# Optical or Magnetic



## Omnimill (Jun 17, 2011)

As title. I'm considering adding X, Y DRO to my VMC mill but can't decide which is best although the magnetic looks like it may be more durable? These guys are one supplier I've looked at:

http://www.machine-dro.co.uk/

What do you guys think, Mag or Optical?

Vic.


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## Davo J (Jun 18, 2011)

I have had 3 DRO's with glass scales for 4-5 years with no problems what so ever.
I have seen the magnetic ones, but wonder what happens if a mag base comes close to them.
As long as you put covers on the glass scales they will last a long time and you can get the slim line ones to fit in combined places.
Those budget read outs they sell are copies of the Meister on ebay. I am not sure how much the Machine DRO UK charge for a set, but it might be cheaper buying them through Meister on ebay.
http://shop.ebay.com.au/meisterdroshop/m.html?_trksid=p4340.l2562

There is also the Sino which can do mill, lathe, EDM and grinder all out of one read out
http://shop.ebay.com.au/xiao1207/m.html?_trksid=p4340.l2562
He charges about $10 an axis extra for slimline scales and around $20 an axis extra for 0.001mm scales.
I have dealt with both these sellers and highly recommend them.

Dave


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## djc (Jun 18, 2011)

Davo J  said:
			
		

> ...There is also the Sino...



...which in the UK can be bought, inter alia, from Jade Products http://www.digital-caliper.co.uk/ . No connection, just someone else to consider.


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## Omnimill (Jun 18, 2011)

Thanks for the info guys I'll have a look. The reason I started to look at the Magnescale was due to the published advantages over Glass scales. The manufacturers will always promote their technology but they say it is far more robust and doesn't require maintenance or cleaning. Also mentioned was that glass scales expand and contract at different rates to the machine? I wish one was a lot cheaper than the other then it would be easy for me to decide :big: I think I need to see both types up close.

Vic.

Much smaller so leaning towards the Magnetic although it will end up a bit more expensive:

http://www.allendale-stores.co.uk/dro/info/linear_encoder_comparison.pdf


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## BillTodd (Jun 18, 2011)

> The manufacturers will always promote their technology but they say it is far more robust and doesn't require maintenance or cleaning.



Well, I can say the Sony Magnescales on my HLV-H when I got it were absolutely chock-o-block with congealed coolant to the point where one would only move 2" - I flushed them out with jizer and WD40 re-oiled the ball races on the pick-up head (these things are beautifully made) and they are now working fine (still resolving down to 0.00005" - yes that is five decimal places)

I can't believe glass scales would have survived the cleaning, let alone the work environment that got them in the the state in the first place

Magnetic bases or swarf pick-up tools don't affect them at all .

Bill


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## Omnimill (Jun 19, 2011)

Thanks Bill, I've seen pictures of some of the Sony ones they do look solid.

Vic.


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