Hello Manfred,

I am using a stainlesssteel screw with a pitch of 1.25 mm per turn. My motor has 48 steps for turn. I just divided 1.25/48 and got mm/step =0.026041667.Is it wrong? II dont think so, because if I tell motors to jog in any directions it move's with high precision. On the other side, it seems to me that compensate the kerf fo every size of wing is the problem. The last wing that I cut using 2.5 as skin thickness gave 177,6 mm instead of 177,8 mm as was programmed. First of all I do not know if this is important to the flight and if I should change the heating or still playing with skin thickness. Any way, I think now I am in the right way to build gliders. Since I was a kid I am fascinated with low speed flight,
I d like to thanks you and Jerome for all the help that you provide me as well for the nice soft that you developed.
Best regards,
Alfredo

Alfredo,

the caculation is correct.

When the heating is to much, or the cut-speed is to slow, the geometrie is wrong.

This error is greater, when you cut thin airfoils.

You must test, which is the best parameter.

Manfred