help needed with my set up

[Clive S]

I think I read some where that it may be that the input from the parallel port is only 3.7v dc saying it need to be 4.5v dc to activate something on the bob .

The bob will convert the 3.7v to the required output so that will not be the problem.

[cropwell]

Have you got the 12-24v power connected ? - there is no mention of it so far ! That is needed to drive the electronics of the BoB. The 5v USB connection only powers the input opto-isolators.

[amxen]

it is my understanding that connecting the 12 24v to the bob is only to enable the use of the limit and estop on the other side of the bob.

[Clive S]

Have you got the 12-24v power connected ? - there is no mention of it so far ! That is needed to drive the electronics of the BoB. The 5v USB connection only powers the input opto-isolators.

Rob you are getting old like me It is the other way round, it needs the 12-24v for the inputs to work

[cropwell]

Rob you are getting old like me It is the other way round, it needs the 12-24v for the inputs to work

So why bother with a 5v USB connection from the PC ? Either way you need the 12-24v and the OP from his latest post indicates he has not deemed it necessary.

Somewhere in the deep brainfog of age I have a memory of a simple BOB circuit. I must look it out on t'Interweb and try and understand it better.

http://www.embeddedtronics.com (Several points of interest in this site !)

Aha! there it is - looking at the schematic pdf, now I understand the 5v from the PC is used to lift the output of the optos which feed homes, limits and Estop info back to the PC and power the input opto LEDs.

[amxen]

Yay did a little victory dance around the workshop. its working its WORKING. I ordered a new parallel port cable when i ordered a new breakout board and other bit to replace the parts i thought did not work. The cable was the last thing to turn up today, So i thought what the hell ill fit it befor i do the video then moved everything in to position to do the video. I Turned on the computer and the system and CLUNK, i turned around and thought NO WAY fired up mach3 and pressed the right jog button beeeerrrrrzzzzz went the stepper YESSSSsss

[Doddy]

This particular BoB (and I have three of them), uses the 12-24V supply to drive the 10V regulator (LM317) for the 0-10V spindle control, as well as the opto-isolator inputs.

The 5V supply (either via terminals or USB) is used for the logic devices (and therefore the drives to the stepper controllers).

To the OP - if you need to use the E-Stop/limit inputs, as Clive-S says you'll need that 12-24V supply - or that'll be your next problem.

[amxen]

would i need the 12v input and the 5v input or just 12v when i need to add this

[Doddy]

Both, unfortunately.

[amxen]

Both, unfortunately.

no thats fine as long as i know. then im not trying to find a fault i dont have if i remove the usb