Synchronous Modelling Guidance
Synchronous Modelling Guidance
(OP)
Hi,
While looking at synchronous modelling, I've found some great uses for it, such as:
- editing features in an un-parametric (imported) CAD model
- creating machining operations in a machined casting (i.e. linked in casting, then machine it)
- edit complex parts (several hundreds of features) where normal editing will not work
- editing parts where design intent does not allow you to make the changes you need
All of these are methods for editing existing parts, and record the changes made as features.
I've also found that synchronous commands can be used as normal parametric modelling features.
Typical examples would be replace face to change a shape, or rotate face to change its angle.
BUT
I've also seen a lot of models almost built entirely using layered synchronous commands, and these are awful.
They're hard to understand, difficult to edit and just plain messy.
My question - does anyone know of a freely available training guide to good and bad use of synchronous modelling that I could distribute, to save me the trouble of re-inventing the wheel?
Thanks in advance, Carl
While looking at synchronous modelling, I've found some great uses for it, such as:
- editing features in an un-parametric (imported) CAD model
- creating machining operations in a machined casting (i.e. linked in casting, then machine it)
- edit complex parts (several hundreds of features) where normal editing will not work
- editing parts where design intent does not allow you to make the changes you need
All of these are methods for editing existing parts, and record the changes made as features.
I've also found that synchronous commands can be used as normal parametric modelling features.
Typical examples would be replace face to change a shape, or rotate face to change its angle.
BUT
I've also seen a lot of models almost built entirely using layered synchronous commands, and these are awful.
They're hard to understand, difficult to edit and just plain messy.
My question - does anyone know of a freely available training guide to good and bad use of synchronous modelling that I could distribute, to save me the trouble of re-inventing the wheel?
Thanks in advance, Carl
www.jcb.com
NX 8.5 with TC 8.3





RE: Synchronous Modelling Guidance
Are you referring to a history based native NX model that uses synchronous commands almost exlusively, or a history-free native NX model?
www.nxjournaling.com
RE: Synchronous Modelling Guidance
I think if your fundamentally changing the fit, form and function of a part during its development then you should do it properly ie rollback and remodel or just start again.
If your doing minor tweaks to add draft and other 'hot fixes' to a part which you haven't been involved in designing but not changing its fundamental fit, form or function then its acceptable to have a number of synchronous features AT THE END of the history tree.
There are a few features in synchronous modelling which are just a quicker method of performing a string of standard features ie replace face effect could be achieved through a combination of offset face, untrim face and trim body. The same goes for delete face, move face, make offset. I think these features are perfectly acceptable within the modelling history when used in moderation.
Khimani Mohiki
Design Engineer - Aston Martin
NX8.5
RE: Synchronous Modelling Guidance
Hi Khimani, you've hit the nail on the head with what I'm seeing. Synchronous definitely has it's place and is very useful, but not when used to create a model from scratch. Think I will end up putting something together, so focussing purely on the "bad use":
- too many features causing longer updates than necessary
- complete loss of design intent
- other engineers won't understand the design
- a model that's impossible to edit without adding more (synchronous) features
- failures due to consumed features / features depending on themselves - saw that one this week
With models like these, you'd be just as well to extract a body and delete all previous features when finished, for what use they are.
Thank you for the input!
www.jcb.com
NX 8.5 with TC 8.3
RE: Synchronous Modelling Guidance
Tim Flater
NX Designer
NX 8.0.3.4
Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB
RE: Synchronous Modelling Guidance
Just as it wouldn't be good practise to put an extrude on an extrude on an extrude, stacking of synch features should be avoided, I think thats just about as far as guidelines can go without getting barraged with questions from engineers about their correct usage.
Khimani Mohiki
Design Engineer - Aston Martin
NX8.5
RE: Synchronous Modelling Guidance
Point being: extensive use of synchronous commands is not inherently bad practice, a bad modeler will create bad models no matter what tools he has. Limiting a powerful set of tools to one or two "approved" use cases may be counterproductive in the long run.
www.nxjournaling.com
RE: Synchronous Modelling Guidance
But I would like to provide some guidance on how not to use them. Agreed a bad modeller can produce bad models with any commands, I just have a feeling that layered synchronous makes it "extra easy" to produce something that no one else could use.
The feedback here has been very useful.
www.jcb.com
NX 8.5 with TC 8.3