What would be the narrowest strip of material that could be cut on 1/8" mild steel?
I tried cutting some strips 7/16 x 32 & it did not work very well
Try again and add tabs to hold the material. I assume the heat warped the material.
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Phillip gave a great suggestion.
This is also something worth considering:
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Water pan full when cutting?
What kind of plasma cutter and what settings? (Particularly Amperage and Cut Speed (IPM) )
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narrow long strip can do a totally nightmare especially with aluminum. I normally flood the sheet while doing it and cut as fast as possible. I also found that cutting strips on the 4’ direction on a 8’ sheet will wrap a little less.
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trying to make cuts in the y axis on a sheet that is 72" long, have sheet clamped to table, water pan filled to about 1/2" from top, hypertherm 45xp set to 45 amp 129 in first, then tried 100
try production speeds on the chart at 181ipm. Also dump a bucket of water on the sheet during the cut.
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will try that, are the cut charts generally in the ballpark?
Yes. Hypertherm charts are very close but varies with:
- Actual cut height (confirm that your cut height is actually what the gcode was planning)
- Good quality air (volume and dryness)
- Consumables in good condition (for best results you will want new consumables so this is going to be expensive both trialing as well as your actual cut)
- Stable power supply (if you have marginal power to your shop and the air compressor kicks on this could affect the cut). If you have everything resting on a 50A breaker (plasma cutter and air compressor) you will be in trouble. If you have 100A you should be fine.
- Gremlins…always a risk of gremlins.
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I would ignore the charts, make some test cuts starting at a low speed then bump up 10 each time. Example start a test cut at 30, then 40, 50 60 70 80 90 100 110 120. Run these first batch at 30amps, then run a test at 32.5, 35, 37.5, 40, 42.5, 45. Somewhere on the tests you will find the best version. You can get a water bottle or pump sprayer like for spraying weeds etc, run it while cutting and you will get a benefit for warping.
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you see a difference in 2.5 amps?
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I tried cutting 1/8” wide slot tests in 1/8 6061. The accuracy of the slot changed every 2.5A on razorweld. I found 37.5 at 70 produced the most accurate .125” slot. 35 was tight when trying to push in a piece of .125 scrap into the slot. 37.5 was snug but fits. 45 got slightly loose.
your RW 45 must be different than mine there is no way I could tell if I was turning the knob 2.5 amps I would have a hard time judging 5 amps.
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Squirt some grease up in the knob.
Success, increased cut speed & sprayed it with water.
Thanks for the suggestions
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Nice when I’ve been cutting these long 4 ft strips that are only 1 in wide, I’ll put in my 65 amp consumables and run at 65 amps so I can move at 280 in per minute cutting speed.
Pretty simple. less time cutting = less heat.
I’m depending on what I’m doing . Eg if I’m cutting quarter inch aluminum strips I’ll use 85 amp consumables. I know you don’t have the option to put in bigger consumables but you probably noticed from the cut charts that hypertherm likes you to match the machine output amperage to the consumables rated amperage. There’s a few exceptions like some fine cut settings, gouging settings and marking settings.
Hypertherm spent a considerable amount of time energy and research on the cut charts in your manual they are an exceptionally good starting point for 99% of situations.
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More likely less heat differential which is what causes the warping.
I feel like these are the same things.
Less cutting time would =less heat =less heat differential 
Yes you have the added amperage difference between 45 to 65 amps ,in my case. But the torch running correctly should be putting 99 plus percent of the power in two cutting not to making heat.
I know faster works better for me on large nests.
Yeah fast doesn’t produce the best edge profile sometimes but there is so many circumstances where having a great edge profile doesn’t matter at all. It’s also a lot better than dealing with a warp that’ll end up scrapping the part.
The water is also a big part of the heat differential cuz it doesn’t allow the heat to build up. Which is the one problem with cutting a thin piece right against the edge of a sheet is that little scrap off cut between the finished piece and the edge can’t absorb a ton of heat because it’s a small amount of square inches. So when nesting you’re going to want to have strips near the middle of the sheets and cut first so they have large square inches of scrap material for heat to absorb into.
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Oh Tin, what am I going to do with you!!!???
You have forgotten that Aluminum has a heat flow. Heat it faster, less time for a difference between the cut point and the neighboring material to develop and therefore less warp… ipso facto
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I know the wrapping effect on Aluminum is way worse then on mild steel .
This statement was crafted around my understanding of heat flow.