Parallel angle issue

[jounila]

Hello, I have trouble getting decent plasma cut quality on my home built router. The plasma cut is very angled when cutting thick steel and when cutting thinner steel with lower amperage/lower speed.

The CNC router produces very nice circles when equipped with a marker.

On these cuts I am using: 80A, 1.5mm nozzle, 6 bar air. 5mm was cut with speed of 2000mm/min, thicker (16mm) is cut 500mm/min. Pierce height: 3.5mm, cut height 1.5mm

The plasma is a 100AMP Stahlwerk with pilot from ~2010, so a chinese shitbox but I was hoping to make it work.

[adbuch]

I would recommend checking to make sure that your torch is perpendicular to the table. In other words, at 90 degrees - so in a perfect vertical position.
David

[jounila]

I would recommend checking to make sure that your torch is perpendicular to the table. In other words, at 90 degrees - so in a perfect vertical position.
David

It was checked with a square but maybe its not absolute 90 degrees. Is it possible a 0.5-1 degree misalignment can cause a bigger angle on the cut?

[adbuch]

Yes. Also if the cut height is too high or too low this can cause excessive edge bevel. Also if your consumables are badly worn, this can sometimes result in more edge bevel on one side of the part. Also check your o-rings in the torch. A leaky o-ring can can cause the edge bevel to be more pronounced on one side of the part.

David

[jounila]

Yes. Also if the cut height is too high or too low this can cause excessive edge bevel. Also if your consumables are badly worn, this can sometimes result in more edge bevel on one side of the part. Also check your o-rings in the torch. A leaky o-ring can can cause the edge bevel to be more pronounced on one side of the part.

David

CutHeight2.png

Okay, thank you, I will try to align the torch better. If u have time; can insufficient air flow problems cause problems like this?

[adbuch]

Yes. Also if the cut height is too high or too low this can cause excessive edge bevel. Also if your consumables are badly worn, this can sometimes result in more edge bevel on one side of the part. Also check your o-rings in the torch. A leaky o-ring can can cause the edge bevel to be more pronounced on one side of the part.

David

CutHeight2.png

Okay, thank you, I will try to align the torch better. If u have time; can insufficient air flow problems cause problems like this?

Possibly.

[weldguy]

That looks to me like it could be a damaged nozzle/tip. Once the orifice is no longer round the air flow will veer the arc off to one side. Important things are good consumable condition, clean dry air, for holes smaller than 1" reduce cut speed by 50% from what you would cut a straight line at, and cut direction is important also so the bevel edge is in the waste material viewtopic.php?t=30272

[jounila]

That looks to me like it could be a damaged nozzle/tip. Once the orifice is no longer round the air flow will veer the arc off to one side. Important things are good consumable condition, clean dry air, for holes smaller than 1" reduce cut speed by 50% from what you would cut a straight line at, and cut direction is important also so the bevel edge is in the waste material https://www.plasmaspider.com/viewtopic.php?t=30272

Hi, I am still struggling with this parallel angle problem. The work piece is squared, torch squared, air is dry, nozzle good, cutting direction is correct.

We even borrowed a friends better quality plasma cutter and still we get the same parallel angle when cutting. The arc marks on the cut are more straight with the friends plasma, but on the piece there's still the parallel bevel present.

I'm lost on what to try next. Could a THC solve this issue?

[Joe Jones]

Increase your Pierce time and slow down your cut speed. The flame is going to take the path of least resistance. If you pierce a hole and begin moving before the pierce is fully through the material, the leading edge at the top of the material will be hotter than the trailing edge through the bottom of the material. Therefore, the flame will Lag behind and caused that angle type of cut.

[adbuch]

That looks to me like it could be a damaged nozzle/tip. Once the orifice is no longer round the air flow will veer the arc off to one side. Important things are good consumable condition, clean dry air, for holes smaller than 1" reduce cut speed by 50% from what you would cut a straight line at, and cut direction is important also so the bevel edge is in the waste material https://www.plasmaspider.com/viewtopic.php?t=30272

Hi, I am still struggling with this parallel angle problem. The work piece is squared, torch squared, air is dry, nozzle good, cutting direction is correct.

We even borrowed a friends better quality plasma cutter and still we get the same parallel angle when cutting. The arc marks on the cut are more straight with the friends plasma, but on the piece there's still the parallel bevel present.

I'm lost on what to try next. Could a THC solve this issue?

Have you installed new consumables into your torch?
David

[weldguy]

In your pictures above you are cutting small circles. For test cutting and trying to get squarer edges I would cut 2" squares or 1"x2" rectangles. Once you have it dialed in for those you would run with those settings and just reduce your cut speed by 50-60% for holes smaller than 1" in diameter. Can you cut a square and post pics?

[jounila]

Alright thanks for the tips again. I'll try them and post pics of cutting squares soon.

Yes I have tried new consumables on my own plasma and a new set of consumables also on friends plasma.

[ROKCRLER]

You said you're cutting at 6 bar, on both of my cutters, one hypertherm and one thermal dynamics, I had beveled cuts due to low air pressure.
I now have my shop air set at 120psi/8.25bar since the machines self regulate, TD has a manual regulator on the back.

Try increasing your pressure, unless the machine states it only needs 6bar.

Air pressure, dry air and lubed orings on the torch has improved cuts for me.

[Joe Jones]

You said you're cutting at 6 bar, on both of my cutters, one hypertherm and one thermal dynamics, I had beveled cuts due to low air pressure.
I now have my shop air set at 120psi/8.25bar since the machines self regulate, TD has a manual regulator on the back.

Try increasing your pressure, unless the machine states it only needs 6bar.

Air pressure, dry air and lubed orings on the torch has improved cuts for me.

Right! As I recall (I haven't use my plasma cutter in four years, since the covid zombie apocalypse) but I remember that it requires NINE bar of air pressure.

Joe

[adbuch]

You said you're cutting at 6 bar, on both of my cutters, one hypertherm and one thermal dynamics, I had beveled cuts due to low air pressure.
I now have my shop air set at 120psi/8.25bar since the machines self regulate, TD has a manual regulator on the back.

Try increasing your pressure, unless the machine states it only needs 6bar.

Air pressure, dry air and lubed orings on the torch has improved cuts for me.

[jounila]

Hello, I cut a couple of 50mm x 50mm 10mm thick squares with:
1.1mm nozzle, 43A, 400mm/min, 7bar, cutting height 1.5mm, pierce height 4mm, pierce delay 1500ms

After increasing the air pressure I got 3 kinda straight sides (good enough for me) and one VERY angled. Previously the angle has been parallel on two opposite sides so I guess some progress, but kind of weird. I cut 3 squares and they all came out the same.

Then i changed the nozzle and the bad angle stayed but i got an angle on another side next to the bad side, but not opposite side.

Also I measured the arc voltage with a multimeter and it showed crazy voltage hovering between 1600 and 1800 volts?! How can the voltage be this high? Users with THC always talk about arc voltage in the range of ~100-160

Here is pictures of 3 good sides 1 bad. I had to slow down cutting speed a bit because after the first cut it wasn't cutting through on the side with bad bevel.

[weldguy]

Looks pretty good but ya that extreme angle on the 1 side is strange. Def looks like you could slow it down a bit more also which may help