Transistion from Fusion 360 to BrisCAD

fredericklim

In Fusion 360 I sketch on construction plane and then perform 3D modeling function like extrude, revolve. What is the equivalent of construction plane in BricsCAD?

Roy Klein Gebbinck

In BricsCAD by default all 2D entities are drawn in a plane parallel to the XY plane of the current UCS. With the Z coordinate of that construction plane being determined by the ELEVATION setting. You can use the _Ucs command to align the UCS. Or, alternatively, rely on the DUCS (Dynamic UCS).

Some useful hints:

1. Be aware of the WCS (World Coordinate System) and the position of the origin in that coordinate system. In many cases it is the most logical base point for your model.
2. Keep the ELEVATION set to 0.
3. Use the _UcsIcon command to make the UCS icon visible at the _ORigin.
4. To disregard the Z coordinates of snap points change the OSNAPZ setting.

fredericklim

I hope there is a BricsCAD for Fusion 360 user,

Here is some screen of F360, I disable the history feature, all direct modeling.
1. I create a cylinder.
2. Then I make a Construction Plan Along a Path, the path is the top circle. (What is the equivalent feature in BricsCAD?)
3. I draw a circle on the Construction Plan. (Is it possible in BricsCAD?)
4. Apply a fillet on top side of cylinder.
5. Extrude the construction plane circle symmetry with cut.
6. Create a Circular Pattern of the cut.

My questions is how to do the step 2, 3 and 6?

Roy Klein Gebbinck

2+3: See my previous post. Just experiment with the _Ucs command.
5+6: Create a solid, array with_ArrayClassic, and finally _Subtract.

To get a symetrical cut you will probably have to extrude in two directions.

fredericklim

I cannot fully understand how to use UCS to simulate the use of construction plane.

Any video or tutorial demonstrate that?

Roy Klein Gebbinck

Here is a GIF animation:

fredericklim

@Roy Klein Gebbinck said:
Here is a GIF animation:

Thanks so much for the GIF animation, now I can create similar drawing in BrisCAD.

If I want to change the number of objects in the array, or I want a different radius of the cylinder cutter, is it I have to undo and run all the functions (cylinder, array, boolean) again?

Roy Klein Gebbinck

BricsCAD is not a history-based modeler. To create a fully parametric model you will have to use 3D constraints and (sub)components. But BricsCAD does have the DMRECOGNIZE setting.

fredericklim

@Roy Klein Gebbinck said:
BricsCAD is not a history-based modeler. To create a fully parametric model you will have to use 3D constraints and (sub)components. But BricsCAD does have the DMRECOGNIZE setting.

What is DMRECOGNIZE? And how to use 3D constraints?

Roy Klein Gebbinck

DMRECOGNIZE?:
DMRECOGNIZE is one of many settings that can be searched and changed in the dialog of the _Settings command. It controls which similar features of the same solid will be recognized and automatically updated.
Example:
If the DMRECOGNIZE setting is 64 (= recognize cylinders and spheres of equal radius) and you have a plate with 4 holes with the same radius, a _DmPushPull operation on the cylindrical face of one of the holes will cause all the holes to change.

3D constraints?:
That is a hard question to answer. I suggest you look at the (online) Help and check the samples that are part of the BricsCAD installation. Jason has recently shared a nice example.

fredericklim

I encounter another problem, I draw a sketch and applied 2D constraint, after perform 3D solid revolve, my sketch and all constraints are gone!

Is that the sketch saved somewhere or gone?

Roy Klein Gebbinck

For a 3D model only 3D constraints should be used. And you should never mix 2D and 3D constraints. Up to now you have worked with a history-based modeler but BricsCAD does not work that way. In BricsCAD you first create 3D solids and then apply 3D constraints to those elements or features of those elements.

fredericklim

Yes I am struggling switching from Fusion 360 to BricsCAD. I tried to Google tutorials for BricsCAD but most are target for AutoCAD users.
I don't have experience in AutoCAD, so is BricsCAD not suitable for me?
Or where can I learn about 3D constraint modeling better? I read the Help it is just one page!
https://www.bricsys.com/bricscad/help/en_US/V18/UsrGui/index.html?page=source/10_Drawing_Entities/03_Drawing_Solids/10_03_05_3D_Constraints.htm

fredericklim

I learned about 3D constraint from BricsCAD Training Basic material, it blew my mind away. But still have problem I cannot figure out.

My problem is, how to simulate pattern constraint in parametric direct modeling?

Taking my example above, I want to change the number of cut, history based modeling allow me to set the number of the array in the history, or even I can suspend the feature.

In BricsCAD once I set the number of cut I cannot go back unless undo.

Roy Klein Gebbinck

@fredericklim:
What 'BricsCAD Training Basic material' are you referring to? Is it available on-line?

fredericklim

@Roy Klein Gebbinck said:
@fredericklim:
What 'BricsCAD Training Basic material' are you referring to? Is it available on-line?

I bought BricsCAD on CADREBEL, they provided the download link by email. Very good for beginner. I wonder why Bricsys not publish it online.

[Edit]
Found it on AERTWORKS website. Link is bottom right.

https://www.aertworks.com/support/

fredericklim

I encounter another problem, create a main solid object, then a polar array circle around the object.

I want to use the circle array to cut the main object. So I select Extrude, select the polar array entities, press Enter, I got "Invalid selection."

I tried another method, extrude to create the tool model first, then create polar array of the tool model, but then when I perform boolean subtract, I cannot select the polar array as ACIS objects, I have to explode the array, perform boolean subtract, and select the tool models one by one. Not convenient and not efficient.

What is the correct steps to do that?

Roy Klein Gebbinck

@fredericklim: Thanks for the link.

Some time ago I have used your original model (which is different from your last model) as a test case for BricsCAD's new array feature. I'll try to explain the procedure I have followed with a short description, an image and a drawing.

1. Open CutArray.dwg.
2. The solids are on the BC_SUBTRACT layer and are logically positioned relative to the WCS origin which will be the center of the array.
3. As you can see some parameters and 3D constraints have already been added.
4. It is important that you do not apply expressions to the dimensional constraints now, you have to create the array first.
5. Using the _Array command create an associative polar array, using the origin (0,0,0) as the center. Don't worry about the number of items, just accept the default.
6. BricsCAD now complains about lost constraints. But you can ignore this.
7. Using the information from the image change the parameters of the array and the expressions of the dimensional constraints.
8. You should now have a parametric array that can be controlled through the drawing parameters.
9. Save the drawing.
10. If you now _BmInsert this CutArray component 'on' a 'parent' solid it should create notches in that solid. Note that this can still be a bit buggy. Changing component parameters will not always lead to a correctly updated parent solid.

Please let me know if anything is unclear.

Patrik Sparrman

My take on this
https://drive.google.com/file/d/1NQyCC7GIFIDbFjaWCImQT6SWv5XF-hJI/view?usp=sharing

fredericklim

@Roy Klein Gebbinck said:
@fredericklim: Thanks for the link.

Some time ago I have used your original model (which is different from your last model) as a test case for BricsCAD's new array feature. I'll try to explain the procedure I have followed with a short description, an image and a drawing.

1. Open CutArray.dwg.
2. The solids are on the BC_SUBTRACT layer and are logically positioned relative to the WCS origin which will be the center of the array.
3. As you can see some parameters and 3D constraints have already been added.
4. It is important that you do not apply expressions to the dimensional constraints now, you have to create the array first.
5. Using the _Array command create an associative polar array, using the origin (0,0,0) as the center. Don't worry about the number of items, just accept the default.
6. BricsCAD now complains about lost constraints. But you can ignore this.
7. Using the information from the image change the parameters of the array and the expressions of the dimensional constraints.
8. You should now have a parametric array that can be controlled through the drawing parameters.
9. Save the drawing.
10. If you now _BmInsert this CutArray component 'on' a 'parent' solid it should create notches in that solid. Note that this can still be a bit buggy. Changing component parameters will not always lead to a correctly updated parent solid.

Please let me know if anything is unclear.

fredericklim

Thank you very much for the files.

I am not sure about step 10. Do you mean I have another model file and insert the object array into that file? After insert I cannot change the number of items in array.

Now I perform boolean subtract, select the main solid, press Enter, then I cannot select the array as ACIS object. [drawing3.dwg, CutArrayTool.dwg]

And how to control the array distance from center? I tried to create a sphere at 0,0,0. Add fix constraint to the sphere, then distance constrain between the item and sphere, then create the array, However as you mentioned above, all the constraints lost, cannot set the distance of items from center after created the array. [CutArray2.dwg]

Roy Klein Gebbinck

@fredericklim:

2 (numbers point to the description in my previous post):
Your solids are no longer on the BC_SUBTRACT layer therefore they will not subtract. Either the solids or the array they are nested in must be on that layer for the subtract mechanism to work. The _BmInsert command recognizes this layer and should automatically perform the required boolean operations.

7:
You have added a drawing parameter and 3D constraints instead of changing the parameters of the array. Please look carefully at the image, expand the 'Arrays' node in the Mechanical Browser, select the polar array en fill out the parameters as indicated.

10:
Yes, the _BmInsert command requires an external component file. But it is possible to change external components to local components.

fredericklim

In the CutArray.dwg I cannot found the BC_SUBTRACT layer, should I create it?

Actually I don't know what is BC_SUBTRACT.

Roy Klein Gebbinck

You are right. Looking at the model I now see that the solids nested in the array are actually on layer 0 and the array itself is on the BC_SUBTRACT layer. Sorry for the confusion. So you should create the BC_SUBTRACT layer and put the array you create in step 5 on that layer. For more info about BC_SUBTRACT please consult the Help.

I have attached the final model.

fredericklim

I found my mistake and correct it. I can produce the same result now. Thank you so much!

fredericklim

I found if I reduce the cap fillet radius the TubeRadius_7 will change to purple color. Increase the radius does not have problem, but increase than reduce will have problem. i.e. change the CapFillet to 12, then back to 10, the TubeRadius_7 turn purple. Is it normal?

[edit]
I also found if I increase then decrease the array diameter the subtract will not perform. i.e. change to 120 then 100. Enclosed is the result of the array diameter change.

And I got error "An unexpected error occurred. The application became unstable." dialog quite frequent. Should I file a support request?

Roy Klein Gebbinck

@fredericklim:
I have already sent in a support request concerning this model outlining several similar scenarios. But I have not encountered 'An unexpected error'. So reporting that last problem may be useful. Although perhaps it is the same as this problem?

fredericklim

@Roy Klein Gebbinck said:
@fredericklim:
I have already sent in a support request concerning this model outlining several similar scenarios. But I have not encountered 'An unexpected error'. So reporting that last problem may be useful. Although perhaps it is the same as this problem?

Yes, similar, it seems when I insert a component the Quad manual appear under my mouse cursor and the error pop-out, but BricsCAD not crash. So should be fine in future update.

Thank you very much for your help, really learned a lot from you.

fredericklim

In F360 I can create component from body, how to do that in BricsCAD?

I guess I found it, is it BMFORM command?

fredericklim

I encounter another difficulty.

In F360 I can easily sketch a profile and do a sweep along a path to cut the shape I want, I can able to change the cut shape as I can go back to change the parameter in profile sketch.

But I cannot figure out how to do with BricsCAD, enclose is the screen of F360 and the dwg of BricsCAD.

I create a constrained sketch just like in F360, but I cannot figure how to do that as if I move the sketch inside the solid model, I cannot select the profile to do the sweep.

Roy Klein Gebbinck

@Roy Klein Gebbinck said:
For a 3D model only 3D constraints should be used. And you should never mix 2D and 3D constraints. Up to now you have worked with a history-based modeler but BricsCAD does not work that way. In BricsCAD you first create 3D solids and then apply 3D constraints to those elements or features of those elements.

You cannot use 2D constrained geometry to control a 3D model in BricsCAD. Should your parametric 3D model require auxiliary 2D objects then you must use 3D constraints for those elements as well.