[topduck]

I've had this problem from the start

Jogging the Z axis upwards always seemed a bit jittery.
I've tried many options to no avail.
I always noticed the z axis stepper motor struggle when moving/jogging/step setting the axis

I took the stepper motor off and made sure that I can turn the lead screw freely without any resistance
I adjusted the jib to what I thought would be good tension.
Put everything back and the same problem.

Finally I decided to take the spindle motor off and try moving the z axis, same problem
then I took the head stock off and tried jogging the axis up and down and the axis move smoothly, no problems at all

With the spindle motor and the headstock off the z axis move fine, however if I apply any weight to the axis, the same problem
The more weight I apply the worst it get. ( I am talking about applying little pressure with my finger can cause the stepper to make loud noise and the machine stops with an error message saying " limit switch triggered " ( I don't have limit switches )

I tried adjusting the jib in either way, no joy.
I also made sure everything is clean and well oiled

If any of you nice people can help me resolve this issue, I'll be most grateful

Thank

[mavericks]

Where'd you get the stepper motor from? What if you switch the x-axis motor with the z-axis?

[topduck]

Where'd you get the stepper motor from? What if you switch the x-axis motor with the z-axis?

Thanks for the reply

I bought the whole machine directly from taig
I did swap the motors - that didn't help either

[mavericks]

Are you using mach3 for the controller software? If so, I'd check the motor tuning settings in it.

The one I picked up had to be set to 40000 steps per inch, accel 4, vel 20.

http://www.deepgroove1.com/tutorials.htm
http://www.machsupport.com/videos/

So does that mean you have the "Closed Loop Servo MicroMill DSLS 3000"? Because if your motor stops and the program says you've hit a limit switch, it sounds like a servo based system...

[cncbayer16]

Looks as you have hit 90 percent of the possible issues, hate to tell ya but you'll probly have to check overall concentricity of those componants, ie wheys,and there doves, the upper adjustment screws(as in your lathe's) tails, the more canted you can set it up, at a dgree that when you put the weight back on it will level itself out(parallel it ) and you mys well sit and take 3 days to ensure you are looking at it strait DONT forget to check the sevos amp load, position of the motor mount and so on and adjust as specs say cause the motor WILL burn out and there goes 1500.00 ,,,, good luck.. that type of job sucks thats why they get 180 an hour to do it,, oh yea ive got the same on an Y if you can believe it but i dont get paid that much to fix our yet,, i compensate with the amp value lol

[lsces]

Thanks for the reply

I bought the whole machine directly from taig
I did swap the motors - that didn't help either

Assuming this is a DSLS3000 ... It should work fine from the box
You say you have swapped the motors, but was that still using the same channel out of the controller for Z? If you have a four channel controller, Try using the A channel to drive the Z motor, and copy the settings from Z to A in motor tuning settings. If not, then make a note of the X and Z settings and use the X channel to drive the head.

It does sound as if perhaps you have lost a FET in the driver, although normally that does not give any smooth motion ... AH - but if the high voltage feed is not connected to the Z axis board , only the X/Y - then that may give the same effect. Check the power connections on the top board inside the controller. If Z moves fine using the X output, then there is a fault on the Z board and it will need to go back to Kurt for repair

[topduck]

Yes it is the DSLS3000

I swapped the Zaxis with the Aaxis including the channels and I did get better response but still not good enough when I attach the Spindle and Headstock

I'll try few more things tomorrow, if it doesn't work I'll try sending it back for repairs

thanks for all the replies

[lsces]

Since Z and A share the same board, f the problem is a missing power connection, then they will give similar results. Using X instead will probably prove the point.

[topduck]

I am sorry guys I meant to say swapped the z and x steppers and channels
I haven't tried swapping the z and a axis , will do tomorrow and let you know what happens

thanks

[rowbare]

You say you adjusted the gibs but have you adjusted the clamping shoes? (see midway down the second page linked)? If those are too loose or too tight, you will have grief...

http://www.cartertools.com/millset.html
http://www.cartertools.com/millset2.html

That site has a lot of good info on Taigs.

bob

[cartertool]

Call up Taig and talk to Kurt, he designed the DSLS system and should know what to do to fix it.

Yes it is the DSLS3000

[topduck]

Thank you guys so much for all your help and support
I finally found the problem, there must have been a loose connection inside the servo, I took apart and made sure everything was connected properly and it worked now.
after weeks of suffering with machine when I thought it was a mechanical problem, it turned out to be electrical.

Thanks once again

Sam DeHays

[fretsman]

Hi Sam,

Glad you got it fixed-

Just curious about something, you mention a loose wire connected to the "servo", doesn't your DSLS 3000 have stepper motors?

I looked on the website to see if they've gone to servo motors but didn't see anything.

Thanks,
Dave

[mavericks]

i think the last S in DSLS is Servo. But i saw another site show steppers with encoders on it... Strange.

[Jeff-Birt]

The DSLS 3000 uses steppers with encoders. Any form of motion actuator that uses a form of posistional feedback to activly control its position is a 'servo'. The type of motor uses is not importnat.

[fretsman]

The DSLS 3000 uses steppers with encoders. Any form of motion actuator that uses a form of posistional feedback to activly control its position is a 'servo'. The type of motor uses is not importnat.

Jeff, while I understand what you're saying is true, it's misleading just a little bit, isn't it?

That's giving the idea that these are true servo setups and that if they "get off course" they'll speed up and catch back up like real servos. The DSLS 3000 does not do that. If they "get off course" they throw an E-Stop/Reset situation, which you end up losing position anyway, you're just not continually crunching into your part, or worse yet, your machine.

I remember having a great conversation with Lester Caine (a dealer of these in the UK) and he explained exactly what it did.

Please correct me if I'm wrong.

Thanks,
Dave

[Jeff-Birt]

What I said while not misleading was perhaps not thorough enough.

Any form of motion actuator that uses a form of positional feedback to actively control its position is a 'servo'.

That is a pretty good definition as a 'servo' requires feedback and that the feedback be actively used to control position (or velocity). Your right though Dave that just having an encoder does not mean a 'servo loop' is being used. Using an encoder to fault in case of lost steps is a form of supervision.

A quick look at MicroProto's website reveals the true facts about the DSLS system:

Digital Sync Lock Servo (DSLS) control technology

DSLS control utilizes a new advanced proprietary mathematical servo control algorithm that locks the encoder feedback pulse signal stream with the command pulse signal stream. If the encoder pulse rate deviates from the commanded pulse rate the algorithm forces the two signals back into synchronization. In this way the commanded velocity and position are always followed. With the addition of an optical encoder this allows a standard open loop stepper motor drive system using step and direction software to be turned into a true closed loop servo system.

Sounds like active control to me

[fretsman]

What I said while not misleading was perhaps not thorough enough.



That is a pretty good definition as a 'servo' requires feedback and that the feedback be actively used to control position (or velocity). Your right though Dave that just having an encoder does not mean a 'servo loop' is being used. Using an encoder to fault in case of lost steps is a form of supervision.

A quick look at MicroProto's website reveals the true facts about the DSLS system:

Digital Sync Lock Servo (DSLS) control technology

DSLS control utilizes a new advanced proprietary mathematical servo control algorithm that locks the encoder feedback pulse signal stream with the command pulse signal stream. If the encoder pulse rate deviates from the commanded pulse rate the algorithm forces the two signals back into synchronization. In this way the commanded velocity and position are always followed. With the addition of an optical encoder this allows a standard open loop stepper motor drive system using step and direction software to be turned into a true closed loop servo system.

Sounds like active control to me

Yes, but I always thought "they're" description was misleading as well, and that was what prompted me to ask Lester all about it as he was expounding about the DSLS system one day on the Yahoo forum.

Not saying that the description is not fact, but when most people think of "true" servo systems, they think of a system that will correct itself. This system indeed does not do that so therefore I (in my opinion of course) think it's misleading and I think the play on words helps sell a few more of these

Just as a note, I have been very happy with my DSLS 3000, but I know what it is, and what it isn't

Thanks, Jeff, I appreciate the input-
Dave

[Jeff-Birt]

Taig's own description very clearly says that the encoder input is use to correct the position of the stepper to keep the commanded position and the actual position the same. That is a servo loop, again the type of motor is not important.

[fretsman]

lol, well, anyone can just repeat what someone else says so I guess this is going nowhere as you obviously have no real world experience with one of these machines.

I'll bow out of this gracefully since you obviously know so much more than me since you're a Taig dealer.

Dave