45 amp hypertherm cutting 5/16" plate

[Waylon80]

The dross is from cutting too slow. The varying angularity indicates a damaged nozzle and/ or shield orifice....probably caused by the previous (not cutting all the way through) issue......this causes blowback on the torch and damages consumables.

Physical cut height is more important than setting the arc voltage to book specs. The "book" voltage is correct when everything else (cut speed, cut air pressure, new consumables) is correct. Adjust the voltage once you have all other specs where you want them.....until the physical height during cutting is correct (.06" in this case).

Some height controls (Plasmacam and others) use voltage sampling to auto set the arc voltage.....so on those systems you do not need to set arc voltage)

Jim Colt Hypertherm

Well Jim I was able to figure out how to do a test cut with THC off to figure preset volts. Cut height was set to 0.06 and it never moved. I used all the settings for 3/8 steel accept bump federate up to 40 Luke you had suggested everything else was done just as the manual suggest. I even put a new nozzle and electrode in. Here are some pictures of the part after cut. It looks like the dross is still alittle heavy though it was much easier to knock off then last time too. It was still alittle beveled on a couple sides. The top looks good but can't say that about the bottom of it.

[Waylon80]

I then tried cutting one of those brackets at the same settings as the test cut I just did even with the THC off. Which by the way I forgot to mention that the recommended preset volts I got from running the test cut was 105-108. Anyways the bracket turned out alittle better than the last bracket I tried to cut though this one still had a pretty decent amount of bevel but this time only in one direction not both.

[Waylon80]

Here's pictures of all the consumable after cutting the test cut and new bracket. Here's the electrode and nozzle

[Waylon80]

Here's the swirl ring and retaining cap.

[Waylon80]

And here's the nozzle shield. My only concern towards the consumables is that on the shield when you hold it up to the light the little holes at the bottom (which I figure is for the air) are all practically clogged up in the close up picture you can see that there is only one hole letting light in which means it's not clogged up.

[muzza]

Always a bit hard to tell for sure in a photo but the nozzle looks OK, when i zoom in on one pic it looks slightly out of round but to tell for sure you need to inspect it with a magnifying glass or similar, it doesn't take much to throw the flame off a bit. Your shield appears to have blocked holes and also one hole looks badly damaged so I'd ditch that, The inside looks like mine did when my old compressor dropped a cylinder and sent oil through the system. I'd clean the thread on the retaining cap, not that I think that has anything to do with your taper and the only time I get dross like that is by going way too slow.
For what it's worth I cut 3/8 at book specs only slowing down to 60% for holes and get similar results to Sean's pic above, when I'm doing 5mm or 5/16" I normally just run it at the 10mm or 3/8" settings and bump the speed up a bit in Mach.
Murray

[SeanP]

Definitely looks like the shield, those holes need to be kept clear and the centre hole perfectly round, I would try a new one if you can.
At a push you might be able to recover that with a right size gas torch tip cleaner, but need to be careful not to open up the holes.
That voltage setting would be same as what I get on new electrode.

[jimcolt]

Looking inside your shield I see where steel has blown back inside.....and the center hole is not round. This , along with the nozzle orifice is what controls the shape of the arc.

Steel blown inside the shield shorts it to the nozzle and blocks the concentric shield air flow that controls the arc. Steel only gets inside the shield from faulty piercing (too close, inadequate pierce delay time). Your nozzle looks good from the pics.....though you need better pics....I use a 10X jewelers eye loupe to inspect the nozzle orifice.

So....whether you want to believe it or not...the wildly varying angularity is caused by damaged consumables (shield definitely, nozzle...I cannot tell from your pics).....unless your torch is mounting is wildly "unsquare" to the material.

The dross is affected by damaged consumables.....but also speed. I posted a pic earlier of a piece of 3/8" cut with consistent angularity. I am 100% sure I could cut that same part on your machine. Pierce height, pierce delay, good consumables, the correct arc voltage to maintain .06" during stead state cutting.....and the right speed are what it takes.

On some of your pictures you show a fork shaped cut.....which shows a lot of cuts close to each other. When this occurs heat will build on the close proximity cuts....which can also produce dross....this is unavoidable in many cases.

Jim Colt Hypertherm

[acourtjester]

I had a shield cause a problem some time back now I keep spares it very easy to change one out and if the problem changes toss it, if not go back to the old one. You can waste a lot of metal or spend $18. for a new shield.