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Novamill not homing
Posted: Wed 13 Mar , 2013 12:54 pm
by Clive
Hi,
I'm new to this forum and guess what? I'm in trouble!!!!
On Friday my Novamill was operating normally and was shut down without any drama. (The world was a wonderful place)
On Saturday morning it wouldn’t “Home”. The Z-Axis position changed on the screen but nothing moved.
I found the secret home override and established that the same is true for X, Y and Z.
The spindle works as it should.
I have investigated all of the fuses that appear relevant, including both which are claiming to be F6. That’s the one on the rail and the one on the board.
Fuse F8 on the 24v PSU is sound and I have a nice juicy fat 25.9 volts DC coming out of it.
When the box is powered up, the display at the top left, shows “.L” and the “.” is flashing. There is also a steady red LED on the spindle board. Not the stalled one.
I originally thought that I had managed to corrupt the VR Milling software on the pc so I have reinstalled it but the same fault persists.
When originally booting up the system on Saturday I may have been a tad impatient and hit the button to load the real machine before the system had finished its initial processes. Other than that there was nothing strange.
The mint data seems to load properly.
Any ideas?
Getting a bit desperate!
Regards
Clive
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 13:48 pm
by Steve
There is a fuse on the control card where the 24V goes into it.
Have you measured the control voltage and motor power into the nextmove.
It may be the motor power is not present. See the attached picture
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 14:31 pm
by Clive
I will check the voltages when I get home.
The fuse is ok.
Thanks
Clive
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 20:06 pm
by Clive
Have booted the system up properly and 7-element display now shows "8".
I have checked for the power and logic inputs to the board and both are zero.
Guess the problem now is to figure out where the 24v has gone, as the psu is still fine.
Clive
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 20:16 pm
by Steve
If the seven segment display is showing an 8 then the 24V supply must be there.
Suggest you remeasure.
Also photos of the electronics would help se we can identify relays etc
I suspect you have the logic supply but the motor power may be missing. Could be E stop button or relay problem.
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 20:37 pm
by Clive
It would appear that the power and logic are both connected to the 28v AC supply.
They are both healthy.
Clive
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 21:04 pm
by Martin
Have you tested the emergency stop button?
Re: Novamill not homing
Posted: Wed 13 Mar , 2013 21:17 pm
by Clive
Martin wrote:Have you tested the emergency stop button?
I have pressed it and watched the indicator move from I to O.
Do I need to do anything else?
Clive
EDIT: The 28v makes it as far as the on-board fuse F6.
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 7:20 am
by Martin
Do the drives power up?
If you remove the rear cover plate the Y axis motor should be solid when powered up & free when under estop.
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 8:07 am
by Clive
I can't check that until tonight but I would say no on the basis that the machine has stopped making the little "thump" noise when first switched on.
Clive
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 9:38 am
by Martin
Hi Clive,
It does sound as though the stepper drives have failed.
I may be worth checking the fuse holder as well. I have seen it before where the clamps have opened up on the fuse holder.
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 10:20 am
by Clive
Oh dear!
Sounds expensive.
Why would all three go at the same time?
Clive
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 15:47 pm
by Martin
All three drives are integral on the Baldor base board so depending what fails it could show up on all 3 axis.
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 19:34 pm
by Clive
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 22:01 pm
by Martin
Before you go too far,
1. Is the drive voltage present on wire 24 & 26?
2. Is fuse F1 on the baldor card OK?
3. Do the motors energise?
Re: Novamill not homing
Posted: Thu 14 Mar , 2013 22:46 pm
by Clive
Actually I only checked for the voltage between 24 and 26.
Can't do any more investigating until tomorrow night now.
The fuse is definitely ok. I removed it and checked it with a multi-meter.
Will check motors tomorrow.
Thanks for your help.
Clive
Re: Novamill not homing
Posted: Fri 15 Mar , 2013 20:31 pm
by Clive
Voltages at 24 and 26 as measured from the earth connection:
24 30v~
26 0.5v~
For good measure I also looked at cores 28 and 29 wrt earth:
28 15v~
29 15v~
30v~ between them.
So that I don't do more damage. Just what am I supposed to remove to get at the end of the X-Axis motor shaft?
Re: Novamill not homing
Posted: Fri 15 Mar , 2013 22:08 pm
by Martin
If you remove the four M4 cap head screws holding the motor plate to the crosslide the stepper motor will lift out. When the machine is powered up & drives enabled the stepper motor should be locked. If you then press the estop button the motor sholud de-energise & turn freely.
Re: Novamill not homing
Posted: Fri 15 Mar , 2013 22:50 pm
by Clive
Motor is free to turn before and after pressing the e-stop.
Re: Novamill not homing
Posted: Fri 15 Mar , 2013 23:44 pm
by Martin
Check Fuse F1 again but if it's still the same then it must be the base board.