Moving a model perpendicular along a spline

Henk_de_Vlaam

For a motion study I like to move a model along a spline while it stays perpendicular on that spline.
I do not succeed at this moment. The model does not follow the spline at all.
Is there already a way to do that with Onshape or do I have to wait?

Narayan_K

@ henk_d_v . You can do it by applying tangent and planar constrain between the part and spline.For that you need a curved or circular portion in part.

 

Henk_de_Vlaam

Narayan_K, thanks for your answer. Now I see your example I have to be more specific.

I like to examine the running of a kind of a rollercoaster train over its tube. The train rollers fits around the tube which is simulated by the centre of the inscibed circle. That centre should move over the centre line of the tube. See example.

When moving the disk in this example, he does not follow the bend but only moves up and down, even beyond the end points of the vertical spline segment.

john_mcclary

There is no path mate yet unfortunately. Or 3d sketches so you are limited.

Taking @Narayan_K 's concept a bit further.

create some parts that define the path, and mate parts to the faces. 
then hide the parts when your done.

see example:
https://cad.onshape.com/documents/d40f5136cf73e5f7c4501627/w/6884f21f1020aafa16405244/e/de9751c009595ff2cb0a907c

you can use the square piece as your mating surface for your actual part you want to follow the path. This is a hack obviously, but it should work for the time being. It takes fineness to get around the straight-up portion, into the spline portion, but it does transition.



Edit:

In hind-sight... You could probably do it with just the blue part and the red part...
I kinda over thought it a little with the yellow pin. But my lunch break was over run.. no time to refine it
Don't tell my boss :P

Henk_de_Vlaam

@john_mcclary, Thank you for spending your lunch time to this topic. Your idea is quite nice and worth to remember, but does not fully fulfill my needs.

Unfortunately your statement 

There is no path mate yet unfortunately. Or 3d sketches so you are limited.

is very true in this case. Especially the 3D-spline defined by coordinates with radii between the straight segments - the Creo pipe feature - is crucial.

I think I have to be patient and wait for these two features.