Cut height, (What say Ye?)

[RunsWithScissors]

So, my new(ish) machine that I ordered was DOA yesterday so I am waiting on an “actuallly new” machine to be delivered by the Amazon Fairy later today.

In the mean time, I decided to check my cut height as per y’all’s advice.

But I got to thinking that I should probably install the THC “thing-a-ma-bobber” before I do that.

I ordered it when I bought the machine, but decided not to install it in order to “keep things as simple as possible” for a noob. My reasoning was that I should get a few successful cuts under my belt before complicating things with the THC.

So it went really well, and it was basically a “plug and play” operation.

I did a few test cuts, and was not very impressed.

I purposely bent up a scrap piece to simulate a warped work piece, and the first result was not stellar.

Here is the before pic of the set up (with my man-made warpage)

Then my first cut…Not impressed.

Second cut was even worse.

So I started analyzing things and I can’t see anything wrong, but since I have almost no idea what I am actually looking for, that is not not surprising.

So I decide to look at the voltages when it’s running. I have no idea what this will accomplish, but at least I will have something to post here.

F’ing ran perfect for some strange reason…I ain’t complaining, just sayin…I have no idea what happened.

With success as a starting point I decide to give the old “cut height test” a whirl.

Here are my results. Although technically not “statistically significant” I ran the machine 10 times and stopped the cut about 1 inch into it, and broke out the feeler guages.

The 'outlier" made it perfect, but I don’t like “outlier’s”. However even not including that .018 pass, I am still at .064", so I bet that I am damn close to .060 if you factor in “measurement error”

What say you?

[Phillipw]

With that much bend in material you would probably want to change the settings in the THC. Increase the speed the z axis will compensate. I did that cutting pieces out of roofing tin. I had to slow it back down later because I noticed bobbing in the corners of my mechanical parts.

You can run the cut height program that was shared. It doesn’t fire the torch so no slag or top dross to mess with. I would always recommend doing it on thick plate and thinner to see the difference you get

[RunsWithScissors]

Phillip, if I were actually cutting a piece that badly warped I would change some settings, but this was simply a test to see if the THC actually followed the curve.

It worked pretty good the 3rd time, so now that I see it works, I am good.

I put a piece of 3/16 on to test the cut height and weighted it down to try and prevent any movement.

If the optimum result is .060, then I am thinking that these results are acceptable.

[Phillipw]

I got you I was just getting at the fact a good chance the first cut wasn’t that great the bend was to much for the z axis speed.

[ChelanJim]

As Phillip said, some changes in the THC menu will help it react quicker but your extreme “warping” test is going to be a challenge.

Another setting that would increase reaction by THC is to decrease the sample size:

If you have an idea what is a good voltage for cutting that thickness of steel, since you are in the “testing mode”, enter it in the Nominal Voltage section. Decrease sample size to “10”, Increase Z speed to 25% and see if that improves.

Those numbers are all just a shot in the dark…I have never done anything like that.

As far as testing the height: Are you testing on a flat piece of steel or on this bent steel? It needs to be a flat piece of steel because that warped piece is introducing lots of variation of springback.

[TomWS]

@ChelanJim

your extreme “warping” test is going to be a challenge.

It is??? It didn’t look extreme to me. You’ll get those kinds of curves with thermal warping on skinny pieces.

[ChelanJim]

Not saying it won’t happen. Just saying that it is going to be a challenge.

I am eager to see if he can change some settings and get THC to perform up to the challenge.

[RunsWithScissors]

Thanks fellas. Next testing session I will make the suggested changes and post my results.

I just got my new computer and it is running Alibre flawlessly so far. I have a few “hand drawings” that I need to convert to CAD.

I’m hoping to get some more “shop time” this weekend.