Choosing a DRO for my mill

[SemiSkilled]

I'm researching dro's for this mill




Thinking of magnetic scales http://www.machine-dro.co.uk/magnetic-linear-encoder-reading-head-5-micron-resolution.html

and a sino http://www.digital-caliper.co.uk/product_info.php?cPath=35_39_64&products_id=214 readout, looked on the Sino website no manual, is this the same thing regarding functions ?

http://www.dro.com.tw/pdf/Manual.pdf

Thanks

Lee

[udimet]

Lee,
               You should look at the DRO's from Newall.  I have Newalls on both my lathes and, the 3 axis C80 on my milling machine and have had them for over 10 years with never any problems and they are totally swarf and coolant proof. [they can even be fully submerged in coolant with no untoward effect] They are very pricey compared to the makes you mention  but they are built to last and available in resolutions down to 0.005mm
 They would be quite a bit more expensive than comparable ones from Mitutoyo and about the same as Heidenhain, good luck.
                                                                                                                   
 

[j_e_f_f_williams]

Hello,

A friend of mine has Newall on his mill & lathe.  I have used them a few times and they work great and I found them easier to use than my DRO.  That said, I put a Sino DRO on both my Lathe and mill for about 1/2 the price of his Newall Mill DRO.  And for 99% of the home shop hobby stuff I do the Sino is all I need.  The 1% the Sino will probably do as well, you just have to figure out the Chinglish manual a bit   I bought the Sino from eBay and it was shipped from China but was still at my door about 1.5 weeks after I sent it. 

I have yet to calibrate the lathe DRO to make sure that the distance it says is really the distance it is BUT the DRO I added to my mill at minimum matched the dials out of the box so I am no worse off and I don't have to count revolutions any longer

No experience with the magnetic strip DROs.

The manual you linked to looks like the same topics for the Sino and some of the key presses I have used look the same though that one is better English than the Sino one  

TTYL, jeff

[Jonny]

Lee if its any use i did the conversion on my lathe last year.
I will confirm the magnetic types you can submerse in coolant and still work as normal.
Fair bit dearer than glass scales but they are not obtrusive and take up little room.
Bought mine from DRO UK on two separate intervals, one encoders light blue the other is black, they need the specfic magnetic strip or will read differently.

Thinking about changing glass scale fitted to rear of bigger mill to the magnetic type, scares me with the swarf build up and only a matter of time before the glass breaks.

The glass scales DRO UK sell are Sino units with different plugs fitted. Positive they sold Sino readouts a few years back and a few others inc Newhall, settled for ease of use the basic 3 axis mill and lathe ones.

Magnetic on tailstock and Y axis. The Y axis encoder is covered up doubling up with X axis glass scale as a protector from swarf build up in the tray. In other words just pushes the swarf away.
http://i1140.photobucket.com/albums/n563/Jonhareng/Harrison%20M300/M300DROCABLING004.jpg
http://i1140.photobucket.com/albums/n563/Jonhareng/Harrison%20M300/M300DROCABLING005.jpg

[Jonny]

Reminds must have another word with DRO UK it really narks me any form of readout on Y axis will double the amount taken off. They may have some magnetic strip that reads  1/2 the actual movement!

[SemiSkilled]

Thanks for the replies,

I've ruled the newall stuff out on price  

I'd like the magnetic strips as  the mill has an odd sized table and I can custom fit the magnetic strip

I'll give the vendors a call ~

Johnny ~ I'm sure DRO Machine did sell Sino stuff a bit back, BTW are you sure your y axis isn't set to a lathe function ?

I re read your tail stock mod last night as I remembered you had used the mag strip, hows it working out?


Lee

[Jonny]

Havent really had a good look, but did find 1/2 measurement on readout but that affects the X and tailstock as well.
IE wind in Y axis 1mm, 2mm taken off diameter.

You are right the magnetic are more expensive but what they really offer is far less restriction in specific installs.
If you have the metal you could easilly embed the readout and scale in to the bed.
Main thing is nothing unsightly as glass scale installs, look at that Myford thread always in the way - a bad thing.

[Davo J]

Jonny,
You should be able to change the resolution in the menu to fix that up.

I have had 3, 3 axis DRO's for 4 years, all glass without and any problems. I made sure the X axis on the mill was protected by a metal angle, since it was on the front and venerable. On the lathe I put a bolt in the front of the tail stock to stop it hitting the x axis scale.
My preferred choice is the Meister and Sino, but the Meister is more expensive and only single machine where the Sino will do all machines, lathe, mill etc.
Here is the X scale install with the metal angle.
http://www.woodworkforums.com/f65/installing-dro-scale-front-table-hm50-52-a-115786/

Dave

[Jonny]

Nice install there Dave good for a change to see a job well done.

I have the same C type scales fitted to X, Y Z on larger mill and only the X axis on lathe, very easy to do with those backing extrusons. Magnetic on lathe is Y and Z tailstock.
The reason theres so much aluminium is to protect the glass scale from build up of swarf, it pushes it away.
http://i1140.photobucket.com/albums/n563/Jonhareng/Harrison%20M300/M300DROCABLING002.jpg
Found a way to get rid of some horrible brass.
http://i1140.photobucket.com/albums/n563/Jonhareng/Harrison%20M300/M300DROCABLING001.jpg
There will eventually be depth stops off the backend
http://i1140.photobucket.com/albums/n563/Jonhareng/Harrison%20M300/M300DROCABLING003.jpg

That wouldnt work in my situation, i need the same X axis power feed stops with the trip, carriage stops and two bed locks.
Unfortunately the only way would be to mount the scale outboard around 3" clear but would then foul the dividing plates that drop down the side.
Mounting direct would loose all or most of above, the scale overhangs the T slot.

Just had a quick look again the magnetic will fit, its a lot thinner and would sit above or below the T slot plus still allow dividing plates to drop down.

I will have a read of the manual about halving the Y axis only.

[Jonny]

That works Dave, just set Y axis to Radius rather than diameter.
Still retains when powering off, so great.