topic Re: Twisted patterns along a path in Fusion Design, Validate & Document Forum

Twisted patterns along a path

hs1444 — Thu, 31 Jan 2019 14:01:23 GMT

Hello all,

I'm trying to design various miniature roller coaster track sections which will be manufactured and assembled later on.

These consist of two rails and a central spine, with spoke-like shapes connecting them every 50mm or so.

Making straight and arced rails has been relatively straightforward with sweeps for the rails and patterns along a path for the spokes, but I've run into difficulty getting this to work for a twisted section of track, as you see below:

As you can see, the sweep is able to twist through 45 degrees but I don't see any option to twist the spokes along their path so that they align with the rails and spine.

I've heard some rumours that i'll need to get to grips with inventor to be able to do this but I would appreciate it if anyone has a suggestion for a workaround (even if it seems tedious it will probably take me less time than switching over to inventor and getting set up on it)

Thanks very much

Harry

Re: Twisted patterns along a path

chrisplyler — Thu, 31 Jan 2019 16:31:57 GMT

It is unfortunate that Pattern-on-a-Path does not allow for a Guide Rail or a Twist Angle.

Re: Twisted patterns along a path

cekuhnen — Thu, 31 Jan 2019 17:14:50 GMT

@hs1444

To my understanding this is one of those geometry types Fusion traditionally is weak at because Fusion is more supposed to be for mechanical design less for 3D modeling in general.

Re: Twisted patterns along a path

chrisplyler — Thu, 31 Jan 2019 19:04:45 GMT

I'm pretty sure this is mechanical/structural design.

Re: Twisted patterns along a path

davebYYPCU — Thu, 31 Jan 2019 22:15:55 GMT

Emphasis on 3d, not mechanical.

@hs1444 tedious, may be, but doable,

Use pattern for points / articles along the Path, where the strut component can be pasted, and aligned.

Depends on how the file is structured, but can be done with little steps.

Might help....

Re: Twisted patterns along a path

cekuhnen — Thu, 31 Jan 2019 22:30:29 GMT

@davebYYPCU

Doable but with such a painful workaround I am not sure if it is advisable.

fusion main shortcoming is already that it is pretty weak with 3d sketches.

a 3d sketch could be used here along which in even intervals he puts planes along path

on those planes he can position the sections and then use them as helpers to create the 3d sketch for the rail pipes.

my comment about fusion modeling tools is that it is rather focusing on basic to medium complex shapes. Bend and twisted shapes are already pushing it.

for this real 3d modeling sketching tools are needed

...

Re: Twisted patterns along a path

davebYYPCU — Thu, 31 Jan 2019 22:53:59 GMT

Ah, he has the 3d Sweep for the spine and rails,

what he hasn’t got is the way to incorporate the spacer strut.

My suggestion, is to copy, paste, rotate the stunts in positions, from a pattern on the same path. I have not tried to pattern a Joint Origin, but might be the simplest, plane on path, then Joint Origin, then paste component, and rotate. Tedious, but doable. An API job.

Implementation, is file dependent.

I also agree with your 3d modelling sentiments.

Re: Twisted patterns along a path

davebYYPCU — Fri, 01 Feb 2019 00:02:34 GMT

Just having play around, I can get a twisted pattern.

The 3d sweep is in the first component. I extruded two struts in the second component,

Played with the Pattern settings, and the simple one here has worked, (press ok, was OK.)

Trash my workaround, and Joint Origin is not selectable.

Might help...

Re: Twisted patterns along a path

chrisplyler — Fri, 01 Feb 2019 13:42:58 GMT

I don't think that is twisted. Bent in one plane, sure. Twisted, no.

Re: Twisted patterns along a path

davebYYPCU — Fri, 01 Feb 2019 14:00:25 GMT

Your right, I had no twist in the sweep originally, however when editing the feature changed to 10 deg, and probably cancelled instead of confirming the edit, of course I missed that at the time.

Sorry to mislead, as the pattern is not now following the twist.

Re: Twisted patterns along a path

cekuhnen — Fri, 01 Feb 2019 14:16:11 GMT

Regarding twist it was a general comment not specific only to his design

Re: Twisted patterns along a path

hs1444 — Fri, 01 Feb 2019 19:12:03 GMT

Thanks everyone so much for your suggestions. I'll have a go doing things manually and report back.

Re: Twisted patterns along a path

Anonymous — Fri, 01 Feb 2019 19:37:51 GMT

Im doing the same thing as you, but I resorted to using flexible track pieces instead of the sturdier fully printed track pieces.

Re: Twisted patterns along a path

jttrachsel — Tue, 18 Jun 2019 20:36:08 GMT

My workaround for this problem (no twist in pattern along path) was to sweep a second profile with the same twist as the first but with the section of the "struts" as a new body. I then placed construction planes with plane on path at regular intervals of the strut sweep, offset those planes with the strut thickness, multiple split bodies on the strut sweep, removed the unwanted strut sweep bodies and finally combined all bodies. Worked for the limited number of struts I needed.