cut quality Hypertherm 1650

[hok]

Dear all,

I am experimenting with the hypertherm 1650 with duromax torch and mechanized setup. So far the results are very poor. I attached a couple of pics.

the thinnest material i tried it on is 4.3 mm. speed 3300 mm/min, 130v, 60A
Then there is 9 mm, speed 700 mm/min, 130v, 60A
and 12 mm, speed 500 mm/ min, 130v, 60A

No matter how i change the speed, the lines on the cut are still visible with intervals between them becoming larger as the speed increases.

If anybody could give me any pointer on the matter, it would be much appreciated.

Thank you beforehand for the help.

Hok

[hok]

Sorry, the picture of the cut with the 4.3 mm material is this one. One could see very well the lines on the cut.

[jimcolt]

You seem to have roughness in your motion....or perhaps an oscilation in the z axis (height control). Attached is an edge picture of 6mm and 9.5mm cuts with the Powermax 45 torch.....these cuts were done at 45 amps, cut quality with the Duramax torch will be the same. Smooth, fluidic motion, correct height and speed....will produce smooth edges.

Make sure the cutting bed slats are not oscilating as well...this is very common!


Jim Colt

[hok]

Thank's Jim for the prompt reply.

Wow, I didn't expect the cut would be that good with plasma after all i have been through.

I don't understand what you mean by the "cutting bed slats are not oscillating as well... this is very common."
wouldn't the thc compensate for any distance change between the nozzle and the material? Unless the thc itself is not working well. hmm...

hok

[keebler303]

I think what Jim means is that when your gantry is accelerating and decelerating, it introduces a lateral oscillation in the whole machine. If your slats are not well fixed to the machine, they can wiggle back and forth, which means your material is wiggling back and forth under the torch, obviously that is not ideal. Have your machine run through its paces and keep a finger on the workpiece to see if you can feel it moving. A more accurate way would be to put a dial indicator between your machine base and your work. As Jim said you need smooth, accurate motion, which cannot be obtained if everything is swinging back and forth as you cut.

Matt

[hok]

thank's Matt.

it is definitely something i am going to check. However, the table where I put my steel plates itself is not attached to the whole system. The gantry hangs independently from the table. So when the gantry's moving, it wont shake the table. Still, I am going to check for any movement in all elements.

I have a question though, would a 100 amp powersupply like the 1650 produce different result at low amperage such as 45 amps from a 45 amp powersupply like the powermax 45. Since this is an inverter system, I have worries that the 1650 is not optimal to cut plates with thickness of 4.3mm, 6 and 9. The PWM signal would be too chopped up.

A colleague told me, using the same mechanical gantry that we have but a different powersource (thermal dynamics A120), his cut on a 20 mm plate is much better than on a 6 mm plate. Could it be or is it just because they couldn't find the right parameter yet?

I tried slower speed, although the lines don't appear sharp but they are there with different interval (larger) than before. (pic is the left of the three from my first post in this thread).

Sorry if my questions sound silly. I am THIS new to plasma cutting.

Hok

[hok]

oops sorry, wrong info. with slower speed, the lines are more prominent. higher speed, the line intervals get wider and the cut side is almost bumpy.

hok

[jimcolt]

If you have the Duramax torch on a 1650.....and use the 45 amp shielded consumables...then your cut quality will be virtually identical to cutting with a Hypertherm Powermax45, Powermax65 or Powermax 85 using the 45 amp shielded consumables. The process design (conical flow nozzle/shield technology) is the same.

By oscilation of the slats....I mean the the slats....if loosely mounted...can develop an oscilation in the x or y direction that will allow the part to vibrate back and forth...creating pronounced lag lines on the cut edge.

I have also seen z axis movement (up and down) or rapid oscilation that will produce a similar edge appearance.

When I see pronounced lag lines as evidenced in your photos I will place my hand on the torch while it is cutting....if there is any roughness in the torch motion...you will feel it and often be able to determine if it is related to one axis, or one direction. If the torch motion feels perfectly smooth.....then do the same (place your hand on the plate) to the plate to determine if there is any movement there.

Any slight anomaly in motion will show up as a gouge or lag line on the plate.

Jim Colt

[hok]

thank's Jim,

so basically mechanical aspects of the table/gantry instead of the electrical aspect of the power supply.

i'll get back to you guys with more updates.

hok

[jimcolt]

Most likely motion related. Could be a gas (air) flow or restriction issue.....could be damaged consumables, could be incorrect height or speed......but I suspect you have already verified that those issues are set to the specs in the Hypertherm manual. It would be extremely rare for an electrical issue to cause cut quality problems.


Jim Colt

[Sunmixed]

Originally Posted by jimcolt Make sure the cutting bed slats are not oscilating as well...this is very common!

Jim, what CNC brand is being used to cut this extremely high quality part?

[hok]

thanks Jim.