Problem- Oxy-Fuel Setup

[Feckless]

Hi All,
We have been cutting a few months now with the plasma on our TM3 8x4 with great sucess but it's time we got to grip with the oxy fuel setup, we tried it a few times at the recomended pressures but the heating flame is about 2 feet long and anything we cut is just a mess, we are using acetelene. we have plenty of expierence on a manual torch but cant figure this out. How high must the heating and cutting flame be from the material, do you need to pilot drill for piercing, what speeds are best. The thickness of materials is 20, 25 and 30mm (mild steel), its a bit expensive to mess up on these plates. It seems there is just too much heat and we can't reduce the flame any further, four nozzles came with the kit and we tried them all. Any help on this issue is greatly appreciated.
Regards
Gordon

[Mike@Torchmate]

Are you matching the pressures to the Tip size? I know the Victor torches have a very specific chart with feedrates and pressures based on material thickness and tip sizes.

With varying tip sizes you need to appropriately match the chart's specifications based on Tip size and Material thickness.

[Feckless]

Hi Mike,
We are setting up pressures exactly as in the charts for the specific gas tips, should the distance from material be changed after heating and before cutting and how do I program the preheat time, what thickness should I expect the gas to pierce.
Regds Gordon

[Mike@Torchmate]

The distance from the tip to the material typically remains static through-out cutting and travel motions. With the preheat flame set we would typically recommend the blue preheat flames be just above touching the material for pre-heat and cutting.

One way to do the preheat is to add in a G04 X15 (X15 defines the number of seconds up to 30) in the Additional G-Code section of the Configuration Screen that pop's up when you import a DXF file. If you add in this command in the section labeled "Start if Feature - After Rapid Move", it will dwell that amount of time, preheating the material and then activating the cutting oxygen.