overall turns ratio and encoder line count questions

[TRM]

Happy New year everybody!
I have made some progress with my lathe, but there is something odd going on.
I can move the X axes with the wireless MPG as many time as I want 1 inch back and forth and the indicator needle it rock sold on zero every .100.
There is no back lash.
I can put G0 X1.0000 in the MDI box and hit cycle start and it moves the needle on the indicator 1 inch plus just enough that it's not dead on 0.
I put G0 x0.0000 in the MDI box and it returns and the needle is just a touch off. I use the up arrow to toggle between G0 X1.0000 and G0X0.0000 hitting the cycle start button on the wireless pendent jogging the axes back and forth and it accumulates error each time the axes is jogged.
The error is +1.0000 and it takes about 45 cycles to accumulate almost .010.

One other thing that is happening. On the axes second cycle using the MDI box the spindle turns on.

[agsweeney1972]

Why is your turns ratio for X 5.0800001?

[Commotion]

Have you tried it with a g1 of slow feedrate to see if you get the same result? Is it less than 1” or greater than 1”? Is it overshooting or not reaching 1”? How close is the rapids to the max rpm of the steppers (assumption), maybe it’s loosing steps. Try reduce the acceleration time so it’s ramps up slower.

[Chaz]

You also have the RPM issue, correct?

I cant help but think you have some noise within the system. Worth checking every connection / shielding?

[TRM]

Have you tried it with a g1 of slow feedrate to see if you get the same result? Is it less than 1” or greater than 1”? Is it overshooting or not reaching 1”? How close is the rapids to the max rpm of the steppers (assumption), maybe it’s loosing steps. Try reduce the acceleration time so it’s ramps up slower.

It moving at 10 ipm. It has Siemens nema 42 1.3 Kw motor on the x. the factory rapids were 500 ipm on the x. I don't see how it's over shooting.

[TRM]

Why is your turns ratio for X 5.0800001?

It has a 5mm pitch ball screw.
5/25.4= .19685039
1"/.19685039= 5.0800001

[TRM]

You also have the RPM issue, correct?

I cant help but think you have some noise within the system. Worth checking every connection / shielding?

Keith has a video of a lathe on there shop with the PC in the cabinet with the VFD and motor drives. I haven't read where it's a no, no.
I do have a noise filter and have plans to install it. I'm going to move the PC and see if things change. I'm going to move the Acorn board too.
I did buy VFD rated motor cable but there maybe noise coming from other places.

[agsweeney1972]

Why is your turns ratio for X 5.0800001?

It has a 5mm pitch ball screw.
5/25.4= .19685039
1"/.19685039= 5.0800001

Actually its not. . . you have a rounding error; granted it won't really make a difference.

5/25.4 = 0.1968503937007874015748031496063
1/0.1968503937007874015748031496063 = 5.08

[martyscncgarage]

Find the attached Coarse and Fine DRO Adjustment docs. Use them as a guide.
Your motor turns per rev is pretty high, you have 5000 count encoders on the servo motors? OR are you trying to factor in your pulley reduction in there? (which you should NOT be doing, that is taken care if in your OVERALL TURNS RATIO entry)
As for the spindle coming on. Your description is rather vague. Are you using the REQUIRED Relay board on your Acorn outputs?
Post a video showing what it is doing.

ALWAYS post an update report with your questions/concern.

Marty

[TRM]

Hi Marty

I have a mount coming for my phone so I can video hands free whats going on.
I put 10000 in wizard and got 2.5 turns out of the motor. I put 20000 and got 5 turns. The X axes has a 5mm ball screw and is directly coupled to the motor.
I spent a few hours looking for info on the encoder. All I could find was on the TS 5214 was the 52 is the type of encoder and 14 on the chart meant it is a 2500 line. I'm confused as to why I have to put 20000 in the wizard to make it work but it works.
Here is the encoder that is on my motor.