2D Helix

[DBC]

Alibre doesn't seem to have the capability of creating a 2D helix/spiral. Is that the case?

I am trying create the centrifugal pump I just created in TurboCAD in Alibre to see if can do it there. I start with a helix that will be used for a sweep path, but Alibre's helix tool doesn't seem to allow for a 0 height construct. Am I missing something?

 

[HaroldL]

It's an option from the drop down for the Settings:

 

[NateLiquidGravity]

Just to be clear the Helical Boss tool make a helical feature from a profile sketch but does not create a helical sketch. However if you want it as a sketch simply make a small square profile sketch and create the helical spiral feature and then project the edge of the feature to a sketch.

Here is a video on the tool.

 

[HaroldL]

create the helical spiral feature and then project the edge of the feature to a sketch.

Bingo!
I thought I'd just drop a hint and that there wouldn't have to be a step-by-step explanation for this.

 

[DBC]

Thanks for your replies, but this does not give me what I need. The tool seems to be simply too primitive to give me what I need. I didn't want to have to import a sketch from a different program but that seems to be what is required,

 

[simonb65]

The tool seems to be simply too primitive to give me what I need. I didn't want to have to import a sketch from a different program but that seems to be what is required,

Following this thread and the helix tool is there to create the path. You still need a sketch for the shape you are going to extrude/cut along that path! If your not wanting to use a sketch ... how do you expect it to work?

For your example, that sketch would be the outer tubular cross section of the pump.

How does TurboCAD achieve it? If it creates a sketch for the helix, what does it then do to create the solid from that? It sounds like it is just a case of aproaching the problem from a different angle to one your used to.

EDIT: Just seen your tutorial preview and it looks like the issue or limitation in Alibre might be to do a tapered profile along a helical path! I'm sure someone will have a solution to that!

 

[DavidJ]

Sweep with draft (and tidy the end up).

 

[DBC]

View attachment 28379

Sweep with draft (and tidy the end up).

Can you show how you achieved that, the initial path?

 

[DavidJ]

I used the methods suggested earlier in this thread, projected an edge from a spiral extrusion and used that as sweep path.

Attached part made in build 20055 - it's only a 'lash up' to show the approach.

 

[DBC]

Thanks for the "hints". I still think this is way to convoluted for a process that should take 15 seconds or less to get exactly what one wants (the initial spiral). The gymnastics required with the method hinted at here makes it unworthy of a CAD program in my opinion. Yes, I realize Alibre is its own program and is good in its own class, but I still find that is missing a lot of functions one would expect it to have. I am also confident that now it is operated by Max and the former employees it has a better chance of growing and maturing and that is partly why I invested in it.

Here is a hint for you longtime forum posters. Keep in mind that new users who ask for help would typically like fuller answers to their questions since they are not as familiar with the program as you are. You seem to forget what it is like to be a new user and often expect them to read your minds. Sorry if this sounds like a rant, and perhaps it is a bit of one. At any rate, thanks for taking time to answer.

 

[DBC]

Here is another problem with the hinted at method. When you project the sketch it become a spline and you cannot trim it as it will only trim the whole spline out or the other objects. It doesn't recognize the tangential intersections.

 

[simonb65]

@DBC , So how does TurboCAD achieve it? ... what is the feature, function or workflow that is missing, that Alibre could benefit from??

 

[DavidJ]

The part file can be 'played back' one step at a time, by moving the 'dog bone' in the Design Explorer (admittedly in this case you have to manually un-suppress to see the helical feature).

I don't claim the method is perfect. It's a lot easier if you don't try to do everything in one sketch - instead split the geometry into simpler items that can be modelled as individual features. You'll note that I 'trimmed' the final extrusion rather than the sketch - I could have then added a bend as a new feature by using a revolve for example.

I could have adjusted the initial helical feature 'number of turns' to alter the end point of the spiral.

By all means suggest new features - but don't expect Alibre to work exactly as another package you are used to does (TC is a rather different beast).

You can always ask for more detail of a method. Please remember that almost all here are posting out of goodwill in their own time - sounding off isn't likely to elicit more offers of help (or make people want to take the extra time to annotate multiple screenshots with a blow by blow how-to).

It sounds much more positive if you say "I'm used to tackling it this way (give detail), but don't see that option in Alibre. How can I achieve the same results?" You'll probably get 3 different suggestions for ways to model the item, and some interesting discussion about whether your 'missing function' should be a priority for adding to Alibre.

 

[DBC]

The part file can be 'played back' one step at a time, by moving the 'dog bone' in the Design Explorer (admittedly in this case you have to manually un-suppress to see the helical feature).

I don't claim the method is perfect. It's a lot easier if you don't try to do everything in one sketch - instead split the geometry into simpler items that can be modelled as individual features. You'll note that I 'trimmed' the final extrusion rather than the sketch - I could have then added a bend as a new feature by using a revolve for example.

I could have adjusted the initial helical feature 'number of turns' to alter the end point of the spiral.

By all means suggest new features - but don't expect Alibre to work exactly as another package you are used to does (TC is a rather different beast).

You can always ask for more detail of a method. Please remember that almost all here are posting out of goodwill in their own time - sounding off isn't likely to elicit more offers of help (or make people want to take the extra time to annotate multiple screenshots with a blow by blow how-to).

It sounds much more positive if you say "I'm used to tackling it this way (give detail), but don't see that option in Alibre. How can I achieve the same results?" You'll probably get 3 different suggestions for ways to model the item, and some interesting discussion about whether your 'missing function' should be a priority for adding to Alibre.

I totally get what you are saying and usually operate on that premise. I just don't make a very good newbie. . It is like having to learn how to ride a bike again after having a stroke. Not so much fun.

 

[DBC]

Hi Simon,

In TurboCAD just create the helix (spiral) (zero height) and add to the sketch to get the desired path. Tangent arc, etc. See image 1 for TurboCAD. Then sweep with appropriate draft. See image 2

 

[simonb65]

Hi Simon,

In TurboCAD just create the helix (spiral) (zero height) and add to the sketch to get the desired path. Tangent arc, etc. See image 1 for TurboCAD. Then sweep with appropriate draft. See image 2

Thanks, so it just needs Alibre to be able to treat the helix generated path as an editable sketch object that can have other sketch items appended to it to make a compound path.
The way most use the helix in Alibre is to produce a helical feature and then 'extend' it by projecting off the end faces and adding additional geometry, but of course in this example, you can't 'easily' maintain that progressive draft this way.
Would be a nice enhancement for Alibre.

 

[DBC]

I gave this a whirl in SolidWorks since my seat seems to be still active. In SW one could convert the helix into a spline and add the additional sketch components. SW does not have the ability to sweep with draft angle, so I had to loft, but that was very easy. So just as Simon says, Alibre needs to be able to treat the helix generated path as an editable sketch object that can have other sketch items appended to it to make a compound path or allow the helix to be converted to a spline that can then edited and tweaked as needed.

 

[DBC]

I tried this in MoI as well, and it was pretty easy to do in there, both to create the path and to sweep.

Curious if MoI is still packaged with Alibre. If my memory serves me, I think that it was at one point in time. I have it, but rarely use it.

 

[idslk]

Hello Don,

here is a little AlibreScript...
It is not "fully loaded" and it captures not all exceptions, it is only to show that a lot of things are possible with scripting.


You can fit it for your needs. If you have questions, don't hesitate...

Regards
Stefan

 

[simonb65]

I tried this in MoI as well, and it was pretty easy to do in there, both to create the path and to sweep.

There is a lot of good features, plus ease of use features (particularly 3D splines and lofts), in MOI that Albire Design would really benefit from. It has been said numerous times by a few of us on this forum. But we still wait and hope!

Curious if MoI is still packaged with Alibre.

Unfortunately it's not!