For anyone thinking of fitting a DRO I recommend this chap on Youtube : Stuart de Haro.

He has just done a series of videos showing in detail how to fit a Sino DRO to a milling machine.

Replying to 'not done it yet', my thinking isn't so much flawed, it's just that you and I go about things differently. Perhaps the type of milling we do is different also.

I do use the quill for milling, and its travel is 50mm. On my Centec the table elevation control is at the L.H. rear, and not very convenient, so I tend to use it only occasionally. Gary mentioned hearing of someone who was able to fit scales to both quill and table raise/lower, and have them combined as the Z-axis readout. I asked if this was possible but both suppliers apologised and said it wasn't. It's something to think about though.

Replying further to 'not done it yet', I apologise and concede that you are probably right. Given that the quill control is pretty good, and given that my plan to fit riser blocks to the head will allow much more use of the table rise/fall travel than at present, it does make sense to fit the scale to the latter. Coincidentally, Gary emailed me and said much the same thing, so there's two great minds thinking alike. Thank you both.

The notion of combining both Z-axis motions in one readout is an ideal still worth pursuing, and I haven't given up on it yet. Gary, can you recall where you heard about it ?

Going for the hat-trick here, three posts in a row. John Baguley seems to have negotiated the 'direct from China' route withiut mishap or nasty financial penalty, so that's very encouraging.

As an amusing aside, when Gary looked at my two suppliers he remarked that apart from the colour of some buttons the two DRO units looked very similar, and he woudln't be surprised if they were made in the same factory. When I was firing questions at them I started getting replies from both, in each case from a lady named Helen. I asked if Helen and Helen were one and the same , and she admitted she was. Soo ..... one factory, two button choices. more to come.

I normally don't reply much on forums, but I recently purchased a 4 axis magnetic DRO system for my new Warco VMC mill. I got it from EMS-I in Lancashire. They have a EM750 LCD read out that has 4 axis display and any 2 axis can be summed together. Not the cheapest DRO system but seems very nice so far. I'm just starting to fit the magnetic scales to the VMC over the Easter holidays.

See https://www.machine-dro.co.uk/m-dro-linear-encoder-summing-interface.html for combining quadrature interfaces

GordonH

I'm not Gary but I looked into this a few years ago too.

Short answer: buy one of these M-DRO "Summing" boxes and compatible DRO console and scales

Long answer: You need either

(a) a three axis console with a "summing" box as above feeding the Z input; or

(b) a DRO console with four inputs and the capability to "sum" two of them to display as Z. At the time I looked there were few options for this apart from some higher end models from Newall, and some top end models from e.g. Heidenhain (sit down for the price). But maybe in recent years that's changed...; or

(c) something like the now apparently discontinued M-DRO PC Interface Kit which had four inputs and (IIRC) Windows software that could do the 'summing' before displaying it on a PC monitor.

First option looks most realistic now.

That's a separate box which would be great if you already had DRO fitted and wanted to add a 4 axis to you existing read out. The EMS-I EM750 LCD read out does the summing internally, minimizing the amount of cables and connections required.

Following recent comments with interest as that on my to do list soon...

Or you could buy a universal 2 axis and a mill 2 axis readout.
Using universal for both Z.

All my Sino glass 3 on mill and 1 on lathe plus the magnetic are still going 9 1/2 years on pro.

Have seen the Indian made EMS there pretty good.