Any updated advice on DROs?

[RCW]

DROs seem to be a recurring topic, but I have not noticed anything recently.

As some of you know, I am working on an old Gorton mill. At this point, I haven’t decided whether to go with a 3-axis DRO or a 2-axis with Wixey-type readouts on quill and knee. I’ve read some strongly opinionated posts here on the Home Machinist and on the other forums as to the merits of glass vs. magnetic scales, and the relative merits of several retailers.

Any advice you might have on the questions above would be appreciated.

[Jaxian]

I have been using a Korean Jenix unit I got here http://www.digitalreadoutsystem.com/Jenix/jenix_dro.htm. They are out of southern California and their service has been great. Only annoyance is the time it takes to get ones not in stock when you order. Like a month to ship from Korea. I am impatient so that bugs me.

They have full 6 year warranties and every one of the three I have had have been repeatably accurate when I have tested them now and again to see if they are holding tolerances. Admittedly to just .0005, that is the smallest graduation of my test indicators so I don't know if they are actually good to the .0002 they say. But that is a lot more accurate than any of the machines I use them on so not really an issue. Surprisingly good quality but then that's usually how the Korean stuff is. Much more in line with Japanese stuff than Chinese or Taiwanese. Die cast aluminum cases, screw on metal cables, etc.

At this point they are still trying to establish themselves so the prices are basement. I just finished the set up of a X,Y,Z,Q on my Lagun. Went for all the axis because at those prices why not. They are glass scale type and sealed (as much as possible and still allowing function) and I have cascaded coolant and swarf over them for months on a previous machine with no ill effects. Plus for the price and with a 6 year warranty I am not worried about it much anyway. So if you like the glass type they are nice.

This is the X,Y,Z,Q on my Lagun. I know, attack of the wires, two power feeds plus limit switches and four axis and a light makes for way too many cables. And they have to stay loose to allow full range of motion. Ah, well.

[Metalman]

Jaxian
That web site regarding Jenix confused me. A lot info but no answers such as what scales you got and what did it cost? I couldn't find a price for a 3 axis mill system or a 2 axis for a lathe.

[redneckalbertan]

Jaxian
That web site regarding Jenix confused me. A lot info but no answers such as what scales you got and what did it cost? I couldn't find a price for a 3 axis mill system or a 2 axis for a lathe.

I saw prices at the bottom of the link jaxian posted.

[RCW]

Thanks, Jaxian!

I will definitely add Jenix to the list of candidates! I particularly like the fact that they have a 4-axis readout. The Jenix website will be a site for me to do some homework for a few evenings. At first glance, it looks as though the manuals may be better than some of the "Chinglish" versions.

Thanks again!

Bob Williams

P.S. Nice looking mill.

[Davo J]

Hi,
Just a warning not to buy from this company below on Ali express
http://www.alibaba.com/product-gs/830111...adout.html

And this is there website
http://en.szhxx.com/_d271552726.htm

Full right up about my nightmare here
http://www.metalworkingfun.com/showthread.php?tid=1494

I did in the end get a working 5 axis and 4 axis DRO, but the memory buttons on the calculator and the transfer from calculator to an axis doesn't work, along with a damaged case which was done before packing.
They need the software bugs sorted out before offering them for sale, and advertise them as a multi machine when they are all Milling DRO's from what I have seen and received.

With 3 power feeds and the 5 axis DRO on the mill (X,Y,Z quill and ram) along with light cables etc, I am in the same boat as Jaxian concerning wires but managed to get them organised a bit.

I would not ever buy from this company again, no matter how good there prices look. The scales on the other hand look to be fine, but time will tell.

Dave

[dmartin]

I just finished installing a 3 axis DRO with glass scales From TPAC tools ( http://www.tpactools.com/ ) and it works fine.
They have a great price and shipped it quickly. I installed it on an 8" x 30" Grizzly Mill and cannot comment on longevity because it is only 1 week old but it does work well and is accurate. Here is a picture of the mill.

click here

[pete]

RCW,
A Gorton is a pretty fine mill. If it's in a good enough condition to be worthwhile adding a DRO, then I'm not real sure the Wixey level of accuracy is what your looking for. I might ruffle a few feathers, but Wixey equipment is about at the woodworking levels of accuracy. At least to my way of thinking they are. A DRO on any GOOD mill is going to be your primary measurement system. It probably shouldn't be an area your trying to pinch too many pennies. Despite all the cheaper manufacturer's claims and misunderstood specifications, those bar type scales somewhat like digital calipers use are at best only good to right around +- .002. Even Mitutoyo and Starrett don't and won't claim any better. At 25% of Mitutoyo's or Starrett's price? Your not going to get a real accurate measurement system if the best Mitutoyo or Starrett can do is that +- .002. Resolution to .0005 is not the accuracy level, that's resolution. A far different number than actual repeatable accuracy. If your needs are or might even become better than that +- .002? Then those bar type scales are just about worthless. They will save counting handwheel turns though if they don't miscount.

All of the following is of course dependent on the manufacturers build quality and in plant quality control. The glass scales are usually better for accuracy than the magnetic type, although that gap is slowly narrowing. It's also just not a dead simple answer. Newall to name just one manufacturer build both spherosyn and microsyn models of magnetic scale. If your interested enough you can find Google on your own and check the differences. Even Mitutoyo along with a few others have started using the magnetic scale technology. At one time all they built and sold were the glass scales. But AFAIK, those glass scales are still the most accurate DRO scale system around unless you get into the real super accuracy setups like laser feedback systems that I know zero about. But the glass scales do have some faults where they need very good seals, and those scales do need to be kept very clean. The glass scales can also be scratched and then need replacing. The magnetic scales don't have that problem. I bought Newall microsyns on all 4 axises because I felt the variety of materials I'll be machining might add extra cleaning maintenance or even problems with scratching the scales. Maybe I was worried about nothing.

Strongly opinionated is worthless. What are the actual DRO specifications? Those can't be argued on good reliable equipment, and opinions no matter how strong don't get accurate parts built. But your original question needs to be a little more specific to properly answer it. Besides the Glass verses Magnetic, what are the accuracy's needed or at least wanted? There's an unbelievable amount of built in canned programs on most good DRO's, and that doesn't even include what the user can program in for there exact requirements. Bolt hole circles are just the bare minimum. I bought maybe quite a better than I could probably afford, and I'm glad I did. You can't add accuracy after buying.

Pete

[Davo J]

Agree about the Wixey.
As long as the scales are mounted correctly (X,Y seals facing down) there is not much chance of scratching the glass and not something you hear of. A lot of glass scales these days have double seals, and in my 6-7 years of owning and running single seal glass scales I have never had any problems or even had to clean the seals.

The scale would need to be mounted upside down for chips to scratch the glass as it's attached to the top of the housing and only comes down about half way in the housing. A lot have the glass vertical which makes it even more unlikely because the chip would just lay at the bottom if they did manage to get in past the seal.

When fitting a 3 axis DRO the only scale that could cause problems (never has with me) is the Knee scale, but if you face the seals to the rear of the machine and use the chip cover it should be fine.
I went one step further and added a cover into the top mounting bracket that extended out over the reader head as well, this way is chips did fall on the top of the scale they would clear the reader head on the way down when they fell off.

Dave

[GlennW]

I've had glass scales marinating in coolant on my lathe for about six years now with no real problems. (Fagor DRO system) I had to clean the X axis scale once as it did get some coolant in it a year or so ago, but that problem was quickly remedied as it was as much an installation problem as anything. It had gone five years being regularly flooded with coolant without a single glitch. About a year ago the glass in the Z scale actually loosened up in it's casing when the adhesive deteriorated from the temperature and humidity here in my shop. It had become became intermittent. I went a couple of rounds with the manufacturer on that one as they claimed that it was impossible. Round one, I shipped them the scale and informed them that the glass was loose, and all they did was clean it and ship it back since it was impossible for the glass to loosen up. I shipped it back for round two and got the phone call a couple of days lather: "Hey, the glass is loose, I can't believe it!". They sent me a new scale and kept the old one to be shipped back to Spain for "further research". All said and done, I wouldn't hesitate to use glass scales again.

[Davo J]

Hi Glenn,
Just wondering, is your scale/reader head mounted vertical or is it laying on it's side?

I have seen them mounted both ways on factory fitted machines, and think the lay down type of install would be more prone to coolant getting in.

Dave

[GlennW]

Hello Dave,

Both scales are vertical. There is a shield over the X scale and coolant was getting around the shield, so I sealed the seams with a bit of gasket sealer and it's been fine since.