View Full Version : Currently designing a BOB - Would you be interested?

21-01-2017, 01:18 PM
Hi all,

After getting frustrated with cheap BOBs, I decided to design my own (EE by profession - maybe I shouldn't mention that :playful:) and I am currently a good way into the design. A couple of people have expressed an interest in buying one if I were to make a couple of boards. I am just gauging interest here as it will affect a few of the design decisions I'm making. As anyone who has done small scale production like this before, it's not cheap. To make it financially viable and worth the hassle I would have to be looking at a sale price of ~140. I appreciate this is a lot of money so it might not appeal to many. Either way, the boards will be made as I need one for myself so no loss!

Rough feature spec below:

Housed in a plastic DIN rail mount enclosure
Designed for easy connection to Smoothstepper but will also work with parallel ports with IDC-> DB25 cable
15-75Vdc Input Voltage Range. (Actually its 95Vdc or 65Vac Max - theres an internal rectifier. However this would be an unofficial maximum as I want this to fall outside LVD)
Isolated, regulated 5Vdc output (to power Smoothstepper etc.)
Non-isolated, regulated 12Vdc output for sensors etc.
Non-isolated, regulated 5Vdc output for touch probes etc.
Port 1 & Port 2 support.
All inputs support Volt free contacts (switches etc.) as well as open collector/drain sensors (NPN etc.). No external pull-ups required.
PNP sensors are supported so long as they are 24V
All inputs have LED indication when active

Port 1:

10x Inputs
4x Step/Dir Outputs
1x Spindle Speed Controller Output (Fixed 10V output - internal ref) with calibration POT
2x 230Vac/10A Relay Outputs (with LED indicators)
Charge pump feature allows Mach3 charge pump signal to be input to the BOB. Loss of this signal disables all outputs on the BOB (also turns on a fault LED). This feature can be disabled via a DIP switch.
If using the dedicated E-STOP input, this can also disable all outputs on the BOB. Again, this function can be disabled via a DIP switch.
All outputs are buffered

Port 2:

4x Buffered Outputs (On an IDC header, unlike terminal blocks used for other I/O)
5x Inputs
2 of the inputs have a "merge" capability which is useful for Probes etc. This allows a normally closed and normally open contact to be merged together to drive a single input. This can be disabled via a DIP switch.
Pins #2-9 brought out to IDC header. These are protected but have no buffering.



21-01-2017, 01:52 PM
What about one of these? http://www.cncroom.com/break-out-board/smooth-stepper
Already does a lot of what you want.

22-01-2017, 10:00 PM
Why re-invent an expensive wheel.?

23-01-2017, 12:33 AM
i haven't compared the specs directly but for not a huge amount more you could have the CSMIO which also comes with direct pulse control and Ethernet unless I'm missing something.

John S
23-01-2017, 12:52 AM
i haven't compared the specs directly but for not a huge amount more you could have the CSMIO which also comes with direct pulse control and Ethernet unless I'm missing something.

400 plus ? ?

23-01-2017, 08:00 AM
I was thinking of the CSMIO/IP-M at 229 EU (198)

http://www.cs-lab.eu/en/produkt-18,2-CSMIOIPM_4axis_Ethernet_Motion_Controller_stepdir_ with_connectors.html

I might not be comparing like for like so here is the overview (last column):


23-01-2017, 09:01 AM
CSMIO has floating inputs - neither side connected so flexible options. Also differential outputs for noise-rejecting connections to stepper drivers. Don't forget that it is also a pretty good motion controller with Ethernet input. But everyone has their own views on "ideal" configuration, and for some of us part of the challenge is in the building, not just the finished product. Otherwise, why would we take so long to finish?