1/2" Cutting troubles, asking for insight

[LMironworks]

The 80S has been a great addidtion to the shop, espically 1/4" plate. I decided to try cutting some 1/2" parts for my personal cart and this was the best I was able to achieve, here are my settings.
70amps
.50" material HR
2.6 sec pierce
10 ipm
73psi
1.7 tip
.200 pierce
.125 cutting
Running a M60 filter

I should be up and running my drier soon, but should I be getting this much dross with this speed of cutting. I have tried up and downs cutting this part at various settings. The dross is hard to knock off, but the parts come off clean, when cleaned up. I am just worried about the IPM I think I should be getting a better speed than 10 ipm.
The 80S is a upgrade in amps over a PM 30 for the past 2 years. I do get alot of moisture in the air lines, because I swap in a air nozzle and I can just see the moisture spraying out at 80 psi. This is all before it goes through M60 filter. Also another issue is with the white spacer that protects the tip only after 20" of cutting through 1/2" HR, it is toasted and broken off, I'm sure this has to do with the heat and the low IPM. And with the addition of the air dryer soon, I know the speed will pickup, but in the meantime and insights would be great.

[geezer]

Here is some interesting reading on Dross,,,,,http://www.centricut.com/TA_CutQuali...lems.htm.....I assume you have a breaker on your set up that is larger than 50 amps at the wall plug,,,,cause the rule of thumb is you can only get 10 more amps out of the plasma cutter than the supply at the wall plug,,,,eg,,a 50 amp breaker will run a 60 amp plasma cutter,,,I have a PP80 and if I want to get the full 80 amps my breaker for the wall plug must be at least 70 amps,,,

The dross I see looks like low speed dross,,,try a little more speed or reduce your amps...

[performance]

The thing you really need is a Sq05 or S-125 Autocut torch for dedicated CNC cutting. They don't make a 1.7 tip for the S-75. You are way too far off for cutting too. You should have a less than 1/8" down to 1/16".

[LMironworks]

Yes I do run a 70 amp breaker, and have run the full 80 amps with no problem with the breaker. Great article and I;ll print that on out and catch up on the info today at the shop. Thank you for the input.

[LMironworks]

I;ll defintely have a look into that torch setup. The tip size is 1.4, sorry about that. Yes they only come in
1.0=(20-40amps), 1.2=(40-60amps), and 1.4=(60-amps), is what I run them at, hopefully these are good to go.
But that S-125 torch sounds interesting, do you think that is what is causing the problems with the white spacer to melt off?

[performance]

The S75 torch doesn't have those sizes. I think you need to recheck that. The info you have regarding size versus amps is way off. 1.0 is for 50 amps or so. 1.2 is for 70 amps.

[LMironworks]

Holy smokes, yeah I am, now you got me very curious reagarding the cut quality. I;ll keep you posted on the results. I did check out the S105 torch and it sure does look beefy, espically around the nozzle end. I;ll be giving a call in to get more information about that.

Thank You

The S75 torch doesn't have those sizes. I think you need to recheck that. The info you have regarding size versus amps is way off. 1.0 is for 50 amps or so. 1.2 is for 70 amps.

[geezer]

One thing I should have mentioned about low speed dross,,,,is how all that metal gets there,,,if you think about a flame as having 4 sides like a box,,,a back side a front side (direction of travel) and a right and left side,,,as the flame moves it spits the metal down and out on the front side,,,but because it is moving too slow the left and right side continue to melt metal and eventually the cut widens to the point where molten metal is no longer spit out ,,,rather it drips,,,,and the metal shows marks on the cut wall in a jerk jerk pattern,,,almost like you can see every movement the stepper motors made....A rough discription on my part,,but I'm sure you get the idea about what happens when you travel too slow...

[geezer]

Check out this utube vid,,,try and estimate the travel speed compared to your setting of 10 ipm....http://www.youtube.com/watch?v=CILxSlricyc

[geezer]

Check out this utube vid,,,try and estimate the travel speed compared to your setting of 10 ipm....http://www.youtube.com/watch?v=CILxSlricyc

After watching this video many times, I came to the following conclusions.

The machine and the plasma torch are not part of the issue…I doubt if the CNC machine moves in such a silky manner or the torch has a magical flame to account for this fine cut.

Is the machine or the torch superior to what you and I have…I doubt it….rather what we see here is a superior setup guy….a fellow who knows what he is doing…

When I first saw the height of the pierce cut,,,I thought it was too high,,,well,,,it works and probably helps keep the nozzle clean from splash back….

Notice that the “lead in” is little longer than you would expect…this longer lead in gives the torch and flame a chance to settle down and stabilize prior to starting to cut the piece…torch height and air pressure are now consistent for the cut…

Speed,air pressure and amps are always variable,,,however they can adjusted through trial cuts…

What I really learned from this video was the importance of having the water in the water table high enough to contact the plate…..the advantage of this …is to cool the plate and prevent residual heat from building up and creating a widening of the cut and resultant Dross,,,,water in a water table is just not for controlling sparks….

Like I said before…the operator is very skilled and knows his machine…that’s why it looks so good..

At least that is my take on the whole affair,,,hope this helps someone…