offset dimensions box

[eric@velmex]

Another offset problem,

When I enter simple equations in the offset box it just disregards them and resorts to the last dimension use.

This is often when I am creating from a 2d that uses ordinate dimensions. Seems like a feature that should work as it does in everyother dimension box.

 

[jc-s]

+1 This is very annoying and also means that you can't create a design that is fully controlled from a set of equations/constants.

The only way I've found to do this is to manually calculate all the offsets, knowing that if anything changes in the future these all need to be recalculated -- not exactly great.

Recently, I had to create a complex pattern and used several reference points on which to base the pattern. However, the reference points can't be driven by an equation - frustrating!

 

[bigseb]

... the reference points can't be driven by an equation - frustrating!

How are you placing the points? If you using planes and axis these can equation driven.

 

[jc-s]

How are you placing the points? If you using planes and axis these can equation driven.

"Insert Reference Point" from the ribbon. None of the options in this dialog seem to let you use equations. I have a single point that I'm using as the reference for all the other points. I've just tried creating an axis from this point to then use this axis as the reference, but I still can't use equations to create a reference point from this.

 

[simonb65]

"Insert Reference Point" from the ribbon. None of the options in this dialog seem to let you use equations. I have a single point that I'm using as the reference for all the other points.

Can't you just insert a reference point then dimension it from your single 'datum' reference point? then use the equation in the dimension!

 

[jc-s]

Can't you just insert a reference point then dimension it from your single 'datum' reference point? then use the equation in the dimension!

Yes, in a sketch this works. Indeed, it could be done like this, but it seemed better to keep the points visible at the top level to easily see what was going on (clearly visible points), rather than hiding it all inside several sketches. Also these points will probably be used later as references for other features.

I didn't want to push this off-topic, though. I think the main point is that EVERY dimension should be able to be tied to an equation, regardless of where it appears.

 

[idslk]

Hello @jc-s ,
i opened a blank part and choosed insert reference point:


i entered values to give the point the coordinates and pressed apply and then close.

After this i opened the EE and there they are:



So you can drive your reference point with the equation editor!

Not so difficult, or?

Regards
Stefan

edit:
Added Sample:

 

[bigseb]

"Insert Reference Point" from the ribbon. None of the options in this dialog seem to let you use equations. I have a single point that I'm using as the reference for all the other points. I've just tried creating an axis from this point to then use this axis as the reference, but I still can't use equations to create a reference point from this.

You can create a reference point using the interestion of an axis and plane. The axis is created where two planes intersect. The placement of the planes can be controlled by equation or global parameters.

 

[jc-s]

Hello @jc-s ,
So you can drive your reference point with the equation editor!

Not so difficult, or?

Regards
Stefan

edit:
Added Sample:
View attachment 30772

View attachment 30773

Yes, this works. But the point is that it's a cumbersome workaround. If you have lots of points trying to match up which parameters these correspond to in the EE gets confusing. Moreover, I'm sure I tried to do that and modify the equation, but as soon as you "edit" the point and the dialog appears, it trampled on the equation.

Just being able to have everything equation driven would make Alibre more consistent and more accessible to new users.

 

[jc-s]

You can create a reference point using the interestion of an axis and plane. The axis is created where two planes intersect. The placement of the planes can be controlled by equation or global parameters.

Yes, agreed. But this just adds even more reference geometry unnecessarily, adding clutter. So instead of a single point, I have a point an axis and two planes. So if I need 100 points .... you get the idea.

 

[idslk]

I need 100 points

from where do you get them? Are they from a 2D drawing? Are they from a list? Are they calculation results? Are they (groups of them) on different planes?
May there is a different more likable workflow...
Regards
Stefan

 

[idslk]

Seems like a feature that should work as it does in everyother dimension box.

that makes sense

This is often when I am creating from a 2d that uses ordinate dimensions.

Can you describe your workflow more detailed?
For me the "offset" is more a drawing help(it does not create any "Equations" at all) than a design function and therefore i don not use it often...
Regards
Stefan

 

[jc-s]

that makes sense

Can you describe your workflow more detailed?
For me the "offset" is more a drawing help(it does not create any "Equations" at all) than a design function and therefore i don not use it often...
Regards
Stefan

In this case I only need around 20 points or so. Each of these is used to define the centre of a sketch. The sketch is imported using the Catalogue tool, thereafter the imported sketch (which itself includes a centre reference) is constrained to be coincident with one of the points.

Each of these new features then becomes the source feature for a new pattern so that a more complex larger pattern can be created.

Ideally, this could be done with a single pattern if the tool could work with arbitrary complexity so that you could define (offset) coordinates for every instance of the patterned feature. A simple list of coordinates would be a good start, but ultimately if it could also be defined by a python script that would be best. Simple, effective, and only one item in the feature tree.

Maybe this should be another topic, but how would you create a complex pattern (of a feature(s)) where the source feature(s) is(are) easily adjustable and everything is parametric via equations?

 

[DavidJ]

Note: not only does the offset value field not link to equation editor, the value for an existing feature that has been offset can only be edited whilst the offset dialogue is still open. As soon as the offset tool has closed, any change requires the offset feature(s) to be deleted and re-created.

Just wanting to make sure you are aware of this limitation.

 

[Lew_Merrick]

Whereas I have used Stefan's approach many thing, I support jc-s's request for greater integration of Equation Editor values directly into any operation where a value is applied to a Feature. -- Lew

 

[bigseb]

Whereas I have used Stefan's approach many thing, I support jc-s's request for greater integration of Equation Editor values directly into any operation where a value is applied to a Feature. -- Lew

I think we all support that. Have you forgotten this thread?

https://www.alibreforum.com/forum/index.php?threads/alibre-team-please-add-this.21291/

 

[Lew_Merrick]

I think we all support that. Have you forgotten this thread?

Hi Sebastian -- Not really (though it did "slip my mind") I igure that it is worthwhile to "demand" the extensaion of isage for the Equation Editor values whenever the case arises. How else can I prove that I am a sharp as a drill and twice as boring? -- Lew

 

[bigseb]

Hi Sebastian -- Not really (though it did "slip my mind") I igure that it is worthwhile to "demand" the extensaion of isage for the Equation Editor values whenever the case arises. How else can I prove that I am a sharp as a drill and twice as boring? -- Lew

I like using global parameters and it bites that so many entry boxes don't allow for parameters/equations. The sooner they implement it the better.

 

[Lew_Merrick]

I like using global parameters and it bites that so many entry boxes don't allow for parameters/equations. The sooner they implement it the better.

Hi Sebatien -- At the risk of sounding more anal-retentive than usual; a parameter is a value that is determined either by (A) a calculation by an external function (read: equation) or (B) developed through an external database look-up. Otherwise, it is merely a variable vakue. Additionally in Alibre Design they are not Global else they would accumulate and apply to everything we do with Alibre Design. [Which is why I define them as Project Variables.] If you look at the Resource "SAE Tierod Hydraulic Cylinder Paper.7z" I added recently, you may pci up some "hints" of value.

On another topic, one of the things I am currently working on is a spreadsheet (currently only in Open Office Calc format) that will provide access to materials & types of sheetmetal and plate to generate the appropriate "Lockheed K-Factor" values. I am currently "limited" to US (American) values as I am decades out of date with German, French, UK, and other "standard definitions." If you have such data I hope you will be able to share it with me. -- Lew

 

[bigseb]

Additionally in Alibre Design they are not Global else they would accumulate and apply to everything we do with Alibre Design. [Which is why I define them as Project Variables.]

I'm pretty sure Alibre intended them to be global to a project, not Alibre as a whole. For my own purposes I don't have a list of values that apply to all projects; each is custom. That said, I would like it if global parameters could be opened from within a project to update values. To close all the windows and open the GP file to change values and then reopen the assembly/parts is a real schlepp.

On another topic, one of the things I am currently working on is a spreadsheet (currently only in Open Office Calc format) that will provide access to materials & types of sheetmetal and plate to generate the appropriate "Lockheed K-Factor" values. I am currently "limited" to US (American) values as I am decades out of date with German, French, UK, and other "standard definitions." If you have such data I hope you will be able to share it with me. -- Lew

Sorry, no. Not really my area.