View Full Version : Don't Do It?


CharlieM
04-28-2005, 03:18 PM
My little home built mill, drilling .035 diameter holes in stainless,the drill dulls, starts to scream and then breaks off in the part! Not so easy to get it out. I grab the mouse, search for the pointer, manuver it over to the emergency stop and the drill has already broken. So - - I put a 4 pole switch on the Z axis stepper motor and I can kill the down feed in a fraction of a second. Then I read, NEVER disconnect the motor while the drive is powered up!

Is this the reason I burnt the Z axis driver out on the Xylotec ?

DieGuy
04-28-2005, 03:39 PM
My little home built mill, drilling .035 diameter holes in stainless,the drill dulls, starts to scream and then breaks off in the part! Not so easy to get it out. I grab the mouse, search for the pointer, manuver it over to the emergency stop and the drill has already broken. So - - I put a 4 pole switch on the Z axis stepper motor and I can kill the down feed in a fraction of a second. Then I read, NEVER disconnect the motor while the drive is powered up!

Is this the reason I burnt the Z axis driver out on the Xylotec ?

I bet it is, the docs say to never disconnect a drive with power on.

Al_The_Man
04-28-2005, 04:24 PM
Not so easy to get it out. I grab the mouse, search for the pointer, manuver it over to the emergency stop and the drill has already broken. So - - I put a 4 pole switch on the Z axis stepper motor and I can kill the down feed in a fraction of a second. Then I read, NEVER disconnect the motor while the drive is powered up!
Is this the reason I burnt the Z axis driver out on the Xylotec ?

That is why I would NEVER use an on screen software e-stop, it defeats the purpose as it can never be used the way it is supposed to be, don't Xylotex board have an enable pin? At least if these are wired to a hardwired e-stop button it would be more effective.
Al.

ger21
04-28-2005, 04:48 PM
Yes, Al they do have enable lines, but I don't think too many people use them, as they are jumpered to ground when you get the board, so you can pretty much ignore them.

Charlie, send an email to Jeff at Xylotex. He can probably repair your board pretty cheaply. The Xylotex is very intolerant of miswiring. (removing a motor under power falls under this category.) Other than that, it's a great drive for the money. fwiw, the current model Gecko drives are just as intolerant, it's not exclusive to the Xylotex. The newer soon to be released Geckos will be better, but at a higher price. Much higher than the Xylotex per axis.

Al_The_Man
04-28-2005, 05:13 PM
Yes, Al they do have enable lines, but I don't think too many people use them, as they are jumpered to ground when you get the board, so you can pretty much ignore them.


Gerry, Surely these can be used though for e-stop I would think, if it's just a wire jumper on the terminal block, why are'nt more people using that?
Al.

pminmo
04-28-2005, 05:48 PM
The Allegro 3977 drivers used on the Xylotex board are pretty sure fire to fail if the motor is disconnected with power on. The 3977 part has an enable line on each, which I suspect is the jumpers on the board. My interface board http://pminmo.com/4axis/4axisinterface.htm has a simple electonic latch for an estop that implements a panic button (estop) and estop reset on it. By wiring the estop signal to the enable on driver boards, the drivers become disabled to move regardless of what the computer is telling them to do. If you goto the document on that webpage, the last page of it has the schematic. The estop circuit is the portion like this pic attached:

Phil

ger21
04-28-2005, 08:23 PM
Gerry, Surely these can be used though for e-stop I would think, if it's just a wire jumper on the terminal block, why are'nt more people using that?
Al.

Probably because it's a molex connector, and not as easy as just plugging wires into a terminal. You need to get the appropriate connector and wire it up. I'd guess that a lot of Xylotex users don't even use a hardwired e-stop, as most are hobby machines. Until you realize that you really could have used one, most people probably don't see the need. Just a guess on my part, though.

strat
06-30-2005, 04:09 PM
when i was setting mine up i saw these so i ran to a switch......flip switch motion stops :) still looking for a cheap mushroom kill switch but for now a simple toggle

jo_tigger
04-04-2007, 01:04 PM
The enable switch is used to activate or deactivate individual drives. I have a toggle switch on all mine and use it lock/unlock the stepper drive to allow for hand cranking the axis for alignment purposes while the job is paused. When the drive is in enable mode the motor is locked and you can not crank it by hand. I use a separate e-stop switch to kill the system. Perfect for drilling circuit boards.

Richard

SORCHEROR
04-04-2007, 01:44 PM
why not use a hand held E-stop button?the reason the board blows is when you disconnect a motor is the software is still pumping full power to the driver,but use a kill button for the software e stop stops everything and should work fine,i have some cheap hand held buttons with 6 foot cord if anyone is interested let me know

Regnar
04-05-2007, 03:44 PM
jotigger, can i get a picture of your setup. I kinda have an ideal of what you did just want to make sure I dont make smoke.

jo_tigger
04-05-2007, 07:30 PM
Regnar,

Sure no problem. You might want to read the following document from Xylotex if you haven't alreadyhttp://www.xylotex.com/XS3525V400.pdf. Page 6 has the enable info. Basically there is a 5 pin header between the parallel port and the breakout screw terminals. You remove the jumper from the enable pins located by the step setting jumpers. This will take it out of enable mode. Then connecting a switch between the ground on the 5 pin header and the other 4 pins. Closing the switch will then enable the drive. I have a DeskCNC board so I use it for my E-Stop which requires a normally closed switch.


Header Connections
Using 1 Switch ($) to enable/disable all drivers at once.
X Y Z A Ground
| | | | ` $
| | | |___|
| | |_____|
| |_______|
|_________|

Using 4 Switches ($) to enable/disable individual drivers.
X Y Z A Ground
| | | | ` |
| | | $___|
| | $_____|
| $_______|
$_________|

alexccmeister
04-21-2007, 11:06 PM
Hi,

I sometimes don't connect all my motor to the axis socket on my cnc controller box. I just connect one up and do test on one axis of my machine. Will this cause the driver to burn out? After reading this thread, I am concern.

Alex

jo_tigger
04-22-2007, 01:30 AM
Hi,

I sometimes don't connect all my motor to the axis socket on my cnc controller box. I just connect one up and do test on one axis of my machine. Will this cause the driver to burn out? After reading this thread, I am concern.

Alex
My understanding from Xylotex is that this is okay as long as you do not connect or disconnect with the power on.

Richard

alexccmeister
04-22-2007, 02:45 AM
Hi Richard,

Thanks for your response. So even if the other drivers are sending signal to the motor (when the motor is not connected) is fine? If thats ok, that will great. But I should have all motors connected just in case. I think I only did that once or twice.

Alex

jo_tigger
04-22-2007, 03:03 AM
Alex,

No problem. I have a 4 axis board but have never used the 4th. It was preferrable to buying a 3 axis board and having to get another driver or new board later.

Richard