Member postings for Nige

I am having trouble locating engineers studding in 1/4" BSF with the right proportions of thread at the ends to plain shaft in the middle. Is there any reason I shouldn't just use a 1 1/2" piece of 1/4" BSF studding or will it do? The studs hold down the head stock on the Myford ML4 and screw into cast iron with nuts at the other end.

Can somebody explain what the rear sheer is please. I can't visualise what it could be on the ML4!

Question of technique. If I mount a piece in the 4 jaw chuck and bore out the centre so that it will fit the current register on the mandrel, can I unscrew the chuck from the mandrel, complete with the work, to offer up the work to check the fit and then screw the chuck back on and reasonably expect the piece to still be in alignment if it needs a little more machining?

Dave:Thank you, I think it was 1/2" and I will be glad if that s the explanation. I am in the process of ordering something thicker to repeat the test on and I guess I will get more from that

Having got the head stock aligned as best I can for the time being I mounted a piece of EN1A and took a test cut over about 1 1/2" measuring diameter at both ends of the cut after each pass and noting the difference. After 6 or 7 cuts the difference was averaging out at about .001" the narrower dimension was always nearest the chuck.

Not sure what conclusions to draw from this...Good, bad or indifferent ?

NJH: Thanks, something along those lines is on the list of things to make.

JasonB: Thanks, I do have a couple of what I think are reasonable sized boring bars. Just need to get some steel and have a go

Russell: I used your method in the end and got mostly sorted as described in my' Mandrel thread', thank you.

Andrew: Now doing exactly that, cutting stuff

John: Thank you, a lot of good advice there which I am following up slowly

Again, thank you everybody

What sort of 'depth of cut' would you use on EN1A or similar if you were say putting a flat on a cylinder?

Wow. never seen anything like it so surprised at the capabilities!

Dave, has she got a sister

Will/does it cut steel Neil or is it non ferrous metals only?

Water of Ayr stone. It looks like french chalk sticks but harder. I also have some in a tin. Used it long ago for removing very light blemishes from copper and aluminium.

I was looking at the ML4 thinking about how I would make the sleeve to enable me to mount series 7 back plates etc. My concern is how far the machining area id from the tool post. The ML4 has a permanent gap in the bed and with the saddle as close to the head stock as possible while still being fully supported the cross slide edge is 3 1/4" from the rear of the mandrel at the furthest point that i would need to cut. My worry is that 3 1/4" is long way for a tool to overhang that is having to make an accurate cut.

Questions: Should I be worrying about the distance the tool will have to reach?

Can I bring the saddle closer to the headstock even though it means less support from the bed and if so how much saddle overhang might I get away with?

Anything else I should consider?

I will browse Model Engineer in Tescos this morning and see how diverse the content is Much as I like to look at steam driven models I wouldn't want a magazine that does nothing else and I'm hoping ME would be quite varied ?

Edited By Nige on 06/08/2017 09:06:28

Hi Howard: I think the cantilever design of the ML4 bed makes it most unlikely I could effect any twist in the bed, I believe it will be far too stiff. I will get the tailstock lined up tomorrow and then try some test cuts. Fortunately I have a very nice live centre on a MT1 arbor that will fit the tail stock !

The bore on the ML4 is 19/32" so you are right nothing much bigger than 1/2" is going through it and of course modifying the mandrel to take 7 series chucks, back plates etc. wont change that aspect but would make fitting modern chuck tooling, collet chuck etc. much easier. Once I get some actual turning under my belt I will have a much better idea if the ML4 is worth keeping or whether I would be better off selling it and putting the proceeds towards something bigger and/or newer. Have to get on and do some turning

Will I see you at PMES on Monday night Howard?

Thank you Howard. I just need to get in some steel stock and practice turning etc. Also sort out tool height adjustment method but that shouldn't be too much of a problem.

I took the test bar out and cleaned off all the blue and put it back. I mounted a Dial gauge on the cross slide and used a method suggested by Russell.

With the dial gauge at centre height I had put it up to the test bar about 2 cm from the nose of the mandrel and definitely clear of the end of the taper. I rotated the bar and took a note of the highest and lowest readings and averaged them. I then moved the dial gauge to the far end of the test bar, about 10 cm away, and repeated the readings, averaging them as well. The difference in the averages gave me the error in alignment of the spindle.

I had slackened the head stock clamping nut and studs so I could move the head stock by placing a G-Clamp and moving it relative to the bed.

The first test told me the alignment was out by .0232" so I wound the head stock across a bit repeating the readings. After about 10 tests and subsequent adjustments of the head stock I was able to get the misalignment down to .0019" at which point I had run out of adjusting space on the clamp and reckoned I was about there.

Having tightened the head stock clamping arrangements down tight I checked that nothing had moved. As a final measurement I put the dial gauge back against the test bar and slowly ran it along it's the length. I was surprised, and pleased when deflection of the gauge along that length was between .01 and .02 mm i.e. .00039" and .00078" Admittedly I did not rotate the bar and try it again.

Edited By Nige on 05/08/2017 19:26:31

Today I made the tap wrench for the MT2 reamer

Then I put a lot of oil on the reamer, introduced it to the orifice, pushed gently and twisted. I felt something 'give' so repeated the operation. Something 'gave' a little then it all went very smooth so I pulled out the reamer and on inspection found a couple of tiny bits of metal. I put the reamer back and pushed gently but firmly but it all felt smooth, there was no 'cutting' going on. At that point I felt I probably had the taper as clean as I was going to get it. I thoroughly cleaned out the taper. I then put blue on the taper of the test bar, pushed gently into the spindle and twisted it. On removal I could see that all I had was a smooth smearing of the blue; no signs of high spots rubbing it off and vague darker rings where the taper finished at the bottom and at the mouth of the taper.

Nick_G: This advice, which I have had more than once, is what I am doing.

" Why not put a piece of 1" bar in the chuck and take a light test cut along the length of it, say about 4 inches? Measuring the diameter at each end will give you a pretty accurate indication of spindle to bed alignment."

I realise it is yet another method of checking alignment and to be honest I don mind using a multiple of methods as at my level of ignorance every one of them has something to teach me

I need to align my head stock with the lathe bed which is hopefully coincident with the axis of the carriage travel. In doing this I need to test alignment. I can do that before and after the head alignment and both will give me info on how things are set up. Whether or not I am able to make best use of that info is another question.

Thank you everybody for the advice, all of which I appreciate, I now have to get my head round it but I think I am there with the way I will proceed

I want to mount a piece of 3/4" round bar to take a test cut. Is there a rule of thumb that says what length it is safe to have sticking out of the chuck unsupported?

And should I use the 3 jaw or the independent 4 jaw chuck?