Sprues

cad

#1

So how do folks create the laser-cutter equivalent of sprues – tiny uncut bits that keep stuff attached to the main piece of material? The main use for GF seems to be for things you pick up off the bed by themselves, but sometimes that’s a pain, or sometimes we may be creating kits that shouldn’t come apart until they’re ready for assembly.

So do people just shorten one line in the design (which would play hob with export for fitting) or make a layer of little borderless blocks, or something else entirely? I was briefly thinking that there should be a “sprue this” button in the GF UI, but that would be wrong for so many reasons…


#2

I think that some software has this built into it. But it doesn’t seem like it would be difficult to add a few lines into the design as the last step. (Assuming a designed piece as opposed to a scan/cut)


#3

This made me laugh…:sweat_smile:


#4

Those are called “tabs” in the cnc world. I doubt that it will be provided for in gf software as they are generally unnecessary in laser work.
As others have said, if you do need a tab, just insert a small gap.


#5

Yes, these are called tabs. We use them in sheet metal work all the time for various reasons. To eliminate tip up of odd shape parts, Sometimes when you cut a thin strip, the heat from the laser causes the part to warp up which could cause a collision with the laser head. Tabs are also used to hold parts together in a kit just like paulw mentioned. We might want to bend alot of small parts on a press brake. tabbing them together and bending all at once gains efficiency in the down stream operations.

Tab size and design is dependent upon your material and thickness. In our software at work, we can assign tab sizes per material with a subsort of thickness and save this information in a database. There are rules in the software that we set up that tabs are automatically added if a part is of a certain size or a certain condition.

Alternatively, there is a “tab” button that allows us to add tabs wherever we want.

I have used other software that did not have this and you have to start and stop your lines manually in the CAD geometry to place the tabs where you want them.

It’s not too big of a deal, as you normally don’t need tabbing and shouldn’t use it unless you have a good reason.


#6

Just learned a new word. Thanks. :grin:


#7

I was just using tabs in Vectric Aspire for a CNC job yesterday. I also plan to experiment with using Aspire with the Glowforge. In that software, you select the tab feature, define the length, and click where you want them.


#8

In my opinion tabs are like kerf compensation: it’s better to add these things during the manufacturing phase than during the design phase. I think it would be cool if Glowforge added it to their CAM software at some point.

I’m glad I don’t feel passionately about this being a “need” so I won’t be contributing to another kerfuffle. Yay! :slight_smile:

(I won’t be a tabble-rouser.)


#9

Let us know as I use Vcarve pro.


#10

All I know is I saw your “Sprue this,” and immediately had a picture of Garth saying, “If you’re gonna sprue, sprue into this.”


#11

Funny.

Me too!

Also very funny.