Refurbished original BeBoPr capes are on sale at boardzoo.com for $49.99, limited qty available…
That's a good deal! The boards will work with a BBB if you make a
bridge board. I have some PCBs available if you don't want to fab your own:
Don't forget that CircuitCo doesn't ship any mating connectors with
these, so if you get one you'll probably want to order a set of the
power connectors unless you have some on-hand. The other connectors are
either standard 0.1" headers (steppers, thermistors, limit switches) or
screw terminals (heater outputs).
That's very cheap, even if you add the costs of the extra hardware you need to use it.
But beware: Some of the information on the boardzoo site is misleading: These capes are not supported by me (I'm owner of the design) because Circuitco has broken the agreement for distributing these capes by withholding my fee for the design. These 'refurbished' capes are first generation boards designed for the BeagleBone White and come _without_ firmware and stepper code license. These boards are a cheap way to run LinuxCNC on a BeagleBone Black provided you buy a Bridge, but my BeBoPr 3D printer software will not run on these capes. And I don't know whether Circuitco has solved the problems with the FETs overheating and fixed the other assembly errors on these 'refurbished' boards. So be warned, careful and know what you're buying.
That being said, the boards are very cheap, and if you only want to control some stepper motors, grab your chance!
IIRC there were some boards with LEDs in backwards (or was that all of
them?). Any other issues? The board I got from them (at full price) to
test with seemed to work OK, but I haven't put in a lot of time printing
with it. I'm now up to (I think) 4 BeBoPr's (one from CircuitCo, two
and a ++ direct from Bas via group buys), a Replicape, several CRAMPS
prototypes, and then a bunch more CNC oriented boards. No one board
seems to stay connected for very long!
I also mostly run 24V (I manually modified a couple of the older Rev3
BeBoPr boards, the ++ does 24V natively), which would help to keep the
FETs cool even if there was an issue with the board FETs, and one of my
printers uses an AC line power SSR for the bed heater (so virtually zero
current and no FET heating on what is typically the highest current output).
On the boards I've seen, J5 is also missing and the EEPROM is not programmed, so IOmux configuration must be done manually. IIRC MachineKit will do this properly at start up.
I've solved a potential FET issue (thermal runaway) on the BeBoPr+ by adding a heat sink to the HPB FET and using a fuse with lower rating. On the BeBoPr++ the entire circuit has been redesigned: the FETs have been replaced by lower RDSon types and proper gate drivers were added.
One other thing: The BeBoPrs that I've made and sold all use double weight (2oz) copper plating for reduced dissipation in the high current section, and beater heat spreading on the board. I don't know how much copper Circuitco has used for their R3 boards. This could also be a reason for the FET problems with their boards.
Reducing dissipation in the power section was one of the reasons to change the step down converter. But many people still use 12 Volts / 120W heated build platforms, 19.5Volt or 24 Volt versions are less common. Another advantage of using 24 Volts is that you can interface directly to industrial components that run at 24 Volts DC (e.g. Festo valves for pneumatic control).
But let's not start promoting all the advantages of the BeBoPr++ since this thread is about 'refurbished' BeBoPr boards .
These units are brand new builds but had some of the LEDs populated backwards. they were corrected, but since “rework” had been done to them, circuitco can’t sell them as new, only as “refurbished”.