Trying to use DXF

paul_breed

I have a tool that makes a DXF of a specific nozzle shape.
I need to import that into a sketch adjust it rotate it and create a solid....
I'm finding the onshpe sketch tool  very frustrating...

1)When I import the DXF it looses the origin?  How can I get the DXF to import and keep its orign?

2)Why are all the segments of the DXF separate entities?  How do I Join lines arcs etc to make one entity...

3)When I select all the segments and choose the offset tool it destroys the original line?
I'm trying to make the line 0.125 thick square the ends and rotate to make a cone like nozzle....
I can do this in solid works or Rhino in about 30 seconds..... I've been trying to get On shape to do it for two hours....

I've made a document with the DXF I want to import and the parasolid of what I'm trying to create.
I made the parasolid in rhino...Its public under my profile and called motorOverwrap

Can someone help me?

https://cad.onshape.com/documents/98147560ecdf4930b217f0e1/w/a8ecc94cbce34744b11a7038

andrew_troup

paul_breed said:

........
I'm finding the onshape sketch tool  very frustrating...

.....

2)..... How do I Join lines arcs etc to make one entity...

....

Paul: Your frustration is understandable, because the tool kit for this workflow is currently very limited.
Here's a tip which will help, though, for the specific issue I isolated above:

Import your dxf to a dedicated sketch, and do not edit that sketch thereafter
(for a durably robust model, you might want to add some constraints, probably mainly "Fix"...)

On the same plane as the above sketch is drawn on, make a new empty sketch, select ALL the entities from the first sketch (easiest way is simply to click on the name of that sketch in the feature list) and invoke "Use/Project"

Now your second sketch will contain trimmed geometry*, located identically with the dxf geometry, and which is provided with the necessary Onshape sketch constraints so that nothing can be moved (Onshape differs slightly from Solidworks in that the endpoints of converted geometry are constrained in the former)

*provided the original dxf entities were trimmed, in other words, entity endpoints coincided

If you need to move such a sketch, the easiest way at present is to derive it, and use "Transform" to move it by known distances (or possibly a mate connector to move it to a defined location - this is brand new so I can't yet vouch for whether this works for sketch geometry)

philip_thomas

Hello Paul. Thank you for your post. I may have missed nuances of your request and of course there is always more work to do on our part to make this more efficient. That all said, i did meet your criteria of 30 seconds or less and so i post here my work flow. Please let me know if I have completely missed the mark and whether you have any follow-on questions.


https://cad.onshape.com/documents/b4ec0d6ca4c34a50908cc910/w/051e4090ade6489d8e8f4a48/e/bba1ff48d3e94c4e8b1a759e

paul_breed

Except since it lost the DXF origin the part is the wrong shape.....

philip_thomas

@paul_breed- just to repeat my understanding of your problem - this methodology works (sub 30s) BUT, the imported origin of the DXF is incorrect?
Would you please post a picture, sketch or hand drawn note showing where you expected the imported origin to be?
Thank you.

paul_breed

Ok I exported the DXF from the onshape project and loaded it in Rhino.... The attached picture shows where the origin is supposed to be  in the DXF file. The first item in my list of questions was why does onshape loose the DXF origin? 

paul_breed

If you go back to my shared document and look there is now a part 2,  I did these operations.... 1)Created sketch and Imported the DXF, 2)Selected all the arcs and segments in the dxf  3)hit offset and entered 0.1  4)Thought better of hit hit ctrl z to undo and entered 0.2 for the offset.... now the lines are seriously screwed up.... why does offset corrupt the existing line when its only supposed to create an offset from the existing line?

philip_thomas

Paul - i have opened a support ticket for you regarding the origin (i have verified that the origin comes in correctly into other applications).
For your other questions - i now need to teach you to fish. Here is how you can create your own support tickets - and even better, how to track them!
https://www.onshape.com/support

paul_breed

I've opened a support request thanks!

philip_thomas

Paul - more research. For any imported DXF/DWG, we are currently assigning an origin at the geometric center of the imported entities. This makes sense where an imported profile may have an origin a long way from the profile, but we also agree that in situations like yours that we need the option to preserve an origin or assign one. At this point the ball is in our court and it is being looked at