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Spatter on bottom of lens

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sparky4808

Agricultural
Apr 27, 2015
34
Amada FO-3015NT. 3rd lens in a month, 2nd in a week these guys have trashed. The top of the lens is clean but there are pits and burn marks all over the bottom of the lens. Good tape shot, HS calibration done/passed. Running .500 High carbon steel. I will post the cutting conditions. It seems that our first shift can run fine all day and once 2nd comes in, all hell breaks loose. I hate to blame the operator but is there anything I could be missing? The cone was just rebuilt by hypertherm and the nozzles are in good shape. we run 1.4 nozzles on this machine
 
 http://files.engineering.com/getfile.aspx?folder=270b0edb-f001-43f5-83f3-ef45fe5e2e0d&file=IMG_20151123_070145995.jpg
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Is there anyway of watching the operator? If the conditions don't change then the spatter might be coming off the plate from rust or oil?

 
I am not here to watch the 2nd shift operators. The conditions shown are what I walked into this morning. which seem pretty common for this material. I can tell you that they coat this particular material with an "Anti-spatter" spray chemical, but they have used this since I can ever remember without having this problem.
 
How do the different operators handle piercing issues? If the pierce doesn't go all the way through does he jack up the power and blast through? That would cause spatter to shoot back up.
 
Usually increasing the pierce time takes care of it. So as it cuts now, there is no pierce condition. it is pretty violent and blows shit everywhere but makes a good cut.
 
I have this issue with 2nd and 3rd shift changing cutting condition, it would only be his fault if hes changing cutting conditions without knowing what hes really changing, if not your laser might be pre-focusing this happens to us when our C.O.E. is getting high, check your C.O.E.
 
New internals/externals under 1000hrs ago. COE is 994. Alignment is dead nuts.
 
I hate to go "Old School" but it seems like a good place to start.

In my experience, spatter on the lens almost always comes from the pierce. With that in mind, why is the pierce type set to zero? I am not sure what the heck that does but it cant be good. Second, assuming it actually does go to pierce, there should be a 7 in the last column of the pierce page. Search around the forum for "nozzle pierce matrix" I am pretty sure I have posted it before. I will do it again if you cant find it.

The 7 does the 6 pierce three times. Half inch is the only time we use it but with the 1.4mm its awesome.

Last, Its my preference to have all the gas pressures the exact same when cutting with oxygen. Cut pierce edge approach. Its a lot easier on the NC regulator and more predictable for trouble shooting.
 
@LaserNinja

I have to agree 100% with you that the pierce data should NOT be 0. Almost every other program has pierce data for .500CRS. I don't know why they programed it this way for high carbon. We have 2 lasers, 1 FO3015NT and 1 FOM2-3015nt. Both have been victim of this lens problem. Coincidentally they run the same program on both lasers at different times.

I found a post on the nozzle matrix but it seems the link doesn't work anymore. I would really appreciate if you could post it again. I don't know a ton about conditions other than what i've learned in "cutting Know-how"
 
Please don't laugh. I left Amada almost ten years ago so my information is old and for some reason they won't let me have anything current... Go figure. My point is that the matrix is a bit confusing because it pertains to older style machines but is still useful. The last column says something like M103A7. In your case, as for all NT, and M2, just put the 7 in the last column of the pierce page.

The newer version of the chart also specifies the AO settings which is very helpful.
 
 http://files.engineering.com/getfile.aspx?folder=5449fe3b-fe77-49ac-94a4-fa916edfa61c&file=nozzl&pierc_matrix4.xls
For some reason it just brings up a blank page like the last 2 I found while searching the forum. I cant figure out how to private message you my email ( sorry I don't want any more spam than I already get) what is the best way to do this?
 
Got it, thank you. I will try this condition change next time they run these parts.
 
It shows the last update on the pierce page was on the 23rd so if not you someone changed something.
 
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