DRO advice?

[dave h 2]

That would maybe depend on a shield being in the cable or you not having a cheap VFD radiating rf turned on at the same time. Your 2pin plug has no earth so there is no shielding either and may have no fuse. There may be no earth contact in the back of the DRO anyway.
I have a cheap 'they're all the same' older type DRO that has a separate earth tag as well as the mains earth which I connected to the machine earth.
This stuff is made to Chinese electrical regs not UK. I don't think it's double insulated due to the D types on the back.
If the read outs are not stable you may have local interference

 

[Chris152]

That would maybe depend on a shield being in the cable or you not having a cheap VFD radiating rf turned on at the same time. Your 2pin plug has no earth so there is no shielding either and may have no fuse. There may be no earth contact in the back of the DRO anyway.
I have a cheap 'they're all the same' older type DRO that has a separate earth tag as well as the mains earth which I connected to the machine earth.
This stuff is made to Chinese electrical regs not UK. I don't think it's double insulated due to the D types on the back.
If the read outs are not stable you may have local interference

Yes, it'll be a short distance from one of the cheap xsy-at1 vfds that's on our lathe. But they wouldn't be running at the same time.
I'll do some reading about the earth and other regs - thanks for the heads up.

 

[Richiew]

Some experimentation tonight with the bits I've bought.

This is my spare scale. It's wired to fit the JCS 900 series of DROs and not my new one.

This is the wiring scheme for it.

There's a ground wire soldered directly to the metal part of the socket.

Wiring translated from one to the other. The ground is wired in as well as there's a dedicated slot for it. I checked for continuity to the metal part of the socket and it is there.

Pretty tidy. The new plug comes with long screws to hold the socket in place to the back of the DRO. They aren't showing here.

DRO power supply plug removed. There was an earth wire at least. British plug to go on.

It all works a treat.

In this shot I have the VFD switched on and the Bridgeport running. No problems encountered. The scale was picked up and moved near to the VFD which sits on the side of the column to see if I could create an issue. It was only a brief test but everything worked fine.


I'll attempt to get my current X and Y scales adapted for the new DRO. Hopefully I'll only have to buy and fit the Z scale, so there's a good saving on time and money if it all goes to plan.

 

[Chris152]

Some experimentation tonight with the bits I've bought.

This is my spare scale. It's wired to fit the JCS 900 series of DROs and not my new one.

View attachment 445398

This is the wiring scheme for it.
View attachment 445399

There's a ground wire soldered directly to the metal part of the socket.

View attachment 445400


Wiring translated from one to the other. The ground is wired in as well as there's a dedicated slot for it. I checked for continuity to the metal part of the socket and it is there.

View attachment 445401

Pretty tidy. The new plug comes with long screws to hold the socket in place to the back of the DRO. They aren't showing here.

View attachment 445402

DRO power supply plug removed. There was an earth wire at least. British plug to go on.

View attachment 445403

It all works a treat.

View attachment 445404


In this shot I have the VFD switched on and the Bridgeport running. No problems encountered. The scale was picked up and moved near to the VFD which sits on the side of the column to see if I could create an issue. It was only a brief test but everything worked fine.


I'll attempt to get my current X and Y scales adapted for the new DRO. Hopefully I'll only have to buy and fit the Z scale, so there's a good saving on time and money if it all goes to plan.

View attachment 445405

That's great Richie. Just to be clear, there's an earth in the readout power cable but it wasn't connected to the plug it came with?

 

[Richiew]

Not really. It was a moulded plug and I'd have to tear it apart to check, or use a multimeter which I didn't. I think it has an earth, it uses a metal tab, I think. It wouldn't have been earthed if I'd continued to use that cheap Chinese all-plastic adapter though.

I'll check it out later.

 

[Chris152]

Not really. It was a moulded plug and I'd have to tear it apart to check, or use a multimeter which I didn't. I think it has an earth, it uses a metal tab, I think. It wouldn't have been earthed if I'd continued to use that cheap Chinese all-plastic adapter though.

I'll check it out later.

Will you be able to check if the earth wire is connected to anything in the readout? If it's not connected at the plug maybe they've just used three core wire but only connected two? As is already clear, I have no idea about any of this :-)

 

[Richiew]

I'll check for continuity from the earth pin in the DRO to anything metal on the DRO. It's mainly plastic. I expect there's a ring of metal on the input sockets. Is it an issue for you?

 

[Chris152]

I'll check for continuity from the earth pin in the DRO to anything metal on the DRO. It's mainly plastic. I expect there's a ring of metal on the input sockets. Is it an issue for you?

Only because I figure it should be earthed, but again that's based on my lack of understanding. We fitted a vfd for the lathe a while back, and it seemed everything needed earthing!

 

[RichardM]

I think you'll find the top bit of metal on the plug going into your adapter in the previous picture of it plugged in is the earth.

 

[Richiew]

Everything is in order. Plug earth checked out fine with the multimeter. The DRO seems to be earthed correctly too. Continuity from the earth pin at the plug socket to the metal bits on the X Y and Z sockets. There's also continuity to the spare brass earthing point too.

Oil was ficked off the Bridgeport quill when I was testing yesterday.

 

[dieselsamurai]

Found this on the Touchdro site might be of use

 

[Chris152]

Quick one - are Sino and Sinpo the same thing or completely unrelated?

edit - unrelated as far as my net search went!

 

[dieselsamurai]

@Richiew where did you get your table scale from ? I need 900mm as I have a 48" table whats the chance of that traveling from the other side of the world and not looking like a banana

 

[Richiew]

It's an old Accurite and came with the mill. Probably 40 years old. It has aviation connectors rather than serial plugs. It has a serial adaptor lead connector for the current DRO which I think is a modern replacement.

 

[dieselsamurai]

Mine came with scales but they are minging , i'll see if I can clean them up and they still work . I know one axis doesnt work but im sure that was Z

 

[Chris152]

Quick one - are Sino and Sinpo the same thing or completely unrelated?

edit - unrelated as far as my net search went!

I'll reframe that question - are Sinpo DROs any good compared to other generic ones?

 

[dieselsamurai]

If it looks the same i suspect made in the same factory...

 

[dieselsamurai]

this is the wiring on the scales i have , hopefully i can re-solder them



i bet there isnt a colour code standard

 

[Colin Barron]

So, we get the read out panel but where do we buy the scales and are they a standard fitting with plugs on the ends of the cables that will fit the dro?

This is a very good question. If you buy a complete kit (including connecting cables) you are more likely to get back up if you hit problems.

 

[Chris152]

this is the wiring on the scales i have , hopefully i can re-solder them

View attachment 445517View attachment 445518

i bet there isnt a colour code standard

Did you get a diagram labelling the connections/ can you get one, for the scale and the readout?