Relocating the center of rotation for components.

[John_C_Hansen]

I do not know what caused my center of rotation to remain at the center of desk top rather than each individual leg. But now, I am unable to relocate each center for the legs. The legs now are created correctly but I just cannot move them easily or rotate them to where they must be located.

Can you please speculate what I did incorrectly that caused this?

Would you please tell me how to get back to where they belong and rotated correctly?

Thank you!

[jeff_strater]

What do you mean by "center of rotation"?  Rotation in the Move command?  Move Component or Move Body?  Or view rotation?  Joint rotation?

[John_C_Hansen]

The move/copy command. I want to rotate the left and right leg by 60 deg, and then move the right leg to where it belongs under the desk. 

[davebYYPCU]

Sorry - I am responding to @John_C_Hansen 

Easy to fix with Joints.

Appears to me that you would also be wanting a Mirror Assembly, not as you have it?

Might help...

[John_C_Hansen]

I found that in the move/copy dialogue there is an option to set the pivot point and while I was clicking on it I failed to hit the checkbox but I figured it out and I'm well on my way to finishing this project now.

[Drewpan]

Hi John,

WHY are you MOVING things?

If you want to make two components or assemblies join together you should use a JOINT. A joint will automagically

move the component to exactly the place you want it and fusion will consider those two components joined together

with whatever type of joint you have set. This means that if you actually DO have a reason to move something then

the whole jointed assembly will move together.

If you just simply MOVE a component to another position then all you have done is tell the electrons to display that

component at that point on screen AND caused fusion to do a full recalculation of the design up to that point,

including full recalculations for each and every other move you might have in the timeline up until the latest one.

This uses much greater processor time and resources than using a joint. Also, if you then subsequently do have a

reason to move the design, because the two components are not associated with a joint, the one you move will move

and the other one will remain in the original position.

Having review an earlier version of this design, I think you should have a minimum of the following joints to make

the desk actually do what you want it to do. I am assuming that the desktop goes up and down on the leg

assemblies.

Your Desktop should have a minimum of three Rigid joints to join it to the top of the sliding Leg Assemblies.

Your Leg sub-Assemblies appear to be made of two sides and a center piece that joins them together. These should

be a sub-assembly with three rigid joints.

Each Leg assembly is made up of two interlocking sub-assemblies. These interlocking assemblies should be a

Slider joint. The slider joint should be motion limited to how far you want the desk to move up and down.

The foot of the sliding assembly should be joined to the bottom of the sliding leg assemblies with a rigid joint.

The Feet should be the only components actually Grounded so that the desktop goes up and down. The alternative

is to Ground the desktop and the legs go up and down in space. The feet grounded will get the affect of the desktop

going up and down, the desktop grounded will make each leg go up and down independently.

For the purposes of the model the imported McM-Carr components lock the legs but this is not necessary in the

actual model unless you really want to make them do this. You can please yourself if you use a Rigid or Revolute

joint to join them to the appropriate leg assembly.

By doing what I have shown you, your model will show a desk on three sliding leg assemblies. When you move the

desktop the grounded bottom half of the legs will stay; the inside leg assemblies will go up together with the

desktop. The locking clamps will go up and down with the leg assemblies but not do anything else.

There will be no parts floating in space for no apparent reason. You will be able to make proper engineering plans or

drawings from the model and even program CNC if you want to.

What I am trying to say to you here is that the Move command exists but it is very rarely needed to be used when

modelling. You NEED to learn how joints work properly and use them instead. Once you learn how joints work your

modelling will be much better and you will actually KNOW when those rare occasions you actually need to move

things in a model is appropriate.

Cheers

Andrew

[John_C_Hansen]

Hello @Drewpan,

The simple answer to your 'Why" question is that I arrived at Fusion with an extraordinary amount heavy baggage after years of working in a variety of other software.

I agree that joints will ultimately be the tool of choice when I become familiar with them. But until then, tell me why the first word in "Move/Copy" is "Move"? How do you rotate things? Panning and orbiting the viewer does not solve everything. Every once in a while I use the Move/Copy to line things up. I am sure other new users do it as well. 

I simply did not have enough knowledge of Fusion to use joints on this project.

As pointed out by another forum contributor, my workflow stinks! (This is my description not his. He was incredibly polite.)

So, point me to a good on-line resource to learn joints that is NOT focused on moving parts. Point me to a good tutorial on mastering the workflow so that the Browser is logically structured. I got the Browser close to being useful, but it still deserves some work. I will surely do better on my next project.  Point me to a good tutorial where the presentation includes EVERY sketch being fully constrained and every component is logically named. AND the presentation does not include the use of any Move/Copy.

This project is born out of a need to make this desk for my two monitors and a teleprompter with room for the computer underneath.

At 75, I will never earn a living as a draftsman or a designer. But I still have a few projects to finish.

I am unable to find these tutorials on workflow and organizing the browser and reading the tea leaves in the timeline. Point me to your tutorials. Show me the PDF file that illustrates every icon used in Fusion. Show me the resource where I can search for every one of the 1488 commands and learn what they do while still being written in concise terms.

Thanks again.

-30-

[Drewpan]

Hi John,

I wish all of those tutorials existed but they don't. All I can point you to are the tutorials I know about that DO exist.

I do actually feel your pain. I came from an AutoCAD background that is drafting based and very different to any kind

of modelling, let alone parametric modelling, which is what fusion is. I learnt the hard way and got critiqued and

pushed quite a lot along the way. I am still learning a lot of things, I am far from perfect but I do have the basics

worked out by simply doing it and reading other posts on the forum.

When I came to the forum, RULE #1 and #2 already existed. After I had put in the hard yards I posted what became

RULE #0 about how to learn fusion. It is the only way to learn it. Pick something you like, practice a lot, recognise

that people like me are trying to help you. Trust me. You are not the first beginner who has gone through this kind

of battering by the forum and you will not be the last. Some of us are a bit blunt with our posts not because we are

nasty people on our high horses but because we are seeing ANOTHER post asking for help that many of the forum

has answered before many times. I still get pipped by some of the Gurus but I just learn and move on. Everyone on

the forum wants to help others using it.

Persistance is the answer. There are some good tutorials in the self paced learning about joints. Joints are not hard

to master but you do have to understand them first.

I must admit I was a little frustrated when I posted this last one because I had spent a long time going through your

file and critiquing it and telling you what needed to be fixed, only on the very next message I see you post you are

talking about what I just told you was the problem. Don't take it personally. I am Autistic and I am a bit blunt

sometimes too.

One thing that I think will help you a lot is to learn about As Built joints. These are where you design a part in the

place it goes and then instead of moving it around you tell fusion it is joined to another component already. What

many people do not realise is that you don't have to put all of your sketches on the three Origin planes. You can

actually put a sketch on the face of a body or component. This allows you to build you first part starting at the Origin

and then start building the next component where it actually goes in the model. In essence you have a portable

origin for each part. Another useful tool is to put an offset plane somewhere for your sketch. Same deal, put the

plane where you want the part to go; project some point from the rest of your model for reference and then start

sketching. Building in place is just one method of designing, the other one used the origin for all parts and you then

use joints to join them together. Some people use one, some the other and some use both. With experience you learn

which one is appropriate. Learn build in place to get the hang of it then move onto the other method and general

joints.

None of these techniques are advanced. They are the next logical step from where you are now, you just have to

learn them. One of the things I have always said to beginners is that time spent doing the tutorials and self paced

learning is NEVER wasted time. There are certainly things I do not know about fusion. I am an engineer only a

couple of years from College. There are some very experienced people on the forum but most started somewhere

and all have gone through some or all of the pain you are currently going through.

Keep practicing things you like to do. Keep asking questions. Keep learning. You will be fine.

Cheers

Andrew

[TrippyLighting]

@John_C_Hansen I wonder if you even looked at the model I posted in one of your threads yesterday. That model answers al the questions you had so far 😕

If you have questions in respect to that model, you should ask them!

[g-andresen]

Hi,

Joints are not the devil's work if you are concerned with their behaviour.
You can watch it at your leisure in the screencast

günther

[John_C_Hansen]

This version now has the sliding joint that works as I intended it to work.

The three 'feet' and three lower legs are pinned so they cannot be moved.

The desk top has a sliding joint that allows 4 inches of motion per my design intent. And the three upper legs are grounded(?) to the desk top.
Again, thanks to everyone for helping me accomplish several "firsts" in my use of Autodesk Fusion.

I will post picture in a few weeks when I have finished building the actual desk. Some of the components have already been cut. I paused in the construction  of the desk to do this design to verify that everything actually makes sense to me  and fit together properly. 

[TrippyLighting]

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@John_C_Hansen wrote:

...

The three 'feet' and three lower legs are pinned so they cannot be moved...

... And the three upper legs are grounded(?) to the desk top.

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Wrong workflow!!! 

[TrippyLighting]

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@John_C_Hansen wrote:

I found that in the move/copy dialogue there is an option to set the pivot point and while I was clicking on it I failed to hit the checkbox but I figured it out and I'm well on my way to finishing this project now.

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I've unmarked this as the solution.

It might have temporarily "gotten you by" but it isn't a recommendable workflow.

That same applies to the last model you posted.