Lead in divots in 14 ga

[Dirtmotor]

I know this has been discussed many times , I still have issues with lead in /out divots , The piece in pic is as small as I have tried to cut and is really too small (3 inch circle) its cut out of 14 ga hot roll .

. I have tried all sorts of lead in lengths, and perpendicular , arc etc. as well as played with lead out , and even tried no lead out, still having same issue .I have tried moving start points since this piece and it helped some .I played with amps from 25 to 45 , not much difference , played with cut speed from 120 to 190 didn't make much difference with the divots .Its using a hypertherm 45 xp on a premier plasma 4x4 table .

[weldguy]

My guess is that you have some slop in your drive system on 1 or more axis. If your machine is turned ON, your motors will likely be "locked" up under power allowing you to place your hand on the torch lifter and gantry and gently try to move the XY axis back and forth and feel for any slop. Should be tight and rigid with no movement. That is the first thing I would check.

[Dirtmotor]

My guess is that you have some slop in your drive system on 1 or more axis. If your machine is turned ON, your motors will likely be "locked" up under power allowing you to place your hand on the torch lifter and gantry and gently try to move the XY axis back and forth and feel for any slop. Should be tight and rigid with no movement. That is the first thing I would check.

Thanks , will check it for slop tonight .

[tcaudle]

I would run the file with a marker on paper to narrow it down to either mechanical or electrical. fine point marker taped to the torch and adjusted so it draws on a sheet of flat paper would show any mechanical issues You also need to watch the Z and if the THC is maybe causing diving on turns . You also need to realize that a plasma running at 30,000 degrees and blowing out molten metal wit compressed air is NOT a laser and cutting really fine detail on thin metal is not the best task for plasma. If you are using lead ins where is the divot showing up? Where the lead- in joins the cut?. You may simply be asking too much of a hobby grade machine to cut jewellery.

A.

[Dirtmotor]

I would run the file with a marker on paper to narrow it down to either mechanical or electrical. fine point marker taped to the torch and adjusted so it draws on a sheet of flat paper would show any mechanical issues You also need to watch the Z and if the THC is maybe causing diving on turns . You also need to realize that a plasma running at 30,000 degrees and blowing out molten metal wit compressed air is NOT a laser and cutting really fine detail on thin metal is not the best task for plasma. If you are using lead ins where is the divot showing up? Where the lead- in joins the cut?. You may simply be asking too much of a hobby grade machine to cut jewellery.

A.

Thanks .I will try the marker .The divots are at the lead ins , I do understand the limitations of cnc plasma , I just want to push it as far as I can ,Most of the parts and art work I cut are much larger , however still have a divot problem . Wish I had a laser machine , maybe some day ! The THC was a process to get set up , It does works perfectly now .

[ROKCRLER]

This file is a total guess, but I wanted to test my settings to give you something to compare to. I hope this helps.
Hypertherm 85, finecuts 45a on 12ga.
Top side wire cupped

Back side wire cupped, still has a divot, i think its when the drop out drops and folds the flame.

Assuming you're using sheetcam, here's the SC settings, dynatorch software takes care of the rest that's not filled out in SC.
Keyring hole in separate layer

The rest of the inside cuts get a longer leadin

Dirtmotor3.png (41.17 KiB) Viewed 4132 times

Dirtmotor3.png (41.17 KiB) Viewed 4132 times

[rdj357]

The back side divot is likely from double cutting when the cut path comes back around and meets the point where the lead in came into the part at the beginning. Is there a way in Sheetcam to have the torch stop firing or the path stop short at that point? Maybe it already does but can be adjusted? You can have that happen up to a distance of about half the actual kerf.

[djreiswig]

I think you can program a negative overcut.

[Dirtmotor]

Found an old post on here about using the m10p1 code to quick stop your torch fire ? Not sure I am smart enough to try it . Has anyone used it ? And does it help with the divots ?

[Dirtmotor]

I think you can program a negative overcut.

Thanks for the tip I did try a -.02 over cut and it helped a bunch !

[djreiswig]

Great. Glad it worked.