What metal to use?

[little blue choo]

Extra 100 amp service installed, new compressor, refrigerated air dryer and filters installed, Table set up and motors tested. I'm finally ready to start burning metal, hopefully cutting will follow but probably just burning for a while. Going to purchase metal on Monday. My question is what should I purchase to learn on. I'm sure I will be ruining a lot of metal to start with so I would like to keep my cost down but don't know if a certain gauge is better to learn on. Any help would be greatly appreciated.
Thanks
Rick

[tirediron]

If you have a metal business near you ask to see if they have drops. Drops are left over from someone who only needs a portion of a full sheet. I try to get drops as I don't really have room in my shop to store the larger pieces. Usually you can get any size gauge, that way you can experiment.


G

[little blue choo]

Thanks Tirediron. I will ask them about drops. Is there a gauge to thin to learn on or should I use the thinnest (cheapest) I can get?

[Metriccar]

The Arclight should already have the settings for the Hypertherm loaded in SheetCam. I would use the FineCut consumables slow chart settings. The chart goes down to 26 gauge, which I don't think many of us cut that thin of metal. Most of what I see is 16 gauge or up. You'll just want to use whatever metal that's cheapest to start, so long as it doesn't have any plating/coating on it. For example galvanized steel will create toxic fumes. If you just get cold rolled or hot rolled it will be fine. I do about half and half cold rolled and hot rolled. A lot of people say cold rolled cuts easier, which I have not found to be the case. They both cut about the same for me. hot rolled will be cheaper, but will have mill scale on it which depending on what you are doing may need to be taken off. I must have good sources, because most of my hot rolled metal does not have any mill scale on it.

I think you'll only want to get the basics figured out on the cheap metal, in other words once you have figured out how to operate the controls to cut a complete shape out, then just go to the metal thickness you plan to use and start cutting out the shapes you want to fine tune the cut settings, because you'll have to have different machine control settings dialed in for different thickness metals, and if you never intend to cut 26 gauge, for example, it may not be helpful to get 26 gauge dialed in for the best cut because you'll just have to dial in with whatever gauge you actually plan to use all over again. I just use the chart settings in the Hypertherm manual, I see no need to deviate from that. But the manual does not give all settings, such as lead in length, how long to overcut/undercut at the end of a cut, how much slower to cut when cutting small circles, acceleration rate, etc. This may take some trial and error, and going back and looking at old posts by other Mach3 users may help to see what settings they came up with for the cut path.

[michmetalman]

I use 16 gauge most often and get it for around $50 for a 4x8 sheet, but yes...try to find some drops, always a bit cheaper.

[Capstone]

Just to add... Steel companies, the ones that sell only metal, typically sell by the pound, so regardless of the size, whether it's a drop or not, the amount of metal you buy regardless of thickness will ultimately cost you the same per pound. The other thing is that some of these steel companies have a free delivery range for orders over a certain dollar amount. So, by the time you travel and take time to look through a drop pile, it might make more sense to just buy a single 4x8 sheet of 16ga, 1/8in(10ga), 3/16in and possibly 1/4in and have them delivery it all at once. Just keep in mind, the two bigger sheets are not one-person manageable if you don't have specialized handling tools on site.

I went the "hunt for drops" route early on too, but when the place I had really nearby go out of business, it just made more sense to have full sheets delivered because the minimum for free delivery in my case was $200.

Just some more input to consider.

Good luck

[steel 35]

Somewhere I read it is not the easiest to use thin sheets for the first time, and I would recommend 10-11G; try to cut widths at sizes you can use later 12 to 16 inches long instead of 6-8 that you no are going to be in the way, widths from 1/2 to 4" or more. Have a ball and don't be afraid to make something! That's when you don't want someone around to see you giggle like a kid!

[acourtjester]

For test I would say make a ink pen holder and check out the operations on paper. With this you can visualize the lead in / out and how the table reacts to turns or circles. With lead in/outs you just want them to be so the pierce and ending cutting are away from the actual cut. There are other posts here the deal with this action. As stated the cut charts in the book are very close if not right on some small changes in speed may be only for dross amounts when actually cutting. When I buy (1/4") metal the whole sheet most of the time is the cheapest I use a trailer to to pick it up. When I get it home I slide it off the trailer back edge and cut 2 foot sections off. At 72 it is easier to handle (2' X 4') and I don't cut large pieces either. With thinner metal you get in to the warping that is when a DTHC comes very handy.
I also go along with the giggle phenomenon it does you good.

[urbnsr]

I stopped by the local scrap yard and asked for the location of their flat stock. I pulled a bunch of different sizes just for practice. Very cheap. I think I still have some of it on my remnant stack.

HTH
Paul

[beefy]

I wouldn't say any particular gauge is best to learn on. What I'd say is learn on the gauge you plan using the most.

Every thickness has a different set of cut parameters so learning on one particular thickness may not be much use for a different one.

Keith

[little blue choo]

Thanks for the help guys. I THINK I'll be cutting 16 gauge a lot so I'll start with that. I buy tube, angle and flat bar from for by Train building business from Pennsylvania steel in Stanley NC. Their delivery truck comes by my shop twice a week on its regular route and they don't charge me a deliver fee. Will also check with my local scrap yards. I may leave them a card and have them call me when they get in flat stock. I feel like I can't fail with the help of this website and all it's great members. Can't wait until I can contribute something.