topic Re: Help with rotation and sliding joints in Fusion Design, Validate & Document Forum

Help with rotation and sliding joints

tina_s_white — Mon, 27 Jan 2025 22:27:49 GMT

I am trying to contruct a lock that when you turn the knob at the top it moves two arms out at the bottom through two brackets. I have the basics down but cant get my head around the movement and joints (I have put slots in the wheel I know theuy arent correct but I dont know how to cut them so the move inwards like the first picture). Can anyone please help The first picture is what i am attempting to do, but only the two bars and no rails just the bar and it had a post and knob to drive the wheel. I am still very new to design and its all self taught so please be kind. Thanks

Link to model : Locking Mechanism

Re: Help with rotation and sliding joints

TheCADWhisperer — Mon, 27 Jan 2025 22:40:56 GMT

@tina_s_white

Can you File>Export your *.f3d or *.f3z file to your local drive and then Attach it here to a Reply?

Re: Help with rotation and sliding joints

Drewpan — Mon, 27 Jan 2025 23:00:00 GMT

Hi,

If you are new to design then this type of model is ambitious. You have suggested

that you have put in your slots but not actually calculated where they should be

precisely, this is bad design. You need to know exactly where the slots need to be

or the model will not work. Most commonly this method will lead to the mechanism

jamming.

What you can do is use your model to calculate the exact place that these slots need

to be. You know that at one end of the slot, the bar will be in the retracted position.

This is the first critical point. You also know that at the other end of the slot that the

bar will be in the extended position. Another critical point. Now you need to work out

another critical point to create the correct slot curve radius. I would suggest putting

the bar in the middle of these two points at the half way measured position and marking

this as the third critical point.

Once you have three critical points, it should be fairly straight forward to create the

slot by putting the diameter of a circle equal to the width of the slot around the three

points and joining them with an arc or curve.

In order to make your motion in the slot make the bar extend and retract you may also

need to set up a Motion Link between the two joints.

Cheers

Andrew

Re: Help with rotation and sliding joints

davebYYPCU — Mon, 27 Jan 2025 23:58:31 GMT

Determine how far the rods have to move (T)

and the angle the plate is turning to get that result, (A = 90 deg) and it is a simple centre point Slot

Circular Pattern count 2 for the other one.

Add dimensions to suit your application.

Might help....

Re: Help with rotation and sliding joints

jhackney1972 — Tue, 28 Jan 2025 01:09:24 GMT

Your link to your model does not have a Download feature. Either you are using a Fusion Personal License or you forgot to check the Download box on the Share screen.

If you do not know how to attach your Fusion 360 model follow these easy steps. Open the model in Fusion 360, select the File menu, then Export and save as a F3D or F3Z file to your hard drive. Then use the Attachments section, of a forum post, to attach it.

Re: Help with rotation and sliding joints

tina_s_white — Tue, 28 Jan 2025 11:14:48 GMT

Yeah I only have a personal licence so am restricted what i can download, I have a FBX file if that helps.

Re: Help with rotation and sliding joints

tina_s_white — Tue, 28 Jan 2025 11:15:44 GMT

only have a fbx (Personal licence)

Re: Help with rotation and sliding joints

tina_s_white — Tue, 28 Jan 2025 11:19:07 GMT

Yes I know it's ambitious but then I like to stretch my brain and theres nothing wrong with that. I have made some complex contraptions before using mainly ball and rotation joint combinations but this is a little more complicated which is why I am asking for help. I know the slots are in the wrong place, as mentioned, these are me remembering how to put slots in in the first place :). I just couldn't get my head around how to work out the positioning so the rods moved through the bracvkets.

All constructive help is always welcome. Thanks.

Re: Help with rotation and sliding joints

davebYYPCU — Tue, 28 Jan 2025 11:31:15 GMT

Can't make it any easier,

Extrude the plate, automatically has the 2 slots.

Move / Rotate the plate 90 degrees, and the slots match the layout sketch.

You already have the bars and pins.

Might help....

Re: Help with rotation and sliding joints

TheCADWhisperer — Tue, 28 Jan 2025 11:56:26 GMT

@tina_s_white wrote:
only have a fbx (Personal licence)

@tina_s_white

This kind of surprises me.

I thought personal license could Export *.f3d files.

Re: Help with rotation and sliding joints

tina_s_white — Tue, 28 Jan 2025 13:44:29 GMT

ok sorry been working on it and this is what i have. can you take a look see if it will work twist top spindle to retract bars .. I will probably need to scale it up a bit to strengthen it but see what you think. Thanks all.

Re: Help with rotation and sliding joints

tina_s_white — Tue, 28 Jan 2025 13:45:21 GMT

sorry see my last post ive done a bit of work thanks

Re: Help with rotation and sliding joints

TheCADWhisperer — Tue, 28 Jan 2025 14:30:36 GMT

@tina_s_white

I saw a large number of unresolved issues highlighted in your Timeline...

I also see unnecessary Moves.

No Sketches?

It will be necessary to start over.

Are you ready?

Re: Help with rotation and sliding joints

TheCADWhisperer — Tue, 28 Jan 2025 14:34:33 GMT

...also, you should make use of symmetry about the Origin.