What acceloration value????

[matttargett4]

Hi Gents,

In the many discussions about plasma systems and cut quality i have often read jim mention that for a hy definition plasma system you need an acceloration value in the order of 40 milli g's but ive never read anyone talk about what sort of values they use for their air plasma machines, i find at 40 milli g's i cant achieve the feed rate in the book but with a lower accel value i can, i have asked the question elsewhere and been told its because my machine motion is poor, i can see the argument but ive done a bit of testing and im sure its good so im interested to hear what other people are doing.

Thanks

Matt

[jimcolt]

Hypertherm does not specify acceleration values for air plasma systems Plasma cutting...in order to control dross and control edge angularity is very dependant on speed. Machines with lower acceleration capabilities will naturally spend more time at incorrect speeds...as they must decelerate and accelerate for every turn, corner, or intricate detail. While the machine is running slower, the plasma is still burning at its set output, the kerf gets wider, more heat inputs to the metal. The result is warpage, dross, and wider kerf (which affects cut part tolerance). If it takes 1/2" to get to the required cut speed of say 190 ipm on very thisn gauge steel....and your part has some 3/8" diameter holes....expect the holes to be pretty drossy, with a lot of heat discoloration and possibly warpage...as the machine will not achieve speed.

Jim Colt