Snap-to and hinge

probarbly some simply way already ,or create the tool as a default snap-to junction ,this started as a simple test drawing that has yet to conclude.To join multiple TETRAHEDRAN 's face to face , for structual studies, ,hours latter tangled-up with protractor angles ,I even attempted to use the physics hinge that obviously does not save , so an optional hinge ,or possibly the default snap -to points could be hindged if you then choose to GRAB a further point that resultantly hindges and snap-it , to a point or line . tho I consider the probem
with endles more tools ,is clutter and possibly infrequent use , so much better to be clever with wot-we-got,um, Jon trying ,(to be clear )

There may be a way of doing what you want already. If you share the SketchUp file we might be able to give you some guidance. What version of SketchUp are you using? Please complete your profile.

hinge snap joint.skp (212.7 KB)
see if I get this right ,
1/ snap yellow to red >black ball
2/snap green to yellow >1-2 brown ball
3/snap blue to green > move ball
these could be hinge (universal) by default till cliq> closed
4/grab black cone > hinge to yellow
5/grab brown cone >hinge to green
6/grab move cone >hinge to green (either edge)
all pending groupings

this file was just hurried ,my origials awaitig file recovery,
good news is I have managed to recover test 500mb
of erased files with cleverfiles recovery program and
await ± $60 to get the other ± 40gb Jon,

Do you also want to move the end cones and balls, or are they just to label the corners for your description?

This is what I see in your model.

Ignoring the endpoint markers for the moment… (I just deleted them)

When you do your step one, rotating the yellow pyramid, do you want the other two (green and blue) pyramids to move rigidly with yellow, then make successive moves along your arcs?

And having done that, do you want the triangular faces to meet, so if I were to rotate all three of yellow, green and blue together about the blue axis so the two black and nearer brown ball edges coincide, then rotate yellow, green and blue together along the black ball to black ball line the yellow and red triangular faces would meet?.

And so on for the other pyramids?

So they end up like this, with the triangular faces meeting on the whole face with the adjacent pyramid?


Or do you intend the whole thing to be a ‘universal hinge’ as you suggest in part of your post?

In that case do the pairs of pyramids only connect along one joint edge, but rotate freely about that edge?

I’m finding what you want to do, not entirely clear.

a typical Jon errour
1/ should read > red to yellow so no > yellow & green are stationary
this can be done with the present move tool
yes yellow + green (&blue) if grouped could hinge on black ball
to red ,this is all fair with present move tool
to hinge the yellow to the red face would be a snap to instead of
angle , although maybe the problems I had with the odd tetrahedron angles
was when hindging with the protactor ,not nowing or not finding the snap-to.
this was all a year ago l’will have to redraw the tets ,possibly a hinge (by default) can utilize the one tool without loss of normal move fuctions,
plus hinging blue to green is an undefined or odd angle

I’ve used just the Rotate tool (shortcut Q) first to get the edges to meet, then to rotate the pyramids about those edges.

This time I end up with something like this - where the dotted guide lines show the ‘hinge lines’ about which the pairs of pyramids rotate, and the arcs the plane of rotation.

From a different point of view…

But although you get three degrees of freedom, only two are orthogonal.

I’m still unclear what you intend this mechanism (? - if that’s what it is intended to be) is supposed to do.

Maybe I’m getting clearer, rereading your first post for the second or third time.

Another interpretation: “How do I join successive tetrahedrons face to face to build up a structure in space?”

One problem I see is that you have pyramids, not tetrahedrons.

Tetrahedrons have four (tetra) equal triangular faces. Your pyramids have a square base with four triangles rising up from it.

Did you really mean tetrahedrons? Or are your pyramids the shapes you want to join face to face? If the latter, only on triangular faces, or on matching square faces too?

Tetrahedra are much easier to join. Start with one (red) flat on its base, with a corner at the origin.
Move the second (yellow) corner to corner.
Rotate on blue where the corners meet to join the two along an edge.
Drag the protractor tool along the joined edge to set the axis of rotation, then rotate until the top of the yellow meets the top of the red.
The next one gets a little harder. Move the green one corner to corner where the red and yellow meet.
Rotate around blue axis where the three join to get the right hand green corner above the yellow corner.
Draw a triangle to define the plane of rotation to align the two faces
Align the Rotate tool centre at the triple join, and in the plane of the face (hover over the face, then use Shift to lock it), then rotate the green corner to the yellow

Delete the face
Rotate the green along the joined edge to face against either yellow or red.

That’s three joined.

And so on…

Is that any help?

I have to stop for the night - it’s after midnight in UK

Or make a ‘glue on any’…:wink:


Works well, Mike. I made the origin (at the corner of the red tetrahedron) the component origin, added Glue to Any face property, and it makes it much easier to link them face to face.
joining tetrahedra.skp (29.2 KB)

Worth noting, though, that tetrahedra can’t solidly tile space.

Though apparently a combination of octahedra and smaller tetrahedra can do so - see

Waiting for a response from OP to see if this is going in a useful direction for him.

1 Like

I deffinatly need more protracting practice …/ yes yes yes , you clearly remind me of this puzzel oragin
way back 1997 ,3 years of intense mental designing, tetrahedron to, as they say,fill-space , I could
not mentally solve ,and attempting to make DIY models never concluded the theory, so SU was just right for this, pending IC skills ,and now I no the answer to filling space (for mechanicle strength
studies of solids, tet’s would have been good, like stars in space) any way still left with a new puzzel ,
to possible change the normal MOVE tool into a HINDGE , with no possible loss,
when innitially joining ; yellow to red , ; ( note ,SU , to considers all junctions as HINGES )
point,/ as 1,when snapping yellow to red
correction red to yellow
there are now 2 hinges on the junction line
so it would now be easy (1 tool) continuity
to snap the red peak to yellow peak
the ability for single tools to be powerful ,so far ,I think is better than multiple tools ,although
obviously not SU proficient yet,
I have tryed many CAD programms and think SU has good FLOW for mid skill use , that in 3d
can match 2d drafting ,. There are a few other old posts here, or sketchUcation, all relavent to
the interactive flow , that I will try and refurbish 1// m-doc model dock for quick file referencing,
2// create a floating, relavent HOT-KEYS window,doubles as a FAST EDIT NUMBERS,
plus I was drafting ideas to manage the tool bar re plugin congestion, note ; there was some
possible similarity to a CHINEESE or JAPANEESE plugin found by a member , all a year ago
These test drawing for me , are all learn to do things I will need when creating design drawings ,
I must sort these problems out ,outside of more complex STUFF…another example is trying to create
a moving CONVEYOR BELT with PHYSICS , / my design focus is, the culmination of technology,
Jon 2020-02-17T00:00:00Z