Help with adding square hole to model for 3D printing

New to forum old guy

I’m stuck. Trying to precision model (for 3D printing) and
could use some help.

I’ll try to describe part. A Cylinder with a blind circular
hole from flat end along central axis. Non-pierced end terminates
at an ellipsoidal curve. This I’ve done and is not a problem.

I’m trying to now add a co-axial rectangular hole from the
curved end to intersect the (now) blind round hole coming
from the other end.

My approach is to spin (lathe) a 180 degree half section
from which I would remove one half of the rectangular section
from the half lathed object, then duplicate it, mirror and
paste the two halves together. This should work. However
I’m unable to figure out how to create the rectangular
hole part; I’ve tried unsuccessfuly to do it using
boolean objects and by trying to create a mesh joining
the round inner cylinder’s end to the elipsoidal end of the
outer cylinder.

I prefer using Blender 2.45. I’ve tried both 2.68 and 2.69
and both are buggy on my system and crash frequently
(are they video card dependent on acceleration)?

Oops, now I’ve asked two questions. Any help on either
will be appreciated.

Not even trying to picture that in my head. You would have saved half of the text by uploading an image of what you’re trying to do.
Show a screenshot of the model and its wireframe (in solid shading), perhaps put that it in an image editing program to draw what you want and where and then upload in here, or http://www.pasteall.org/pic/ and share the link.

Why 2.45? That is old even for old Blender. 2.49b was the last with the old user interface.
Blender uses opengl to draw the interface. If your graphics card or its drivers are so old/bad (I’ve had that with an old intel card) then there’s not much to do other than upgrade. If it’s a desktop machine, gamers throw graphics cards away that could be still used. Might not be good for games or capable of rendering with Cycles in GPU rendering mode, but still usable.

Thanks for your reply. Hope crude attachment explains what I need to accomplish.
<attach>tst.png</attach>

And also for confirming video card. I’m an old timer 78 yo, have never played an
interactive game on a computer despite working with computers and programming
since early '80s. 2.45 is old but, at least so far, has done all I need to do and I
did try newer versions, hoping there might be a solution to my problem there.

I really don’t want to learn a new interface but maybe I’d be better off with a
solid modeler?

Sorry, I’d like to help but there’s no way of getting to your attachment. If you upload to pasteall.org, you have to copy and paste the address here after the upload has finished so that there is a direct link to it, or use image attachment button on top of the text field.

That is very respectable.

Not sure if it’s the video card. I had to upgrade my computer when Blender 2.65 came out. It had an old AMD AthlonXP processor which didn’t support SSE2 which is now a requirement in Blender. It was about 10 years old hardware.

Can’t recommend anything without seeing what you’re trying to accomplish. It’s a shame that you can’t use the latest Blender though, because newer versions just included tools to do checks for 3D printing.

Edit: found this old post about square holes on curved surfaces, perhaps it can give some idea for what you’re doing http://www.blenderartists.org/forum/showthread.php?315708-Subsurf-Extrude-a-cuboid-from-a-cylinder-without-ruining-the-cylinder-s-form&p=2501707&viewfull=1#post2501707

Your attachment isn’t showing.

Thanks everyone for trying to be helpful. Noticed (finally) that I’m getting message that I’m not allowed to do attachments! Too much hassle. Thanks again.

Thanks everyone for trying to be helpful.

Noticed (finally) that I’m getting message that
I’m not allowed to do attachments! Too much hassle.

Thanks again.