Been busy the last couple of days.. Blew a fuse on my power board and had to hunt it down.
Seems the brake coil on the wrist joint (#4 motor) dropped from 60 Ohms down to 4 Ohms.
This usually happens on coils that are wound too tightly or with thin enamel on them when they over heat. The enamel softens and eventually the wires in the coil begin shorting between layers.
as the wires short and the coil resistance drops, the coil heats even more and the process accelerates. Eventually the coil melts down or a fuse blows.
I have entirely disassembled the motor for the joint and removed the coil. I plan on wrapping a new coil and rebuilding the motor this month. Why? Just to say I did.
I have taken many photos and I hope to post them on the board very soon.
I am going to try attaching a jpg to this msg. The right of the diagram shows the LSI-11 CPU above the memory, then the Serial cards for VDT, TEACH, FLOPPY etc.. After that are the Parallel IO cards.
From my adventure this week, I leaned that the IO cards also send some signals back to the power boards (The next row of cards over) through the back plane. Finally the Digital Servo and Arm signal cards. these are Input cards from the Encoders and POT outputs.
If the CPU, CMOS and Serial cards work, then you should at least get the NO-VAL error on your teach pendant , or a LOAD VAL prompt on the VDT. Before VAL is loaded, the other cards are not even talked to by the computer.
You might also want to look at the second diagram. it is of the same stuff, just at a conceptual level.
I have published the datasheet for the JAWS-11 chipset on theatronics.com
Look at your processor board. I hope it is labeled M8192.
It should have a large white (60 pin) chip on it that looks like it has two smaller chips mounted to it.
On the back of the processor board along one edge should be the label: KDJ11-A PROCESSOR
This is the main processor board I have and that I will be sampling signals from.
I will post my findings tonight or tomorrow evening.
The datasheet is very helpful in identifying the pinouts for the main chip.
I'm surprised to see there is an active forum for a PUMA robotic arm, but pretty cool nonetheless.
I'm a student a georgia tech, and for our senior design project we are interfacing a modern PAC (an Allen Bradley ControlLogix) with an PUMA 500 6 axis arm. Finding documents on the PUMA has been a bit tough. Does anyone have the pin outs or a spec sheet for the umbilical connector they care to share or point me at?
Friends, meet my mentor! When I had a giant coat rack , he helped me get it moving .
I ahve been trying to help others as best I can. It has been very stressful at the day job
so getting home at a deicent hour and having any time to do some research has been hard.
Interesting note: I had a Eletromagnetic brake on Joint 5 go out. I completely disassembled the motor,
Removed the burned up winding (Dropped from 60 Ohms down to 4.) it was quite cripsy.
Then I made up a teflon bobbin and wound my own replacement. I took plenty of pics and I hope to
add it to the website. (http theatronics com)
I am already shopping around for more parts. I'd like to have at least 2 functional arms and some spare parts.
(maybe even a 260 to complete the collection... <grin>) My workshop isn't big enough for the 720 but some day.......