How many axes on a lathe DRO?

[propforward]

Hello.

I added DRO's to my mill last year, and that was a really positive experience (despite the dent in the wallet). So now I'm considering making similar improvements to my lathe.

In researching what is available, and installation methods and such - I am very surprised to find that 3 axis set ups are very uncommon, and 4 axis set ups non existent.

Why is this? I would think that adding DRO capability to the top slide for sure would be useful, and the tailstock perhaps not critical but very beneficial. I do see a number of single DRO installs on the tailstock, but the relative infrequency of adding a scale to the top slide surprised me. Is it just that once you have the carriage on a DRO, the top slide does not get used much, other than setting an angle? I guess I don't use it for very much more than that now, thinking about it.

I'm wondering because a 2 axis set up, even magentic scales, can be had for significantly less money than a 3 axis set up - but I don't want to install a 2 axis set up only to wish I'd bought the 3 axis.

I'm not in a hurry anyway, I can turn to diameters very accurately now, but I would like more accuracy and resolution on the carriage.

[Dave Otto]

I only have a 2 axis unit on my lathe and have never really had the need or want for a scale on the compound.
An absolute must for me was to have a scale with 50 millionths resolution or one tenth on the diameter on the cross slide. I had one of the CBX units for a while and the .001" resolution was almost a waste of time. I have a Newall readout now, and have been very happy with it.

Dave

[kvom]

On many lathes a cross slide slide mount would be difficult if not impossible.

[Bearcar1]

Hmmm. It would seem to me that unless one had one of those super expensive industrial lathes with air bearings, anything with more than .001" capabilities would be a waste of money. Now having said that, I must admit that there most likely are such setups out there in a home hobbyists shop. Not mine unfortunately. I am old fashioned and incorporate manual means to measure distances and size.  A lathe really is only a two-dimensional tool. Oh there are attachments and software to run those 3D  attachments available. But at what practical cost to anyone that is using the lathe for purely hobbyist applications or are gunsmithing. SO, it would seem that only two axis becomes truly of any use. OR, a three-axis unit, which is usually a bit cheaper in cost and can be used on other machines should the need arise, and not incorporating the Z option, be the best practical unit to employ.
 
BC1
Jim

[Dave Otto]

It doesn't have air bearings but it is deserving of a decent DRO, 

Dave

[Bearcar1]

That is a beautiful machine Dave, very nice. No air bearings? Whaaa?    Just kidding.


BC1
Jim

[Dave Otto]

That is a beautiful machine Dave, very nice. No air bearings? Whaaa?    Just kidding.


BC1
Jim

Thanks!

Dave

[Art K]

I don't have a dro on my lathe but would like to add one. Dave I like the idea of one that is accurate to the tenth couse sometimes I'm trying to hold 5 tenths and that is tough. I really can't think of many reasons to have a third dro. Unless single point threading and have the angle set and are cutting the threads properly using the compound rest. Or are cutting a taper? But even so you're measuring a lot and doing the last few passes with the cross slide. A third would seem redundant. Thats my take and I'm sticking to it.
Art

[AOG]

I’ll agree on the higher accuracy scales at least on the cross slide. A one thousandths scale means that the closest your going to get in diameter is +/- 2 thousandths. I highly recommend  spending the money on a good scale for the cross slide as a minimum.

My 2 pennies

Tony

[AdeV]

I've put a 4-axis 1 micron DRO on my lathe, even though there's no way it will hold that kind of tolerance (nor can it's operator!). In Imperial mode, this means it'll read down to tenths, but the tenths number tends to flicker when the lathe is running, due to vibration; so it was definitely the right choice.

Fitting the scale to the compound slide was a challenge, and in fact I still need to make one minor modification to make it work correctly - the oil wiper cover on the end of the cross slide is about 5 thou above the surface of the compound slide, just high enough that it fouls the bracketry holding the reader & prevents me from swinging it around, unless I take the wiper cover off. It won't take long to fix with an angle grinder, or a file; it just needs the very top lip scuffing off it.

4th axis for me will be the tailstock quill; but I haven't fitted it yet, due to the need to refurbish the tailstock first; the leadscrew nut is worn almost to nothing (in fact, how it's holding up drilling still I have no idea!), and even then it's going to need some crafty bracketry to hold it in a way where the DRO scale reads usefully, but doesn't get twisted, e.g. when a drill bites, there's a noticeable twist on the t/s quill. I'm not 100% sure which part is worn that lets it do that; it's probably the pin that stops it spinning in the t/s barrel.

Anyway - the purpose of the 4th axis was so I could accurately drill holes to depth. My tailstock either doesn't have depth markings, or they're worn off, and more than once I've wanted to drill a hole Xmm deep; or cut a bore to a certain depth, & so on.

One last thing - the DRO I bought was a Chinesium one from a company called Ditron. Nothing but good things to say about them - they shipped it quickly, the price was good (less than £500 for the 4-axis setup), and it all worked perfectly. I do, however, plan to make my own DRO head unit in the future, because I want to be able to link the Y & Z-axis readouts with the compound axis + an angle, e.g. if I've got the compound set over at 45°, when I move the compound slide I'd want to see both the Y & Z axes moving. I think this would be ideal for thread cutting, and taper cuts. However, I'm not aware of any DRO head units which will do this..... so currently my 4th axis is in the "laboratory" (er, bedroom) for electrickery experimentation.

PS: Sorry, no photos yet; the lathe is absolutely caked in rust from a job she just did, and looks about 200 years older than she is! I'll take some photos of the installation once I've cleaned her up a bit...

[Jo]

If you already have a 2 axis DRO then upgrading to 3 axis is expensive as the Display also needs to be upgraded (it automatically combines top slide and saddle)

If you don't have DROs on your lathe... 

Jo

[Daggers]

I fitted a dro kit to my Myford last year it came with 2 axis scales but used a 3 axis dro so later i could update with a third scale if needed.
What i liked about this kit was that the cross slide scale is hidden under the surface. It did require a groove in the cross slide base, but this was a very simple job.

[crueby]

If you don't have DROs on your lathe... 

then, I wouldn't be able to make complicated engines like this... Oh - wait, yes I can, and do!

Just means I have to take a direct measurement a little more often and count on the handwheels.   

[Jo]

Just means I have to take a direct measurement a little more often and count on the handwheels.   

Yup 

And don't forget to wear the glasses 

Jo

[propforward]

To be honest all I really "need" is a bit more resolution on the carriage. It's not like I can't hit dimensions accurately, but whereas it is quite simple to hit within a thou on diameters, turning lengths is trickier. Similarly I'd like some more accuracy on the tailstock. That could actually be achieved by adding a manual vernier scale (for example).

After all this if I do add DRO's I'll likely just make it a 2 scale job, and maybe a single standalone scale on the tailstock.

Interesting to read perspectives. Thanks everyone for your input.

[steamer]

Undet the heading of its better to be looking at it instead of looking for it....id go with the better resolution and 2 scales...with a seperate unit on the tailstock....jmo

Dave

[john mills]

Hi   
lot of smaller lathes just don't have rome to foot scales on top slides even bigger lathes i have used ( one that would swing 2meters  on the face plate )would be difficult to fit and manage the wiring to servive for long in amongst swarf  .   tail stock scale could be useful but dials  and scale are usually sufficient .whith CNC machines then digital readout for positions are there . even fitting the x and y  to standard machines restrict the amount of travel on lots of machines .It would be good if machine biulders designed and built machines to incorporate the scales internally inside the slides now that DRO are more standard  and price is more affordable.   

       John

[Pete49]

Nope no axes on a lathe just 2 commonly used axis.  Sorry but someone had to do it.

[steamer]

Hi   
lot of smaller lathes just don't have rome to foot scales on top slides even bigger lathes i have used ( one that would swing 2meters  on the face plate )would be difficult to fit and manage the wiring to servive for long in amongst swarf  .   tail stock scale could be useful but dials  and scale are usually sufficient .whith CNC machines then digital readout for positions are there . even fitting the x and y  to standard machines restrict the amount of travel on lots of machines .It would be good if machine biulders designed and built machines to incorporate the scales internally inside the slides now that DRO are more standard  and price is more affordable.   

       John

Agrre John...I dont see a Cowells getting a DRO anytime soon.  That said, some of the recent products have gotten quite small indeed    1/2 × 1/2 read heads.   

Dave

[Dan Rowe]

Sony makes a really small unit for Levin lathes....the price is not small!!
https://levinlathe.com/sony.html

Cheers Dan

[zeeprogrammer]

Interesting thread for me.
I've been considering the LMS HiTorque 7350 (7x16) which has DROs on the compound rest, cross slide, and tailstock (but they don't account for backlash).
The tailstock is of most interest to me, for the same reasons that Ade mentioned...e.g. drilling holes to depth.
The compound rest was also of interest but mainly for turning short distances when square with the compound rest.
I'm less interested in the cross slide. Probably because of trust issues and would rely more on caliper/micrometer. Seems more accuracy is needed there rather than drilling holes.
I'm curious why there isn't one on the carriage as I've always had trouble getting accuracy there.
I may go for the DRO-less model 5100 and add a DRO just to the tailstock. Well...if I did that I may as well go cheaper and mount a caliper.
But...I'm still a newbie!

[AdeV]

Something I haven't seen mentioned is accounting for wear: On my lathe, using the handwheels was always a wing-and-a-prayer job; because the leadscrews on my lathe are worn, particularly the cross-slide, e.g. if I took a 0.020" cut at 4" diameter, it'd maybe take 0.039" off the diameter, but the same 0.020" cut at 2" would take 0.046" off the diameter; purely due to wear in the cross slide lead screw. Wear in the nut is detectable as backlash (somewhere between 1/3rd and 1/2 turn of the handwheel on my lathe), and between the two, hitting an accurate-to-1-thou dimension could be a real cat and mouse game.

Adding the DRO has massively reduced the effect of this wear, as - having taken a cut + measure + set DRO, I can pretty much trust it until I change the tool.

[propforward]

Nope no axes on a lathe just 2 commonly used axis.  Sorry but someone had to do it.

The plural of axis is axes.

But there are definitely no hatchets.

Well, I've seen a few hatchet jobs come off my lathe, and a couple of jobs that got axed. 

[propforward]

But...I'm still a newbie!

I'm an eternal newbie. And quite happy about it.

Zee, weren't you going all CNC? Or are you looking to add a machine. I may have missed something there. Easily done when life and work distract me from my fun for months at a time. 

[zeeprogrammer]

But...I'm still a newbie!

I'm an eternal newbie. And quite happy about it.

Zee, weren't you going all CNC? Or are you looking to add a machine. I may have missed something there. Easily done when life and work distract me from my fun for months at a time. 

I don't mean to hijack the thread. I had gotten Sherlines and converted the lathe to CNC. I'm still in process of converting the mill to CNC.
I have a PM1030V and PM25MV and intend to sell them off. Too big for me.
I intend to get back to a mini-lathe and mini-mill and am considering the LMS 7350 or 5100 lathe and LMS 4190 mill.
But it will be a few months before I can do anything (wife's illness, pandemic, and still too cold for me).

[crueby]

But...I'm still a newbie!

I'm an eternal newbie. And quite happy about it.

Zee, weren't you going all CNC? Or are you looking to add a machine. I may have missed something there. Easily done when life and work distract me from my fun for months at a time. 

I don't mean to hijack the thread. I had gotten Sherlines and converted the lathe to CNC. I'm still in process of converting the mill to CNC.
I have a PM1030V and PM25MV and intend to sell them off. Too big for me.
I intend to get back to a mini-lathe and mini-mill and am considering the LMS 7350 or 5100 lathe and LMS 4190 mill.
But it will be a few months before I can do anything (wife's illness, pandemic, and still too cold for me).

I fully understand the other reasons, but too cold? I thought you had that beautiful newly built indoor shop as part of the house? 

[zeeprogrammer]

Too cold to drag them out to garage and load them into whatever comes along. 

[propforward]

But...I'm still a newbie!

I'm an eternal newbie. And quite happy about it.

Zee, weren't you going all CNC? Or are you looking to add a machine. I may have missed something there. Easily done when life and work distract me from my fun for months at a time. 

I don't mean to hijack the thread. I had gotten Sherlines and converted the lathe to CNC. I'm still in process of converting the mill to CNC.
I have a PM1030V and PM25MV and intend to sell them off. Too big for me.
I intend to get back to a mini-lathe and mini-mill and am considering the LMS 7350 or 5100 lathe and LMS 4190 mill.
But it will be a few months before I can do anything (wife's illness, pandemic, and still too cold for me).

I certainly don’t mind a change in direction for the thread. You can only talk about DRO’s on a lathe for so long. Sounds like you have a solid plan. Will look forward to seeing more in due course.

[crueby]

Too cold to drag them out to garage and load them into whatever comes along. 

Hmmmm... That may explain why the shop elves were packing up thier truck and trailer with bolt cutters and little ninja outfits!

[Pete49]

The plural of axis is axes.

But there are definitely no hatchets.

Well, I've seen a few hatchet jobs come off my lathe, and a couple of jobs that got axed. 
[/quote]
 Quite right of course Prop, back to the dunces corner. looking for my pointy hat with the red 'D' on it. Might get my eyes tested too 

[gary.a.ayres]

I guess the size of the machine is quite a factor. A DRO on the topslide might be easy enough on a big lathe but a nightmare of fiddliness on a small one.

Would be good to have a lathe with a DRO though. I once saw an immaculate Myford Super 7 at a model engineering exhibition in England with one on it- probably just the two main axes if I recall. The lathe had a pristine paint job in an unusual pale beige colour and it all added up to an unattainable little object of desire that has had me wanting to DRO-ify a lathe ever since.

The nearest I have got to it is that I have a Myford ML10 which had X and Y axis scales on it when I bought it. It should be just a matter of getting a display and hooking it up. The ML10 is in excellent condition. Or I should say 'was', as it was right under the part of the roof of my workshop in France that blew off. I haven't yet been over, and it remains to be seen what kind of state the ML10 is in now or if the DRO scales will even work.

Anyway, I guess that's just a very round-about way of saying Yes! to DRO's on lathes, and I'll be following this thread with interest...

[propforward]

In looking at my compound slide, I think I can get a magnetic type scale on it OK, but I suspect the trailing cable will be a pain in the proverbial when I make angle adjustments. So most likely when I do this I'll just go the fairly standard 2 scale approach, and add an independent one for the tail stock. It looks to me now that the quite substantial extra expense for adding the compound slide DRO doesn't get you very much extra functionality.

I do appreciate the comments and input. Good food for thought.