SolveSpace Logo SOLVESPACE -- parametric 2d/3d CAD
Examples
Tutorials
Features
Download
Reference
Technology
Library
Forum
Contact
USER FORUM

(you are viewing a thread; or go back to list of threads)

Can't locate the remaining DOF (by Henré Botha)
I'm trying to fully constrain a 3D shape to be tangential to a construction circle. I've extruded the circle (along with some helper lines) in order to give me enough points to constrain against. But no matter what I try, I always end up with 1 DOF remaining on the 3D shape, and I can't for the life of me figure out which DOF that is.

I'm attaching the files. Any ideas?

As an aside, the menu option "Show Underconstrained Points" doesn't seem to do anything. Is the point of it to help me locate DOF, and if so, how am I supposed to use it?
Wed Dec 8 2021, 10:50:22, download attachment column.zip
(no subject) (by Andrew)
You need to constrain the switch plate in both position and rotation, the latter no being easy to see. When an assembled item is to align with the axis, select an vector on it and the vectors at the bottom left, which constrains all rotations. If you want the assembled object at an angle, you can use parallel,lines and angles between line to fix its rotation. see attached files.

Analyze is not helpful in this case because it is the assemble object that is not fully constrained, rather than points in the drawing, (perhaps the developers could handle this with a message).
Wed Dec 8 2021, 11:51:42, download attachment column.zip
Describing remaining DOF, naming it, constraining it (by cmpxchg)
It would be nice if there is only 1 DOF left, to describe it and allow an easy way to create a new constraint. If there are more than 1 DOF left, there are way too many options and combinations to display.
But for a single DOF, for example, related to a complex linked object with an 'anchor' ([0,0,0] point in the linked object), it could be relatively simple:
- Rotation relative to an anchor -> browser symbolic link command to add angle relative to one of the three normals of the 'parent' object. (e.g. linking a gear obscured by other shown objects)
- 1D along a line -> constrain distance of anchor relative to 'anchor of parent object'
- 1D along a arc -> add angle constraint between two points on the curve and its center, OR distance between the two points
- 1D along a bezier curve -> impossible with solvespace, no datum can be constrained to a the curve or segment of it
Thu May 12 2022, 19:50:22
Post a reply to this comment:
Your Name:
Your Email:
Subject:
(no HTML tags; use plain text, and hit Enter for a line break)
Attached file (if you want, 5 MB max):
© 2008-2022 SolveSpace contributors. Most recent update June 2 2022.