Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.

First time visiting? Here are some places to start:
  1. Looking for a certain topic? Check out the categories filter or use Search (upper right).
  2. Need support? Ask a question to our Community Support category.
  3. Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
  4. Be respectful, on topic and if you see a problem, Flag it.

If you would like to contact our Community Manager personally, feel free to send a private message or an email.


Create a Plane tangent to cylinder

I cant seem to figure out how to place a plane tangent to cylinder.
I am trying to place a .50 hole .25 deep on the main body of this model train for the smoke stack


  • Options
    PrachiPrachi Member, OS Professional Posts: 262 ✭✭✭
    I like to use mate connectors for holes as it lets me select several locations at once all tangent to the surface. It's another option than creating normal planes for each location. Locations are mate connectors at the end of each line.

  • Options
    alnisalnis Member, Developers Posts: 451 EDU
    edited November 2020
    Edit: Oops! I wrote this as @glen_dewsbury replied and didn't see his response. Sorry for the double post!

    There are a few ways to approach this. I made a copy of the model with some possible solutions. I'm sure there are also other ways to do it.
    1. Use the tangent plane custom feature with the cylinder and the top plane (probably what you're looking for)
    2. Make a sketch using an implicit mate connector offset from the end of the cylinder, then revolve (works well in weird orientations)
    3. Use a midplane for the cylinder, then revolve the sketch (simplest)
    As a side note, I recommend making your model symmetric about as many planes as possible right from the get-go to make these sorts of operations easier. Rather than having to construct midplanes and use dimensions, it will be easier to use symmetric extrudes, and your mirrors/sketches/etc. will be a lot cleaner. Here's where I would probably have modeled this part if I were to do it from scratch:

    There's also a great video that I know of for best practices when starting a new CAD model (it's for Inventor, but most of it applies to Onshape), but I'm having trouble finding it at the moment. I'll reply here if I do find it.
    Student at University of Washington | Get in touch: contact@alnis.dev | My personal site: https://alnis.dev
  • Options
    steve_shubinsteve_shubin Member Posts: 1,070 ✭✭✭✭

    Here is another way to do it

    1. EDIT Sketch 3 — add a point at the apex of the arc
    2. Now make your plane using the PLANE POINT type

  • Options
    loic_gaulinloic_gaulin Member Posts: 2
    All of these answers helped me, but I took them and found a slightly different way because I have non-cardinal orientations.  I started with Prachi's mate connectors and was able to get that to work, but it took longer than I wanted to repeat over and over due to having to orient and move each connector.  I then took Steve's idea and ran with it.  

    By making a sketch that has the curve I need planes tangent to, that has radii lines at the appropriate locations, I was able to create a line tangent to the curve (using the tangent constraint and starting the line where the radius line meets the curve) at the required locations.  Using the "line angle" plane, it was a simple matter of picking the correct line and setting the angle to get the plane tangent to the curve (here i had to rotate by 90, but the first two required no modification). 

Sign In or Register to comment.