Messages

1821

General Mach Discussion / Re: Can't get stepper to turn, but drivers receiving code

« on: December 05, 2013, 06:42:34 PM »

hmm......
So when using Mach to control the output to the motors via the TB6560 all is well as you can use Mach job buttons to move the axis and
also you can also run a program. Is this correct? YES or NO?

Now when yo try to use the TB6560 controls to move the axis they do not move.  Is this correct? YES or No?

Did you get any instructions with the TB6560?
If you did can you post them? If not I can't be of any help.

RICH

1822

General Mach Discussion / Re: Mach3 and 3D-Printer Problem

« on: December 04, 2013, 02:28:54 PM »

Info in the link is in Chinese which i can speak but can't read nor understand   

I can hear the stepper skipping, so try lowering  the velocity and acceleration.

RICH

1823

General Mach Discussion / Re: Closed loop control using encoders?

« on: December 04, 2013, 02:17:38 PM »

Your machine is not capabale of doing what you want it to do. So quit pushing it, modify the way you work, or
upgrade it or even get something different. If you have backlash but want more accuracy or assurance of position
when  machining then get rid of the backlash. You don't need encoders to find the backlash. If the backlash varies
then you have additional problems which only axis component replacement can cure. You have what you have and
if dosen't work for you encoders will not be of any help.

I am not against encoders. I have a digital display unit on the mill for each axis, so similar to having encoder readout, but, provides
nothing of real value other than confirmation that i am at some point / home or whatever, BUT, the Mach DRO is more accurate
than the digital readout and just as reliable becuase i have confidence in my machine and the way it is run.
Do as you wish, I don't think you'll learn any faster.

I don't have big steppers on any of my machines. I replaced the old 34's with 23's. I do have the axis adjusted such that I get
 max torque out of them while still minimizing backlash and having reliablility. Bearing adjustment gave me almost 70 oz-in
improvement.

 For any given stepper what you are after is max power which is torque times speed and that occurs in rather narrow range.
Go over that max which is required for some machining task and you have an unreliable situation.

Just some opinions,  
RICH

1824

General Mach Discussion / Re: Closed loop control using encoders?

« on: December 04, 2013, 05:37:23 AM »

Tom,

Why not take a moment and run some tests on scrap stock to see what your machine can do with different tools and see what
feedrates you can use. In general you should have the velocity and accel values set that you have headroom which would allow for
things like a knot in the wood or whatever. You have what you have and running anything to it's limits without proper consideration
in the program to address the task at hand just shows lack of experience.

I echo what Ray replied if your machine dosen't satisfy your requirements.

RICH

1825

General Mach Discussion / Re: Getting DRO values out of Mach3

« on: December 04, 2013, 05:02:26 AM »

I guess because it is an open loop system and it is how it suppose to behave.

Not true if you have your motor tuning done correctly. Lower the velocity and accel so that you won't skip when machining.

RICH

1826

General Mach Discussion / Re: Probe? Whats that? cnc3040

« on: December 04, 2013, 04:57:54 AM »

You don't need a probe to use your machine. There are different types of probes, but in general, it's just  something usualy put into the spindle / chuck which allows the user to find a surface spot and inform the software. Thus you can find the center of a circle, an edge, digitize a surface, etc.

RICH

1827

General Mach Discussion / Re: "A" Axis Help Needed

« on: December 03, 2013, 09:17:46 PM »

So, you're saying the answer is in here somewhere?

Your steps per unit:
200x10 ( i assume your are microstepping )x (1/360) x 36= 200 steps per unit.

For tuning ( same as the yo tuned the other steppers...)
Start with a low velocity say 5 and accel of 1, then just double the velocity until it skips. Then reduce the velocity at skipping by 40%.
Now start increasing the accel until it skips .  
That should get you in the ballpark quickly and you can refine later.

RICH

1828

General Mach Discussion / Re: "A" Axis Help Needed

« on: December 03, 2013, 09:11:00 PM »

BTW,
Rotary Resolution is 1/ steps per degree.

Linear conversion:
1 second per inch of distance = 0.000004848"
1 minute per inch of distance = 0.00029888"

So the Klinger at 1000 steps per degree has a resolution 3.6 seconds and at 1 foot that equates to a linear change of 0.00021".

Just some stuff,

RICH

1829

General Mach Discussion / Re: "A" Axis Help Needed

« on: December 03, 2013, 08:44:13 PM »

Allen,
Your steps per unit for the A axis are 10000.
You would have a gear ratio of 1800:1 which dosen't seem correct.......
ie;
200 steps per rev for motor x 10 micro steps x 1/360 degrees per rev x 1800 gear ratio = 10000 steps per degree

What is your gear ratio for the rotary table?

I know my Sherline is 72:1 ( 400 steps per degree) and for my Klinger it's 180:1 ( 1000 steps per degree).
 

RICH

1830

General Mach Discussion / Re: "A" Axis Help Needed

« on: December 03, 2013, 07:03:20 PM »

Usualy the rotary table is configured in degrees.
Thus,
G01 A 360 F1 would have the table rotate 360 degree's at a feedrate of 1.

Not sure what motor is driving your roatary table,ie; you need to tune the A axis just like the other axis's calculating the appropriate number of steps per degree, enabling it, and tuning for acceleration and velocity.
All in the manual.....

RICH