Thread: DRO Advice

Gday Guys,
I took the plunge and my DRO has arrived. tbh I'm a little disappointed as apart from not arriving with an AU mains lead(wrong lead) there are no detailed instructions regarding possible setups to mount the scales /readers. I know there are many types of machines that these fit but some idea of potential setups would be good just to make sure i can use the brackets supplied. I am feeling that maybe the brackets supplied won't work on my Mill/drill. I am feeling a little overwhelmed as i don't want to over complicate the process but would like to see some detailed photos of setups on similar machines and see if the brackets supplied will suffice?
Also do i totally remove the red and blue plastic parts on the reader. I assume they are just for transportation?
Cheers

Max if I recall correctly the brackets that came with mine are still here in the scrap bin pile. I may have salvaged some to actually use, but can't recall doing so. I'd suggest machining up something bespoke to suit your machine and where you want to put the scales. I squeezed mine onto The Noodle, but it was tight. REAL tight, to get it on the cross slide (I know we're talking different machines). For what it's worth I'd suggest pouring yourself a nice cold beer/hot coffee (depending on the time of the morning) and just sit there offering the scales up to different parts of the machine. Eventually you'll see the "right place" for it and it will jump out and be obvious. Once that's sorted just make up some brackets from aluminium.

Agree. The brackets that came with mine are also sitting in the recycle pile. Although it is used as a selling point in reality it's a clunky way to do things. The red and blue plastic things need to stay there until you are ready to bolt everything in place (finally). They hold the reader head in the correct relative position. Successful DRO installation is not hard but the line up is crucial.
As Pete says, spend time thinking and planning first. I even had a wooden mock up of the scales that I positioned (clamps, cable ties, double sided tape) while I wound the table back and forth to check for clashing etc. Once you know where the scale is going to go then you can work out where to put the reader head bracket. Remember that the scale mounting may not be symmetrical because you want the reader head bracket to rigid as you can in the direction of travel, so a compact/ short bracket is good. I had the covers in place for several weeks before I actually put on the scales as (apart from being lazy) I wanted to check that I was not going to make things more difficult to use. As it was I repositioned one because it was in the way, modified the end of another so that I did not rip chunks out of my hand if it brushed by and had to extend one of the handles on the mill so that I had enough space to use it without bashing my hand against the scale cover all the time.
The sequence I used was to mount the scale and then run along it with a DI to ensure it was parallel with the axis; mount the bracketry I'd devised for the reader head and then as a final step using feeler gauges work out the spacers needed to attach the reader head to the bracket without pushing/ pulling it out of alignment. Once the hardware was ready I bolted up and removed the plastic brackets. Save those plastic bits (at least for a week or so) in case you need to remove it for mods.

The power cord thing is a pain but there are plenty of those style cords floating around.

I haven't got a mill/ drill either but I'll get some photos later of my installation - if nothing else they will show how inappropriate those bits of Al that were supplied are.

Michael

Quick photos between shopping duties -
This scale is a magnetic strip type but the thing to note is the lack of symmetry due to the (enforced) position of the reader head and even then the bracket has an offset to it.There is also a joggle to clear the travel stops. It would have been better on the back of the table perhaps but then I lose travel and run the possibility of damage when the table is skewed.
P1030140 (Medium).JPG
This is the one where I had to extend the handle give clearance to the scale. You must have a flat surface behind your scales so you don't induce a twist when you bolt them down. In this case there is a 10mm thick piece of Al that the scale is attached to. This also helps if there is draft on the castings as you will need to shim them to make sure that the scale is parallel to the axis motion (as close as you can get 0.01mm over the distance?) Note too the reader head mounting - rigid in the direction of mounting but not so much side to side. The surface it is attached to is the travel motor guard, used because it was the closest surface available
P1030142 (Medium).JPG
Last is the Z axis. This had to me moved down after initial fitting because the table when swiveled could have hit. Note too the rounded corner next to the gearbox change handles.
P1030141 (Medium).JPG
With glass scales, try to position them so that the opening is away from the chip source. In this last instance it meant a wrap around bracket but again it is rigid enough to provide decent positioning without being too bulky. These brackets are probably a bit on the light side (3mm Al) if this was an industrial application but for one user machines I figure I can trust me to not damage the equipment. One of the issues is to find mounting holes that don't interfere with other machine functions - for example, screws into gear boxes, oil galleries or travel stop slots. Murphy's law would suggest unless you have a hard stop, relying on memory to prevent over travel or crashing into scales is a bad thing.

Hope this helps,
Michael

Thanks Fella's much appreciated. I think it is a case of looking at the mill and holding the scales and reader in different positions to get the best result. Not a job I want to rush. I was trying to look at photos from the hare & forbes website of the HM47 and 48 as these have DRO fitted and are essentially the same machine. I have mounted the arm for the DRO as that was fairly straight forward. Looks like a few nights in the garage are on order to slowly plan and install