ML4 setup

[bazmak]

I think a laser would be a waste of time,not accurate enough.You would be better by eye with a loupe. Can you fit push/pull screws for front to back
you would have to shim for vertical.A fe photos as a reminder what i did
to my small sieg.Also give us a few photos so we can make comments
If you have flat ways can you fix a central plate to the u,side to keep the setting when you have obtained it

 

[goldstar31]

I think a laser would be a waste of time,not accurate enough.You would be better by eye with a loupe.
/QUOTE]

When I DID my City and Guilds some 30+ years ago, we used a laser alignment jig. Alan Robinson- Repair of Vehicle Bodies- Gateshead Tech- Thatcham and all that. Presumably we can do better than that but we were told that our alignment techniques adopted were better than some manufacturers used- on the production line.

As for machine tools, the laser accuracy obtainable is phenomenal-- and EXPENSIVE.

For us more lowly mortals, I recall Peter Rawlinson writing in Model Engineer and making peep holes in children's cheap lasers. Somewhere in my filing system, there is a pass to use a computer program by a Mike Trethewey(Sp?) but 'he's gawn alas like a youth too soon'.

Now I have to settle for a laser on my cheap jack saw bench and my jigsaw in the wood butchery department.

I rest my case- as it is heavy!

Cheers

Norm



Added


CentreCam but probably wasn't a laser:wall:

 

[JCSteam]

Hello guys, here's some pictures of the tailstock so you can see what adjustment is there, as mentioned there is an inherent flaw in that there is no mating surface to reference the tailstock.

The rough sketch I did was for a new plate for the rear, instead of one that's only 4.5cm wide, it could be the same length as the tailstock casting, giving more stability, for even more accuracy, holes drilled and tapped, and fitted with a tie rod adjustment system would be able to hold the setup more accurately in position each time. I will still need a new gib strip for the front, so my thoughts are to make a plate for the back on which alignment can be roughed out, then the gib strip at the front failed in to fully align the tailstock. Does anyone think this will work or am I over complicating it.

Baz the ways are unfortunately not machined in the middle, it's just the rough casting so wouldn't line up properly each time, unless the middle portion was also milled out.

 

[goldstar31]

It appears to be solvable with a corollary of the 5th Proposition of Euclid.

It should be noted that I have earlier spoken of this gentleman!

N

 

[JCSteam]

I be-cleeve you have Norm

I know there's an article on setting it up somewhere, just havent got the article yet, though impressed at getting my lathe to turn to within a thou, just got to get rid of that last thou. A little more setting up and checking, (without a tailstock for now).

 

[bazmak]

if you can get to 1 thou then be happy.That last thou is difficult and you cant hold it.On small cheap,old benchlathes dont try to obtain accuracy to Nth degree.You are for ever chasing your tail

 

[JCSteam]

if you can get to 1 thou then be happy.That last thou is difficult and you cant hold it.On small cheap,old benchlathes dont try to obtain accuracy to Nth degree.You are for ever chasing your tail[/QUOTE]

Yep that's the issue I'm trying to sort next!

 

[JCSteam]

An explaination of how to set up a tailstock from Brian Wood.

Setting the tailstock alignment on an ML 4 lathe
Ideally the method needs a 1MT test bar, the actual diameter of the plain parallel section is not important other than being a minimum of 3/8 inches. Also needed is a decent three jaw chuck with self aligning jaws, one that can be really trusted for true centreing. And finally, a sensitive DTI mounted on a magnetic stand.
Fit the chuck to the spindle nose and fit the test bar to the tailstock barrel. Slacken all the soleplate screws on the tailstock and the clamp used for gripping the bed
Slide the tailstock so that the test bar enters the chuck as close to the section just beyond the M/T taper that can be reached over the saddle and gently close the chuck jaws to grip the bar. A decent bar is hard enough to resist any marking from the jaws, but neither do they want closing up hard.
The tailstock barrel and headstock spindle should now be correctly aligned with each other. Set the DTI up off the cross slide, offer it up to the exposed section of the bar and zero it.
It is now a question of tightening the tailstock sole plate screws to avoid straining the alignment just achieved and testing that by easing the chuck jaws to watch for bar flexure on the DTI. Repeat the alignment procedure if necessary until satisfied with the result. Finally, test the effect of the tailstock clamp to check for DTI movement when that is clamped.
Some notional movement may be inevitable with this final test, in which case it might be helpful to note by how much.
For putting on a taper turning offset to the tailstock in future, a short dead centre turned to fit a tool hole in a boring head fitted into the tailstock barrel is probably a lot easier to work with than upsetting the alignment achieved above.
In the absence of a test bar, a fair substitute can be made with either a long Morse taper drill or machine reamer. They should not be slender in cross section; at least 3/8 inch diameter is suggested.
i. Myford themselves would have used a production line aid to simplify setting up these lathes; it was very probably a hardened bar, perhaps 12 inches or so in length, with Morse tapers on both ends so that socket to socket alignment was made. In use, the headstock would have been aligned to the bed first and then bolted down, followed by the tail stock soleplate setting. Any over height tailstock would have had the top surface of the soleplate scraped to fit; low versions would have been shimmed.

Brian Wood 2016

Thanks Brian 😉

 

[JCSteam]

I have gone about it another way, and I've a video which demonstrated the frustration in setting it up. In that there are three items that can all influence the angle of the tailstock.

So I put a piece of rust in the three jaw and mounted up a R/H cutting tool, I set the compound over as far as I could and turned a point onto the bar, this makes a reference point for center hieght, and eliminates if there is wear in the taper of the spindle.

Once a point was turned the tailstock received a MT1 dead centre. Since all tools will have a taper connection to this part then it seems logical that if there is wear in the tailstock then this must be taken into account. A reamer in the chuck would be a better idea but im not that brave yet, or confident about it's alignment.

The tailstock is brought upto the chuck, as far as it'll go, then the quill extended to meet the other point on the turned bar.

Horizontally I look good so proceed to make adjustments to the gun slide, making sure everything else is locked up, (be sure if your tightening the gibs the the clamp has opposite force applied. Ie screwing in the adjuster, will mean you have to loosen the clamp, and visa versa.

With a 6inch ruler between centers, the ruler tells you which direction the tailstock gibs need to go. To adjust the gibs make sure the bolt on top is slackened slightly to allow movement, and tightened back up after before proceeding to make adjustment to the other screw. Once you are happy that the tailstock is centred, move the tailstock up the bed, and extend the quill as far as you can, low and behold a different reading, and frustration en sues, what I did was adjust half of the difference of the duller with one screw, then the other half with the second screw. If your lucky when you move it back to the first position you'll be darn close to level, I was using the dovetail on my saddle to determine where I needed to be, and the whole thing was done by eye.

Video will be uploaded to YouTube and posted later today, just to give some insight to the daft design.

 

[JCSteam]

Here's the frustration of the ML4's tailstock

https://youtu.be/RIclNqCD50w

 

[JCSteam]

 

[JCSteam]

Done a few bits today, things that have been bugging me. Firstly the dials would not rotate, on the feed screws for the cross slide and the top slide, so instead of dialing in a dimention I was adding subtracting ECT. Which was a bit of a pain.*

I disassembled it and cleaned the parts before lubricating with light oil, the metal washers were firstly rubbed on some fine wet and dry with oil, then on a stone to remove any sharp edges.*

The parts were reassembled as above all recieving *a light dose of oil to stop corrosion. A small flat blade screw driver was inserted to the rear of the dial so the nut could be done up. The tension on the dial, (or resistance for turning), is adjusted by how tight this nut is. The handle was then screwed back on and the same was done for the cross slide.

Story of the apron and lead screw to follow....

 

[JCSteam]

I had removed the shims that were under the lead screw bracket at the change gear end, by them been there it meant that the alignment of the change gears and the lead screw was been thrown out. Plus it looked ugly and I didn't like it.*

Once all was cleaned back up and the grime removed. The bracket was bolted back in place.*

The disadvantage of this was that now the lead screw didn't line up with the half nuts and was pulling the lead screw 80thou from centre, not good for a smooth gear train.*

I loosened the screws off the saddle which hold the apron in place, cleaned the underside of any muck, and remounted the apron. Just this adjustment halfed the amount of deflection on the lead screw to 40thou. I began to think how I could make this better, and I thought to shim one side of the apron to tilt it into the lead screw. I started with one of the shims removed from the bracket. This was 16thou. By mounting this to the outer edge it tilted the apron at the bottom into the lathe. This removed all of the deflection on the lead screw. But the lead screw jammed and was stiff to turn.*

Next came good old beer can. Beer cans are made of 5thou thick metal and make for a great packing material. Two strips were cut. And mounted under the edge as before. This gave a deflection of just 15thou, but the leadscrews was free to turn when the half nuts were engaged.*

You can just see the two 5mm strips of beer can under that saddle. The deflection now reads 15thou, but since it's so smooth the length of the bed I'll leave it alone.

It did however present another problem in that the gaurd for the lead screw now touched the rack, so that was removed and the offending edges that touched filed off.*

 

[JCSteam]

I also tried a rudemetary way of aligning the tailstock. Using one of the largest taper drills i have, (think it's 7/8") mounted in the tailstock. The quill was extended out as far as I could and the gib adjusters loosened off. The drill was fed as far into the chuck as I could get it, and the jaws nipped up, not locked tight just nipped up. Then the gib was brought to mate with the ways and tightened, the clamp at the rear was then loosely tightened. Just enough to give some pressure to the rear. The adjusters were then tightened up making sure the whole setup wasn't moving, and locked into place. I've yet to check it's alignment, but the quill by eye looks to be perfectly parralel to the ways. The worn gib strip is also sitting nice and flat against the ways, whereas before it was slightly tilted.

 

[goldstar31]

I've been looking at your feed screw dials and wonder whether the engraved '80' was the limit-- and didn't go further to say 100 or 125?

If it is 80, it's wrong because there is no commercial thread which will give 80 divisions. The nearest, correct me if I'm wrong, is 12 which approximately 83.5 divisions- and not 80.

Ho Ho?


Norm

 

[JCSteam]

Nope your not wrong Norm, the thread is 12TPI, which doesn't equate to a 1thou increments in practice. I was already made aware of this when I bought the machine.

It will never be accurate to tenths of thou, as there is inaccuracy built into the machine. It even tells you so in the manual that came with the machine new, which means that one full turn of the handle =0.0833 of an inch. As the dials are indexed to 80 divisions, then each division is actually 0.001041" which when taking a cut means that 0.002082" is removed. Not a terrible problem but once aware of it, it can be compensated for.

I plan to fit a DRO on the cross slide for this purpose. Just a simple vernier gauge and some bracketry that will allow quick removal if needed.

Jon

 

[JCSteam]

I've seen the offerings of RDG tools for small oilers which would fit my lathe and cost less than £2 each.

I thought about buying them and then thought I've got some brass and Ali I might as well make some, I'm wondering what size the hole needs to be at the bottom for the oil to drip into the bearing surfaces. Or would a piece of cotton wool (the type for knitting) work as a wick to allow a drip fed oil system? I have four large ones to make for the headstock and layshaft, and three smaller ones for the lead screw and saddle handle. These will be simple cup oilers not the fancy tap ones.

Thoughts please??*

 

[goldstar31]

You should specify the wickers for basket cases .

woohoo1

N



.

 

[Blogwitch]

Jon,

Check and then double check the size of hole that the lubricator will go into if you are going to make your own..
On early machines with a small oil cup I think it was 2BA and on later with the sight glass, 1/8 BSP.

Whatever wick or hole size you use, make sure that the wick is a fairly tight fit as the head is a total loss oil system, and if things are too loose, the oil will be gone in no time, you need to make the oil last at least a couple of hours.

John

 

[bazmak]

I agree with what you say John however my reasoning would be thus
If the small oil cup is filled say daily prior to lathe use then its not relevant
how long it takes to lose the oil.Once its gone then then the moving parts are lubricated and will stay thus for the rest of the day.Then repeat the following day.I regularly used a guillotine with a piped hand pump system.First thing every morning 2 pumps and that was it till the next day.Same with the lathe
that small cup will be enough for one day