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geb
02-23-2007, 09:27 AM
Gentlemen,

I thinking about putting DRO on my Delta/Rockwell Mill.

Does anyone have any advice or suggestions regarding this venture?

Price ia a condideration.

2 or 3 axis?
Whose product
Best buy
Service/repair (parts available)
etc.

Thanks you,

geb

SGW
02-23-2007, 10:10 AM
"It all depends." Maybe the first thing to decide is, how much precision are you looking for. If +/- 0.001" is good enough, then products like the Shooting Star DRO become very attractive. If you want +/- 0.0001", guaranteed, on the other hand, you're probably looking at high-end Acu-Rite or Heidenhain or something like that. I'm not sure if you can find a "package" to fit the Rockwell, so you'll need to deal with somebody who will put together a custom package for you.

I looked at DROs for (literally) years before I finally decided to get one. I finally got an Acu-Rite 200M with +/- 0.0002" resolution scales, which pretty well assures I can put a hole within half a thousandth of where I want it, anywhere, and the quality leaves nothing to be desired. Mike at www.candomachinery.com was very helpful, both before and after the sale, and he quoted me a really good price for a custom package. (Usual disclaimers....)

The Newall has a lot of attractive features (most notably, indestructibility) but the scales are +10" longer than the actual measuring distance, and they wouldn't fit on my milling machine because of that. Something to check.

Other guys have had good luck with imports (Jenix, Sumatech, etc.) but I decided I wanted no doubt, at all, about the precision or reliability of my DRO setup and went with the Acu-Rite.

DRO choice has been flogged to death in this forum, so a search of the archives ought to yield a lot of information.

Bill Pace
02-23-2007, 10:26 AM
As suggested, find your self a couple -- or more, hours and do a search on "DRO" here in the forum, its a pretty far ranging subject...several suppliers ranging from relatively inexpensive, to costly, that have to be fitted to a large variety of machines. I think if you would just read through the many threads you will begin to get an impression of whats out there and what will fit your needs.....

It IS a really nice addition to a mill and will add a lot of pleasue to using one.

SGW
02-23-2007, 10:49 AM
One drawback to installing a DRO, which may or may not be worth considering: once you install a DRO, it may become a lot more difficult to take the table off the milling machine, if you ever want to, because you also have to remove the DRO.

And removing the DRO, so it doesn't get broken, may not be trivial if you have glass scales. You'll have to re-install the shipping brackets on the read head before removing it, then when you put the DRO back on you'll need to re-align everything.

Probably not a reason to avoid getting a DRO...but it's something I realized only after I'd installed mine.

Michael C
02-23-2007, 11:24 AM
Ganesh machinery in Cal used to have killer deals on Newall, Accurite, etc. I got the Newall and never regretted it. As SGW alluded, they are a completely different league than Shooting Star. I had a Shooting Star on an old Clausing mill, even with the best set up, repeatibility end to end was still only within .001 to .002. Buy the best you can afford and only cry once.

Michael

torker
02-23-2007, 02:15 PM
I use a Shooting Star everyday and love it. Zero problems with it.

lazlo
02-23-2007, 02:50 PM
The Shooting Star, Spokane Metal Works, etc DRO's are based on rack-and-pinion digital calipers, and have an accuracy of +/- 0.001"
An inexpensive DRO with glass scales has about 5 times that accuracy: +/- 0.0002".

Forrest summed it up perfectly here:
http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/1/21292.html

"At one time the hobby type kits like Shooting star, BW Electronics, Ortec etc were good value for the money as the glass scale units were expensive.

However it's now go to the point where with a bit of shopping around you can get glass scale units with multi function displays, bolt circles, tool offsets etc for the same or even better prices.

Resolution of the cheaper glass scale units is 0.0002" against a published 2 thou for a lot of the cheaper units.

A cheaper unit may be OK on a mill but it's totally unacceptable on a lathe, That 2 thou error is now 4 thou because of the radius cutting function of a lathe. Hell decent dials can get you better than 4 thou."

torker
02-23-2007, 04:50 PM
The Shooting Star, Spokane Metal Works, etc DRO's are based on rack-and-pinion digital calipers, and have an accuracy of +/- 0.001"
An inexpensive DRO with glass scales has about 5 times that accuracy: +/- 0.0002".

Forrest summed it up perfectly here:
http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/1/21292.html

"At one time the hobby type kits like Shooting star, BW Electronics, Ortec etc were good value for the money as the glass scale units were expensive.

However it's now go to the point where with a bit of shopping around you can get glass scale units with multi function displays, bolt circles, tool offsets etc for the same or even better prices.

Resolution of the cheaper glass scale units is 0.0002" against a published 2 thou for a lot of the cheaper units.

A cheaper unit may be OK on a mill but it's totally unacceptable on a lathe, That 2 thou error is now 4 thou because of the radius cutting function of a lathe. Hell decent dials can get you better than 4 thou."
Ya...I must have to agree(cuz you guys said)...I'm sure my Shooting Star is out at least a foot in 6 inches :D

DeereGuy
02-23-2007, 07:47 PM
Ya...I must have to agree(cuz you guys said)...I'm sure my Shooting Star is out at least a foot in 6 inches :D

I thought they were talking about my Shooting Star.

John Stevenson
02-23-2007, 08:38 PM
The Shooting Star, Spokane Metal Works, etc DRO's are based on rack-and-pinion digital calipers, and have an accuracy of +/- 0.001"
An inexpensive DRO with glass scales has about 5 times that accuracy: +/- 0.0002".

Forrest summed it up perfectly here:
http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/1/21292.html

"At one time the hobby type kits like Shooting star, BW Electronics, Ortec etc were good value for the money as the glass scale units were expensive.

However it's now go to the point where with a bit of shopping around you can get glass scale units with multi function displays, bolt circles, tool offsets etc for the same or even better prices.

Resolution of the cheaper glass scale units is 0.0002" against a published 2 thou for a lot of the cheaper units.

A cheaper unit may be OK on a mill but it's totally unacceptable on a lathe, That 2 thou error is now 4 thou because of the radius cutting function of a lathe. Hell decent dials can get you better than 4 thou."

That quote was one of mine and the last bit has been omitted.

"To put it in a cost perspective the hobby DRO's need to come down a lot in price but that's not going to happen, quite the reverse in fact as their parts and assembly costs go up."

As an example the Shooting star is listed as a two axis DRO at $599.
On Ebay in completed auctions we have Reliable Tools who are not regarded as the cheapest seller with a 2 axis glass scale DRO with 2 tenths resolution for $561
http://cgi.ebay.com/NEW-9-x-42-UNIQ-DIGITAL-READOUT-MILLING-SYSTEM-DRO_W0QQitemZ130081271785

The Meister brand are available again on Ebay for $454 plus $88 shipping, again glass scales and two tenths resolution.

http://cgi.ebay.com/Meister-S2000-2X-Digital-Readout-Scales-Mill-Lathe-DRO_W0QQitemZ140081245630

By rights Shooting Star should be around the $350 mark tops for the features / resolution they offer.

Over here BW Electronics offer their 2 axis unit at 383 UKP, about $690 with plus or minus 0.002 or 0.003" depending on length of scale.
Now compare this the the Meister ones paid for in $$ and still shipped for $88 to the UK, these then cost us 300 UKP.

Even buying in the UK the glass scale units are on Ebay UK for 265 plus 50 shipping making these 315 total.

Technology has moved on.

.

lazlo
02-24-2007, 02:02 AM
That quote was one of mine

Damn, sorry John -- I don't know where I got Forrest out of that thread! :)