Thread: Compact DRO options

Hi

I am looking at DRO options for my little BCA jig borer and know many have been happy with Glass scale DRO’s from Ali express and the like. I am not having much success looking for compact versions and I wonder if any members have been successful in this?

I see H&F have their compact sino scales on sale ending today but a 3 axis system there is double cost of elsewhere. Maybe I just have to suck it up…

I have looked at magnetic tape versions but not so sure. - any experiences would be welcome on these.

Thanks
Ian

1) I bought a compact version from here:

https://www.aliexpress.com/item/32836113271.html

plus a new read head for my broken Hare & Forbes MK500 scale.
(actually a KA500 head, I took a gamble that they were fully compatible)


Both seem to work OK.



2) How compact do you need the scales? From what I can tell, there is ...
the normal size, 34.5x25mm (KA300/MK300),
the compact size, 20x18mm (KA500),
and the mini size, 16x16mm (KA200).

(all dimensions scale only, read head roughly doubles it, and "optional" frame/cover adds 30%?)



3) These guys in Sydney have kits for $329:

https://extramachinery.com/collectio...ear-scales-kit

that seem to include either normal or compact size scales?

I have the magnetic scale version on the X axis of my mill. It works well enough, although once a bit of swarf got in between reader and scale and caused some confusion. The other two axis have glass scales on them as compactness was not an issue. No problem with the display coping with the different types of scale either, so mix and match does not cause a problem.

Michael

Originally Posted by nigelpearson

2) How compact do you need the scales? From what I can tell, there is ...
the normal size, 34.5x25mm (KA300/MK300),
the compact size, 20x18mm (KA500),
and the mini size, 16x16mm (KA200).

I think the KA500 version will work. I wasn't aware of the mini version - thanks for that!

Technical drawings on pages 7–10 of SINO linear encoder manual.pdf
( http://stankoservis.by/Download/SINO...r%20manual.pdf )

That document also describes the largest KA600 size.

About 2 months ago I bought my first Sino magnetic reader head and tape for my Douglas shaper downfeed, as the rest are glass.

I didn't think glass would hold up being right next to the clapper and cutting shock, also the extra size of the reader head and housing would not have fitted and it would have stuck up like a sore thumb.

Boy the magnetic reader heads are tiny being only around 30mm long overall compared to my other 15 odd glass scales as well as my compound slimline scale, but I didn't know you could get super slimline as mentioned above, so will be looking after I write this.

I have no hands on experience with magnetic like Michael as I haven't even fitted it yet, but the position I have it in I doubt any swarf will get near it, and with a good cover I don't see any problems.

I've squeezed glass scales into confined swarf prone places with good custom covers and never had problems.

The only problems I've had in the last 2 years after owning some for 15 years is wires breaking from flexing all those years, a simple replacement shielded cable soldered in fixed it.

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I just had a look at the KA200 glass scale, it's still way bigger than the Sino magnetic reader head and tape for confined spaces.

The magnetic tape is only around 2-3mm thick from memory and a slot could be milled in to recess it if need be to save more space.

I wish all this was that cheap years ago as I paid $2150 for 2x Meister 3 axis readouts and 7 scales in 2007, magnetic scales where unheard of back then.
About 9 years ago I bought a 4 and 5 axis HXX readouts with a few scales for around $400 which are still going great.

Pictures to follow

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2nd photo

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Thanks very much Dave. SO I am getting myself a bit confused (nothing unusual), I had though teh glass scales were better/more accurate but maybe I am wrong. Other than the potential for getting swarf caught up is there any other real downside to the magnetic sino option?

Thanks
Ian

Originally Posted by Danger Mouse

Thanks very much Dave. SO I am getting myself a bit confused (nothing unusual), I had though teh glass scales were better/more accurate but maybe I am wrong. Other than the potential for getting swarf caught up is there any other real downside to the magnetic sino option?

Thanks
Ian

The way I look at is every glass scale on the market is good, same with DRO reader heads as I own a fair few different brands and even $36 cheap scales from Vevor.

Miester are actually made by Sino so I found out replacing seals recently from a knolagable seller on AliExpress who knows Kerwin who owns miester.

As for the magnetic scales they are just as accurate with there range of 5um and 1um scales offered.

The only downside I see of magnetic is swarf attracting to them.

On the other hand glass scale always needs a cover anyway, but a magnetic scale being smaller can get away with a much smaller cover if needed