I am in need of a breakout board.
I see many on eBay but am not sure of what I need.
I'm building a small lathe, 2 axis, maybe a relay for the spindle and one for coolant.
Input requested.
Links to reliable designs, suggestions welcome.
Thanks

I used this board on my knee mill, and have had no problems and good support.

http://www.cnc4pc.com/Bidirectional_Breakout_Board.htm

olf20

olf20
That looks good, good price too.
I see they also have a dual relay board for $18.
I also notice that this one is not opto isolated.
Is the isolation necessary ?
Thanks

"Is the isolation necessary ?"

You are going to strike quite different opinions on that question.

Really you need to read up a bit and make your own decision.

Just know that there are many builders very happily using those particular boards with no problems.  Me included.

Optoisolation is a little bit overkill IMO.  As you will soon see others will have a different opinion. 

Greg

Extra precautions have been taken when designing this circuit, by taking into consideration the extremely high voltages that stepper drivers can achieve and lack of experience that some users could have in wiring circuits of this kind.

Greg,
     The above is from CNC4PC catalog.
 It appears to me that the primary reason for isolation is the chance of inadvertent mistakes when making the connections.
After the connections are properly made, does the isolation offer any benefits ?
All I read about is fried ports being expensive to repair...especially on laptops.
Thanks for the help.

hi,
 for my two-pence worth, I would not use a break out board,and thats nothing to do with cost cutting.
firstly, practically all stepper/servo drives have optoisolation built in.so it is purely to safeguard against bunging
more than 5 volt back down the port by mistake.Treat your port with respect!
 Alternativly use a pci card,best to use them +5volt common though (as a laptop) taken from a spare usb port.
Secondly,if the optoisolater or its wiring isnt quite right,that can be a bitch to trace,giving you mis-steps, and
hours of fun! Some drivers,aparantly dont like being fed through secondary opto's.
Just my opinion!
   Tony
   

This is new to me.
I have not seen or heard of this before. (limited exposure)
I see where it would go in the PC, beside the modem I suppose.
How would you use it with a laptop ?
Can you tell me where I can find more information on using the PCI card for this application ?

Thanks Tony,
Good stuff

i agree, breakout boards have given me endless hours of troubleshooting to remedy lost steps.i use 1 but only for inputs and relay outputs.a heads up on an ebay seller wilhelmjason.a dispute this guy resulted in him threatening to target me with his hacker forums to spam the crap out of me.real creep.

Man ! Thanks for that , I use eBay quite a bit.. been lucky so far.
I'll make a note on this guy.
Thanks for the heads-up.

 
  only for inputs and relay outputs

I assume that you mean inputs to the PC like tach, home/limit switches and encoder feedback ?
And relay out to spindle motor, coolant and the like ?

And the step/dir are directly from the PCI ?

I'm still interested in more info on this.
Thanks

Greg,
     
 ...................It appears to me that the primary reason for isolation is the chance of
inadvertent mistakes when making the connections.
After the connections are properly made, does the isolation offer any benefits ?
All I read about is fried ports being expensive to repair...especially on laptops.
Thanks for the help.

I'm not interested in participating in a debate about connection methods but as you asked me a question I will not be rude and ignore it....

"After the connections are properly made, does the isolation offer any benefits ?"

I can't think of any.  Over the life of a machine faults may develop.  It might help here.

More likely I think with a self built machine you will at some time start making alterations to incorporate some new beaut feature.  Maybe then it might help.

"All I read about is fried ports being expensive to repair.........."

I've been following this forum among others for a while now.

About once a week I read about someone who has fried drivers, power supply or some other component.

Can't remember a report of a fried printer port.  I'm sure it happens.  I don't think it happens very often.

I use a PCI printer port.  Costs about $20.  Probably the cheapest component in my control setup.  I don't lose sleep about it. 

".........especially on laptops."

I certainly would not use a new expensive laptop in my shed.  Dusty very anti laptop environment.

However I have used an old laptop that has been retired from daily use.  Not worth much.

Greg