Setting Dimensions

tom_mort

Maybe I'm dense.  I'm new to onshape and CAD in general, but, I must be missing something.

I'm having troubles with things that seems like they should be very simple.

• I have gotten things as I want them, but, somehow they manage to change.
• I try to place an inscribed polygon on a face, but, I don't see how I can adjust the dimensions to what I want.  I can drag it to make it bigger as I place it, but, I don't know what the actual dimensions will be until I place it.  After that I can go back and get the diameter of the circle and change it, but, this moves the center point as well and it is no longer centered.  Isn't there some simple way to just change the dimension of the diameter?
• I also can't figure out how to adjust the dimensions of an extrusion I have already made.  I can toggle to sketch and select edit, but, when I select the measurement tool I can't get a length for the line I want to adjust.

There has to be a simple way to specify the exact dimension you want something to be is.  Just dragging to get it approximate is nice, but, there has to be a way to adjust it to the size you want or change it later for other reasons.

I've used Slimjet (a Chrome derivative) and Chrome for Linux.  Is there some sort sort of browser issue?

NeilCooke

Hi Tom and welcome to Onshape. Please follow the in-app tutorials or watch the videos on our website. All will be explained

tom_mort

The in app tutorial says to drag the polygon to the correct size and then how to select how many sides.  No mention of setting the exact size.

NeilCooke

Hi Tom, please see the videos here: https://www.onshape.com/learn/learn-cad especially the dimensions and constraints video.

tom_mort

Also, videos are fine, but, there is no sort of indexing that I can find.  Watching all the videos prior to doing anything on the hopes that I will remember a technique at some future time when I need it seems like a big waste of time.  Back in the day  when all there were was books if you wanted to learn new software, I always picked the book based on how big the index was since I would want to look up individual topics as I needed them and likely would not know the correct terminology.

I guess if someone took the time to make a good index of videos, including where in the video to go to find the answer this might work well.

Below is a link of a list of video tutorials as they appear on my screen (I can't post a screenshot here).  The tiles of each video are truncated and in all but one case, the actual topic of the tutorial is the part that is cut off: https://www.onshape.com/videos/topic/tutorials

TimRice

I believe this is the video Neil mentioned:
https://www.onshape.com/videos/dimensions-and-constraints

owen_sparks

tom_mort said:

Maybe I'm dense.  I'm new to onshape and CAD in general...

Hi @tom_mort

I was in exactly the same position as you a few months ago. 

(a) I found spending a few hours watching all the videos enabled both an understanding of specific methods (such as how to re-dimension a previously created feature) and as importantly gave a pretty good overview of what is possible, and what order to think about doing things.  Personally I'm glad I spent the time as it prevented a lot of frustration and dithering about at the beginning and just getting frustrated.  At a minimum have a look at sketches and extrude for starters.

(b) Periodically @cody_armstrong holds webinars on various topics.  I highly recommend that you attend his "Onshape Essentials" next time he runs it.  You'll get to see OS being used in real-time and be able to ask questions as he goes through it.  I learned as much from just watching someone familiar with OS using it as from the actual topics covered.  Oh it's free too.

This was all it took for me to be able to take the training wheels off and design whatever I need at work.  Often I'm pretty sure there's a better way to go about a feature than I've come up with, but those few hours were enough to provide sufficient info do just about anything.  After all you can build just about anything with a sketch, extrude revolve or sweep...

Cheers,

Owen S.