cnc 3040 and mach3 problems

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Originally Posted by hoggy

native units inches....steps per 12800...velocity 1999.8....acceleration 200....steps pulse10...dr pulse 3....3 axis all in one board hope this helps..john..

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That's step per indicates far too high micro stepping. It would appears to set as if your drives are set at 3200 micros steps and using a 4mm pitch screw.
I very much doubt these drives will be set at that figure and if they are it needs changing to half that and either 1600 or 2000 definatley not more.
Suspect that the steps per is wrong for the drives and if that was the case then the machine will move the wrong amount.

Try this.! Type G0 x0 into MDI window and see how far it moves. This will tell you if set wrong or not. It should move 1inch but I suspect it will only move 1/2".?

if wrong then easy way to save you messing around is to use the built in Set Steps per option on the settings tab and measure the distance moved. Mach will then enter the correct amount for you.

If it's correct then I would change the drives to a lower micro stepping because that will be too high for these drives and put more strain on the PC parallel port.

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Originally Posted by hoggy

its not the motors or screws I think it is the linear bearings..john..

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Oh in that case then either send it back if new or get it stripped down and find the issue. Grease is marvelous stuff but it seems in short supply in china so chances are it's drier than desert.?

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Originally Posted by EddyCurrent

It just shows how naff g-code files are when the units are not specified in a file header,

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They are if you know how to read g-code the G20 says it all. It's always at the top of G-code or in the intial string and Mach displays this on the top bar so there's no excuse really.! . . . . Every one should try and learn a little G-code and Units to be cut in is one of the must's along with offsets and mode codes.

going to try greasing it and see what happens

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Originally Posted by JAZZCNC

They are if you know how to read g-code the G20 says it all. It's always at the top of G-code or in the intial string and Mach displays this on the top bar so there's no excuse really.! . . . . Every one should try and learn a little G-code and Units to be cut in is one of the must's along with offsets and mode codes.

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Yes but I meant in a proper file header, not the code itself, so that Mach3 for example could scale it automatically.

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Originally Posted by EddyCurrent

Yes but I meant in a proper file header, not the code itself, so that Mach3 for example would scale it automatically.

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Ok last word from me on this as it's not the OP's problem.!!

Mach won't scale it automaticly because it's native units are set to metric so 1 in G-code equals 1 unit and if thats metric it's 1mm or 1" if imperial.
The G20/21 doesn't change any of mach's settings so the native units are the same. It's mostly to identify the units not set or change them.

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Originally Posted by hoggy

native units inches....steps per 12800...velocity 1999.8....acceleration 200....steps pulse10...dr pulse 3....3 axis all in one board hope this helps..john..

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From a similar machine manual they have it set to 400 steps per (that's for a metric machine)
It had 1404 trapezoidal screws, microstepping likely set to 8, motors were 1.8deg.

step per = "The number of steps Mach3 must send for one unit of movement"

So for a metric machine one unit of movement = 1 mm;

a 1.8 deg motor has 360 / 1.8 = 200 steps per rev.
with microstepping set to 8, 200 x 8 = 1600 steps per rev
with a screw pitch of 4mm, 1mm movement = 1/4 turn
1600 x 0.25 = 400 steps per

So for an imperial machine one unit of movement = 1 inch;

a 1.8 deg motor has 360 / 1.8 = 200 steps per rev.
with microstepping set to 8, 200 x 8 = 1600 steps per rev
with a screw pitch of 4mm, one inch movement = 25.4/4 = 6.35 turns
1600 x 6.35 = 10160 steps per

All of that assumes a 1:1 ratio between motor and leadscrew

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Originally Posted by JAZZCNC

Ok last word from me on this as it's not the OP's problem.!!

Mach won't scale it automaticly because it's native units are set to metric so 1 in G-code equals 1 unit and if thats metric it's 1mm or 1" if imperial.
The G20/21 doesn't change any of mach's settings so the native units are the same. It's mostly to identify the units not set or change them.

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You are correct but what I'm saying is, this leads to issues where the machine cuts to the wrong size.

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Originally Posted by EddyCurrent

From a similar machine manual

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Where would I find an online manual for this type of machine. It seems they are awash with them on ebay but no parts or after sales are in existence lol