Which DRO for 833TV

[j-becker]

I have a 833TV coming on the boat linked in the other thread and am considering my options for a DRO. On my lathe, I went with the PM DRO but I feel confident enough to install it myself. Unfortunately that really opens up the questions which one to get. I know I would love to get a graphical display and a feed rate on the display sounds like a great benefit (but may only be available on the high end options). So here are my options and questions:

1) Eason 12B got a lot of recommendations in the past. I can get it from China for about $5-600 with glass scales (w/o brackets, questionable warranty). This is similar to the price level of the basic PM option but somehow I like the idea of a graphical interface. Does that make sense or is a graphical interface not that useful? I read in one threads that the Eason can display feeds but have not seen that anywhere in the descriptions (e.g. DRO Pros) . Can somebody confirm?

2) PM's MagXact has the advantage of magnetic scales for a great price ($800) and warranty but has neither graphical interface nor feeds. How big of an advantage are magnetic scales for a hobby user in terms of durability? Is it worth the smaller dimensions e.g. for Y-travel on the 833? Apart from that it is probably the least hassle to install and come with great support.

3) EL700 via DRO Pros has all the features I want but at a high price ($1600+ with mag scales) for a hobby user. Are there other sources than DRO Pros for the system, maybe without similar responsive support. How much is support worth for a DRO?

4) Sino DRO from Aliexpress with glass scales can be had for ~$280 shipped. It gets pretty good reviews considering the price. This is seriously cheap in comparison even if I would need to replace a scale or two down the road. Or I could upgrade when I have some experience and know what I really need (want)...

All the above assumes a 3-axis DRO setup with a separate battery operated quill DRO. Has anybody actually implemented a fourth axis for the quill on the 833? Looking at the price of a Mitutoyo scale a fourth axis is probably not ta question of cost.

I have been leaning to the Eason option for a while now (but I currently don't think I can get feeds displayed). So now I am thinking Sino for starters and invest the difference in tooling (David Best' great list implies I need to budget at least as much for tooling as for the mill..). If I don't like teh Sino DRO in use I am not out that much money after all and would have a bit more experience to judge whether the money for an EL700 is worth it to me.

Where did all the other 833 owners land on this question? What are other features should consider in comparing the DROs (e.g. "usability")?

Thanks!
Johannes

 

[mksj]

I have the EL-700 on my knee mill, ES-12B on the lathe, and have also worked on other machines with a wide range of DRO's. Graphical interface is easier on the eyes, and on the mill they have a range of additional features. Ofteh use the feed rates and near 0 warning, bolt holes, etc. Graphical interface costs more.

You can get inexpensive digital DRO's with glass scales on eBay, I do not see the value of Aliexpress for a saving a few dollars if you have a problem. They also have inexpensive graphical with glass scales, they work for some individuals. Many of these eBay vendors are in China and ship through a US site, at least through eBay you have some immediate recourse if it is not as described. Warranty is probably not going to happen.

Why buy an ES-12B from China with questionable service, and I do know of people that have had problems with their ES-12's and were rectified by US seller. You can buy it from PM/QMT for ~$700 with brackets. You could also check with them if they are going to carry the MagXact Magnetic MX-200L in a mill configuration.

https://www.precisionmatthews.com/shop/pm-935droes12/

You can buy the ES-12B/C from the UK with 3 axis magnetic scales for ~$750 with air freight and arrives in 1 week, quite a few people have gone this route. You can trim the scales and the reader heads are small so you can either put the 3rd axis on the column or the quill.

Easson ES-12C LCD digital readout package including 3 linear magnetic encoders

3 Axis Easson ES-12C LCD graphic digital readout package with three magnetic encoders. The encoders offer a very compact profile size and can be cut to length to custom fit the machine being installed. The package is suitable for mills up to Bridgeport 42" sized machines or 30" between centre...

www.machine-dro.co.uk

Easson ES-12B LCD digital readout package including 3 linear magnetic encoders

3 Axis Easson ES-12B LCD graphic digital readout package with three magnetic encoders. The encoders offer a very compact profile size and can be cut to length to custom fit the machine being installed. The package is suitable for mills up to Bridgeport 42" sized machines or 30" between centre...

www.machine-dro.co.uk

There are also tablet interface type DRO's

 

[davidpbest]

Johannes,

This is one of those topics where opinions differ wildly, largely based on the commenters confirmation bias (justifying what they own), and how they use the machine. I'll give you my two-cents, which I'm sure will be a minority opinion. My comments are based largely on experience with and RF-45, which is similar in many respects to your 833. If you were getting a knee mill, my views in some aspects would be different.

• I had a Z-axis DRO on the head and almost never used it. After repositioning the head, I would re-calibrate the Quill DRO instead - by touching off and then lowering the quill the required depth of cut using the quill DRO for accurate positioning. A stand alone Z-axis head DRO without axis summing to the quill DRO means you'll be doing a lot of math, and I never found the head DRO that accurate because of the inherent slop in the head-to-column interface.
• I have used DRO's with graphical interfaces on a couple of mills, and never found the graphical user interface of much value. Recognize that I don't find myself drilling circular hole patterns very often, and I am usually working from a print or detailed CAD drawing.
• In contrast to the touchscreen user interfaces, I prefer a display with real push-buttons that confirm you have pressed the button with tactile feedback. There's nothing more frustrating than pressing the "Half" button and not realize it didn't take your key stroke and your assumption about position is way off.
• I do find the feed rate display is very helpful, particularly when working in ferrous materials where feeds & speeds are more critical. I will routinely go to a Feed/Speed calculator app on my iPhone to understand the RPM and feed rate for a given material and cutting tool. If the calculator says the feed should be 3-inches/minute, that's pretty hard to judge within a 50 percent tolerance without a feed rate display. Before I added a DRO with feed rate display, I broke a LOT of end mills by misjudging the actual feed rates. Some will say "just slow down the feed" which works sometimes, but leads to excessive tool wear and is exactly the wrong strategy when machining stainless steel.
• My DRO brand preference is Newall. I have a DROPro's EL400 on my lathe to get the 1 micron resolution on the cross slide (which Newall doesn't offer), and it's been fine. But I prefer the Newall display head for readability and the tactile button interface, and the Newall is the easiest of all the DRO's to install. You might consider the Newall NMS300 - it can be configured with scales that match the 833 if you call and talk to the US rep. That model is limited to two axis and does not have a feed rate display. I have a 3-axis DP700 Newall kit on my PM-933 and love it, but it's clearly in a different price categoy from the others you mention in your post.

 

[j-becker]

Hi Mike,

Thanks a lot for the input. I originally wanted to get the Eason 12B from PM but it turns out they don't sell them any longer. Hence I looked at he more reputable Aliexpress sellers (I have been lucky so far), but probably buying from the UK is worth the extra few dollars going that route.

Am I right that the Eason does not have feed rate info and I would only get that with the EL700 or similar range of DROs?

 

[j-becker]

Hi David,

Thanks a lot for your explanations! I had a quick look at the Newall options and it seems at first glance that a DP700 is in the same price range as an EL700. I am still a bit hesitant to spend that much money without any first hand experience (but I guess this is the step up to a professional unit which are probably all going to work well). I would love to have the feed info but it seems to come with a hefty price tag indeed.

I am not sure I fully understand the comment about the inherent slop in the head-to-column interface. Is that a potential source of error when adding both axis? Is that particular to a bench type mill?

The point about primarily using just the quill DRO is a good one. That implies that I could potentially just get away with a two axis DRO. In that case the Newall option you were linking would be only slightly more than the MagXact. However, the scales withteh Newall seem to require some additional length (they are listed as travel +10") so not sure how well that works on a bench type mill.

 

[davidpbest]

I am not sure I fully understand the comment about the inherent slop in the head-to-column interface. Is that a potential source of error when adding both axis? Is that particular to a bench type mill?

You will understand this once you get experience with your mill. Suffice it to say that the movement of the head is not as precise as the movement of the quill simply because the head hangs on the dovetail ways of the column and must have some freedom at that interface for the head to move. You can tighten the gib to remove muck of it, but if you remove all the play, the head will not move, or will move in a very jerky fashion. DM me if you want further explanation. The bottom line is that positioning the cutter via quill movement an subsequent locking of the quill will always be more precise than moving the head.

My last RF-45 had a 2-axis Newall DP700 DRO with Microsystems scales, and a Multitoyo digital scale DRO on the quill. I never felt the need to have a DRO on the head.

Installing a Mitutoyo 6-inch scale on RF45 Quill

Explore this photo album by David Best on Flickr!

www.flickr.com

And as I said in my original post, Newall kits can be configured to your specific mill including shorter scales than the published versions. Call the rep and discuss your needs.

 

[j-becker]

Thanks again, I am going to look into that some more. The Newall option was definitely not on my radar before.

 

[Dallas]

unless it's a CNC graphics are useless IMO. i bought a 3 axis readout from banggood . I was skeptical. but when i got it, and installed it, wow it has a ton of features and works perfectly. zero issues with the DRO or the scales. only thing was i had to make my own brackets for the scales and reader heads. and i paid around 300 for everything.

 

[mksj]

Easson has feed rate and tactile sealed buttons. Although I have the EL700 on my mill, it was more for the 4 axis and magnetic scales. The touch screen is OK, but a bit of a pain if your fingers are oily or wet. It also does not have a screen protection overlay which I added. Newall is an expensive option and there are some limitations as to the scale resolution depending on the application, only their microsyn scales are rated to a 5 um resolution. This is more of an issue with the lathe cross slide where one typically use a 1 micron. I do not care for their displays, but that is a matter of opinion.

I previously had a benchtop mill and only went with an X and Y scale (Acurite DRO) and never felt I needed a scale on the column. The quill had a battery operated DRO that was good enough. When moving the head up and down, the position changes when it is locked. Also over time due to uneven wear you can get some inward nod of the head. Depends on the work and the accuracy.

QMT/PM still list the ES-12B but seems like they are replacing it with the newer version of the EL-700 which is the EL-750 under their brand name. It all comes down to how much you want to spend and features. The cost of the magnetic scales have come down and they are an easier install, in particular if you are going to use the 3rd axis for the Quill.

 

[j-becker]

Thanks Mark, I found the feed speed function in the ES12 manual. Sounds like you can only choose to have speed or position from a disclaimer but I don't think that matters. The new Accurite DROs look very nice. Didn't know that this is a German brand.

And thanks for the explanation with the locking and the potential nod -- that would clearly defeat a DRO.