Triac homing problem

[rbarnes]

We have a 1998 Triac which has not been used for 4 years. The computer which ran the software (VR Milling) has crashed. We have re-installed the software on a new computer running windows XP professional and the programming and simulations work fine. I can drive the Triac, using the secret button, in jog mode and all axis work OK. If I try to home the machine the Z axis moves down, the Y axis moves in and the X axis does not move at all, but I can hear the motor running. Is there a procedure for setting the machine home position ?
Ray Barnes

[Martin]

Have you got the correct machine selected?

Depending on what control is now fitted try selecting it as Triac VME.

[rbarnes]

Tried the VME settting but does not work as well as the basic TRIAC machine setting. I am unable to read the original floppy disc as it seems to want to re-format.

[Denford Admin]

When you jog the axes without homing, do they move the correct amount ?
Do they go the correct way ?
Z +ve count is Head UP
X +ve count is Table LEFT
Y +ve count is Table TOWARDS front

[rbarnes]

Yes. The axis move the correct direction and amount until all axis display zero on the control panel, but the machine is not at its home position

[Denford Admin]

It sounds like either the home switches aren't working, are stuck or the machine should be travelling the opposite way when trying to home - 1st thing to check is the switches...see this post:
viewtopic.php?f=2&t=3587

[rbarnes]

Thanks for the info. Our version of the software is too old. I have ordered a site licence of the new version and then I will give it another try.

[rbarnes]

I have installed new software and re-checked axis movement.
Z+ head moves up correctly
X- table moves to the right
Y- table moves to the back
could it still be the homing switches ?

[Denford Admin]

Is it just the problem of the X not moving when homing ?
What happens if you move the table to the middle of travel in X and then try home ?
Does it move or just make a noise ?

[rbarnes]

the X axis does not move but the motor runs and the display position changes. The Z axis moves down and the Y axis moves in, but neither move to the home position. On the control panel a small green Y and Z are displayed all the time, which from the link you posted me should only be shown in a test procedure I think.

[Martin]

It sounds like both the X & Y axis datum sensors are high. It may be worth checking the sensors for debri.

[Denford Admin]

If all the axes run ok in Jog mode and homing used to work OK before installing the software on a new PC, then I can only guess that this machine has a special "mint" logic file which would invert the home inputs (either that or they have both failed at the same time as changing the PC )
Please let us have:
The serial number of the machine
Which machine type is selected in the s/w ?
What is the control board type ? (take a photo of the bit with a red/green/orange 7-segment LED)

[rbarnes]

Just to clarify:- The machine would not home. The new software was to enable me run the tests described in your previous link. I can jog the machine with the secret button and the axis move the correct amount in the following directions:
Page up key Z moves up
Left arrow key moves table right
Down arrow key moves table to the back.
Movement stops when the control panel shows zero on all axis, but the machine is not in its home position. The control panel shows zero on all axis on software start up, with a small green Y and Z displayed.

[Denford Admin]

The control panel shows zero on all axis on software start up, with a small green Y and Z displayed.

Do these stay onscreen even after moving Z down ? (well away from home)
If so, then the home switches aren't working.
My guess is Y and Z are switched permanently which is why they move when homing.
X is probably running past the switch and stalling at the end of travel.

If this is a Triac upgrade to Baldor then it may be to do with the voltage levels of the proximity switches - the old ones worked on 8 or 9 volts IIRC. Sometimes they would switch OK to the newer 5V inputs but usually we had to fit a solid state relay to make the home inputs work reliably or replace them with new home switches.
We could do with some info on the history of the machine in order to help - at the moment it's all guesswork.

Note that wherever the axes are when you power the machine on will be 'home' position,ie machine 0,0,0
The homing sequence runs the axis onto the switch, slowly backs off it, stops and then sets the axes positions to 0,0,0
So, when you use the secret home function the axes will not be able to move the full travel on both direction because the software limits presume the machine has been homed in the proper position,eg, Z will not jog any more positive (up) from where it was when the machine was turned on.
You may need to open up the software travel limits to let you jog far enough to test the switches.

[Martin]

It may be worth checking the motion control card & the custom card in the rack. You should be able to remove the retaining bar & slide the boards out slightly. Also check the ribbon cable between the two. It should clip in.

[rbarnes]

Can I just clarify where the homing switches are ? We have found a switch at the top of the Z axis and the inner end of the Y axis. On the machine debug panel both Z and Y homing switch lights are on all the time. Operating either of the switches manually causes the emergency stop light to come on and the emergency stop message on the control panel comes on, so I am not sure we have the correct switches.
The machine serial number is 807310 and it was manufactured in 1998.

[Martin]

The datum switches will be proximity switches.
The switches you have located will be the axis limit switches.

If you lift up the Y axis bellow at the front right hand corner you should be able to see the Y sensor.
To get to the X axis sensor you will need to remove the 3 screws that hold the front Y axis bellow on to the table. The sensor is then mounted on the Zshaped alluminium bracket along with the X+ & X- limit switches.
To see the Z sensor you will need to look down the back of colum with the head in it's lower position.

Have you checked both cards & the ribbon cable that links thems? It does seem strange that 2 havw failed at the same time.

[rbarnes]

Hi again, we have removed the bellows and covers and cleared the machine of all debris. we have checked the boards and ribbon connectors and cannot see anything wrong. The Y and Z proximity detectors are working in reverse, manually operating them causes the lights to go off on the debug board.changing the software limits I can drive the axis over the switches but they do not operate. the machine was upgraded to the balder control. I have attached photos of the circuit boards

[Denford Admin]

I can drive the axis over the switches but they do not operate

Do you mean they don't change state in the debug I/O or they don't work when homing ?
If they only change state when you manually place some metal in front of them but not when the axes are driven over them, then either the metal actuator on the axis is too far away, or something has altered the sensing range of the proximety switch (either old age or supply voltage is too low/incorrect)

It is probably the voltage to the prox switch is too low from the Baldor (5V) and needs a 12V solid state relay driving from the prox sensors.
Have a look at this post - there is a specsheet for the switches if they are the same as yours...
viewtopic.php?t=2621

[Martin]

Hi Ray,

Where is this machine located?

Is it Selby College?

If it is the Selby machine then you will need a special mnt & mex file. If you unzip the files & then copy them over the original in the VRMilling directory.