# DRO recommendation for Mill



## SirJohn (Aug 31, 2022)

I have a new Craftex CX600 mill/drill and would like to install a 3 axis DRO.   A couple question:s;
1. Any recommendations on sourcing a suitable DRO. 
2. I am baffled on how the scales are attached to the mill. Does this require drilling and tapping the mill frame or is is some other method of attaching the scales as I am not too anxious to drill holes into my new mill.


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## ShopShoe (Sep 1, 2022)

SirJohn,

If you include your location we will be better able to link you with a source.

Taking Your Questions:

2. Most likely you will have to drill and tap some holes, but the DRO will help your work in so many ways it is well worth it. You have a new machine, so you are not modifying a priceless classic. Measure lots of times before drilling and take your time. I strongly recommend you get some new top-quality drills and taps before you start, once you know the sizes you need. I also recommend that you use the same thread standard as your machine, most probably metric on a new machine: Even if you are more comfortable with inches.

1. If you are in the U.S. you should visit: DRO PROS Digital Readout beats Heidenhain Newall Acurite Sargon Fagor   I have no ties to them, but I bought a system from them last year and I was very happy with the product and their help. In advance of purchase I called them and they spent some time on the phone answering my questions and were able to quote a system specifically for my mill. Their website is very helpful even if you can't use them as a source.  I also suggest you read some of the posts on this forum from those who have installed DROs.

I wanted a GOOD system as I tried one of the small scales and readers that sold for around $100.00 and I was very disappointed with that. What I got was a 3-axis system with a mid-range mill-specific display and that uses magnetic scales: It cost around $1200.00. With only two axes, or with glass scales, it would have been $800.00. The ability to cut the magnetic scales and their smaller size made installation easier and made the installation less "clunky." See the DRO PROS website to understand the terminology and the rationale I followed to make my decisions.

I'm wishing you the best of luck with this and I'd like to see you post your process when you do it.

--ShopShoe


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## SmithDoor (Sep 1, 2022)

SirJohn said:


> I have a new Craftex CX600 mill/drill and would like to install a 3 axis DRO.   A couple question:s;
> 1. Any recommendations on sourcing a suitable DRO.
> 2. I am baffled on how the scales are attached to the mill. Does this require drilling and tapping the mill frame or is is some other method of attaching the scales as I am not too anxious to drill holes into my new mill.


Most time you will need to drill and tap. 
Depending on you budget on what you buy. I have in past use the LED display works great but cost a lot. The mill have today installed a low cost LCD display and single display a lot lower in cost from Shars they are also on Amazon too. For under $200.00 great for retirement budget. 

Dave


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## SirJohn (Sep 1, 2022)

ShopShoe said:


> SirJohn,
> 
> If you include your location we will be better able to link you with a source.
> 
> ...


Thanks for the detailed reply SHOPSHOE .  Still don’t like the idea of drilling and tapping.  Has anyone tried holding the scales on with JB Epoxy?  A Canadian in  Calgary.


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## Mike Ginn (Sep 2, 2022)

SirJohn
The key to a successful DRO is the quality of the product.  Cheap systems are based on the digital Vernier.  There are useless and have far too much lag in their reading.  You should use either glass scales or preferably magnetic scales which are smaller and a 2 or 3 axis readout unit.  For a mill I would always use a 3 axis system even if I install the Z axis some time latter when I have worked out how to install.  You don't state your location but have a look at www.machine-dro.co.uk for info about their systems.  Their readouts are generic and available in other parts of the world.
Magnetic scales are smaller than glass and, for a lathe, allow you to insert them into a machined slot in the cross-slide.  Both glass and magnetic give the same performance and I have had no issues with either.  You do need to drill some holes - as I recall they were M4 size - 2 per scale.  My DRO kit came with various brackets which were only partly useful.  Make sure you purchase the correct length of scale for your machine!
Best of luck
Mike


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## Mike Ginn (Sep 2, 2022)

When I purchased my Warco Minor/Grizzly G1005Z mill I found that there was excessive backlash on all axis.  Having tolerated this for several months I decided to fit a 3 axis DRO.  This was a "Wow" moment.  Suddenly I had control of the axis with the ability to swap between mm and imperial, zero where I liked and use many other useful features.  I can't emphasis  how much this changed my ability to machine with accuracy.  Clearly it is possible to work with backlash and badly made index wheels but it just makes simple jobs difficult.  I quickly installed a 2 axis DRO onto my Myford which had very little backlash.  Again machining became so much simpler especially with the added features.

I would always recommend modelers to fit DROs to their machines - yes there is a cost but it is worth every penny!


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## vederstein (Sep 2, 2022)

SirJohn said:


> Any recommendations on sourcing a suitable DRO.



I recently installed a Grizzly T33081 head unit and slides on our Alliant milling machine at work to replace an ancient Accu-Rite that finally died over 40+ years of service.

Considering the Grizzly head unit with the 5 micron 1000mm & 600mm slides was under $700, I was quite pleased with the quality (it's Taiwanese) and its capabilities.

...Ved.


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## trlvn (Sep 2, 2022)

SirJohn said:


> A Canadian in Calgary.


Have you looked at the Canadian Hobby Metalworkers forum?  Example threads:









						Need a Dro what one to get
					

Have a Craftex Cx-601 that has 14” travel on the Z 11.5” in either direction on the X and 8.5” on the Y.  What inexpensive dro do you recommend and what are the correct scales? Also if it gets orders from China then will it make it here?




					canadianhobbymetalworkers.com
				












						Milling Machine DRO
					

Now that I have my RF 30 mill home, I'm considering adding a DRO as the first accessory. I've seen that Amazon and eBay have some at fairly reasonable prices.  Does anyone have experience with these units? Is there a brand/style you would recommend?  I'm also wondering about length of the sensor...




					canadianhobbymetalworkers.com
				




Craig


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## bluejets (Sep 3, 2022)

SirJohn said:


> Still don’t like the idea of drilling and tapping. Has anyone tried holding the scales on with JB Epoxy?


Joking right......???

Any glass scale DRO will do just fine.

Made my first DRO on the old mill using software originally written by bloke Lindsay (DRO40 through to DRO54)and used an old PC with bare bones Windows 95 operating system.
The optical sensors from old PC mouse were used to track the screw on the table X and Y and fed ito the pc via a small interface to the LPT.
Only drawback was one had to remember to take backlash into account as final programming for this feature was abandoned.
Use was simple, run in to the job from the same direction each time.
Dead accurate. Had to re-fit some previous work a couple of times for additions.

Mill with the program etc. still in use today.


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## clockworkcheval (Sep 3, 2022)

Where space permits I would advice glass. Magnetic sometimes looks preferable because it builds in tight places, and easily, but you run the risk of destroying your magnetic unit if you com too close with a magnet. Like a magnetic base or a magnet to pick up hidden chips.


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## AndrewW (Sep 3, 2022)

Hi sirjohn
To be honest I had exactly the same concerns regarding drilling and tapping my new mill, but they were totally unfounded.
Epoxy or any other type of adhesive will not work as you need to be able to introduce some fine adjustment in order to get the scale to run exactly parallel to the axis. Also, adhesive is too permanent and will introduce further problems if you ever need to replace the scales. If you are entering the world of model engineering you will be drilling and tapping holes in all sorts of material, large and small. Treat it as part if your learning experience.
Drilling and tapping one hole in your mill will probably take 2-3 minutes. In the unlikely event that you mess up you can just drill and tap in a different location.
Get a piece of scrap cast iron and practice in order to gain confidence. Also, the factory drilled and tapped numerous holes when manufacturing your mill, so a few extra won't hurt.
Hope that helps.
Good luck.
Andrew


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## Mike Ginn (Sep 3, 2022)

In a word - or two - Don't even consider using adhesives.  The design of an adhesive joint is complex and would require the removal all all paint in the area.  Cast iron is very easy to drill and if you are concerned about breaking the tap then just dill oversize - there is very little strength needed to hold a scale in place.  AndrewW is completely correct.  My experience with magnetic scales is that they are robust and not damages by magnets - I carried out some experiments!  It's obviously sensible to keep strong magnets away from the scales but in normal use with mag bases I have never had a problem.

Oh and use a good quality drill - ideally a new drill - I always use Dormer brand which I find drills holes to size.

Mike


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## djc (Sep 3, 2022)

AndrewW said:


> Epoxy or any other type of adhesive will not work as you need to be able to introduce some fine adjustment in order to get the scale to run exactly parallel to the axis.



Epoxy can have a useful role to play in mounting a DRO as a filler material between the mounting plate and the unmachined castings of the machine.

Very often you will mount a sub-plate to which the DRO scale itself bolts. Rather than trying to shape this plate such that one side is intimate with the casting and the other is parallel with the axis, hang it in place so that one face (the 'front', to which the DRO scale attaches) is correct and use a conformable material (epoxy) to fill the gap on the other side.

You can set the sub plate correctly planar and hold it in position using a rigid but temporary fixture attached to the mill table such as a piece of plate drilled to the same hole pattern as the DRO scale.

You would have to make your own judgement over the reliability and longevity of any strictly non-mechanical fixing.

If I were to pursue this, I would use two securing screws and tighten them only when the epoxy is dry so there is a small compressive load on the sub-plate-epoxy sandwich.

Drill the sub plate tapping drill size. Fill the hole with blu-tack to stop the epoxy coming out. Once the epoxy is set, drill through this hole and into the casting. Open out to nominal size only to the bottom of the epoxy. Tap the casting, open out to clearance size, countersink the hole and install the screw.


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## raveney (Sep 3, 2022)

Sirjohn,
Your Craftex looks very similar to my Grizzly vertical mill. I am very pleased with a 3 axis glass scale digital readout with LCD display that was purchased in 2021. Model YIHAOGD YH80-3. I found it on Bangood for about $350 as I recall. I cannot find my receipt, but measured the scales and took some pictures that may help you. It improved my machining skills alot. The circle pattern is easy to figure out and use, and the global and local readings help with groups of features located on the same part, or performing the same operations on two parts clamped in the vice.









						YIHAOGD YH LCD 2/3 Axis Grating CNC Milling Digital Readout Display DRO / KA300 5μm TTL 70-970mm Electronic Linear Scale Encoders Lathe Tool
					

Only US$61.99, buy best YIHAOGD YH LCD 2/3 Axis Grating CNC Milling Digital Readout Display DRO / KA300 5μm TTL 70-970mm Electronic Linear Scale Encoders Lathe Tool sale online store at wholesale price.




					usa.banggood.com
				




X axis 620 mm
Y axis 270 mm
Z axis 370 mm

I was able to drill the holes into the mill without disassembly, just center punch and drill and tap by hand. The shipment did take a very long time (3 months) but there was a lot going on affecting China trade/shipping.


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## SmithDoor (Sep 3, 2022)

SirJohn said:


> Thanks for the detailed reply SHOPSHOE .  Still don’t like the idea of drilling and tapping.  Has anyone tried holding the scales on with JB Epoxy?  A Canadian in  Calgary.


JB weld at best for most work a temp fix. 
When I work in Machine shops you see JB weld on parts where JB weld failed.

Dave


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## L98fiero (Sep 3, 2022)

SirJohn said:


> I have a new Craftex CX600 mill/drill and would like to install a 3 axis DRO.   A couple question:s;
> 1. Any recommendations on sourcing a suitable DRO.
> 2. I am baffled on how the scales are attached to the mill. Does this require drilling and tapping the mill frame or is is some other method of attaching the scales as I am not too anxious to drill holes into my new mill.


Not all glass scales are equal, that said, I bought a 3 axis system off Aliexpress, it works pretty much the same as any of the others and was half the price of a locally purchased Chinese DRO, the trade off is waiting time for delivery. As for reliability/longevity, the first Chinese DRO I have is over a decade old and still 100% reliable. The only issue I have with any of the Chinese DROs is that, I believe, they are metric based and they have rounding errors in the ten thousandths in Imperial, i.e., if you are working in Imperial the number you preset may be 0.0001 off position, not something that's a problem in 99.999999% of our work or even industrially.

As for using adhesives to attach the scales, screws are a better bet, even if just from the standpoint of the adhesive possibly failing and the scale being damaged when they fall off and your machine won't be bothered by having a few holes drilled for the scales and you'll probably never take the scales off so everyone will understand the screws will have been required anyway.


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## Mike Ginn (Sep 3, 2022)

I suspect we have all come to the end of this thread!  My view, and that of most of the postings, is that epoxy is not suitable for holding scales to a mill.  It just doesn't work.  Please use small screws in (probably) newly tapped holes.  M4/6 size is fine.  You can use JBWeld as a packing/levelling material but it probably isn't necessary.

Get you drill and taps out and enjoy the DRO experience!!!

Mike


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## william_b_noble (Sep 3, 2022)

I installed a SINO brand 2 axis DRO on my logan lathe - it took a few hours because I had to take some things apart, but the installation went exactly as instructed, and the unit is quite accurate - I replaced a Trav-a-dial that I had on the carriage that would slip from time to time.  my lathe is quite a bit larger than your little mill but the installation is basically the same, you install stuff, you do some careful alignment using an indicator, and it works.  make sure you have a indicator you trust and a stand to hold it, and make sure you dress the cables properly and all will be well.


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## gsg (Sep 4, 2022)

I installed a 4 axis DRO on my XC 45, because there was only a 3 axis DRO installed and I missed the spindel heights gauge. So i used the 3 axis DRO for my CJM250 lathe and installed 3 magnetic scales due to the smaler size of the puckup and the scale. I used a magnetic scale also for the mill Spindle, the 3 installed glas scales had an TTL Output, which did not work with the RS242  input of the new DRO is RS422, so I needed a converter TTL to RS422 for the glas scales. For the converter i used a AM26C31 IC for the old glas scales and made a PCB to fit the converter beewtwenn the output of the scales and the input of the DRO. The two systems are workin fine for some years now.

Regards Guenter


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## firebird (Sep 4, 2022)

Hi
For many years I have had this type fitted to my lathe and milling machines






I have no connection to the above company just a satisfied customer

They can be used with the supplied readouts which are ok but I have used a programme called TouchDRO which is a free download and works on any Android phone or tablet. The DRO's are connected to the tablet via Bluetooth. 











Cheers

Rich


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## aka9950202 (Sep 4, 2022)

My TouchDRO has been a game changer to my X2 mini mill. I found that the dials on the handles did not give the right feel when the backlash was taken up. The  accuracy now achievable make the conversion worthwhile. 

Cheers, 

Andrew in Melbourne


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## fltenwheeler (Sep 4, 2022)

I really like the Jenix DRO that I put on my mill. 

Tim
http://www.digitalreadoutsystem.com/Jenix/jenix_dro.htm


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## Rudeboy (Sep 4, 2022)

SirJohn said:


> I have a new Craftex CX600 mill/drill and would like to install a 3 axis DRO.   A couple question:s;
> 1. Any recommendations on sourcing a suitable DRO.
> 2. I am baffled on how the scales are attached to the mill. Does this require drilling and tapping the mill frame or is is some other method of attaching the scales as I am not too anxious to drill holes into my new mill.



I'm installing a 3-axis DRO on a Craftex CX600.  In my case, the DRO is one of the many (countless)  offshore varieties (ToAuto is the brand) acquired from Amazon - the vendor offers pre-packaged sets, i.e., scale lengths, or you can tell them the lengths you need within 5cm increments (which I did).  These are 5um glass scales.  I did have an Easson setup from Dro Pros but parted with that a while ago.  The cheaper products are cheap but functional.  As others have alluded to or, in fact, strongly suggested, do NOT use any adhesive to attach the scales.

As I've more or less disassembled the entire mill - in part, this was to examine everything, clean up/adjust as required and, as much, understand how it all works - this greatly facilitated installing the DRO.  I *am* drilling/tapping into the cast iron as required in order to attach the fittings.  While good (sharp) HSS bits will work well - and I've utilized these - I also switched to equivalent diameter cobalt (5%) bits when the HSS were struggling (whether they dulled or my technique was off).  You will read that tapping cast iron doesn't typically require fluid but, as with all tapping operations, do it carefully.  Clean the holes in between with a (magnetized) screwdriver shank and/or compressed air to ensure the bits and filings are removed.

My approach is simple: threaded M4 and (mostly) M5 rod, spacers and aluminum plate/angle.  Any design should provide some adjustment as to how the scales and reader lay so they have clear travel and allow them to be in alignment with each other - the placement will be your decision.  For the CX600, the sides of the column casting are about 3 degrees off square from the way plane so you may have to account for that.  Although I did my best to drill/tap 'true' in this location for the z axis, I used stainless conical/countersunk washers to accommodate any adjustment.

Google presents enough examples (search via Grizzly G0704 vs. Craftex CX600 - they're basically identical although the former has a longer table).

PS  I'm no expert - just a hobbyist (and a hack at that)...


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## Lloyd-ss (Sep 19, 2022)

Mike Ginn said:


> When I purchased my Warco Minor/Grizzly G1005Z mill I found that there was excessive backlash on all axis.  Having tolerated this for several months I decided to fit a 3 axis DRO.  This was a "Wow" moment.  Suddenly I had control of the axis with the ability to swap between mm and imperial, zero where I liked and use many other useful features.  I can't emphasis  how much this changed my ability to machine with accuracy.  Clearly it is possible to work with backlash and badly made index wheels but it just makes simple jobs difficult.  I quickly installed a 2 axis DRO onto my Myford which had very little backlash.  Again machining became so much simpler especially with the added features.
> 
> I would always recommend modelers to fit DROs to their machines - yes there is a cost but it is worth every penny!


Mike, I have the exact same Grizzly mill, about 10 years old.  And, exactly the same backlash issues, but overall, it is a good value for the $$.  I have gotten into the habit of always going clockwise against the axis locks when I zero the handwheel dials.  I guess I will finally get a DRO. It will be one of those things where I kick myself for waiting so long.

Some of these threads always cost me money, LOL.


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## Mike Ginn (Sep 19, 2022)

Lloyd.  Go for it!  Yes I agree that it is possible to work with backlash - we all did it for many years but to me it is like using a 4 jaw chuck for round material.  Yes it does work but what a pain.  Go for the XYZ DRO and your life will be transformed.

BTW and off subject.  Have you needed to replace the top bearing.  Mine jammed due to lack of lub - my manual said sealed for life  - it isnt.  Its basically a cheap motor cycle steering head bearing.  Not too difficult to change

Mike


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## Brian Rupnow (Sep 19, 2022)

You might find everything you need here. And forget about any kind of adhesives.





						CX601 Milling Machine
					

This thread is going to be a continuation of my trials and tribulations with a new square column benchtop milling machine from BusyBee Tools in Canada. I had started to cover this mill in my oscillating I.C. engine thread, but I was getting so far off the original thread title that I have opened...




					www.homemodelenginemachinist.com


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## Richard Hed (Sep 20, 2022)

Lloyd-ss said:


> Mike, I have the exact same Grizzly mill, about 10 years old.  And, exactly the same backlash issues, but overall, it is a good value for the $$.  I have gotten into the habit of always going clockwise against the axis locks when I zero the handwheel dials.  I guess I will finally get a DRO. It will be one of those things where I kick myself for waiting so long.
> 
> Some of these threads always cost me money, LOL.


Yes, you guys cost me a lot of $$, however, it also saves me a lot time!  Time is $$, so it's a good thing.  I have purchased many things because I read someones blurb and saw their photos.  A few days ago I recieved in the mail my first VFD.  Been studying the utub vids to get a handle on installing it.  The booklet that came with it was _so clear _that I got quite angry.  The booklet is printed for about a dozen different VFDs, but I don't have that dozen different VFDs.  I have a specific one and clawing thru the damned crappy booklet to find the info specific to mhy model was NOT , let me reapeat that:  NOT, pleasureable.  Plus the text is about .5mm tall--had to use glasses and magnifying glass to read it.  What total sh*te.

Anyway, many things have I purchased to ttry or on recommendations from you fellows here.  Thanx.


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## Lloyd-ss (Sep 20, 2022)

Mike Ginn said:


> Lloyd.  Go for it!  Yes I agree that it is possible to work with backlash - we all did it for many years but to me it is like using a 4 jaw chuck for round material.  Yes it does work but what a pain.  Go for the XYZ DRO and your life will be transformed.
> 
> BTW and off subject.  Have you needed to replace the top bearing.  Mine jammed due to lack of lub - my manual said sealed for life  - it isnt.  Its basically a cheap motor cycle steering head bearing.  Not too difficult to change
> 
> Mike


Hi Mike,
No problem with the bearings, but a few other annoyances, all of which I either fixed myself or ignored. 
The contacts burned out on the switch. Replaced the switch.
The bracket that holds the stack of idler pulleys in the top cowling cracked, but is still functional. Ignored.
Noisey vibration from the plastic cowling over the belts. Just wedged stuff here and there till it stops temporarily.
Noisey vibration from the spindle retract spring in the little can on the left side of the spindle. Have not investigated. Ignoring it.
The Z fine feed knob seems to be slipping, but I am not positive. Need to investigate.
The 2 big pinch bolts that clamp the head casting to the column stripped out, and I generally do not do that sort of thing. I replaced them with good high strength bolts and nuts.

I use this mill several times each week, and that's 10 year's worth of problems on a $1,000 machine, so not too bad I guess.

I am about to take the DRO plunge before I get too old to appreciate it.
Lloyd


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## Mike Ginn (Sep 20, 2022)

Lloyd
Apart from the noisy cowling (which in my version is sheet metal) and the bearing issue I have been trouble free.

Take the DRO plunge and rejoice in your "new machine"  Get a "proper" DRO with XYZ display.  If you need photos of my fix just ask

I'll wait for an update..........

Mike


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## Drawfiler (Sep 21, 2022)

I have been through all of this on two mills, I took advice from Machine Dro and they told me to go for magnetic scales as they have less customer problems with those than the glass ones.
The control boxes are mostly made in China and seem to work well. In my experience the digital vernier battery driven one’s are not as robust or reliable as the ‘proper’ scales.


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## Mike Ginn (Sep 21, 2022)

I did the same and used Machine DRO kit.  I have both glass scales on my mill and magnetic on my lathe.  No issues with the glass scales on the mill and there is ample space to fix them.  For the Myford lathe things are different.  The bed could accommodate either the larger glass scale or magnetic.  The cross slide is a different matter.  I did not want the large housing of the glass slide getting in the way of machining operations so I fitted a magnetic scale into a machined grove in the underside of the slide.  MDRO sell a cross slide extension which allows full movement to the cross slide.  It works very well and could easily be made in the shop.  No issues with the mag scales or the adhesive holding it in place under the cross slide.  I was concerned about this as oils can attack adhesives. 

It is possible to install a scale onto the top slide but it is a messy installation which restricts the 360deg movement of the slide and complicates slide removal etc etc.  I have not found this omission to be an issue and I seldom use the top slide.  Should I need to accurately indicate movement I would use a dial (digital) indicator but this is a rare event.

Picture shows the MDRO cross slide extension which is basically a block of Al set about 0.5mm below the face of the slide and has an extended grove for the mag scale.  I have 2 control boxes both from China. (XY for the lathe and XYZ for the mill)

In my experience DO NOT use the cheaper digital vernier scales.

Mike


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