E stop Question

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07-05-2012, 07:42 AM
mike sr1

E stop Question

Is it normal for the Z to drop approximately .040 when the "E" stop is pressed? I am wondering if any of you have had this problem with yours, or could it be something I am doing? The Z DRO doesnt change but the tool will drop .040.

I try to use the escape key as that will just stop the machine, this works fine unless the Z is in rapid down, then pressing the esc key will stop everything but the Z, it will continue down till it hits the part, it isnt under power its "freewheeling" down possibly due to the momentum and weight.

Any input on this would be much appreciated.....
07-05-2012, 01:08 PM
philbur

It's not normal but it's not uncommon.

What series machine do you have? The later machines had a brake fitted on the Z axis motor, take a look. If you have the brake then it isn't working and you need to troubleshoot it. If you don't have a brake then adjust the Z axis gib so that it supports the head weight + a bit of body weight. The adjustment procedure is in the Series I manual.

Alternatively you could buy a motor with a brake, but then at that price it's probably a better deal to buy the whole series III stepper motor package, then you would get the Z axis brake for free.

Phil:)

Quote:

Originally Posted by mike sr1

Is it normal for the Z to drop approximately .040 when the "E" stop is pressed? I am wondering if any of you have had this problem with yours, or could it be something I am doing? The Z DRO doesnt change but the tool will drop .040.

I try to use the escape key as that will just stop the machine, this works fine unless the Z is in rapid down, then pressing the esc key will stop everything but the Z, it will continue down till it hits the part, it isnt under power its "freewheeling" down possibly due to the momentum and weight.

Any input on this would be much appreciated.....
07-05-2012, 01:28 PM
mike sr1

Phil,
I have the series 3 machine, the Z brake is working if the E stop is pressed to stop the machine, but in the process the tool drops .040 into the workpiece.

I like to use the esc key and this works fine except for the Z being in a rapid down motion, then it will freewheel into the work before stopping, I guess tightening up the Z gib may solve the problem there.

Thanks for the input......
07-05-2012, 01:48 PM
philbur

I don't recall seeing the head drop any applicable distance with power off. The gib is adjusted according to the DTI method. Although I haven’t check to see if the head will freewheel with the brake off.

Phil:)

Quote:

Originally Posted by mike sr1

this works fine except for the Z being in a rapid down motion, then it will freewheel into the work before stopping, I guess tightening up the Z gib may solve the problem there.

Thanks for the input......
07-05-2012, 04:24 PM
mike sr1

Quote:

Originally Posted by philbur

I don't recall seeing the head drop any applicable distance with power off. The gib is adjusted according to the DTI method. Although I haven’t check to see if the head will freewheel with the brake off.

Phil:)

It only drops .040 approximately, it isnt very noticeable unless its cutting horizontally, then when the e stop is pressed the head will drop at the instant the brake engages, and it produces a nice gouge in the part.

This happens each time the e stop is used, I know it does this so I use the esc key to just stop the machine, but in z down that will let the head freewheel.

I will call Tormach today and see what they have to say about it, may just need to tighten the gibs a bit more.
If its not a common problem, then I would think it would be mechanical as the dro reads the same before and after the gouge.
07-05-2012, 06:13 PM
philbur

Why are you using the estop to stop the machine when the cutter is in contact with the work piece. Under normal operating conditions you should be making any necessary stoppages of the operation in the Mach software!!! The estop is for emergency stops, which would normally mean the work piece was junk anyway.

Phil:)
07-05-2012, 06:21 PM
mike sr1

Quote:

Originally Posted by mike sr1

It only drops .040 approximately, it isnt very noticeable unless its cutting horizontally, then when the e stop is pressed the head will drop at the instant the brake engages, and it produces a nice gouge in the part.

This happens each time the e stop is used, I know it does this so I use the esc key to just stop the machine, but in z down that will let the head freewheel.

I will call Tormach today and see what they have to say about it, may just need to tighten the gibs a bit more.
If its not a common problem, then I would think it would be mechanical as the dro reads the same before and after the gouge.

I called Tormach and Roy said its normal for the z to drop somewhat when shutting off the power with the e stop on the series 3 machines.

He said it can freewheel (Z) if the power is removed from the motor (hitting the exc key) .

He suggested using the space bar to shut it down at the end of the line of code.
07-05-2012, 09:50 PM
MichaelHenry

Quote:

Originally Posted by philbur

Alternatively you could buy a motor with a brake, but then at that price it's probably a better deal to buy the whole series III stepper motor package, then you would get the Z axis brake for free.

Are you sure that is true, Phil? I bought the Series III stepper upgrade package and didn't think that the Z brake was included.

Mike
07-05-2012, 10:53 PM
philbur

Hi Mike, I'm 100% certain. Mine definitely has a brake, the photos on the website show the brake and the instructions tell you how to wire it up. - See the right-hand motor in the photo below.

http://i186.photobucket.com/albums/x...on-Upgrade.jpg

Phil:)

Quote:

Originally Posted by MichaelHenry

Are you sure that is true, Phil? I bought the Series III stepper upgrade package and didn't think that the Z brake was included.

Mike
07-05-2012, 11:08 PM
MichaelHenry

Thanks Phil - guess I'd better get cracking on installing that upgrade then. Good thing I didn't buy the brake upgrade separately.

Mike
07-06-2012, 12:29 AM
philbur

Be warned that the installation instructions are not necessarily correct when it comes to wiring the brake in. It specifies the terminals to connect to on the breaker, however this actually depends on the existing wiring, which apparently can vary from machine to machine. If I remember correctly the brake connections should connect to unoccupied terminals.

If you have any trouble I can dig out the email exchange that I had with Tormach. It will depend on how electrically challenged you are.

Phil:)

Quote:

Originally Posted by MichaelHenry

Thanks Phil - guess I'd better get cracking on installing that upgrade then. Good thing I didn't buy the brake upgrade separately.

Mike
07-06-2012, 12:57 AM
shred

I got the Series 3 kit mostly because it came with the brake ;)
07-06-2012, 07:15 PM
MichaelHenry

Quote:

Originally Posted by philbur

Be warned that the installation instructions are not necessarily correct when it comes to wiring the brake in. It specifies the terminals to connect to on the breaker, however this actually depends on the existing wiring, which apparently can vary from machine to machine. If I remember correctly the brake connections should connect to unoccupied terminals.

If you have any trouble I can dig out the email exchange that I had with Tormach. It will depend on how electrically challenged you are.

Phil:)

Thanks Phil - I'll keep the offer in mind when the time comes.