I want to make many holes like this. When fold the sheet metal holes disappear. How to fix this problem?
Maha, I think my configuration comment has distracted you from your main issue. Read the rest of my original comment again. In case it is not clear here is a step-by-step to solve your problem:
1) Supress your flat pattern.
2) Roll back (drag the blue bar in the feature tree) to above your flat pattern.
3) Add an UNFOLD feature (NOT "Flatten". These are different. "Flatten" will just toggle your flat pattern on and off)
4) Add your Cut-Extrude, Linear Pattern, and whatever other feature you need. You will have to remake these.
5) Add a FOLD feature. It is the one right next to Unfold.
Now you should have the model that you want.
Insert Unfold, insert holes, insert Fold again. 3 (additional) operations in tree.
Repeat the operation again?
Steve Barry gives the details in his reply. I wouldn't consider this a workaround or a trick though it is just necessary. Standard sheet metal (punching or laser, bending) has a defined process that works very well in SW. Though the modeling process dictates that we create the feature where we add holes to first. To me that is where the power of parametric design come in.
In general it is usually bad practice to put any features AFTER a "Flat Pattern" feature for a sheet metal part. This is because every time you Unflatten the part, the feature tree will roll back to before the flat pattern and you will not see any of the features or changes you have made.
What you will want to do instead is an "Unfold", add your desired features, and then do a "Fold". Normally, with an Unfold you would select a face to fix, but since there are no flat sheet metal faces here, you should select an edge.
Further, after you get the desired results, you might find that some of them now disappear when you do a "Flatten" (or access your Flat Pattern). In order to work around this, you can add another unfold before your Flat Pattern.
EDIT: You could alternatively just suppress your fold feature, assuming you haven't added any more features after that.
I'm not sure if you have learned about configurations, but normally you will have two different configurations; one for your formed part, and one for your flat pattern (It should automatically generate this configuration if you place your part into a drawing). Just make sure that in your formed (Default) configuration you suppress the last Unfold feature, and have it unsuppressed in your flat configuration.
(It should automatically generate this configuration if you place your part into a drawing).
I mean you mention to create a design table. I couldn't understand the above one.
If you insert your sheet metal part (.SLDPRT) into a drawing (.SLDDRW), SolidWorks will create a Configuration for the Flat Pattern:
You can use configurations to show different variations of your model. The "Default" configuration will be to show your formed part, and the "DefaultSM-FLAT-PATTERN" will show your model when it is flattened.
Each configuration can have different elements of the feature tree suppressed or unsuppressed. Between the Default configuration and the Flat Pattern configuration, the only difference is usually whether the "Flat Pattern" feature is suppressed or not.
I have created a flat pattern with hole in default configuration. I do not know to proceed with this.
Thanks for your help
This is because the features exist only when the flat pattern feature is active (unsuppressed) as you can see below. Just like what Bernie says above, you need to include some unfold and fold features so that the cut extrude and patterns exist before the flat pattern feature:
When selecting the fold command, select the edge of the part as per the image below and collect all bends, then unfold it:
Then re-create the features (I don't think it will allow you to drag them above the flat pattern feature) and then fold again, collecting all bends. There you have it! Your feature tree should look like this:
Retrieving data ...