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06-12-2016 #1
Can't give source where to look but I can explain it easy enough.
The Motion control device provides OUTPUTS which it sends out signals and pulses required to tell the drives which direction and how far to move. These OUTPUTS basicly fall into two types MOTOR OUTPUTS for each Axis and General OUTPUTS which provide 5Vdc Signal.
Each OUTPUT as Positive Negative connection.
So DIR connection is MOTOR OUTPUT and controls the Direction to travel. This is done by sending 0V or 5v depending on direction.
PUL Connection is the PULSE MOTOR OUTPUT which gives stream of pulses relating to how far to move.
The En is Signal to the drive to ENABLE/DISABLE. Often this isn't used and left unconnected.
If used this would be connected to General OUTPUT or could be controlled by external device like relay by sending 5Vdc.
So in your case there will be Pins on the BOB which are MOTOR OUTPUTS and Some which are General OUTPUTS. If using the parallel port they tend to stick to standard arrangement. ie: Pin2 =XDir Pin3=Xpul etc.
There will also be pins for INPUTS.
Hope this helps.
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06-12-2016 #2
If it helps, here's a rough wiring diagram that would suit a lot of break-out boards and stepper drivers. As JazzCNC says, the Enable signal is sometimes considered optional; if you leave it disconnected then the stepper driver defaults to "Enabled" anyway. The "Pulse" connection is sometimes marked "Step"; again, previous post explains why.
I've just had a quick look at the "manual" for your BOB; not very helpful, is it? However, you should be able to identify step and dir signals for each axis (=stepper driver). Doesn't appear to be an Enable output anyway but I might have misread it. All ground connections (- connections on stepper driver) go to a single common ground terminal on the BOB. The manual then tells you what pin numbers in Mach3 you should configure for each signal (Mach3>Config>Ports and Pins). However, there is still this question about whether you are running on a 32-bit Windows; the parallel port driver will not work on any 64-bit Windows version.Last edited by Neale; 06-12-2016 at 11:19 PM.
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07-12-2016 #3
Hi Neale,
Thank for the diagram. Very, very handy.
Yep, the instructions for the BoB are terrible! But I'm pretty sure from your diagram and Jazz's description of the system I will be able to figure it out without too much trouble.
As for the version of Windows, I am going to source a 32bit verison of Windows. I was going to go with Windows 7, unless you think a later/earlier version is better suited to the job?
Thanks again for the help. I think the BoB was causing me the most confusion but I think I got it now!
Rob
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07-12-2016 #4
Win7 is the latest that came with a 32-bit version, I believe, so that's the one to go for. Probably the best and most stable version of recent years as well.
- Dr Brian (well, everyone else is boasting about it...)
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07-12-2016 #5https://emvioeng.com
Machine tools and 3D printing supplies. Expanding constantly.
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07-12-2016 #6
Thank you Jazz,
I think with your explanation (much clearer than a lot of info I have found online) and the one from Neale has clarified things immensely to be honest.
I was having a little play with the BoB today and with a meter I could see the voltages coming out of some of the pins (not quite 5V but 3.6V, which may either be normal or it's because I have had to use a PCI expansion slot in the PC as it didn't come with a parallel port). My next step is to get a dedicated PC assigned for the job, install Win7(32 bit) and then install Mach3. Then I think I will be on the home run!
Thanks again for saving me a lot of hair-pulling.
Rob
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07-12-2016 #7
Possibly because of the PCI. It's very common for modern PC's to only supply 3.6V. However this is BAD NEWS for CNC and you need close to 5v to work correctly.
With 3.6V you will have trouble because there isn't difference between HIGH and LOW.?
When I said 0v and 5V I actually should have also said LOW & HIGH because that what really matters to CNC. LOW is anything from 0v to 2.5v HIGH is anything thing from 3.1 to 5V.
So with only 3.6v there not enough difference between Hi - Low signals and just slight difference or drop in voltage can cause missed steps and all sorts of strange happenings.
Only letters could put after my name are "NFC" or "CFS" but Hope that helps expalin little more.Last edited by JAZZCNC; 07-12-2016 at 08:27 PM.
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07-12-2016 #8Only letters could put after my name are "NFC" or "CFS" but Hope that helps expalin little more.
So with only 3.6v there not enough difference between Hi - Low signals and just slight difference or drop in voltage can cause missed steps and all sorts of strange happenings.
Last edited by Clive S; 07-12-2016 at 10:20 PM.
..Clive
The more you know, The better you know, How little you know
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07-12-2016 #9
That BoB is a Larff innit ! £16 for a D25 to screw terminals connector.
A chinese 5 axis BoB will do isolation, spindle control, coolant relay all for a small Bank of England drinking voucher. I wouldn't put that connector board anywhere near my computer (apart from the bin next to it).
Cheers
Rob (if you want the letters behind my name it's 'F. in B.;VD and scar')Last edited by cropwell; 07-12-2016 at 11:41 PM.
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