion. I'll be back.

I hope this will help.

First two objects. Starting at the lower right you can see I've extruded a circle (blue) and subtracted it from the square tube.

Next three objects. This is where I used a line that I extruded to cut off a portion of the square tube. I used the Slice command and its Surface option.

Last object. Union square rod and circle.

A close up showing the surface created from an extruded line and the portion of the tube (yellow) that I erased after using the Slice command.

beautiful. that helps alot. many many thanks for your time!