Centroid Community CNC Support Forum

Hey guys its been awhile since I could play. Cut out a revolution 72 in 3/8 plate. Seem to have alot of dross remaining on the bottom of the plate. Hypertherm cut speed is 33 ipm and some areas were not cutting all the way through. So I backed it to 70% and I had clean cuts but dross is not clearing. How far below my plate should I have my water level. The plate Is to me unidentified I picked it up at scrap yard near me and to me it looks like it was cut from a very large steel beam. I couldnt pass up $0.45 a pound to play.

HIGH-SPEED DROSS AND SLAG
High-speed dross occurs, as its name implies, is when the cutting speed is too high. Higher speeds causes the CNC plasma arc to fall behind the torch, leaving hard globs of uncut metal on the bottom of the plate and requiring tenacious cleanup.

Solutions:

Replace worn cutting tip, especially if the orifice shows signs of wear
Decrease the speed of your cut incrementally until dross in minimized
Lower the torch height incrementally

Boost current, being careful not to exceed 95% of your nozzles AMP rating

I agree with Jeff. If I'm not getting the cuts I want after checking my consumables. I might think about the turning up the Amperage if my feedrate is very slow with the current Amperage setting. For example I try not to use the 45 Amp setting for anything larger than 1/8th steel. If I was cutting larger than 1/8th steel I would adjust the amperage up to 65amps. If I'm dialing in a Profile I usually use the 4 inch line Test and change the job to a 2 inch line. Then ill set the profile to autosense and adjust the feed rate for each cut by 3-5ipm. Once I arrive at a desired Cut Quality Ill set the Voltage that Auto Sense has set during the desired cut.

I Just recently had the 45xp hooked up to my machine and needed to cut 1/4inch steel. Obviously turning up the amperage for the 1/4inch steel was not an option. I used this method to dial in my profile since the Hypertherm profile was not working out. I ended up Getting great results and the THC was super smooth. Cutting at 45amps on 1/4 inch steel was pretty slow but the cut quality was superb! These were 10inch circles and I did disable the THC for the lead out when the torch crossed over the Lead in.

I only have a 45Xp for now so I have to play a little. And learn what speed works best. Nice cuts. Im also noticing a beveld cut which Im pertty sure is the torch height setting. Guess thats the fun part getting everything dialed in for your machine. Especially if you built it and can only blame yourself when it dont work. Lol thanks for the help.

speed settings depend on your table motion Hypertherm 45xp cuts smooth . plasma tables require high acceleration and no velocity slow down. To do Hypertherm book speeds . also check all axis for any play use indicator push on each axis 1 at a time. bevel are cause buy improper Hight. Think of the plasma flame as a candle you want that flame to be in the center as much as possible . Hight under nozzle .06 Hypertherm . Ido a dry run then stop it measure under my nozzle . i found using test button seam a little off from a full motion test. Use heavy plate . this is most important setting . another is good clean air pressure. I use a gauge on back of my cutter on a T fitting . i set my air for 115 psi with cutter on it drop around 108 full compressor cycle .