View Full Version : Cable connector hot

05-14-2006, 01:07 AM
I just noticed that the cable connector for my z-axis motor is rather hot - not too hot to touch but uncomfortably hot to hold on to. It's the little rectangular plug/socket, covered by heat-shrink insulation from the factory, that's just at the base of the arch (I have an Alpha). The only other one I could access to check is for one of the x-axis motors and it's cool - room temp.

For all I know it's been like this since day 1, but I've never noticed it and I was working nearby that connector just the other day. Is this something I should be concerned about?

05-14-2006, 02:14 AM
Any electrical connection that gets hot is loose. This should be repaired before the connection completely fails.

05-14-2006, 10:14 AM
David, I often run my 'Alphabot' for hours, endless hours and have had the same problem on several occassions. The first clue was when I had communication problems between my computer and the control board. The yellow screen popped up bitching about how it couldn't establish communication. Tried all the usual checked the USB cable and the com port etc. While digging around looking for the spare jumper to run some 'pings' I touch the "y" axis cable and it was hot. Looking closer I noticed that the connecter had slid up the pins about 3 mm. Pushed the connector back down to the control board and off we went to work. Changed up to the new cables sent me due to a warranty concerns at Shopbot and the problem has happened again. I am now trying looping the cables in a way that there is a slight downward pressure since there is no locking features at this junction and also I have routed the driver to motor cables above the drivers far clear of the control board. After hours of running the temperature inside that cabinet does exceed 100 degrees F and expansion of the plastic sheathing on the cables is significant enough to work the connection to the control board loose which in turn generates more heat as Roger has pointed out.

Botting to the Bank Baby


05-14-2006, 11:51 AM
I always try have to a few inches of slack on every cable at every connection. Right above the slack, I try to securely fasten the cable to some immoveable fixture with nylon ties. In the past, I've ruined equipment when strain on a connector shorted out wires.

As Roger said, if theres heat, there's a loose connection.