Hi, Spiwrx
In General Configuration, Top Rt. Corner set the "De-bounce Interval" to 1000 for a start, (Helps with stray/spurious signal reduction).
Your Geckos are "10 micro step", Steps Per, In Motor Tunning should be 20000, (10 tpi x 200 stp-rev x 10 micro-stp = 20000).
In Ports & Pins, Motor Outputs, set the Dir & Steps to a "Checked".
If any axis runs backwards.
Opt. 1, Swap the wires on "one coil" (Phase A & Phase B) or (Coil A & Coil A-), Depending on how it's Marked.
Opt. 2, In Home & Limits, Set Reversed to "Checked" for the Axis.
The following steps are a short cut to Tuning Mach3, If you follow this, I think it will expedite your setup and understanding of mach3.
(Mach3 download defaults are a little confusing, Feed-Rate Setting Defaults to 6.0 and causes many to tune to this value).
Under "Operator" (Top row, Click On "Auto Calculator", This turns on a Pop-Up calculator).
Click on the Feedrate Number "Disp.Box" on "Program Run" Screen, Enter the value as described below, 150 or greater.
Your Velocity and Acceleration settings in Config, Motor Tuning set's your max speed's.
If the velocity top's out you need to turn up the "Kernel Speed" in Ports & pins and Re- Start Mach3.
If you haven't setup/calibrated your Step's Per to inch or mm, You need to do that first. (Steps Per set to number of steps to move one Inch or MM)
On the Program Run page set the feed-rate to 150.00 or higher for fast machines, (This puts your feed-rate well above what your Max Velocity will be).
Hit the TAB key for pop-out Jog window, Set the Slow Jog Rate to 100 %, Jog Mode to "Cont.", (Axis will move as long as you hold the key down).
Now your Setup to use the axis arrow key's or mouse arrow button's to set up your velosity and acceleration, (Setting up vel/accl is a balancing act).
Set your vel. to 45 and accl to 15 for a start (Vel is typically 3 times higher than accl (more or less).
Increase the accl up till your servo trips or your steppers slip then back it off 10 % or so,
Then set the vel. up till it trips or slips also, Back it off 10% or so, Or till you think it's fast enough (Speed's can get scary on big servo or steppers).
Then after you get the max'es set, Your slower G01 with F speeds should be fine.
With G00 moves you'll get max speed for your Machine up to your "Velocity Setting".
This should get you pretty close, As your experience grows with Mach, You'll need to adjust accordingly.
Be Careful As You Go.
Hope this Helps, Chip