Re: L298 goes boom on my camtronics :(

Hey Rich,
no, I didn't unplug any stepper (did do that accidently once but was
luckly!). I was using the "jumpers", J8 and J4 on the 3 axis and
single axis board and connecting a switch to it. Instead of
connecting 2 switches independently, I conneted one pin from J4 to
J8. Other pin of J4 to J8 and then a switch from J8. When "on" it
would connect J8 and J4 so technically all 4 axis should be free
wheeling. Guess I learned something! Don't connect them, use two
different switches.

Wonder if I should also replace the L297 as afogassa found out. Well
will wait for Dan and see what he says.

Acutally, the more I think of it, I really don't need the 4th axis
since I don't have a 4 axis CAM program and I plug it into Y axis
anyway. Maybe I will just get another single axix one (fix the other)
and use those 2 for the lathe. Well will see.

thanks
tauseef

--- In CAD_CAM_EDM_DRO@y..., RichD <cmsteam@s...> wrote:
> Taus,
> Arrrrrhhhhhhhgggg!
> You broke rule number one!
> NEVER disconnect stepper windings with drive power applied.
> The high voltage back EMF is a killer to the IC's.
> If you want to disable use the supplied AWO (all windings off)
feature.
> Jumper J8. That's what it's there for.
> OK?
> RichD
>
> tauscnc wrote:
> >
> > well well well, how are you? Me, smelling a little smoke :( I was
> > connecting a simple switch to J4 and J8 so I can "free" my motors
> > without having to turn off the main power on my Camtronics 2A 3
axis
> > board and single board all the time.
> >
> > Well I thought if I connect J4 (single axis) it frees the A axis.
If
> > I connect J8, it frees XYZ axis. So what I did was to install one
> > switch for both boards. I connected a wire from one pin of J4 to
one
> > pin on J8, other pin on J4 to the other pin on J8..I then
connected
> > two wires from J8 to a switch. Switch off and I pluged it in, ZAP!
> >
> > my power fuse blew. I looked it all over and and undid the J4
wires,
> > ZAP 2nd time, I undid all of them ZAP 3rd time.
> >
> > I then spun the motors by hand and ALL 4 AXIS motors felt very
> > gritty,, like they where shorted out or had some "holding power
on"
> > (remember no power is on)!
> >
> > I was so scared I pulled everything apart hoping it was the power
> > supply but it works fine. Intersting is that NONE of the axis
fuses
> > blew, just the main power fuse.
> >
> > Looking around I noticed the L298N cracked on the single board!!!!
> > Got real close and I could smell it a little. Y axes seems to be
the
> > worst where the motor almost seems like it has holding power, very
> > gritty to turn (each motor is free when not connected). Well I
hope
> > it's only the 4 L298 that need replacing. Found a price for them
but
> > waiting on Dans responce first.
> >
> > Pic included of the single axis L298 if you care to share in my
> > depression :(
> >
> > http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/Tauseef%27s%
20CNC%
> > 20Sherline%20/L298-Camtronicboom.JPG
> >
> > (its under files and "tauseef cnc sherline"
> >
> > tauseef
> >
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