Do I need a BoB when replacing a parallel port connection with a UC300 or UC400?

[Doddy]

Nah, you'll need a common ground in any case between the UCx00 and the interface so that's largely by-the-by. I'm surprised you had that problem - but electromagnetic is all black magic to me.

[A_Camera]

Okay, I take it back. That's a new configuration for me. But the advice still stands - you can connect the UCx00 easily enough (though options to incorporate into the physical enclosure are a bit more limited). If that big PSU is a 24V DC powersupply for the board then why not slave the power from that?

Well, that's not entirely true... The UC300 and 400 needs some sort of a BoB, because you need to split the contacts. Doing that without any BoB is possible, and as you said, most drivers have optical isolators anyway, for for that, you don't need a BoB but you definitely need some way of splitting the signals and lead them to the right contact on each driver. So "easy" is a very wide word. With a BoB it is easy, but without it is not so easy.

[A_Camera]

The (stepper) driver normally provides the optical isolation, rather than the BOB but the BOB typically provides the optical isolation for the sensor inputs. All good stuff.

Some BOBs do provide optically isolated outputs to the (stepper) drivers, absolutely. But I’d suggest 95% (random number, guess) of the enthusiast grade machines will have optical isolation within the driver, and adding it also to the BOB is not required (and can be detrimental)

Be aware that many drivers also implement optical isolation the wrong way, so in reality, even if there are opto couplers on the driver PCB and they claim optical isolation, it does not mean that it provides protection when needed. I tried to google documentation about the driver the Op mentioned but I failed, so I have no idea how it is actually built.

[Doddy]

That control box (System 4C - I've found the PDF for it) - implements the functions of the BoB across 2-3 boards. It's fine. Just don't try to power the UCx00 5V supply from it (100mA max).

[Doddy]

Well, that's not entirely true... The UC300 and 400 needs some sort of a BoB, because you need to split the contacts.

Ah, I think I see where our thoughts are not quite joined up - I'm talking (and I'm interpreting Ian's intent here) - of connecting the UCx00 to the 25 pin D-Sub connector on the control box, using the internal System 4C components that implement the BoB and the Driver electronics. NOT, taking the UCx00 device to connect direct to the drivers.

[ian823478]

Ah, I think I see where our thoughts are not quite joined up - I'm talking (and I'm interpreting Ian's intent here) - of connecting the UCx00 to the 25 pin D-Sub connector on the control box, using the internal System 4C components that implement the BoB and the Driver electronics. NOT, taking the UCx00 device to connect direct to the drivers.

Doddy, you have interpreted my intent correctly
So connection wise I think I'd only need a D-sub 25 pin connector to solder on to one end of my lpt cable.

I'm hoping you were meaning the main board 12V (12-24) supply for the UCx00 when you mentioned 5V.
I had realised the 12V board supply isn't rated highly enough for the UCx00, which is a pity.

Back in 2012 I did post on here a few times while I was trying to sort out the earthing faults, but it looks like that is a time that has been lost to internet history!

A_camera, sorry I didn't explain things more clearly . If I can manage it, I'll post the manual and assembly pdfs....
Here we go, at least they are on the site if anyone needs them..
Case Installation.pdfManual.pdf

Ian

[A_Camera]

I see. Thanks for clearing the confusion. Yes, that's easy to do. You just plug in the UC400 to the DB25 on the box. No need of soldering because there is a ready made ribbon cable which is delivered with the UC400, which is the obvious choice for you. Just connect that to a small psu and to the LAN and off you go. It should work immediately once you have configured it. Will you be using UCCNC as well? I think it would be the best and maybe CNCDrive has some special deal when you buy both. I got my license almost for free when I bought my UC300ETH some years ago.

[ian823478]

Well I've spent some money...
Dean only stocks the UC300ETH and AXBB so I've ordered a UC400ETH direct from CNCDrive.
We'll see how buying from Europe works these days...
I'm expecting to have to pay the VAT when it gets over here. I think I should save about £25 compared to buying from CNC4YOU.
I didn't order the UCCNC software cos I was chugging along OK with Mach 3.
I'll let you know how it goes.....

[ian823478]

Hi folks
I said I'd let you know how buying direct from CNC Drive went:
I placed an order for a UC400ETH
I quickly received a paypal invoice for 128 euros confirming they were in stock.
I heard nothing for a week so sent an email, it turned out they were out of stock and would be for another week.
After the week I received a DHL email with no useful on it.
I emailed Balazs and he immediately provided a tracking number which showed it was about to be picked up from CNC Drive.
- it arrived the next day! The tracking showed it was flown over.
So if in stock, delivery is super fast. I'd just email them first to confirm an item is in stock.

I've got the UC400 talking to the computer, will connect it to the mill when I've got it safely in a box.

Ian

[Clive S]

I would be interested if you had any import or other taxes added. Thanks