Re: [CAD_CAM_EDM_DRO] Gecko burned - fixed for now

Hi Keith,

Your symptoms sound very similar to my Z axis. It was always a bit
sluggish and had to be tuned slower than X and Y. After a couple of
months use the Gecko popped. After checking everything I replaced the
Gecko and it worked fine for another couple of months before blowing.
Twice was too much for me and I am replacing all the motors with servos.
Shoulda done that in the first place. I hate steppers...

Fuses are pretty useless when it comes to high current spikes. If you
have a fault the fuse is not likely to save the transistors though it
will probably blow before the tracks so the Gecko will be repairable.

I initially had 5A fuses on my X and Y but they had a tendency to blow
sometimes when making sudden rapid moves (high acceleration). If I
recall correctly I have 8A fuses in there now.

Les

Keith Clark wrote:

>
> The continuing saga of the Bridgeport y axis stepper motor - looking
> brighter...
>
> Discovered some oil dripping on the motor but inside thinks looked
> ok, although there was some oil present near the terminals.
> Replaced the Gecko and turned down the rapid speed setting and no
> more trouble for now. It appears that the y motor likes to go
> slower otherwise stalls and I think that is why the Gecko burned.
> In fact the burn was so bad charred particulates fell out when the
> drive was removed.
>
> I replaced the 10 amp slow blow fuses with 5 amp rapid blow fuses
> with diodes across them as well. We will see if any more problems
> occur and if they do, hopefully the fuses will do a better job of
> protection.
>
> As always, you guys are so helpful and knowledgeable -- I could not
> have gotten beyond the first step without help from the discussion
> group!
>
> Thanks again,
>
> Keith Clark
>
>