Curved Slider Joint

[Anonymous]

It would be cool to have a joint which is a slider, but can follow a selected curved line path.

To set it, one would select a line instead of a point, and then the joint origin would snap to the center of the guide line's length. Outer travel limits would be defined by the line's start and end points respectively, then the dialog would allow setting additional + and - travel limits within this range.

If the selected line is a closed loop or circle, etc, then provide a checkbox for unlimited circular travel, and/or start/stop distances or "phase angle" like a model train set, for example. Phase angle would be calculated by the length of the travel distance = 360 degrees; half the travel distance would be 180 degrees, etc. Or, you could use percentage of length as path waypoint references as well. I am sure someone already did this in other software, so look up examples to see how this kind of animal is mapped out to nice dialog box options.

[RandyKopf]

I have a current need for this. And it is similar to a cam follower but it's a slot I want a ball to track...

[tinkercad]

I'm trying to model an iris diaphragm and I think this is what I need to model the motion of the blade driving pins.

[haughec]

This is something that we'd like to do, but we have a handful of assembly tasks that need to be completed first.  Marking this as a Future Consideration.

Thanks,

Charles

[haughec]

Tracking this internally as FUS-26127.

[fourdimensionaldoors]

It may be helpful to take note of this:

Allow pin-slot joint to follow a spline (not just a linear straight line). [https://forums.autodesk....

and the detail mentioned about the difference between 2D [co-planar] and 3D splines [ball instead of pin] as references for a sliding joint.

This allows use of the already existing pin-slot joint to just follow a spline and only requires one less constraint for 3D splines as a path reference providing a more simple implementation, especially since everything else is already there, no new tools or joints are needed which helps keep complication and confusion down.

IMPORTANT: Also note that more commonly [in mathematics] what you mentioned would use a scalar for the parametric argument to determine position where Zero [0] is the primary position and One [1] is the final position so that if it is out of that range then it goes beyond those positions and if it is a closed loop then this would still apply cycling through that loop and also the value could be cycled in either direction keeping it within Zero to One creating the effect you mention which only requires minimal modifications to the already existing pin-slot joint for this functionality.  Also note that using a different value range like [360] degrees doesn't make sense for this and even for closed loops since there are an infinite number of loop shapes that are NOT a circle [again, infinite many], so that degrees does not apply, makes no sense, and is just confusing.

[fourdimensionaldoors]

[refurbished for clarity]

It may be helpful to take note of this from:

Allow pin-slot joint to follow a spline (not just a linear straight line).

================================================================

Allowing a pin-slot joint to follow a spline [and not just a linear straight line] is essential as currently there is no way to properly represent designs that use curved sliders which are A VERY COMMON MECHANISM [without resorting to turning on slow calculation intensive collisions].  Most of my designs have more than one of these and even the most hardcore workstations would struggle to handle these designs due to this issue.

An implementation of this type would have to discern the difference from a 2D and 3D spline in that a 2D spline could use a revolution based axial "pin" type of pivot, but a 3D spline would likely require a point 'ball' type of pivot since a coplanar reference would not exist to define the 'pins' axis [commonly perpendicular to the plane] and defining an arbitrary plane reference does not make much sense from a mechanical standpoint [unless defining a planar reference at each point in the spline].  Because I have not used any 3D slots in my designs and as a result have not heavily considered the full implications of such a thing, I cannot be certain if it would be better to not allow 3D splines or to allow them and change the pivot type to 'ball'.  My immediate notion would be to allow them so it isn't an issue down the road for those that would use it and since the implementation of this would just be one less restriction on the pivot axis.

In the 2D case it might also be handy to allow a point 'ball' type of pivot [instead of only an axial pivot] which, for certain designs, would reduce the number of additional joints to be defined.

================================================================

This allows use of the already existing pin-slot joint to just follow a spline and only requires one less constraint for 3D splines as a path reference providing a more simple implementation, especially since everything else is already there, no new tools or joints are needed which helps keep complication and confusion down.

IMPORTANT: Also note that more commonly [in mathematics] what you mentioned would use a scalar for the argument to determine position where Zero [0] is the initial position and One [1] is the final position so that if it is out of that range then it goes beyond those positions and if it is a closed loop then this would still apply cycling through that loop and also the value could be cycled in either direction keeping it within Zero to One creating the effect you mention which only requires minimal modifications to the already existing pin-slot joint for this functionality.

ALSO NOTE that using a different value range like [360] degrees doesn't make sense for this and even for closed loops since there are an infinite number of loop shapes that are NOT a circle [again, infinite many], so that degrees does not apply, makes no sense, and is just confusing.  Using the Zero [0] to One [1] range is THE common standard for good reasons and should be adhered to.

[fourdimensionaldoors]

[refurbished for clarity]

It may be helpful to take note of this from:

Allow pin-slot joint to follow a spline (not just a linear straight line).

================================================================

Allowing a pin-slot joint to follow a spline [and not just a linear straight line] is essential as currently there is no way to properly represent designs that use curved sliders which are A VERY COMMON MECHANISM [without resorting to turning on slow calculation intensive collisions].  Most of my designs have more than one of these and even the most hardcore workstations would struggle to handle these designs due to this issue.

An implementation of this type would have to discern the difference from a 2D and 3D spline in that a 2D spline could use a revolution based axial "pin" type of pivot, but a 3D spline would likely require a point 'ball' type of pivot since a coplanar reference would not exist to define the 'pins' axis [commonly perpendicular to the plane] and defining an arbitrary plane reference does not make much sense from a mechanical standpoint [unless defining a planar reference at each point in the spline].  Because I have not used any 3D slots in my designs and as a result have not heavily considered the full implications of such a thing, I cannot be certain if it would be better to not allow 3D splines or to allow them and change the pivot type to 'ball'.  My immediate notion would be to allow them so it isn't an issue down the road for those that would use it and since the implementation of this would just be one less restriction on the pivot axis.

In the 2D case it might also be handy to allow a point 'ball' type of pivot [instead of only an axial pivot] which, for certain designs, would reduce the number of additional joints to be defined.

================================================================

[jrnX56D5]

Yes, a joint that would follow a spline or path would be very useful.

It would give a good and easy way to do Bike or Cable Chain (which I've been trying to do the last couple of hours).

It could at the outset just be an add-on to the planar joint, but i would be cool on 3D-curves as well, so you could make corkscrewing roller coaster-like movements. Maybe with two rails so you can control your moving object's relative postion to the track/path...

[Scoox]

+1 Thanks for posting this feature suggestion, I would find it very extremely useful.

[ShayaGhanbar]

A curved slider joint, or also called Transitional Constrain in Inventor, is a very necessary tool to have in an assembly. I would very much appreciate to see this feature in Fusion 360!!

[Scoox]

Are the Inventor and Fusion development teams completely independent? With both products being under one company, it seems strange that Fusion lacks some key functionality that's been available in Inventor for years.

[ShayaGhanbar]

@Scoox As far as I know, Inventor and Fusion have to different and independent development teams. Here is what you can do in Inventor and unfortunate it is not available in Fusion:

https://www.youtube.com/watch?v=QKezL2zSvKU

[gdolbier]

I am looking to design a part that has a fan element, several blades are attached to a central pin joint, each blade has a pin on one side, and a curved slot on the underside. I'd like to be able to connect the face of the pin on one fan blade to the face(s) making up the base of the slot on the next fan blade. Ideally I would drive the top blade, and all the subsequent blades would open sequentially as their pins reached the limit of the slot from the blade above. (Watch an asian fan and close)

[RandyKopf]

It would be great to have support for a curved slider. This seems to be lost in the dust.

[gdolbier]

Completely agree, I think conjunction with "Contact limited to these two
surfaces" or "Contact limited to this face, and this set of faces"

[lure23]

Upvoted, in 2019.

Very well described, especially when enjoyed together with @fourdimensionaldoors first comment (preferred 0.0...1.0 range). I'm glad you brought in the unlimited circular travel, as well.

I'm creating a roller-coaster like design and this is the # 1 (only?) shortcoming that prevents it to be fully modeled using Fusion 360. 

@haughec Would you like to comment on the state of this, 2+ years down the road?