Re: [CAD_CAM_EDM_DRO] Help, continuing to burn drives

Jeff,

Keith should have our latest breakout board with the anti-chatter feature.
This prevents pulses from going to the Gecko drives until Mach2 has control
and the charge pump signal has reached the breakout board.

Bob Campbell
Bob@...
www.campbelldesigns.com
Breakout board
THC board sets
CNC router plans
Stepper Motors
VisualMill Basic

----- Original Message -----
From: "Jeff Goldberg" <jeff@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, April 03, 2005 4:09 PM
Subject: RE: [CAD_CAM_EDM_DRO] Help, continuing to burn drives


>
> Ron,
>
> This is a cross post (from the mach1mach2cnc group) of what I sent in
> answer
> to Keith's question. The more I think of it, the more this seems to be
> related to Windows sending code out the parallel port when starting up.
> The
> suggestion below about the start-up procedure I use with an additional
> switch may cure this.
>
>
> I'm kinda thinking on the fly on this one.
>
> In order to get the fuse to blow, your Gecko is drawing too many
> amperes somehow. A "surge" on the line side is unlikely to force
> this (unless you have somehow created a floating ground which
> the "enable" relay is clearing). Assuming this, something is going
> on with either the signal to the Gecko doing something vastly wrong
> (don't know if it can, but say telling the drive to do the impossible
> as a pulse from the CPU an boot up). Personally, I've noticed things
> like this, so I have isolated the startup by using a pushbutton to
> engage my enable relay after MACHx is started. I'm pretty sure
> that's the problem. Only other thing I can think of is a bad spot in
> your motor which is shorting out on startup, but that's unlikely if
> it works otherwise.
>
> What I do is use a contact on the "enable" really to latch it with
> the "Start" push button and use the E-Stop button to disengage it
> (N.C. in series with the coil). After I push the button, I then hit
> the "Start/Reset" button of MACH to tell the software it's OK to run.
>
> This way, (while it does create an additional operation of pushing
> the "start" button), any boot up "artifacts" are ignored by
> everything. I also end up with a situation that, while MACH can
> initiate a software E-Stop, when I hit the E-Stop push button, the
> Hardware has no choice but to stop regardless of the state of the
> software.
>
> I just took a look and the circuit I'm talking about is posted as a
> schematic under the files section of the mach1mach2cnc group, under
> pendants
> in my folder.
> Download the JPG file (it's almost illegible when viewing with Yahoo)
> and look at the upper right hand corner of the drawing. The
> schematic is a little confusing because I am using multiple relays in
> different parts of the setup for ENABLE, but the concept I explained
> in my previous post should be able to be pulled from this.
>
> Let me know if you need more help,
> Jeff
>
>
> -----Original Message-----
> From: Ron Kline [mailto:godsone@...]
> Sent: Sunday, April 03, 2005 4:49 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] Help, continuing to burn drives
>
>
> Mine just did the same thing Friday afternoon , for the second time in 6
> months , the machine was running fine I shut it off for lunch and when I
> turned it on after lunch the 4 amp fuse blew so I replaced it , blew again
> I
> disconnected the motor to see if it was shorted and it still blew the
> fuse
>