Hi,
I just started using my Cross fire / Everlast 80s combo and have had good results with cutting mild steel.
I started a project of cutting 3/8 304 SS plate for an exhaust flange and I cannot explain certain problem`s I have.!
As you can see most cuts are ‘‘clean’’ but others have alot of deformation. Since the pierce delay, speed and lead in are all the same, what other settings could cause these issues ?
Any tips would be greatly appreciated.
Thank you !
Couple of the large holes appear to be slightly out of round like make the lead screw is slipping inside the lead screw couple, try tightening the set screws.
But also see what looks to be some cuts maybe starting on the outside not the inside when setting up the contour.
But possible a slipping lead screw putting it slightly out of the correct start position causing that also but I am reaching a bit.
Geometrically are all the holes in the correct spots?
Thank you for the response.
I checked the lead screws and everything seems to be tight. I checked dimension and everything seems to be close.
I tried increasing the distance of the lead in and reduce the radius.
I ran a test 3/8 hole at 25ipm, 70amp and got a decent hole for the top, but the other side is distorted and smaller.
Is there anyway to reduce the bevel of the hole ?
You will need to use F5 gas it makes a world of difference in cuts. The bevel is inherent of plasma, small holes I drill rather than burn.
Good video information on this page for hole quality
Some hole troubleshooting
And irregularity thoughts
Miller has some good tutorials and articles on their website too.
If you know a teacher or Hypertherm dealer, they have a really good set of educational materials (but fairly pricey if you’re not) that can help teach you all about plasma cutting. Excellent source and much of it applies to any machine.
Ok so did more test and something is not right …
The cut quality is good, but its the positionning of the holes that is not good.
Both holes are supposed to be at equal distance from the exterior edge …
Everything seems to be ok except that one hole and the top right one that I cant seem to figure out why its out of round.
If anybody as any tips it would be great, because throwing away 3/8 SS plate is not something I like doing … $$$
Do you have the inside of that hole selected for the toolpath or the outside? Might be cutting outside the line instead of inside where you want to cut so it’s moving a kerf width outside which takes you too close to the piece edge.
I have the inside of the hole selected. I think that even If i had the outside selected, the center of the hole would be at the same place, but the diameter would be bigger which is not the case.
It really seams like the geometry is not good. I dont know if its a program/pc issue or the table acting up …
Still thinking lead screw
Maybe tight lead screw nut or binding in one spot throwing it out of time. Have you tied lubing both lead screws with light machine oil?
Binding in a spot would throw timing off and effect geometry.
If you share your tap I would cut from some lighter gauge and just to verify the file and cut. A have to assume though your programming is correct.
For the most part It appears your holes are now round (except maybe top right) but you bolt hole position seams off a touch on several locations to the right side.
Did you have much time on the machine before going to these parts? Tight bearing pre-load maybe effecting acceleration or causing drag. symmetry looks good to the left side but appears to shift up on the right.
I guess I will try disasembling the lead screws, lubing them and reinstalling everything to ensure that everything is working correctly.
I did cut some other parts before these flanges and everything seemed to be fine. The other parts were all in thinner gauge.
For the top right hole, I really dont understand what could cause this other than a movement problem.
I think I will try cutting the same file in some thinner steel to see if I can replicate the issue.
Is it possible that the steel piece is moving since I dont have it clamped ?
I would have a hard time picturing the 3/8 plate moving unless it was a relatively small piece and some sort contact was made between the torch and the work piece. I assume you are cutting the perimeter of the piece last.
I have only had a work piece move when it was light gauge and made contact. I do however use some 3/8 plate on the edges of my work pieces to hold them in place. Just though of another piece that shifted on my but that was due to the perimeter cut just breaking through the outer edge of my sheet and that cause the sheet to pull close on one side. I learned from that.
If you have some mild steel (cheaper) you could zero the torch at another spot of the table. Maybe the front left corner. If it is a spot or an area on one of the lead screws for learning testing you maybe able to cut the part avoiding crossing over the spot.
You could also download a G Code viewer to look at you tap output file but I don’t expect the problem to be with the geometry itself. an online view is here https://ncviewer.com/
I just realised something, all my other parts that I cut were at over 100ipm (thin gauge) but since these flanges are 3/8 SS im running at 20ipm. Is there a minimum speed for the motors ? Or maybe there is juste more chance of binding/sticking at lower speeds.
Looking at the RW45 cut chart three of us have cut down at 12 IPM on 3/8 but you have a superior machine cutting and can go somewhat faster.
Yes, im running at 65amps.
I think you’re probably right about that. If you mirror the part does it do the same thing on what was the bottom (but the same place on the bed)?
I’d check the coupler set screws too. You could try running it with the plasma cutter off so it doesn’t fire and skip in the G-code to somewhere near that point and watch to see if the lead screws are moving smoothly or if there’s a hiccup caused by interference or a burr or something in that place on screw.
@langmuir-mike or @langmuir-daniel may need to weigh in though to get a definitive answer.
This would have been a good time for the spring loaded “sharpie” in the torch holder drawing all the torch travel on a sheet.
I’ve done that - but used one of those Velcro straps to hold it to the torch. Does all the travel lines as well as the cuts but it can be handy to see how a tricky piece will come out (& if something fails you can cut manually 
).
Knowing the order of the cuts and the travel paths could be helpful
Looks like all four bolt holes to right side appear high and the tube hole on the far right looks high and to the right.
I do think I would like to rig sharpie for the future. Perhaps in a tube with light spring. Then tape or zip tie to torch.
Either way I hope he gets it worked out before burning too much stainless 
why don’t you get some 1/4 mild steel and try it on that first. Eliminate some variables and save some money. I get drops of 1/4" 6x21 for $3. Then work your way up to 3/8 steel then go to your stainless. Also I’d make another cut file that orients the cutting the opposite way you are now on the machine. Or atleast move the part to diff part of the table. I had a a 6x21" piece of 1/4 move on me, did the same exact thing there, moved the hole where it wasn’t suppose to be.
have you noticed having to increase your pierce delay on your everlast?
