Jim,
I usually run several hours at a time with no trouble too. I hate when it messes up at the end of a two hour job.
I am running the 125 oz-in motors (I think they are 1.25 amp). I also have a fan drawing air from the electronics box.
The most trouble I had putting this together was the 6 pin connectors that plug my motors into the box. If I have problems thats the first place I check. I don't know if that connection could have caused my IC's to blow.
I think I am going to eliminate the plugs and use some terminal blocks. Also I am going to solder the UNC5804B IC directly to the board and get rid of the IC sockets. (the socket melts when the chip burns up)
Bill |