[chineshop_guy]

hello all,
a week ago i went to start up the machine noticed z axis wasn't homing correctly. turned it off opened up the cabinets. then turned it back on, noticed when i hit reset to turn servos on z axis card had the surge/ground fault light on. turned everything completely off and started checking connections at the card, looked fine. powered it back up when i hit the reset z axis ran away i positive direction
i then called zps for some trouble shooting switched the y wires over to the z card, y axis ran away. so z card has to be bad. said they would call me back if they still had one.
no call back, so i called a company i had seen mentioned here. the old card i had was servo dynamics 1525-10, they suggested the newer 1525 BR. long story short, the first one they sent done the same thing z axis run away, they seemed to think maybe i had been sent one that hadn't been tuned correctly. so the second one arrived, now the z axis creeps in the negative direction about 3/16 inch and stops and when hit e stop it creeps on down a inch or more. so now they are sending me an original 1525-10, my fingers are crossed.
my real concern here, besides the obvious, during some of the conversations it was mentioned i may have to do some fine tuning as far as "lag" goes. i do some 3 axis contouring. i'm a machinist not a electronic person. i do understand what a pot is on the boards. but even after it was rather quickly explained to me i'm not sure. how will i know if it even needs adjusted.
then i'm also concerned what caused the surge/ground fault to begin with?
if anyone has been through any of this your advice would be greatly appreciated.
thanks in advance

[underthetire]

Many, many times.

It creeping because the balance is off. You absolutely will need to set lag, and probably the x and y as well if doing contouring. Zps should have a set up sheet with step by step. You will need a dvm to set it on the bench, then fine tune it in the machine. Lag display is turned on in the mode select set up. All 3 axis need to have 0 +/- 1 at stand still. That's the pot labeled bal. lag is adjusted by tach or gain, so it's best to bench set these up then fine tune the tach pot. All 3 axis need to be at a lag of .015 at full medium jog.

[chineshop_guy]

hello and thanks for reply,
have not messed with setup mode much but will take a look at that. not sure what dvm means and don't have equipment to check it on the bench. i was kind of to the understanding it would be set close on their bench and i would have to do some tweaking on the machine.
as i said i don't have any experience messing with electronic stuff. but looks like i'm gonna be learning.
i do a little farming, was told a long time ago, if your gonna do this you gotta be part time farmer, part time mechanic to make it. guess this is gonna be the same:idea:
thanks

[underthetire]

Dvm, digital volt meter. Also knows as a multimeter. It helps to have clamp on leads while doing those. I guess close is a relative term, but they may not understand your doing 3d contouring. Lag is basically the difference between commanded position and actual position, you can think of it as the motor speed. If one is off compared to the others, it finished its commanded move before or after the other axis. If this is the case, you get egg shaped holes etc.

[chineshop_guy]

well for now i'm gonna wait on the other board to show up, i have a friend that's an electrical engineer he has the dvm and knows how to use it. also found an old post with setup info and what the readings should be over on pm forum.
will also be in touch zps to get setup info once on the machine.
one more question, with the boards on the machine how do you get to the pots, i assume you have to leave them hang or something other wise they are to close together to get to the pots??
edit: what is best way to get to the z axis servo moter to check the cable. i am still curious what caused the original surge/ground fault light to come on
thanks much

[underthetire]

Those cables rarely fail since the motor doesn't move up and down. You can take an ohm reading at the drive to see if the motor is shorted to ground. Remove the power cables from the drive to motor and check each one to ground. Ideally you want a mega-ohmer to check it, but you can get a rough idea with a meter. Not uncommon for DC motors to short to ground. Usually the pots you adjust are located on the edge of the cards, never really had a problem getting to them myself. The other pots require a bench tune.

[chineshop_guy]

yea i see the pots on the edge now, wasn't actually looking at it when i posted that. so this is what i read on pm forum will this be required when my other board gets here Wednesday ?
Setup Procedure for Servo Dynamics Servo Drives

1. With the boards removed from the chassis, hook a digital ohm meter from TP1 to the left side of R19, adjust R44 for 7.9K Ohm.
2. With one lead of the meter on TP1 and the other lead on:
TP2, adjust Aux for 0 ohms
TP3, adjust Sig for 4.8K ohms
TP4, adjust Tach for 4.4K ohms
TP5, adjust CMP for 570 ohms
NOTE: All plugs must still be disconnected
3. Adjust Current Limit to Maximum Clockwise (CW).
4. Install the modules and turn power on.
5. Reset E-stop, reference machine. Go to mode select 5 (setup), key in TM4, Enter (servo adjust). Then mode select 0 (jog), enter 1 (medium jog), set feederate override pot to maximum CW.
6. Adjust balancing pot for zero standing axis lag +/-.0002
7. Jog the axis, adjust Signal pot for .015” axis lag.
?

[chineshop_guy]

hum, should i try messing with this 1525-BR or wait on the 1525-10. i believe they said the tach in is for balance adjustment on the 1525-BR see pic

as it is now i can't get the z to home because of the creeping issue. the last conversation i had with the company i got this from was it shouldn't be doing what its doing.
my electrical guy will hopefully be here later today gonna try to see if he show me how to check some of this stuff

[chineshop_guy]

update. decided to quit being scared of this thing. when i first tried powering up. it ran away in negative direction, hasn't done that before checked an reseated my connections wiggled the z axis motor cable a bit. fired it back up seemed to behave almost normally, was able to home it out to observe lag.
z axis shows like +/- .0078 with 0 standing lag. also noticed z still creeps a little in negative direction when first powered up and will still creep down about .100 when e stop is pressed.
also z axis seem to be moving a lot faster than x and y
still really bothering me about that run away.

[chineshop_guy]

another update, my electrical guy preformed some checks on the all three motors . x & y were 12k ohms, z 1.6 mega ohms. so he thinks my z motor is grounding. so i figure my next move is to pull the motor. any advice on this as far as what i'm looking for.

[chineshop_guy]

problem solved (i think). nothing wrong with motor, put everything back together. powered up an referenced out machine just fine. jogged it around a bit looked good accept for the fine tuning of lag. the 1525-BR board has adapter cables that came with it, when i went to adjust my lag, one of these cables hangs in front of the pots, when i moved the cable the z axis ran away. my electrical guy was with me, checked cable, low and behold wires had not been seated properly in the connecter was getting intermittent connection.
all that should be left is the tuning thing.