Min Power Max Power Setting

[Gene Uselman]

Post by Doug Fisher » Sun Feb 19, 2017 3:01 am

Many moons ago, I remember watching Russ' videos and/or reading on the internet that you don't always set these two power ratings to be the same. Most of the time for vector cutting you set the max power to the the safest percentage that does not over-drive your tube. The min power setting was usually set to something less. This (as long as you didn't have "default" checked) allowed the machine to lower the power while cutting during areas of deceleration and lower speed. An example would be when the machine approached a corner in the cutting path. Allowing the machine to lower the power prevented over-burn that would occur as the machine slowed down to make the corner cut.

In the recently released videos (Sarbar and ThinkLaser), Russ has said to always keep the min and max the same. He said he will explain why in a later video. Since it may be a while before he posts that video, can anyone explain why, if my memory is correct, he would be motivated to change his mind to now recommend we always leave these numbers equal?

Post by Pete Cyr » Sun Feb 19, 2017 7:33 am

If you are cutting and NOT engraving setting min and max to the same value will result in a consistent cut depth - differing values usually will not.
If you are engraving, setting min and max to different values will tend to give a 3D effect if you graphic has varied shades of gray. If your graphic is black an white and you are engraving differing min and max values will do little to improve the end product. Dot mode is more useful for black and white and setting min and max to the same value is typically the preferred setting.

by Doug Fisher » Sun Feb 19, 2017 10:05 am

Thanks for your reply, Pete. In general, I agree with what you say except for in the instance I mentioned where the laser has to slow down from high speed to low speed for inertia reasons such as at a right angle corner. If I am cutting thin acrylic at high speed using full usable/safe power, there can be a difference in kerf at the the corners where the machine moves slower. It is a very small difference and maybe most people would not notice or care but I have pieces where a small difference has a detrimental effect.

Anyway, I just thought I would ask in case there was new reasoning that would justify the hassle of me doing testing all over again for my current cutting patterns or design differently for future components.

by Pete Cyr » Sun Feb 19, 2017 10:14 am
I agree with you but the laser controller doesn't vary power in corners as a design function.
the RDWORKS manual todays says on pg 61.
Software Ver v8.01.19
"Speed Factor: The speed of turning around corners will increase as this parameter increases."

by Chris Medcalf » Sun Feb 19, 2017 1:41 pm
I believe it's a function of the controller rather than RDWorks. The power is increased from Min to Max as the speed increases from Start Speed to the speed set for the layer. If the layer speed is not greater than the Start Speed, the power will only be at the Min level. If you need corroboration, see videos 55, in which Russ gets it right but doesn't believe it, changes his mind to get it wrong, then changes his mind again.