View Full Version : Breakout board recommendations

14-07-2015, 04:52 PM

I'm new to this forum having recently bought someone else's unfinished CNC router project - now quickly learning as much as I can, and keen to get it up and running in some form!

The machine is essentially complete, but uncommissioned. I had the motors running under Mach3 control for the first time at the weekend, but then saw some issues with the limit switches falsely triggering. On further investigation I realised that the BoB supplied is a totally unbuffered "wired through" Parallel Port board, which is simply not up to the job. As well as the observed noise issues, it also makes the PC I am using a bit too vulnerable for my liking! As an electronics engineer myself, I can see that this is an important part to fix before I go any further.....

So, I'm currently looking for a recommendation for a decent but inexpensive Parallel Port Breakout Board, readily available in the UK. There is of course a huge choice of BoBs out there, many of Far eastern origin, together with an equal number of horror stories about how unreliable many of them are. So, I am hoping that there BoBs on a list generally approved by users that get chosen when you just want something simple and basic that works.

In time I'll likely switch to an ethernet motion controller, as they are clearly the way to go - but I really would like to see the machine working before I invest too much more into it. Hence a good solid, simple Parallel BoB would be ideal at this stage.

Any suggestions? Am I asking too much?

Thanks in advance!

14-07-2015, 10:17 PM
I believe that the BOB'S from cnc4you are ok, I think Eddycurrent on here (if you look through his build log I'm sure he says which one, though can't remember off hand) used one. Can't comment personally as I'm using a CSMIO IP-M...

14-07-2015, 10:41 PM
The board I have looks identical to the cnc4you kk01 board, so far I have had no problem with it, but I'm failry new to all of this. I might suggest that for early stages there is a possibility that you might convince a board to produce the magic smoke. If that were to happen I'd rather it be an el-cheapo board.

15-07-2015, 11:18 AM
The board I have looks identical to the cnc4you kk01 board

Some details here like where from, what model and how much would help the OP.
All cheapo BOBs are not equal and you're more likely to toast a rubbish BOB trying to persuade it to work than a good one which works as advertised and has decent documentation,

My little benchtop mill has an old Routout CNC box running it, inside the box are 4 axis controllers and an unbuffered BOB! It's been working for a very long time on multiple PCs without issues ;-)

- Nick

15-07-2015, 11:22 AM
Many thanks for your input guys. I had a look through Eddycurrent's build log, and the only mention I found of his was a DIYCNC one - but it was a hugely long thread and I could easily have missed what you had in mind!

Agreed on the el-cheapo BoB though - I feel something more sophisticated will be required in the future, but whilst I'm learning and commissioning what is a largely unknown bit of kit, I just want something that will do the basics without getting in the way as well as insulating my PC from the worst of what could go wrong.

I guess my current favourites are the BoBs from DIYCNC and CNC4YOU. The first are designed and made in the UK, but I read some negative comments from John S on these in one thread on this site. The second look like Far Eastern in origin, and certainly the downloadable manuals appear to support that theory, but if people are using these successfully than they could be just what I am looking for.

Any more opinions?


15-07-2015, 12:05 PM
I think it comes down to what you are willing to pay? and the features you want. If you are looking at something like 20-30 then there are a lot of choice and it will be the chinese boards if bought in the UK.
If you need features like more than one relay, charge pump and or a 0-10V output for spindle control then you are looking at spending a lot more.
There are some good boards like the PLC4X from Zapp, the PMDX from pmdx and so on, but because you are asking this question means that you may also need support, so also consider this as well.

15-07-2015, 01:57 PM
Fair question! I guess up to 40 would be ok if it offered fully buffered signalling, a charge pump and one relay I could use for the spindle. I'm not fussed about opto isolation as the drivers include that already, and won't need any more relays initially. I'm just looking for a solid solution to get me started, because when I have looked at motion control options, the choices are overwhelming - and I've not yet even decided what software to use, hence really don't wish to invest in too much before I have a play.

Does that seem reasonable? Maybe I'm being over cautious, but the more you read about the cheaper BoB's, the more you think they are all unreliable - and that is what I'm hoping to avoid at this early stage.

15-07-2015, 02:13 PM
Then you are looking at either the opto board from DIYCNC, the 20 cheap board form Zapp, or what cnc4you are offering.
All are ok.
Then there is the support, i know you can get support from Roy at DIY CNC and also Zapp, but never bought anything form CNC4you.

Clive S
15-07-2015, 02:36 PM
Then you are looking at either the opto board from DIYCNC, the 20 cheap board form Zapp, or what cnc4you are offering.
All are ok.
Then there is the support, i know you can get support from Roy at DIY CNC and also Zapp, but never bought anything form CNC4you.Do any of those boards provide buffered signalling?

15-07-2015, 02:45 PM
What kind of buffering do you want?
Anything which can result in any variation to the relative timing of LPT pin signals being presented to the drives will mess up the part, there is no RTS/CTS handshake involved in the open loop with Mach3, the whole set up relies upon the data at the parallel port being presented almost instantaneously to the drivers, all timings are configured within Mach3 to work within the limitations of the system being driven.
External motion devices are fed move instructions via their plugins and can thus use buffering,
- Nick

15-07-2015, 02:46 PM
yes it looks like it.
The ZP5a and ZApp and the uniport are buffered.
The HG8 at cnc4You is opto isolated.

15-07-2015, 02:48 PM
I think they are all isolated and someone writing the tech specs hasn't read their digital interfacing text books ;-)

15-07-2015, 02:48 PM
Ah - something I can answer being an electronics eng by trade!

The buffering I need is really just signal conditioning - no significant delay, but beefing up the signal and the voltages from/to the PC port. Buffering in itsmore "IT" sense is where data is collected and delayed for some period, so allow streaming of things like video. Not something we want here, as you suggest!

My existing BoB has no buffering at all - just wired straight through - and that is what I'm trying to avoid again.

15-07-2015, 02:48 PM
Its a breakout board it will only be a simple buffering circuit, that gets the existing signals, cleans them up and duplicates them.

15-07-2015, 03:15 PM
Looks like we have three contenders - the HG08 from CNC4YOU, the ZP5A from Zapp and the Uniport from DIYCNC. Although it's the most expensive, the Uniport is currently my favourite from these as it includes a charge pump and two relays, plus opto isolation on the inputs. COmes in at 40 posted, so not too bad.

Anyone have any experience of using one of these in anger?

15-07-2015, 07:24 PM
If you want cheap opto isolation and a spindle relay then the Chinese BoBs like this one http://www.ebay.co.uk/itm/5-axis-CNC-Breakout-Board-w-optical-coupler-For-Stepper-Motor-Driver-MACH3-TE240-/131551113066?pt=LH_DefaultDomain_3&hash=item1ea10eaf6a which is "UK stock" seems a good start.