Jump to content

isometric fillet


KasbeKZ

Recommended Posts

i did search and find several questions about isometric fillets, but none of the suggestions have helped me in my particular drawing.

 

i hope i've done the attachment properly. what i am trying to do is fillet (with radius 5) the other two corners of the triangle in the very middle of the drawing. it is a triangle cut out of a 3-D plane, so i haven't been able to follow my usual procedure on two of the angles. i usually will draw from the corner out 5, then in 5, and have the center of my ellipse. but that will not work with these acute angles. that process causes the ellipse to overhang the triangle no matter which way i do it. any help will be greatly appreciated and i appologise for my poor description.

isometricdrawing.dwg

Link to comment
Share on other sites

I don't draw in iso so I would not be much help regarding your question but, personally I would draw the part in 3d which would solve your fillet problems and allow you to plot multiple views with a single model.

 

KC

Link to comment
Share on other sites

thanks for the suggestion. i would do that, except for the fact that everything is completely done except for that fillet and i'd really rather turn it in without than start over lol. thanks though. i'll experiment with that next time

Link to comment
Share on other sites

  • 8 years later...
9 years later and still no solution:(:(:(

 

As Kencaz mentioned previously, create a 3D model and then you can view it from any angle and you won't have to spend a lot of time and effort trying to figure out fillets and whatnot.

 

I created this model in about 20 minutes. Obviously I don't know any of the dimensions so I had to just guess, but now that I have the model I can spin it around and view it from all angles. Unless you're using Autocad LT and don't have access to the 3D modeling tools, there's no need to fool around with isometric drawing. Just my opinion. ;)

Part.jpg

Link to comment
Share on other sites

9 years later and still no solution:(:(:(

 

Look at drawing arcs and circles in oblique. A good technical drawing or engineering drawing book should describe the method.

Link to comment
Share on other sites

See THIS and THIS for starters.

 

I still do piping ISOs in 2d, just depends on what's quicker, I have lots of ISO blocks for piping. Something like the OP example is just too easy to draw in 3D and use views.

Link to comment
Share on other sites

Thanks, SLW. Wish I'd known about ISODRAFT sooner. Last time I needed an isometric curve, I rotated my UCS, drew a circle, and rotated it. Clunky, and you can't do much with the circle when it's in a non-World UCS.

Link to comment
Share on other sites

Here's some food for thought when thinking about isometric ellipses. You may not want to use this approach as it is labor intensive but I offer it as potential solution.

 

An isometric ellipse has three axes that are of interest (see image below).

Major radius (cyan line)

Minor radius (green line)

Conjugate axis radius (yellow lines)

 

The magnitude of the conjugate axis is the effective radius of the circle that is being viewed at an isometric orientation.

 

For circles that lie on principal planes of an isometric drawing the ratio of the conjugate axis to the minor or major radius is a fixed value as follows:

 

minor radius / conjugate axis = sqrt(2)/2

 

major radius / conjugate axis = sqrt(3/2)

 

Therefore to create an isometric ellipse that has a conjugate axis of 5 we have:

 

minor radius = sqrt(2)/2 * 5 = 3.5355

 

major radius = sqrt(3/2) * 5 = 6.1237

 

Creating an ellipse with these values for the minor and major radii will yield the desire fillet arc of 5.

isoellipse.JPG

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...