topic Re: Tricky slider joint problem in Fusion Design, Validate & Document Forum

Tricky slider joint problem

xxmisiekxx — Sun, 01 Oct 2017 14:44:22 GMT

Hello

I need some help with this joint. I would like to create sliding joint where surface of roller (blue) slides along rod (red) and I'm struggling to find a way to do it.

Any suggestions please ?

Re: Tricky slider joint problem

lucasliraAU — Sun, 01 Oct 2017 15:06:39 GMT

Hello Friend!

In this video a great explanation of the type of movement that you intend to implement in your project.

I hope these guidelines help you to keep up!

Re: Tricky slider joint problem

xxmisiekxx — Sun, 01 Oct 2017 15:14:34 GMT

Thank You for quick response.

So long story short i should align components and then use as build slider joint ?

Re: Tricky slider joint problem

xxmisiekxx — Sun, 01 Oct 2017 18:06:11 GMT

Could i ask for help with how to align those to components. i cant to figure it out

Re: Tricky slider joint problem

beresfordromeo — Sun, 01 Oct 2017 23:11:36 GMT

I might be able to help you but could you provide a public link to that part of your file.

Re: Tricky slider joint problem

beresfordromeo — Mon, 02 Oct 2017 00:26:17 GMT

I take it that you are relatively new to joints so I hope I am not patronising you.

You don't need to use an as built joint to do this and in any event aligning and joining are to some extent the same thing. I presume that the problem you are having is because you are trying to join a cylindrical shape with a slider joint on its cylindrical face to the cylindrical face of another cylindrical component. I don't think that fusion allows this because it does not have sufficient reference geometry to make the slider joint you are looking for.

You could try using the flat face of the extrusion component that is in your model instead of the red part and changing the axis of your slider from Z to Y and also using an offset to get the wheel into place on the red part of your model.

Alternatively you could consider using the flat face of the carriage part of your model for the slider joint onto the flat face of the extrusion part. This is an ideal match for a slider joint. You would then need to add the relevant offsets to get your wheels (blue part) to line up with the red part.

If you wish you animate the wheels you could add revolute joints and use a motion link between the slider and the revolute joints to make the revolute joint spin the wheels. The ratio between the joints would be determined by the circumference of the wheel where it contacts the red part on your model.

Hope this helps.

Re: Tricky slider joint problem

davebYYPCU — Mon, 02 Oct 2017 03:34:39 GMT

This has been done in previous threads, but would not know how to search for them,

You will need to think of the correct location for the Joint origin.

For a wheel, place it between two faces Sides of the wheel, on the axle,

For the smooth rod, axis of the cylinder,

then use an offset to stand the two apart, correct distance.

We can do it if you export the file, and attach it here.

Re: Tricky slider joint problem

SaeedHamza — Mon, 02 Oct 2017 06:50:55 GMT

You can easily set it into position and then use an As-Built Joint

And also you can make a motion link between both the slider joint ( the as-built joint ) and the revolute joint of the wheel, so that when the wheel slides, it rotates as well

Regards

Re: Tricky slider joint problem

SaeedHamza — Mon, 02 Oct 2017 06:59:15 GMT

Re: Tricky slider joint problem

xxmisiekxx — Mon, 02 Oct 2017 18:19:23 GMT

http://a360.co/2yEiBHH

Re: Tricky slider joint problem

xxmisiekxx — Mon, 02 Oct 2017 18:58:50 GMT

Thank You for all your replies.

I must admit I'm absolute beginner when it comes to cad modelling. I always was more of pen and paper guy. Overall i probably have about 30 hours of experience in this field.

I'm in process of designing kind of hybrid cnc/laser engraver and decided to do it using Fusion 360.

This type of sliding compound will be used a lot in my design and i would like to learn how to align those rollers in a way that they are touching rod with this curved surface.

I managed to make joint like on video but only when I extruded rod from sketch i used to create revolve cut on bearing. But if i create rod separately in different position i still struggle to position it properly .

Here is public ling to this part : http://a360.co/2yEiBHH

Re: Tricky slider joint problem

davebYYPCU — Mon, 02 Oct 2017 21:26:51 GMT

I made a slide joint to simulate the action you want,

used the lower edge of the moving plate, and the axis of the smooth rod, as joint origin positions,

I am not able to completely finish off the Joint offsets, until you fix the positions of the blue wheels,

see pictures.

It doesn't have to be wheel to rod, you can offset the set with the edges of the plate and rail, if you know their dimensions.

Re: Tricky slider joint problem

beresfordromeo — Tue, 03 Oct 2017 02:40:08 GMT

I think that building an as built joint would not have been an easy task and exact alignment would have also been tricky.

I recorded a screencast for you which hopefully will give you an absolute way of aligning. It is a bit complicated but it really does the job properly (I am no expert).

First thing I did was turn on capture design history (right click top component). I then made the carriage a rigid group and did the same for the rest of the model, extrusion, rails etc. This makes everything move together.

I clicked on an straight edge on the carriage and (shift) clicked on an similar straight edge on the extrusion to select both, then right clicked and selected align components. This was important to get things lined up from the start because the carriage was slightly out in rotation also. If you capture position at this point things will stay lined up and you can carry on moving the groups around.

I basically then activated the red rod component, created an axis through a cylinder/cone/tourous, on the red component, added a plane at angle to that axis, created a sketch on that plane and projected the intersection of the red component on that sketch. It is probably important to put that sketch inside that component so that the sketch moves around with the component.

I did the similar for the blue wheel; activated the component, placed a midplane between the outer edges, created a sketch on that plane and then projected the intersection of the blue component onto that sketch.

This gave me a centreline for the inside edge of the blue wheel that we want to line up exactly with the outer edge of the red cylinder component. I sketched a line (badly), pulled it longer and placed a tangent constraint between that line and the blue wheel intersect projection. I added a parallel constraint between that line and the projection from the red component.

Doing all this meant that I now had two parallel sketch lines that I could then (shift) click (to select both), right click and use align components. From here you can use an as built joint. Don't forget to ground a component in the 'red' group.

I really hope this helps you get a better understanding of aligning. It is really useful but needs a little input sometimes.