Derived Sketches

andrew_troup

I was excited to see this, and will be even more so when I find out how to:

1) Position the derived sketch on arrival
2) Derive a sketch as a way of reusing it (as a "live copy") within the same part studio it originated from

brucebartlett

Yes this pretty awesome, I have really been blow away by this update. I just have not had time to try these features out fully yet but hanging too.

andrew_troup

Point 2 from my OP has been traversed elsewhere (not currently possible, may be in future, current workaround is to situate master sketches in a different or dedicated PS)

But Point 1 remains a real stumbling block. Somehow I had deluded myself that we could use "Transform" to move a derived sketch into position, (which would admittedly be unwieldy -- and sometimes unworkable, relying as it does on having dimensional info which may lie in the future) but I now realise this currently only moves parts, not sketches or geometry. 

Have I missed something? Is there currently any viable way to reposition Derived Sketch geometry? If not, are there any plans in that direction?

shashank_aarya

@andrew_troup I also agree with you for point 1. At this point of time one workaround we can use if we want to create any part using derived sketch but at some other location as shown below.



It doesn't require to position the derived sketch on arrival but part can be transformed anywhere. I am not sure if this can be a standard method since derived sketch is still in shown condition and presently functionality of hiding it is missing.

andrew_troup

@shashank_aarya
Thanks for that. Nicely explained!

However the sort of usage case I'm thinking of is where I have a number of locations on a part where I want to position copies of a particular sketch in order to perform various operations, and I want those copies to remain driven from a single 'master'.

Imagine a hydraulic manifold with a number of faces (on different sides, and maybe even at odd angles) where valves are bolted, each valve with a complicated pattern of ports which is shared between some or all valves. But I don't have any need or desire to model the valves, because I'm a manifold builder.

Ideally I want to be able to attach those sketches to faces or planes, and constrain points and entities of the sketch to vertices, edges, or elements from other sketches. So even "Transform Sketch" would barely scratch the itch.

It fleetingly occurred to me that one workaround for the moment would be to extrude that master sketch (provided the geometry was suitable) to create a dummy part, which could then be used like a cardboard template in real life, attaching it to various elements of the actual part and "Use/Project"ing the necessary entities from edges of the template.

Then I woke up ... we can't do that, because Part Studios do not support moving the part in such complex and interactive ways (only "Transform" is currently available, AFAIK)

and Assemblies do not permit (nor, I reckon, should they) the creation of "in-context" features.

lana

andrew_troup said:

Ideally I want to be able to attach those sketches to faces or planes, and constrain points and entities of the sketch to vertices, edges, or elements from other sketches. So even "Transform Sketch" would barely scratch the itch.

@andrew_troup
To make sure I understand your request  correctly: you want to use the 'master' sketch as a template, where each instance of its placement would be 'configured' by additional constraints ( controlling sketch geometry position, but also possibly changing the geometry). Is this so? Can you think of any other features/objects you might want to use in similar manner? 

It would be a great help, if you could share a picture/document with a typical example of sketch you'd expect to use and ways in which it'll be modified.

andrew_troup

lana said:

andrew_troup said:

Ideally I want to be able to attach those sketches to faces or planes, and constrain points and entities of the sketch to vertices, edges, or elements from other sketches .....

@andrew_troup
To make sure I understand your request  correctly: you want to use the 'master' sketch as a template, where each instance of its placement would be 'configured' by additional constraints ( controlling sketch geometry position, but also possibly changing the geometry). Is this so? Can you think of any other features/objects you might want to use in similar manner? 

It would be a great help, if you could share a picture/document with a typical example of sketch you'd expect to use and ways in which it'll be modified.

@lana :  I'm not seeking to configure or modify the derived ("slave") sketches,
simply to position them with reference to existing geometry, either solid or sketch.
Internal geometry of derived sketches, I propose, should remain identical with the master from which each sketch was derived. Otherwise confusion and complexity would overwhelm the utility.

ON EDIT:
Positioning would typically involve:
a) choosing a plane or face for the derived sketch, then
b) dimensioning from a point in the derived sketch to a sketch point or vertex on the model, to anchor the sketch position linearly, then
c) dimensioning from a line in the derived sketch to a sketch line or solid edge to orient the sketch angularly

---------------------

You ask which "Features/objects you might want to use in similar manner?" :

I'm seeking to use such derived sketches for any of the usual purposes a sketch serves: they might be the basis for Extrude/Add, as in the instance of cooling fins at a number of locations on a motor or gearbox or heat sink. In some places the fins might travel around corners, in which case the same sketch could provide the profile for a Sweep. In other cases, a revolve or loft.



Or derived sketches might be the basis for Extrude/Remove, say for producing standardised hole patterns as in the manifold example mentioned and shown here, but not necessarily at regular spacings, or on orthogonal or regularly arranged faces. 

lana

@andrew_troup
Thank you for clarification. 

andrew_troup

@lana
Further edits in bold  

andrew_troup

@lana

Forum software is playing up again (sigh) so I lost the artful further edits to my previous post:

Basically the further edits involved adding the words "or constraining" after the word "dimensioning" in my points b) and c)

lana

No problem, that was assumed.

shashank_aarya

@andrew_troup Examples shown by you are very nice and self explanatory. So +1 for this. I faced similar problem when I was creating a model for cylinder head. At the time of building features for fins I observed that some of the fins were having similar profiles on offset planes but not concentric with each other. But since derive cannot define the position of sketch on arrival I had to create separate sketch for each fin on each offset plane. It took considerable time to constrain each sketch which otherwise could be saved if I derive the sketch and place it wherever required.

peter_hall

+1 for this. Positioning a derived sketch to faces or planes and then using constraint tools would be an immense time saver on all sorts of design projects.

andrew_troup

Indeed, @peter_hall - I can think a time or two when that ability (in Solidworks) meant we could go ahead and sprinkle an entire structure with bolting patterns. Provided we'd worked out how many holes each standard pattern would involve, we could finalise the bolt sizes and centre distances later when the loads were quantified, but it meant we could carry on and finish the modelling, and even rough-detail the drawings, in the meantime.

yat_cheung_wong

What do you guys think if OS also allows us to position derived parts using mate connectors? Imagine if I create a component in its own part studio that will be used multiple times in the main part studio, and in the main part studio I create parts that connect and reference these components. This is be great if I can re-use mate connectors when I add derived parts and quickly put them in place. And I can use the same mate connectors in the main assembly.

Apart from the need to reference the component multiple times in the main part studio, there's also a reason I want to create the component in its own part studio - this is a base component I keep modifying from time to time, and if I put everything in a single part studio editing would become so slow and the features history for everything is just too long and very hard to work with.

Did I miss anything? Is there any other way to achieve what I want to do?

gonzalo_chomon

This is togueder with the constrains the most amazing feature on OS.
I am already using basic sketches with major mesurements and shapes that I use them on all part studios as derived, then I constrain those basic sketches to the part sketches. 
So now I can change dimensions or other properties on the basic sketches and all parts modify automaticaly.
I am still learnig how to master it, as it is sightly complicated...
It is quite impresive to see how the software modifies over a dozen parts automaticaly just because a mesurement is changed on the basic Sketch
 Mind blowing in any case.

The only problem I see now is that the derived sketches can not be hidden.

daniel_staudt

it would be fantastic if we could bring a derived sketch into a plane and work with it as a read only copy (aka you could move and flip and rotate the sketch but you could not move it's individual pieces)

i am currently making electronic parts models and want to include a hole pattern sketch to go with it. i can derive the sketch into bit but then have to "use" the derive in my sketch, then translate all the components as one (as they lost all their constraints so any modification messes the whole thing up and any construction lines become solid lines. bleh.)  i have to hope i don't miss any of the sketch pieces and have to manually move it where i like. then i can extrude-remove against it.

a cumbersome process when it would be so much easier to import to a surface or current sketch and dimension over and up (maybe a rotate) and be done.

michael_hills168

+1  I would love to see this feature, especially point 1 (position and select plane for derived sketch), but point 2 would also be really nice. 

S1mon

Super Derive can locate and optionally place something (a sketch or a part) at one or more locations.

https://forum.onshape.com/discussion/19564/update-super-derive-with-mate-connectors

eric_pesty

The "transform pattern" custom feature is able to relocate a derived sketch as well: https://cad.onshape.com/documents/25a0a6dfaa76e64574a5e0db/v/8217d6d96ccc324b8dd86160/e/4c62c06c4e0e4db3703a2d4c