fire pit bends

[dmsigg]

hey, i'm new to cnc plasma can someone explain to me the best way to bend the sides of a fire pit. i have seen where you can cut reliefs but can you bend like 10 gu without a bending machine?? love this forum thanks for your help

[Scratch]

Bending wide pieces of 10 gauge without some sort of brake, press or relief cuts is going to be very hard. I'd make relief cuts if its wide pieces like for a fire pit. If it's small pieces like 4" or so, just put it in a vise and bend it but wide pieces like that are going to need some help.

You could also go with something like the SWAG press brake kits like these:
https://www.swagoffroad.com/collections ... brake-kits

but for firepits where they don't have to be airtight, I'd just do relief cuts. Those also help make the bends exactly where you want them to be unlike bending without them.

[adbuch]

I agree with Scratch. I typically cut slots along the bend lines with a slot width of anywhere from 50% to 100% of the material thickness.

David

[plasmanewbie]

Ah yes, the metal origami technique. Have used relief cuts for years, works like a charm. As David says the thicker the material the wider the relief. Practice on some scrap and get the reliefs dialed in for yourself.

[dmsigg]

thanks for the help, i'll try it on scrap

[adbuch]

Here are a few examples of some pieces with slots along the bend lines. The first one is just a test piece I did to figure out the correct slot width for 11 ga. steel.

11 ga slots for bends 1.jpg

11 ga slots for bends 2.jpg

This one was a replacement bottom to fit a friends fire pit.
I started out by making a cardboard template and fitting it to the bottom of the fire pit with the rusted out bottom.

template.jpg

Then I modeled it up with SolidWorks to create the dxf file for cutting.

sw0.jpg

sw1.jpg

I cut long slots with only short tabs holding the fingers/pedals to the main body, and was able to bend each pedal by hand (a little bit at a time to try to keep then even).

fp bottom bend slots 2.jpg

fp bottom bend slots 3.jpg

fp bottom bend slots 1.jpg

This is what it looked like fit into the fire pit bottom. I welded it in.

David

patch in fire pit.jpg

[plasmanewbie]

Pretty awesome example David. Looks great!

[adbuch]

Pretty awesome example David. Looks great!

Thanks Plasmanewbie! That was a fun project and probably the first time I tried cutting some relief slots for bending. It worked out great and my friend was happy with the result.

David