Warping

[Metriccar]

I've been making some 18" diameter metal discs with art in them out of 14 gauge. There was no warping. I started making a few designs where there is more metal cutout (in other words the remaining metal is thinner/less solid). This coincided with me using a new sheet of metal. Both of the new designs show warping. I'm thinking it's the new design as opposed to the new sheet of metal.

Is there any way to stop this warping? I have a down draft.
Or do I just need to go to a thicker gauge, say 12 ga.

[DXF]

There's probably no way to stop metal from warping when you heat it to around 2000 degrees. I have found that cold rolled steel cuts a whole lot better than hot rolled and cleans up better. Also consider the order that you cut the piece in as far as size of the cuts. Go cut all the small stuff and move around. Then cut the large cuts and sometimes depending on the cuts let it cool till you can touch it with your hand and then cut the next one. If there is a lot of detail I let the whole thing cool before cutting the outline. Almost everything I cut warps to varying degrees. Once you get it basically sanded learn how to roll it thru a sheet metal roll to get the warp out. You'll need a flat surface to lay it on in this process so you can tell which way to roll it. Takes a little practice but if you roll it several different ways most of the warp is gone.

Dave Hanks

[Shane Warnick]

In your design edge software there is a place to change how it cuts, or the cut path order. One of the options is reduce heat. It results in more rapid travel but minimizes the warping.
Shane

[plain ol Bill]

It also may help if you get a spritzer bottle of water and spray right behind the arc.

[jimcolt]

Use the lowest possible power, the fastest possible cut speeds, and use the Design Edge software functionality that spreads out the cut path sequences to equalize heat input. I rarely get warpage.

Jim Colt

[weldor2005]

Not to contradict DXF, but cold rolled will warp more than hot rolled as it has more residual stress left in it from the rolling process. These stresses do funny things (distort) when heated and released.

[DXF]

Not to contradict DXF, but cold rolled will warp more than hot rolled as it has more residual stress left in it from the rolling process. These stresses do funny things (distort) when heated and released.

I don't use hot rolled anymore. Cold rolled steel is stronger, cleaner, easier to tig weld and spot weld and from my experience cuts nicer. You can control the heat stresses a little by thinking thru your cut sequence.

Dave

[beefy]

Not to contradict DXF, but cold rolled will warp more than hot rolled as it has more residual stress left in it from the rolling process. These stresses do funny things (distort) when heated and released.

I had some big square tube steel I got for free and wanted to make some C-channels from it, so I cut it lengthways down the middle. Well that was a lesson learned about residual stresses in steel. I ended up will banana shaped C-channels.

Haven't personally had any experience with plate yet, but when residual stresses are mentioned I talk note LOL.

Keith.

[plain ol Bill]

Keith when cutting tubing I leave a tab on tab both ends and in the center. After letting everything cool off I cut the tabs w/ a zip wheel on a grinder and warpage is minimum.