14x40 lathe DRO

[petertha]

Does anyone have any pictures of their lathes or even web links re outfitting a DRO on a (14x40) lathe like this? Mine is 10 years old, but I'm at the 'seriously thinking about it' stage. I know similar new machines are offered with DRO's already mounted, but I can never seem to find picture details of the mounting. Ive DRO'd my RF-45 mill, so its not a foreign concept, it just pays to see how other people do things in advance.

Also, my lathe has the typical big steering wheel to traverse in the x-axis direction. I think it works on rack & pinion action. It would seem to me kind of a coarse way of making teeny thou-like movements or converging to a X.000 inch position with a DRO. Its not like the cross slide y-axis screw where a full turn is 0.100"and you can creep up on a measurement. Is it just something you get used to or maybe there is another trick?

 

[n4zou]

It's not difficult at all to install a DRO. Just mount the sensors and plug them into the display box.

When you need to make precise movements in the x axis use the compound or use a micrometer carriage stop. Personally; I use a 1" travel dial indicator setting it's dial to zero where the carriage needs to stop.

 

[Blogwitch]

P,

I have a similar sized lathe, if you can wait until later today, I will get some shots of the manufacturers installation, but it might be a bit difficult to get close up shots at the back of the lathe, as my lathe is against a wall.

I have done an extra on mine (for when I was doing production work) I did a top slide and tailstock fit as well.

John

 

[doubletop]

I'll put a tag on this page, this mod is on my 'do' list and I know John has the same lathe as me and also uses Sino DRO's. It will save me asking him the same questions when I get around to the job.

(One specific question would be around identifying the scales. I'd imagine there's not a lot of space round the top slide for a standard profile scale and cover, so the small profile would seem sensible)

Pete

 

[Mike N]

Also, my lathe has the typical big steering wheel to traverse in the X axis direction. I think it works on rack & pinion action. It would seem to me kind of a coarse way of making teeny thou-like movements or converging to a X.trash" position with a DRO.


It is not a problem to stop the X carriage with-in a thou. with the DRO.
I have a 14-40 lathe, I mounted a DRO without any difficulty, just make sure the cables don't get snagged on anything because of the long carriage travel on a 40" bed.

I bought my DRO from: http://www.cdcotools.com/
Very reasonable

 

[Blogwitch]

I can't give you too much info as there might be slight discrepancies between machines, so I will just show points that can be followed.

Please excuse the state of my lathe, I haven't cleaned the back out for ages.


On this picture, it is almost self explanatory. But do be aware that what I am showing is the cover, not the actual head. I think that works out to be about 10mm shorter than the cross slide at each end. You won't be able to 'bottom out' the head if you stick to this sort of measurement as the cross slide moves nowhere near the full cross slide length.

Two major things to notice when fitting this head. The first is that the head will cover up your cross slide lock, more on that later.
The second thing to note is the bolt screwed into the cross slide itself. It is there, and adjusted, to stop the tailstock smashing into and damaging the read head.
Also notice on this pic, the routing of the cable, it has to be tucked in as tight as possible to allow the tailstock to come far enough forwards to be of any use, plus to stop damage to the cable.

The head used for this job is the medium sized ones.

This picture is again easy to follow. Just note that this read head is the large type, and is almost as long as the exposed length of the main bed.

Again, all major points covered in this next picture.

Just one thing to mention, make sure that the main head is exactly parallel to the top of the bed otherwise the small read head will be going up and down inside and maybe be causing damage. You do really need to get them spot of if at all possible. I left the small transit clips in position when fitting and leveling other heads, bolting the small heads to their carrier brackets after the large one is completely parallel, then you know things won't cause a problem.

Because you have covered up your cross slide locking screw with the read head, you will need to do this mod if you want to lock things up.

http://www.atfreeforum.com/chesteruk/viewtopic.php?t=389&mforum=chesteruk

These last two shots are of the extra bits that I fitted to my machine to give me total and accurate control of the cutting on my lathe. They really do allow you to cut or drill to tenths accuracy if you require it.

This one does in fact have a sequence for fitting as when I first fitted it, problems occurred after a short while with swarf settling in the slide grooves.

http://madmodder.net/index.php?topic=1938.msg20503

I do hope that this has helped, and if you need any further more technical info, don't be afraid to ask.


John

 

[Blogwitch]

Just a little note on scale sizes.

The small ones weren't available when I did my conversion, they were only just being thought about importing.

The medium size ones are perfectly fine and no benefit would come from fitting the smaller heads, other than your wallet will be emptied quicker, as it seems the smaller you go, the more they cost.

The big one at the back is a no brainer as there is masses of room there.


John

 

[petertha]

Thanks so much John, those are very good reference pics.

Presently, to re-position my compound (ie rotate to a new angle or completely remove it) I loosen 2 socket screws that thread into kind of t-nut plates inside the cross table. I use a hex wrench for that. One of the issues I was wondering about was how to get at those screws with the DRO scale lying accross that area. I see on yours you have what looks like a stud coming from below with nuts on the top side. Did you do a retrofit or was that the original configuration?

 

[petertha]

Looking at your y-axis cross slide, I see you put the scale on the tailstock side. Im guessing that makes more sense from a swarf & debris standpoint vs closer to the chuck. Im not sure if my lathe is the same but I have 2 holes in the casting on the headstock side. Im not even sure what they are for, possibly threaded? I was considering attaching the DRO business there. Now Im not so sure. I will have to mock this up with some wood blocks or something. Hopefully my pics make sense. Blue = scale rod, green = mounting plate, red = dro reader head.

 

[petertha]

The x-axis looks straighforward & similar to yours. More room back there.

 

[metalmad]

Hi Pete
I have an idea those existing holes are for the Steady rest, so I guess if you ever plan to use it then you will need them.
Pete

 

[Blogwitch]

Peter,

The topslide came with that configuration.

You have a lot of room at the back, maybe you could move the read head further to the back of the cross slide casting, to allow you access to your screws. As long as the read head doesn't hit the backsplash when fully back, then it would be fine. I have seen that setup on some Myford lathes.

As Pete has said, those two holes are for mounting your traveling steady. I did a feasibility study on moving the head to the headstock side, but found it too risky, a chuck holding a big lump with the jaws sticking out of the side would almost certainly hit the repositioned head, so I decided to reposition the lock, it was safer. Also, if doing faceplate work, it could, under certain situations, get in the way.

Your method of trial using pieces of wood sounds like a very good way to try it out for fit before buying.

BTW, the X & Y scales were factory fitted, I only fitted the extras on the topslide and tailstock.


John

 

[petertha]

As Pete has said, those two holes are for mounting your traveling steady. I did a feasibility study on moving the head to the headstock side, but found it too risky, a chuck holding a big lump with the jaws sticking out of the side would almost certainly hit the repositioned head...

Ah, thats what the holes are for. I use the steady so rarely I forgot. Those are very good points. I can see its more desirable to locate the DRO head on the tailstock side one way or another. Were you able to drill the necessary mounting holes in the casting with the lathe assembled (approx orange arrows)? Or did you already have usable holes there?

On my mill DRO fitting I decided to made some drill bushing that were clamped into position, just to be safe & accurate. Although the cast iron wasnt too bad with a hand drill, it was awkward to get much force onto the bit, it was just kind of an awkward position & irregular surface. This kind of looks the same issue on the lathe. Another thing to test beforehand with a drill. Otherwise its pull-apart-lathe time - ugh!

 

[petertha]

Because you have covered up your cross slide locking screw with the read head, you will need to do this mod if you want to lock things up.
http://www.atfreeforum.com/chesteruk/viewtopic.php?t=389&mforum=chesteruk
John

I somehow missed your link on the cross slide hold down screw the first read through. Another important consideration. Thanks for pointing out the details.

 

[petertha]

John I see looking at your other link you have similar hold-down nut plates, what I was talking about in post#7. So did you subsequntly make these into T-studs in order to have a removable nut... in order to be able to loosen & clear the DRO?

 

[Blogwitch]

Peter,

My lathe came with those T studs already fitted, but I don't see as how yours will cause a problem anyway.

I have drilled these lathe castings a few times with an air drill, but that could just as easily have been a normal electric hand drill, and the cast iron on mine was like drilling butter, very easy.

I personally would just take the cross slide off, it only takes a few minutes, then everything can be accurately drilled on your mill, if you have enough throat depth to cope with the width of the cross slide casting.

As I have stated before, I didn't fit these two read heads that you are considering, they were done during the manufacture of the lathe. I have shown you how they fitted them. I only did my topslide and tailstock DRO's.


John

 

[doubletop]

John

I'm convinced those units are smaller than those I had supplied from my mill, at least those on the top and cross slides. Any chance of a close up of the labels on the heads and the covers please?

You've got two x two axis displays there. As you fitted the tail stock scale, did the machine come with top slide and cross slide scales and you fitted the saddle scale?

If I was to go for a 3 axis system what would you recommend , topside, cross slide and tail stock or some other combination?

Pete

 

[Blogwitch]

Pete,

I will try to get a couple more pics for you.

The cross slide and main saddle were fitted by the factory, I fitted the topslide (compound) and tailstock.

If I had to choose, the topslide would be the one I would go for, purely because you could lash something up with a digivern for the tailstock.

As I have already explained to you before, I ALWAYS have my topslide exactly parallel with the ways except when screwcutting or taper turning, purely to keep the tips of my tooling at the designed angle of operation. Doing it that way also ensures that the displayed cut on the DRO is exactly what will come off when I take the cut, if it is at an angle, then it would not be the case when taking any cuts, and I do do super fine facing cuts to get my jobs exactly on length, or if doing say finning work, I can get them exactly the same pitch and width.
I use a combination of saddle stop and topslide to do most of my shoulder cutting from the end face as well, I find it much easier than trying to move the large saddle in by tiny amounts.


John

 

[doubletop]

Thanks John

Interesting that the factory fit is cross slide and saddle, I would have gone for the cross slide and top slide as first choice for the same reasons. Saddle to me would be a nice to have I see myself rarely using the full between centers distance.

Pete