Denford Orac refit

[Richard Evans 2Participant @richardevans2]

Morning all,

Having sold the Denford Triac which was discussed on here a while ago, I’m turning my attention to my Orac lathe. This has a very basic Mach 3 control set-up- breakout board, motor drivers and PSU. No limit switches or E-stop.

 

It’s been giving trouble for a while and now the drivers power up, the motors lock but no movement.

A couple of basic questions:

1. The BoB is the Optoport v3 from diycnc. When powered up, the two red LED indicators for the relays come on (why?) but the power indicator LED does not light up. Is the board broken in some way?

2. I bought a cheap BoB for the Triac on the recommendation of John Haine. This has a 12-24v power input. A friend (not me!) has been trying to sort things out and connected it to the existing 36v supply. I assume this has been fried? Might it have some sort of over-voltage protetction?

 

I’m guessing the answers are obvious but just thought I’d ask!

 

Richard

[John HaineParticipant @johnhaine32865]

I once had an Optoport which initially worked fine but later I was getting all kinds of problems with it.  I also noted that John Stevenson somewhere had a lot of problems with them.  I finally ditched it and replaced it with the type I recommended to you.

Those BoBs are pretty basic and are unlikely to have any over-voltage protection.  They need a 5V supply for the PP input which comes from the PP itself (or can be external) and a 12V (at least) which is needed for some other purpose I can’t recall right now – something to do with the input opto-isolators.  I had to add another regulator to derive 12V from the stepper supply.  I have a vague recollection that even with a 24V supply they need extra dropper resistors for the optos, if connected to the 38V I think you should assume it has been fried!  I have to say that it works perfectly fine in my lathe with a UC100 motion controller.

[Stuart Smith 5Participant @stuartsmith5]

Richard

Just to let you know, I managed to get the Triac working.

As you thought, the small board that converts the pulses to an analogue 0 to 10v signal was faulty.

Luckily, the spindle drive board was ok, but it is not isolated and the inputs are at high voltage.

The first converter board I bought wasn’t fully isolated so I bought a different one which has an opto-isolated input. I have powered it from a separate 24v power supply to keep it isolated from the bob.

I have kept the veroboard bob for now as it is working ok.

Your problem with the Orac could be the same issue with non isolated output.

Stuart

[Richard Evans 2Participant @richardevans2]

Thanks John. I’ve ordered a replacement board of the same type. I managed to track down a manual for the board, it says the 12-24v input is optional and the board will take 5v from the USB connection.

We’ll see when it arrives.

 

 

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