Parametric Woes!

Andrew McIntyre

I wonder how much effort is going into the Bricscad parametric section?

I am at the bottom of the learning curve on this but using SolveSpace (a free program) I had no trouble putting together a 2d parametric drawing for that is rock stable and easy to amend. However when I tried to replicate it in Bricscad to gain access to my symbols library my efforts were beset with difficulties. I am not sure how much of this is due to my ignorance of Bricscad's parametric protocols, but that should not cause the program to crash frequently which it does - nor does it explain the need for me to keep re-opening a drawing in order to get it to behave consistently. Aside from what appear to be bugs, some helpful tutorials that explain the basic principles to newbies like me would I'm sure be well received! The SolveSpace tutorials are particularly good at pointing out bear-traps and how to avoid them whereas in Bricscad which has a very different approach. I have struggled to discover what represents 'good practice' and what doesn't.

Andrew McIntyre


 

Roy Klein Gebbinck

I have recently worked with 2D and 3D constraints and have not experienced any crashes. Try using BmInsert to insert your model as an assembly in another drawing. That way you cannot mess up the original and you can always reload to file to 're-apply' parameters. I am not sure what you mean by 'symbols library' but to my knowledge you cannot apply 2D constraints to blocks.

I cannot comment on the development of 2D and 3D constraints. But I do know that 2D constraints are intended to be compatible with AutoCAD, which limits the scope for development.

I advise you to send in an SR regarding the crashes, and if you want help or tips from the forum you should post a model.

Andrew McIntyre

Roy - thanks for that.

I attach a dwg file in which I show one of my standard drawings at left within a frame. The three views are of a woodburning stove within a sheet metal chamber. The stove is a pre-drawn symbol of the type referred to in my earlier email.

Outside the frame and to the right I show my first efforts at constructing a parametric drawing with facilities to adjust the height width and depth of the box together with the thickness of insulation used and the width of the flange at front. On the extreme right are the resultant four templates used to drive a laser cutter. They incorporate stretch allowances for the folds together with joining tabs etc.

Bricscad crashed three times while I was constructing the parametrics - something that otherwise only happens only very occasionally. Also, although the end result appears to work it needs to be tidied up - for instance I have been unable to discover how to scale up the parametric dimensions to make them legible. For clarity I should also colour code them and put them on a separate layer. However a more serious problem is that some of the components randomly fail to re-size requiring that I re-load the drawing to get it to work properly. Not good news in a productive environment!

Quite possibly my technique is defective - I have picked up the basic procedures mostly by trial & error and have no idea whether (for instance) horizontal & vertical constraints should be used in preference to parallel constraints, or whether it is better to connect as many 'children' as possible to a single parent rather than  to connect the 'children' to each other. Really, really basic stuff but which (as far as I can see) is not covered in the Manual.

Hence my wish to see some tutorials produced that clarify these issues since I feel that even at my mundane level parametrics have much to offer.

Andrew McIntyre.

STOVE BOX PARAMETRIC(3).dwg

Roy Klein Gebbinck

Which BricsCAD version are you using?