Pattern requirements for laser cutting fins

I'm prepping a file for having some fins laser cut for me and have a couple of questions that seem very basic. I just can't find the answers with a search.

1) Do I need to leave 'sprues' / gaps in the cut like I see in commercial kits? I'm thinking not, but want to be sure.
2) Is there a best practice line thickness? Does it depend on balsa thickness?

The line in the file should have 0 thickness and you shouldn't have to leave any tabs.

Check with the driver for the laser printer you're using. I use a local laser printer and a 'hairline' setting in CorelDraw works perfect. If I did a width of zero then it wouldn't cut.

Also, no need for those tabs. Those are only for when a mfg needs to pack up a sheet of pre-printed balsa and doesn't want the fins to fall out. However, you need to watch your sheet of balsa as it's being cut. Sometimes the sheet will move slightly as the fins start to drop out of it. Sometimes by leaving a tab you can eliminate that behavior.

Pat_B said:

Check with the driver for the laser printer you're using. I use a local laser printer and a 'hairline' setting in CorelDraw works perfect. If I did a width of zero then it wouldn't cut.

Click to expand...

This is more accurate, I forgot some software actual has 0 as a thickness option. The line should be a vector line of no thickness. If it has a thickness the laser will think it's meant to be etched not cut.

Thanks for the tips.

My boy's high school has a laser engraver/cutter that he's gotten permission to use. Or at least have parts cut with. I was told that an Illustrator file was appropriate - so I'm going from OpenRocket to PDF to illustrator, extracting the outline and dropping that into a new file. I set the path width to 1.

We'll see how it goes. It's a set of BT70 scale Vigilante fins.

I bring my laptop computer with Corel Draw along to the place where I get my laser cutting done. That way I can make any last minute changes to things like line widths. Or if there is a mistake during the burn, then I might have to move things around in my original file so that the second job run starts in a different place and doesn't want to go over the previously 'cut' lines.