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does anyone have any guidlines for what settings you should run to achieve good cuts in differing materials and thicknesses, or a trouble shooting guide, at the moment have cut some mega clean parts and some terrible and im not sure why the difference any help / guidance much appreatiated
cheers
marc
There are a lot of variables in plasma that define the difference between a good cut and a bad one. First get the cut gap and feedrate recommendations for your plasma unit. It will vary by material type and thickness. If you don't have a torch height control (so you can control the cut gap) trying to get consistant cuts will be frustrating. You have to be able to control all of the variables involved:
1. Pierce height/delay
2. Cut height
3. Cut current
4. Cut gap (same as cut height but should remain constant during the cut)
5. Feedrate ( don't assume it stays constant if you are cutting tight curves or segmented artwork)
6. Constant clean air supply.
Other things to watch (so they don't become variables too) is the workclamp ground and the wear on the consummables.
There is a lot more to getting constantly good cuts than first meets the eye!
What plasma system are you using? if you have Torch height control, you just set the speed and current according to the plasma system operation manual for different material and thickness. If the cutting is bad, then check the consummables and change it.
If you don't have a Torch height control,you will need to spend more time to study the variables and spend more money ( To replace the consummables frequently).
Joe
AC Meca (m) Sdn Bhd
its a gabro system uses torch height control via air pressure onto a moving head with three roller balls, everything is adjustable bar this. the thing ive found today was that if i kept wiping the tip end, then they lasted longer, i managed to cut 40 plates in a nest on one tip is this good or bad ???? the part i was cutting was a hexagon shape with four 1\2 holes in 3mm the first 40 where perfect dross only where the table slats are, and perfect holes and edges, the next 5 where useable slightly more dross and a little bevel
the one thing that did cross my mind is at the moment im using cold rolled sheet which is very dirty and and covered in scale, im sure that when i use proper sheet rather than pig iron tip life will improve, so far im still on the same electrode its just the tip that seems to come to greif
many thanks for the guidance so far, will try and post some pics on tuesday of the machine and parts i have made, so far cut approx 250 parts of very good quality on 6 tips and one electrode is this about right ???
best regards
marc
I think you are losing tips because you are piercing too low. Your tip to electrode ratio should be about 3:1 not 6 :1. You should be piercing at about double the normal cut height. The problem is that without a way to sense the height you can't adjust for a known pierce height.
Dirt and mill scale on the material has no effect on tip life or quality of cut. Just make sure your workclamp is fastened to the material (not just clamped to the table) and you provide a good conductive connection. Grind a clean spot for the clamp on really dirty material. I find rusty material actually cuts better than perfectly clean stuff. Less sparks and slag. (PITA to clean up if it's pitted though)
I cut a large batch of P&O stuff a year ago and I couldn't see where it improved the life of the tips or the quality of the cuts.
Take a look at your cost of consummables VS your profit on a cut. If you are making enough on the pieces you cut then tip life gets to be less of a concern. I can cut almost $800.00 worth of product on 1 electrode and 2 nozzles. That's about 15.00 worth of consummables.....less than 2%
Tom Caudle
www.CandCNC.com
thanks tom
have been going through everything and checked pierce settings etc, then found out ive been using the wrong nozzles ( got some cheap on ebay to get me going ) put the originals back in and hey presto and old nozzle cut me a full 8 x 4 sheet ( indexed ) with many different parts, also put another inline water trap in next to machine, it already ran through two one at compressor end and one at the airline end but the airline to machine is 25ft away and the new water trap is next to machine now and what a diffrence it makes, going to ring the tech support people again today to some more advice on the codes for torch settings on pierce and delay and all the other functions i havent used yet, thanks for all the advice and help ive recieved so far without it i would have been going round i circles. have now found a company to supply me the nozzles and electrodes who helped a lot in recomemding correct parts.
many thanks
marc
i am using actech cnc cutting machine with hypertherm powermax 1650 plasma machine.But the cut height is not remaining constant(along Z-axis). At begining it was constant. but now the cutting torch is just going downward after a few second of starting the cutting as a result i have to stop the cutting operation.i have checked all the variables .please suggest me what to do.