Shut-Off Surfaces

[bkeavney]

I'm using SolidWorks to create shut-off surfaces for a mold. The parting lines are a bit complex, and the shut-off surfaces function choked. I tried drawing my own planar shut-off surfaces, but SolidWorks apparently didn't recognize them as such and gave the error "cannot knit sheets together" when I tried to create a tooling split. Any suggestions?

 

[FireWild]

Sorry B. keavney but that's a problem with Solid Works. My only suggestion is to use Pro/ENGINEER and Pro/Mold. I know this is probably not an option for you, but Pro/Mold does not have an issue like Solid Works does with merging surfaces. In Solid Works before you can knit surfaces together the edges must be perfectly trimmed together and tangent, collinear etc. In Pro this is not required.<?:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" />









Good Luck.

 

[cr&#101;atedsoul]

Hello bkeavney,





I've got a possible solution for ya.





There are two steps to spliting a part within Solidworks. There are many other ways to do this.. but as far as the solit functions, you should only have to worry about the two functions.


Now, it doesn't matter in what order you perform these functions. Once both are complete, you will split.


1) Split Line In this function, you have to establish where it is you want to split the part. You might have to adjust draft on some faces or split certain surfaces to allow for a complete parting line.


2) Shut-off Surfaces Now this is your delima huh. Well, what I can say is that by default, Solidworks tries to plug up the holes and such on the part by using the contact setting. You should see a box by the holes, etc.that says contact. If Solidworks can't patch that hole, you need to click on the box until it says "No Fill".


This will allow you to split the part without creating thos shut-off surfaces. You will create surfaces after the split to "plug" up the holes.


Well, I hope this helped bkeavney.

 

[bkeavney]

Thanks. I've done a few experiments with the current model & with a simple practice part. In the shut-off surfaces task manager I consistently get the warning "The mold is not separable. Please select chains of edges to identify shut-off holes," even when all the visible holes have been selected. I tried creating parting lines around the complicated holes as per a training model I got from SolidWorks, but the software seemed not to recognize them. Is there any way to run a diagnostic to figure out what SolidWorks doesn't like? I've distilled the model down as simple as I can, and have checked for draft and undercut.

 

[cr&#101;atedsoul]

Alright bkeavney,


It seems that perhaps all of your edges are not picked. When you pick an edge of your shut-off holes, do you notice a red arrow? I showed a buddy of mine that you have to "trust in the red arrow" Haha! You see, there might be tiny tiny line segments that you don't see that Solidworks knows is there. All you have to do is hit (N) for no or (Y) for Yes. This will ensure that all of your edges are chosen.





Well, let me know.





One thing you can do is go to Tools, Check and do a check on your part to see if there are short edges or invalid edges, etc.

 

[bkeavney]

I get the warning even when I suppress all but the simplest holes and let SolidWorks choose them. it selects the loops, identifies them as loops, and doesn't show the red arrow, but still says it can't split the mold. A Check identified a few "maximum edge gaps" and "maximum vertex gaps" on the order of 2E-7, at the base of fillets and along extrusion lines, but they are too small to see and I don't know how to fix them anyway.

 

[cr&#101;atedsoul]

I'd like to split this part. You can upload a file you know

 

[cr&#101;atedsoul]

Probably confidential though huh.

 

[greghenson49]

I don,t know what version of Solidworks you are using but have you tried to use the cavity command under molds? You create an assembly of the part and the insert or core pin you are trying to creat a shut off on. Then edit the insert or core pin in context.Next use the cavity command to subtract the part from the insert or core pin. do this to both halves of the mold and you have your shut off surfaces. I do this all the time and hardly ever use Solidworks parting line command. Just a thought.


Greg H.

 

[skateboardkid]

you could try to extend the edges through eachother and then use the trim surface tool to delete all the extra surfaces, using either keep selections or delete selections, this will ensure that your edges are flush with no extra hidden geometry.