G320X Bad choice for my retro-fit?

[toadjammer]

I have a Bridgeport that I am retro-fitting and am having some issues.

This is a list of what I am trying to have wrk together:

300Mhz computer
Mach3
CNC4PC C10 board
Keling KL-7220 70v 20A power supply
Gecko G320X (3)
US digital E5-500 encoders
Original SEM servos

Good results:

The mill homes at 20IPM and runs around 100IPM rapids fine through keyboard jogging.

Problem:

Running a program the drives fault and the motors dither or stall.

I have not placed the capacitor and resistors on all of the encoders as suggested by Gecko. I did this to one of the encoders and didn't see any appreciable response. I also have not been able to take out the jumper between the ERR/RES and ENC+ and still have the drives work.

Please offer any input so I can fix this and get cutting parts for my CNC router.

Thanks
Toad

[Carter3]

Just had the same problem. When trying to run a program the motors would pause and then start moving again. After a couple of days of messing with it. I found that the computer wasn't fast enough. MACH3 pc requirements are a 1 ghz processor and atleast 512 mb of ram. I put a different computer on it and it works flawlessly. Before changing the pc I was also only able to get about 20ipm. Now I can max it out to the highest setting in motor tuning.

[morestuff]

The following discussion assumes that you have
a Bridgeport factory CNC or a well executed
conversion with ballscrews.

The Gecko G320X and other servo drivers that accept
step and direction inputs generally provide a fault
output that signals when the actual position is
mismatched to the requested position by some number
of encoder counts. For the G320X this number can
be set using the DIP switches SW4 and SW5. Increasing
the following error limit may help prevent the fault
condition at the possible expense of less accurate
parts being produced.

Any servo must be tuned in order to provide best
performance. A servo with sloppy tuning will have
greater following error or will overshoot and
dither too much. Tuning should be optimized for
real world cutting conditions as well as jogging.

A jog rate of 100 IPM is respectable, but I suspect
that your machine would be capable of 150 to 180 IPM
using G320X drivers properly tuned.

Do the G320X drivers fault if you run your program
while "cutting air"? If so, your servos are likely
badly mis-tuned. While cutting air, the yellow WARN
LED should not be coming on much if at all. If
tuning the G320X does not improve the response, try
reducing the acceleration in Mach if the G320X is
showing the WARN condition.

If the G320X drivers only fault while actually
cutting metal, then you may be mistuned OR may
be asking for more torque that is available based
on the current limit settings of the G320X. With
the motors normally provided on a Bridgeport you
should be able to run the G320X at more than 10A
continuous and also set SW10 to permit 20 amperes
for up to 1 second.

Once you get things under control, I would still
recommend following the resistor and capacitor
modifications recommendations from Gecko as they
will improve reliability.

Regards,
Steve Stallings
PMDX.COM - Products for CNC and motion control applications

[toadjammer]

This is an older R2E3 CNC bridgeport with ball screws that was previously using these same drives. This has been a non-cutting situation so far. The warn and fault lights come on frequently.

I have made attempts at tunig but will look at this closer.

Resolution isn't an issue as I have 20,000/inch and tried to change dip/switch to X10 and motors would stall so went to X5 reolution on the drives.

I will try switching out the computer tomorrow.

On a side note are the G320X drives easy to repair. (I was removing the previously mentioned ERR/RES to ENC+ jumper and touched the ERR/RES end to ARM+ with the power supply probably sending 70V back through the ENC+ or to the encoder or both. What may I have damaged? Or is easier to just replace? Does Gecko take drives in and repair them?

Thanks
toad

[morestuff]

Regarding repairs, unless you have knowledge of
electronics and experience with surface mount
repairs, I would recommend just returning the
drive to Geckodrive. They are very fair about
repairs so long as the damage does not make
the PCB substrate unusable.

The DIP switches that I mentioned, by the way,
were the following error tolerance, not the
pulse multiplier ones.

Regards,
Steve Stallings
PMDX.COM - Products for CNC and motion control applications

[Carter3]

Did you figure it out? If so what was the fix?

[toadjammer]

I swapped out the computer and I did tune it a little and it seems better. I tried changeing the limit error dip switches and for some reason movement was again hampered. I again set the step multi to 10X and still had issues at this setting. It isn't stalling as much or very little and I am reluctant to do too much tuning till after I make the following changes:

I had fried a drive and am waiting on the replacement, should have that early next week.
I have found that Marcus Freimanis has terrific customer support and would purchase from him again. (I purchased a package from Keling with most of the components and they sold me the US digital encoders with the Geckos)

Am going to swap out the encoders with CUI AMT102-V from Digikey. These are setable at the encoder for resolution and will eliminate the whole capacitor and resistor issue with the US digital encoders. The CUI encoders are recomended by Marcus Freimanis as the encoders to use with his drives.

After that it would seem everything should work better than it is now which is still an improvement over what my first effort was. And I will go through drive tuning instructions slowly to make sure everything works alot better before proceeding again.

This is my first retrofit and I am sure learning alot by trial and error. I did alot of reading before hand but I learn more by getting in there and making it work and figuring out why it doesn't work and asking questions. If this all worked the first time I would have learned very little.

Other items that I have been learning about is the capacity of the BOB. I purchased a CNC4PC C10 from Keling again and pretty much knew that I was planning on using a VFD but wasn't educated enough to know that I needed a C11 to output to the VFD. I will definatley have a better understanding after this is all done and future projects should go smoother. (I hope, because I am waiting on this machine to be done to build a CNC router and CNC plasma)

Thanks for all who contiribute here!!!!
Toad