Thanks everyone for your input. This will be my first DRO. I will be doing the installation myself and am looking forward to it. How does everyone manage all the cables and wires that run around everywhere? Craig's picture of the Z-axis scale shows a black cable that comes out of the switch. Doesn't that get in the way of milling operation?
David, is the feed rate a necessary feature for milling stainless steel? I looked at your Newall DRO install for your mill and read a bit about their scale technology. Was $2500 the cost of the whole package or just the DRO display (minus the scales)? I have plan to work with stainless steel in the future.
I have used Newall DRO’s on several machines and have come to know they are true industrial quality. I also like their scale mounting system which is far easier to install than the usual kit of plates/adapters/jack-screws found with the alternatives. <end of bias blast> LOL
I went all out with my 935 DRO with 5 micron Microsyn scales on all axis - complete overkill. The $2,500 figure included the three scales and encoder along with the DP700 display - it was a complete kit custom configured to my specs. A 3-axis Newall DP700 kit with 10micron scales is ~$1,900. Newall has an entry-level product that is competitively priced against DROPros called the NMS200/300 ($850-$1200) but it lacks the feed rate display function found on the DP700. Good sourcing/pricing for Newall is
https://www.machinetoolproducts.com/digital-readouts/dro-kits/
Although the Newall scales are superior to magnetic in terms of imperviousness to solvent and coolant/oil contamination, their highest resolution scale is 5 microns, and not accurate enough for the tolerances I’m after on the lathe cross slide. If you want to hit tenths accuracy on diameters, you need 1um scales on the cross slide, which is why I went with DROPro’s EL400. The EL400 display I consider “consumer” quality in comparison to the Newall DP700.
As to your question on milling stainless, the most important thing is consistent feed rates. So having a power feeder will give you far better feed consistency than hand cranking the table feed. This is also the reason I power feed the cross slide when parting off stainless down to about 4mm diameter, then I switch to very slow manual feed since the SFM is too low for the slowest powered cross feed. Stainless has a nasty tendency crawl/hop up on top of the parting tool if SFM drops too low, and makes a mess of the parting tool, fracturing the inset and mangling your part. (At 1/4” diameter, you need over 2000 RPM to hit minimum stainless parting SFM)
Having a feed rate display on the mill is helpful with stainless or any hard alloy, but it isn’t nearly as important as
consistent feed rates, and once you get some experience, you will instinctively know how fast or slow is too much for a given cutting tool. Limiting the types/sizes of end mills helps in applying your learned experiences. If you have a feed rate display, it’s easier to just dial in the power feeder to the Feed/Speeds calculator values since none of the power feeders have anything close to a calibrated dial or linear rate changes when you turn the feeder speed knob, but it isn’t an absolute requirement to mill stainless.
