mach3, steps & microstepping

[John S]

Basically boils down to resolution versus speed.
Too much resolution equals slow speed.
Too fast equals notchy resolution.

You can also substitute gearing for micro-stepping which does the same job and if a reduction gearing, like most are, this also increases torque whereas micro stepping reduces torque.

First thing we need to know is how fat the carriage moves for one turn of the motor.

Without this basic information we can't help.

[martin54]

Thanks John, I've got the gantry back on the machine so should be able to measure that, will also take a couple of pictures of the gearing but it is reduction gearing as you say.
Got the user manual but it's pretty hopeless for technical info & can't get any service documents for it as I said in the other thread.

[martin54]

John the X & Y axis are the same size belts & gearing, the Z axis is direct via a screw but I need to remove a cover to see if it's a ballscrew or trapezoidal.

Ten turns of the motor moved the gantry 3 inches for both X & Y axis, ten turns on the Z axis moved it down 2 inches.

Measurements were taken using a ruler so may not be 100% accurate.

[martin54]

Any advice on the best way to start this off now John please. I am guessing I want to set the micro stepping right down on the drivers if the gearing does the same job but is there a way to work out where to start with the steps in mach3.

[John S]

John the X & Y axis are the same size belts & gearing, the Z axis is direct via a screw but I need to remove a cover to see if it's a ballscrew or trapezoidal.

Ten turns of the motor moved the gantry 3 inches for both X & Y axis, ten turns on the Z axis moved it down 2 inches.

Measurements were taken using a ruler so may not be 100% accurate.

Sorry got side tracked, the dog pissed on the carpet and then on my boots when I kicked it up the arse............

OK X and Y ten turns to go 3" so one turn to go 0.300"
200 step motor means each step is 300 / 200 = 0.0015" or a thou and a half per step which is a bit course.
I reckon on a router 1/2 a thou is good enough so you want microstepping of 3 to get 1/2 thou which isn't an available step.

If you choose 5 that gives you 0.0003" per step

Now the Z, 10 turns = 2" so one turn = 0.200"
0.200 / 200 give 1 thou on full steps and 1/2 a thou if you choose 2 micro steps.

That's the maths, you may want different figures.

[martin54]

Will give that a try when I get all the electrics sorted, chears John.