Need Advice on Measuring/Modeling a Compound Angle Plane

alex_franke

Hi all. I'm a hobbyist and I'm trying to model a rigid enclosure for a motion sensor that sits at a specific compound angle... and I'm not getting very far so I'm hoping someone has some tips that might help point me in the right direction. 

The sensor is the half-sphere in this photo, and you can see it's both angled forward and twisted from the surface it's mounted on (near the letter Y). If the mounting surface XY, then I *think* I found the angles that the resulting plane sits compared to Y and X using an electronic level that's aligned along XZ and YZ -- the angle from X to red is 21 deg, and from Y to green is 32 deg -- I think this describes the new plane. But even if that's correct, I'm totally stuck on how to add that plane on Onshape. 

I tried using line-angle using a square on XY and got one plane using the X edge and another using the Y, but that was a dead end for me. Then I tried using line-angle for the X, then drew a new shape on the resulting plane and used line-angle again to try to find the twist angle, but somehow I feel like that's sending my former high school geometry teacher one step closer to her grave. 

Anyway, I'd appreciate any tips -- and thanks for considering this! 

steve_shubin

@alex_franke

Another way, is to make a mate connector that will act as a plane for you to model around, with this plane being at the compound angle you specify

To do that you could install @konstantin_shiriazdanov Multi Mate Connector tool (featurescript) into your set of tools

https://cad.onshape.com/documents/5d8da63844bedebe5cff72b1/w/96a36142be717fc84a504e3f/e/629230d0d394845d93416361

mahir

I'm sure there are lots of ways to do this using a combination of sketches, planes, and mate connectors. Here's one.

As far as measurement goes, you could just make a handful of point to point caliper or ruler measurements and pair that with some trig to get the angles.

steve_shubin

@alex_franke

Another way, is to make a mate connector that will act as a plane for you to model around, with this plane being at the compound angle you specify

To do that you could install @konstantin_shiriazdanov Multi Mate Connector tool (featurescript) into your set of tools

https://cad.onshape.com/documents/5d8da63844bedebe5cff72b1/w/96a36142be717fc84a504e3f/e/629230d0d394845d93416361

steve_shubin

@alex_franke

HOW TO INSTALL THE FEATURESCRIPT

Click on the link below, and then do what you see in the GIF

https://cad.onshape.com/documents/5d8da63844bedebe5cff72b1/w/96a36142be717fc84a504e3f/e/629230d0d394845d93416361

alex_franke

Thanks for the reply, mahir. It looks like this builds the second angle off of the first one. So the first bend is 45 deg rotation around X from the XY plane, and then the second plane is rotated 70 deg around the line that makes the first angle. The green angle (from the image) is 45 deg when I look at it from the right, but the red angle is 14.4 deg when I look at it from the front. 

To get to my numbers, I used your model, set the first bend to 32 deg and then fiddled with that 70-deg rotation until the view from the front was close to my target angle -- rotating the plane 65.5 deg got me to ~21 deg. This is close enough for me for all practical purposes, but I can't help but think it feels backward because I feel like I should be actually *specifying* exactly 32 and 21 somewhere and then ending up with the proper plane rotation. 

I think I'm just either thinking about this entirely wrong or I just don't remember the trig to get me there... Anyway, thanks for taking the time to help! 

alex_franke

That's it, @steve_shubin -- that looks like exactly what I needed. Thanks so much! 

mahir

@alex_franke Sorry, I thought that was how the angle was supposed to be constructed. Oh well. Glad you found a solution.

steve_shubin

@alex_franke

Your welcome
I'm glad to hear it helped