[dan dimock]

I am building a small cnc machine and am planing on using Mark 3 software, do I need a break-out-board?
Dan

[Fifty_ohm]

Long answer: A break-out board goes between the parallel port and the motor drivers. You don't necessarily NEED one but it does make the connections much easier to setup and troubleshoot. Plus some of the BOB's have optical isolation between the outputs and your parallel port. This keeps the voltages isolated from the parallel port so hopefully there is less chance of anything killing the port. Most of the BOB's also have LED's for diagnostic purposes. Free plans are available on Pminmo's website. I can vouch for the 3 and 4 axis boards with and without isolation. They all work great.

Short answer: It's up to you.

[mxtras]

They are cheap and offer protection. I would advise using one - if nothing else, they make connections easier.

Scott

[pminmo]

Short answer, if you can solder no. A solder cup db25 and discrete wires will work just as well.

A BOB or my Interfaces are more of a convience, with some extra features.

[Glidergider]

I'm considering the Keling CNC package which comes with a BOB. There's not much data in the ad. I was wondering if was optical isolating and I was wondering if I could get all 6 hard stop switches in it too. Or will I need a second BOB and parallel port? What do the experts do to get all 6/9 switches hooked up?

[just_lkn]

I'm considering the Keling CNC package which comes with a BOB. There's not much data in the ad. I was wondering if was optical isolating and I was wondering if I could get all 6 hard stop switches in it too. Or will I need a second BOB and parallel port? What do the experts do to get all 6/9 switches hooked up?

The BOB that came with my kelinginc CNC package does not offer optical isolating. The BOB is a (CNC4PC C10 - Bidirectional) . However I believe the inputs (Pulse , DIR and ENA) to your Stepper drivers are isolated.

[Mariss Freimanis]

You must use a breakout board when using any of our drives except for the G203V. Use approved boards from PMDX, Bob Campbell Designs or CNC4PC only.

Mariss

[Oldmanandhistoy]

You must use a breakout board when using any of our drives except for the G203V. Use approved boards from PMDX, Bob Campbell Designs or CNC4PC only.

Mariss

Just out of interest why must you?

John

[Mariss Freimanis]

Sure. Most modern (< 2 years old) PCs output 3.3V signal levels on the parallel ports while the drives require 5V signal levels to work properly. The exception is the new G203V that works with any standard logic level; 1.8V, 2.5V, 3.3V or 5V.

The breakoutboard buffers that change 3.3V signals to 5V signals must be 74ACT series logic. 74LS, 74HC, etc. will not work because of inadequate output current.

Mariss

[Oldmanandhistoy]

That explains it thank you.

John