Opinion on two DROs

[dalee100]

Hi,

After some searching of specs and costs, I've narrowed down my choice of 2 axis DRO for my G0704 mill to one of these two units. And will probably order one this weekend.

http://www.ebay.com/itm/281843999219...%3AMEBIDX%3AIT

or

http://www.ebay.com/itm/331580605203...%3AMEBIDX%3AIT

Neither are top line models, but should be satisfactory for a benchtop mill at home. I do like glass scale units. Even cheap ones are accurate and have good repeat-ability. Durability can be another matter. And the biggest problem for benchtop mills is the bulkiness of the scales. Making tight quarters even tighter.

The magnetic scales are far more trim and slender. And can be easily trimmed for that custom fit. But the accuracy and repeat-ability isn't as good as glass. Though these scales are "good enough" for my usage 99.5% of the time. And the IP54 rating is a plus too.

What do you guys think?

Dalee

[chipmaker4130]

Why do you say the mag scales are inferior? They seem to have a lot of advantages as well as a very good warranty. I've been considering mag scales, so if you know something, I'm all ears.

[quadrod]

This is the one that I got for my mill. It has worked well so far. http://www.ebay.com/itm/220523008542

[vpt]

Subscribe because I want one too!

[danlb]

I have the SINO dro with glass scales mounted on my mid sized knee mill (similar to the G0728 from grizzly). I have the mag scales sitting in a box to eventually go on my 9x20 lathe.

The glass scales with a good readout is way better than the simple "magnetic" scales. The accuracy and repeatability are 10 times greater with the glass scales. When I move the table to X=10.0011, Y=10.0010 I know that I'm within .0002 of the right spot. If I do that with the mag scales I can only trust it to be within a .002 range of where it should be.

This might seem like "close enough", until you are making parts with matching features. If one hole is +.0015 from true and the other is -.0015 the other way, you can make it fit. That does not work as well when you have half a dozen holes that have to match. The work around is to use the DRO to get close, and the handwheel dials to get it spot-on.

The other advantage of the first set of scales is that it will do some neat math for you. Drilling a bolt circle, for instance, is a breeze with the built in function. Mine also has a function for doing curves and angles. Oh, it also remembers up to 100 X-Y-Z positions for when you need to make 10 pieces that are all the same. Of course you can do all this with pencil, paper and a calculator, but it's dead simple with a good DRO.

Dan

[flylo]

I'd go with this from Tpac tools eBay item number:231337080276 Near Chicago 5 year common sense warrenty & if I have a problem no dealing with china. A great guy to deal with & very helpful with fast shipping & under $400/shipped. Tpac tools.com He stocks all sizes of scales.

[dalee100]

Hi,

Yes, glass scales are nearly an order of magnitude more accurate than the magnetic scales. I've even been unimpressed by a Sony mag scale DRO.

But, I'm not trying to match tolerances with someone on the other side of the planet. So absolute accuracy is perhaps only second on the list. And repeat-ability becomes first. I maybe don't care if the holes are off by .001"-.002". As long as the read out brings me back to the same place every time. A spec that is seldom listed with most of the mag scale vendors. But Shar's is honest enough to list their repeat-ability as +/-.0005". Not glass scale good, but pretty darn good for mag scales.

Flylo, I've sent a request to Tpac tools on availability of 200mmx500mm length scales and pricing. Those will fit my G0704. I like the 5 year warranty. Thank you for the direction.

Dalee

[danlb]

But Shar's is honest enough to list their repeat-ability as +/-.0005". Not glass scale good, but pretty darn good for mag scales.

Dalee

I notice that they also mention "Tolerance" as being .002. Any idea what that is a tolerance for?

Dan

[Andrew S. Quinn]

I got this one from TPAC. http://www.tpactools.com/2-AXIS-DRO-...-NEW_p_21.html it arrived in about 2 days after I ordered it.

[BigBoy1]

I debated between a two axis and three axis DRO for many months before I made my purchase. I decided to go with a three axis and I can truly say that I made the right choice. You don't realize how handy having the ability to make measurable changes in the vertical axis can be. I went with the three axis mill unit from DRO Pros.

http://www.dropros.com/DRO_PROS_Milling_Machine_Digital_Readout.htm#DRO_PROS_3M

https://www.youtube.com/watch?v=X-4DtQK5CSM

[J Tiers]

I notice that they also mention "Tolerance" as being .002. Any idea what that is a tolerance for?

Dan

It can be wrong by 0.002.

It will be wrong again the next time by same amount within 0.0005.

That's what those numbers mean.

[mrobertson]

I went with the three axis mill unit from DRO Pros.

We have the same unit on our mill. I haven't noticed any problems with accuracy and repeatability. I've been quite happy with it.

BTW the Grizzly glass scales here are made by the same company as the DRO Pros

http://www.grizzly.com/products/H6091

[Ed ke6bnl]

I have both scales you show. the mag one I just bought long and cut to fit where nice, then I made one of Yuriys Touch DRO boxes for it to bluetooth readout to my android phone that was nice and worked well, I just sold the mill with the readouts. On my new to me old Bridgeport I purchased the other one with glass slides and have not mounted but tested on the bench and I bout 3 axis for about $289 from Aliexpress. free shipping

http://www.aliexpress.com/item/free-shipping-complete-set-milling-lathe-drill-machine-dro-digital-readout-with-3-pcs-linear-scales/1524501216.html?src=ibdm_d03p0558e02r02

took about 7 days to receive. Not much more then I paid for the Stainless Steel mag AccuRemote I had on my other mill.

[tincture500]

If you are intending to only produce marginal output and tolerances why worry? If you exceed the lathes ability in accuracy with the DRO its money wasted. Tom

[Danl]

http://www.aliexpress.com/item/free-shipping-complete-set-milling-lathe-drill-machine-dro-digital-readout-with-3-pcs-linear-scales/1524501216.html?src=ibdm_d03p0558e02r02

took about 7 days to receive. Not much more then I paid for the Stainless Steel mag AccuRemote I had on my other mill.

That looks like a super deal, Ed. Did you pay the extra $18 per scale for the 1um resolution option? the prices on these continues to drop. Perhaps that is due to the proliferation of hobbyists buying new and used mills and lathes, together with the retirement of more baby boomers with time on their hands.

I bought a 3 axis unit from DROpros, and really think that 3rd axis is useful on many occasions.

Dan