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Hi Todd,
I’ve checked everything—the only thing left is the motor encoder, and a lot of people, including an electrician, told me it’s likely the problem. I’ve tested all the cables (several times), the controller, and I’ve even done parameter resets. So, It must be the encoder , because i've powered the motor with a  power supply and it works.Just to clarify: I’m not doing the retrofit only for  the motor. It’s because I’ve been talking to a guy who used to work on the same machine, and he said there are serious issues with the Z axis ,it doesn’t save its position. Actually, before the machine broke, I had experienced this issue myself.Over the last few days, I did some research and found a good shop online Variumetrum and  i have done some research and seem's good so here my choices:

• 3 x Leadshine ELM1 750W with brake
• 3 x Leadshine AC Servodrive EL6 750W
• 1 x Mesa 7I76EU(not from the same shop)

On the old machine i've Sanyo Denki 500W  DC80 Model 850T-0123EL7 , brushed motor .
Let me know what you think!

Ps- I've only to think to the z axis and than i can buy all of them.

Ofcourse! 

I've included them as an attachment.

I hope you have some good insights into my setup. 

Thanks in advance.

EDIT:

I now also use the following step timing:

DIRSETUP   = 500
DIRHOLD    = 500
STEPLEN    = 1000
STEPSPACE  = 1000
STEP_SCALE = 1000

In addition, I changed the |DISPLAY|MAX_VELOCITY and the |TRAJ| VELOCITY settings. I have also increased the other velocity limits accordingly.The machine is now performing better than ever!
Surprisingly, I'm no longer getting any following errors—I'm not entirely sure why, but I’m definitely not complaining. ?Thanks to everyone for the input and suggestions!

Can you post your complete hal/ini files?

Hello Community,
many things are working nowadays with  Linuxcnc 2.9.2 with Probe Basic on a MESA 7i76e. But:

A few weeks ago I had to change my Hitachi VFD because it had no 10V output for spindle supply from the beginning. I sent it to service in April and I had to get the 10V from a separated power supply, this worked fine with a chinese VFD for the time the Hitachi VFD was in service.
Last week the Hitachi came back from service, the 10V Out was working, but surprisingly I cannot make MDI speed commands any more. I set S6000 or S12000, press Enter, in the spindle display on the right side 22000 occurs and I can press FWD Button but nothing happens.
IN the HALSHOW there is
0 at spindle-out
0 at spindle.0.speed.out
0 at spindle.0.on
0 at spindle.0.forward. Tested with S6000, S12000 S24000.

All this worked fine with the chinese VFD before.
So, I thought my 7i76e card is burnt up (I did not change any of my HAL or INI files since I sent my Hitachi away), but surprisingly further experiments could deny that.
Speed instructions from a file are working as they should. E.g. my warmup file - spindle turns in the right direction, right speed, right display down right.
Parameters are the same in the Hitachi as before.

Do you have any idea what could have happened here? I'm totally clueless...
Thanks for any hint and help!

Hanno
HAL and INI Files:
    

Presuming there is nothing wrong with the original servo systems, then usually the best option is to reuse them. You will need to figure out how the existing cnc controlled the servos. If they were using step/dir signals then the 7i76e should be a good option for the retrofit. If the servos were commanded using analog signals or some other way (such as some kind of serial bus), then some other hardware might be more appropriate.

npostma wrote:

... my power supply is a 32V 10A unit running three axes, so it might be a bit underpowered. Could this be the cause of the joint following errors?

It is not underpowered for stepper systems, might be for servo systems, so not the cause of following errors for steppers, but might be for servo systems.

I started getting joint following errors after I changed the following stepgen timing settings to these even values:DIRSETUP = 6000
DIRHOLD = 6000
STEPLEN = 3000
STEPSPACE = 3000This happened even though I set STEPGEN_MAXVEL and STEPGEN_MAXACCEL to be 25% higher than my MAX_VELOCITY and MAX_ACCELERATION values, as recommended.However, my power supply is a 32V 10A unit running three axes, so it might be a bit underpowered. Could this be the cause of the joint following errors?
I do have another similar power supply available, so I could use it to power one axis separately—this would help with the available current, but not increase the voltage.Any advice or experience with similar situations would be appreciated!

Hi everyone,I'm planning a retrofit for my Mécanumeric MF2040 (large-format pantograph) i'll dismantle all the eletronic and leave the structure. After some research, I’m considering the following setup and would appreciate advice or feedback:Controller & Interface:

• LinuxCNC running on an old (but reliable) PC
• Mesa 7i76e Ethernet motion controller

Motors:

• 3x Delta B2 Servo Motors (220V, 750W, 2.39Nm, 3000rpm, ECMA-C20807RS)
  • Alternative: 3x Leadshine ELM0750DH80E-SS
• Z-axis motor: Still evaluating options

Usage:

• The machine is mainly used for cutting and engraving (pantograph work, large panels).

Questions:

1. Does this setup sound suitable for a machine of this size and type?
2. Any experience with these servo motors (Delta B2 vs Leadshine)? Reliability, tuning, integration?
3. Suggestions for the Z-axis motor?
4. Any compatibility issues or tips when using LinuxCNC with the Mesa 7i76e and these servo drives?

Thank you in advance for your advice and suggestions!

The longs motor DM542A is better than you think and is my choice of drives for NEMA23 motors if price is important.
With 25x microstepping and 48v power supply, I used the following setttings

Yes that is what i thought. I find it so strange that i can have ludicrous speeds in the wizard. Not sure what kind of magic is happening there

I have stepgen's maxaccel and maxvel 25% bigger than the linuxcnc maxaccel
and maxvel settings. Also i have to figure out what i can set of DIRSETUP, DIRHOLD, STEPLEN, STEPSPACE realistically for my stepper-driver. A Longs DM542A driver is probably not the best driver in the world. 

This is the max i can do without getting errors:

#******************************************
[AXIS_X]
MAX_VELOCITY = 200.0
MAX_ACCELERATION = 200.0
MIN_LIMIT = -0.01
MAX_LIMIT = 750.0

[JOINT_0]
TYPE = LINEAR
HOME = 0.0
FERROR = 10.0
MIN_FERROR = 1.0
MAX_VELOCITY = 200.0
MAX_ACCELERATION = 200.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 250.00
STEPGEN_MAXACCEL = 250.00
P = 1000.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
# these are in nanoseconds
DIRSETUP   = 10000
DIRHOLD    = 10000
STEPLEN    = 5000
STEPSPACE  = 5000
STEP_SCALE = -400.0
MIN_LIMIT = -0.01
MAX_LIMIT = 750.0
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = -30.000000
HOME_LATCH_VEL = -2.500000
HOME_FINAL_VEL = 0.000000
HOME_USE_INDEX = NO
HOME_SEQUENCE = 2

hm2_7i76e: 0.stepgen.00.maxvel is too big for current step timings & position-scale, clipping max possible.
hm2_7i76e: 0.stepgen.01.maxvel is too big for current step timings & position-scale, clipping max possible.
hm2_7i76e: 0.stepgen.02.maxvel is too big for current step timings & position-scale, clipping max possible.

These warnings are because its not physically  possible to generate the required step rate because
the rate cannot be faster than 1/(steplength+stepspace). You can increase the maximum step rate
by reducing steplength and stepspace or using a lower micro-step ratio in the drives.

Following errors during installlation/setup are often because the stepgen maxaccel and maxvel
values do not leave enough headroom from LinuxCNCs joint/axis maxvel and maxaccel values, so check
that the stepgen maxaccel and maxvel values are at least 25% greater than LinuxCNCs joint/axis values

Hi all,

Thanks for all your input—everything is working fine again! There’s still some tweaking to do, but I’m getting there.

For the inputs, I made a small PCB breakout with terminal blocks, each protected by a pair of 0.5W resistors (2x 3K in parallel, so 1.5K total) to protect the Mesa card inputs. This limits the input current to a maximum of 0.016A (16mA) and 0.384W per pair.

I do have one last question. When testing my axis with the PNCconf wizard, I was able to achieve insane speeds—acceleration around 2500 and a max velocity of 15,000 (even higher values just made it wait or go slower). This seemed very promising. However, those values didn’t end up in the generated .ini file.

In reality, I had to limit my velocity to 200 to avoid errors in LinuxCNC, specifically:

hm2_7i76e: 0.stepgen.00.maxvel is too big for current step timings & position-scale, clipping max possible.
hm2_7i76e: 0.stepgen.01.maxvel is too big for current step timings & position-scale, clipping max possible.
hm2_7i76e: 0.stepgen.02.maxvel is too big for current step timings & position-scale, clipping max possible.

By lowering the timing values like this:

DIRSETUP = 6000
DIRHOLD = 6000
STEPLEN = 3000
STEPSPACE = 3000

(from the original 10,000 / 10,000 / 5,000 / 5,000), I could push the velocity up to 250, but then I started getting joint following errors.

So, I think I must be missing something fundamental, because the speeds I got in the wizard are nowhere near what I see in actual LinuxCNC. I don’t need crazy speeds for milling, but jogging 20cm takes a bit too long right now. Is there a way to make it faster, or can someone explain why the wizard speeds were so much higher than what’s actually possible in LinuxCNC?

Thanks!

So, change made, AC power component is gone and first small test job ran successfully. Hoping for the best . Thank you again!

Ah-ha! The 24V field power GND is not connected to earth ground, I was not sure that it should be. That probably explains it then.

Just weird that the machine ran fine for so long.

Thanks, I was getting frustrated with the constantly changing symptoms. I will connect those grounds tomorrow and test again.

Ack!! 40V is a real issue and indicates a grounding problem. This likely
what damaged the step/dir outputs (accidental contact to shield ground would do it)

I would verify that the drive frame grounds connect to earth ground and that the
7I76E ground (24V logic power ground) is also connected to earth ground.