New Machine Build- Motors tunned at 450 units/minute but slow running gcode

[gmgm]

Hello guys, I've just making initial cutting with my cnc, and facing this problems :

1) Examples like roadrunner, ball, etc, produce a very small figure. I had to scale axis in Mach3 up to 20 times to get a figure of 100mm wide.

3) I made motor tunning in MAch3, and finally set up 760 steps per unit, and 450 units/min max speed. This is 450 mm/min .
The problem is, when running a gcode, Mach3 run very slow the motors, feeding them at 4 units/min. I increase the FRO, but couldn't go higher than 12 units/min.

I cannot push the axes at a reasonably speed, and testing motors in motor tunning can do it much more quickly.

Help PleasE!

[ger21]

I have mach set up in inches, and the roadrunner g-code is about 8 inches wide. If you're set up in mm, then a scale of about 12.5 should get you 100mm wide. IF your steps per unit is set correctly.

Change the first line in the roadrunner file to the speed you want. Mine says F60, but you might want F300 or more.

Because the roadrunner is lots of short lines, it probably won't let you get up to full speed. Try turning on CV mode and it should run a bit faster.

[gmgm]

Thanks!
I'm going to try these tonight.It seems you are right with 12.5 scalation to get a 100mm roadrunner, I remember I did a run with 15 scalation, and got something like that.
Thanks for the F and CV advises, I'll tell you tomorrow.
Rgards.

[gmgm]

Thanks ger21,
I found correct the steps per units config in MAch3, as you said, roadrunner is in inches, so I got a small figure when cutting in milimiters.

I changed F instruction to F400 inside gcode, and the cutting speed changed to 400 mm/min, it seems to be the safe limit for may table, but I'm very happy with that!!

Regards!