ML7 questions

Is there a guide to centering tools to workpiece using a quick change tool post?

I guess the same would apply to using a DTI at initial setup in a tool post?

There is a picture of a DTI in use in the manual but I could not find a device to hold it, not of the shelf.

There are a few ways that a lathe tool can be set to centre height.

One way is to face the end of a piece of metal held in the chuck. If a pip remains, the tool is not at centre height. Retract the tool, turn off the lathe, adjust the tool either up or down by about half the pip diameter and try again until no pip remains.

Alternatively you could use a steel rule trapped between the tip of the tool and the workpiece. With the lathe off, hold the rule vertically against the workpiece, gently (so as not to damage the rule) feed the tool in trapping the rule between the tip of the tool and the workpiece. If the rule leans towards the back of the lathe, then the tool is too high, if it tilts forward then the tool is too low, the rule will be vertical when the tool is at centre height .

You could also consider making a centre height gauge. Not only would you end up with a useful tool, but could also be a worthwhile learning experience. Geo Thomas described such a gauge in the "The Model Engineers Workshop Manual" a book well worth seeking out. Hemingway also do the gauge as a kit seen here

Clive

The heading of this thread is "ML7 questions" so hopefully Brainsparks30 won't mind me jumping in with ML7 related questions of my own.

I recently purchased a late model (1973 - 1975) ML7 in really good condition at a very reasonable price. Although it came with a reasonable complement of accessories, 3 jaw chuck, vertical slide, steadies, etc, none of the standard tools came with it nor a bench.

Currently the lathe is sitting on a dolly in the garage while I contemplate where to mount it. As Myford stands are scarcer than hens teeth in this part of the world, Western Canada, I will likely end up having to make a bench myself.

As I want to be prepared so that I can get up and running as soon as the bench is ready, I would like to order the necessary tools sooner rather than later, so I was hoping that someone could let me know what tools are needed and what they are actually used for?
All I know is that there should be a few allen keys, some spanners and an oil gun. I have ordered the manual and the Ian Bradley book, but thanks to a recent strike at Canada Post I am not expecting to receive these anytime soon.

Regarding the oil gun, I have found a few threads that discuss it on this forum, but these have left me more confused than ever, surly it can't be that complicated, but the thought of buying the WANNER from Myford for £60, which would be more like £90 by the time I have added postage and import duties, is not very appealing.

Thanks,
Clive

Hi Clive, for the oil gun look here **LINK** This outfit is Pressparts and this oil gun works very well, I have two simply because we have 2 Myford in different locations. They are pretty much leak free and work better than the one from Myford.

If you don't have them I would recommend making some raising blocks to mount your lathe on, easy to make and they assist in levelling the machine.

John

I don't know if this is any use to you, I had access to an original stand when I worked at an FE college and was able to construct my own from a scrap steel cabinet using the measurements made as the diagram.  I didn't have any metal folding kit but managed to use a thin angle grinder disc to mark the panel to make some "trouser crease" folds and subsequent strengthening/joining with a MIG welder.  I now have an S7 on an original stand as well and my effort stands up quite well by comparison.  

Edited By Don Cox on 06/12/2018 23:34:25

I have had one of these for some time and recently "added" a flat as recommended by Joe Pieczynski of YouTube which makes the fingernail test more convenient - easy to make and accurate enough for most purposes.

Mine is sitting on the topslide but for the ML7 it will probably be best to use the cross slide or bed.

Thanks John,
Good idea about the raising blocks, I am in two minds as to whether to go to the expense of ordering Myford clones, both RDG and Chronos list them, or to make my own.

I attempted to place an order for the Press Parts oil gun but the web site gave me an error when I tried to enter a Canadian address.
An email to them solicited an almost immediate response in the form of a chatty email in which they advised me that they don't ship to Canada, however they do have a US branch that serves both Canada and the US. Shortly thereafter I received an email from the US branch advising me that they have the oil guns in stock and that they could quote me for shipping once they have my postal address.

For future reference, North American residents can find the oil gun here .

Thanks Don,
Good to hear of your success with your stand, although I must admit that I find the thought of doing any sheet metal work a little intimidating. So I am contemplating either a wooden bench or an angle iron frame with a wooden top. My lathe came with a rather dinged up chip tray, it is much shallower than the original Myford ones but after a bit of "panel beating" I am hoping that it will serve its purpose.

Clive

+1 for making a Centre Height Gauge. A great saver! of time and frustration when changing tools. (thinking in terms of toolposts, other than QCT types, although it helps in setting up those for the first time)

With regard to a bench for a Myford ML7, I would suggest, if wooden, that the wood is substantial and that the top surface is steel. The Myford ML7 bed is not very rigid, so raising blocks, (Myford or shop made) will be a help in removing twist from the bed. (A Hobby horse of mine!).

Howard

Is it really that useful?

I just use my digital height gauge, having put a label on the lathe with the height from both the bed and carriage. Saves having to store a tool that I might use a couple of times a year, let alone making the thing in the first place.

A centre heigh gauge was about the second thing I ever made after I bought my own ML7 (lived 225 miles away from dad's one). Just a bit of 3/4" brass bar with the diameter turned down to 1/2" in the middle and a flange left at the top, with it's base at the correct height for the tool. Before long, I turned some shims (mounted on the face plate) to the right thickness for most of my tools, so I knew that a 12mm insert tool with the shim marked 'M' would be at the right height, the parting tool wanted shim 'L' etc..

Nowadays, I use a Multifix tool post in the HLV lathe and just line tools up with a headstock or tailstock centre, depending on which is more convenient, when setting the tool holders. Very occasionally, I'll adjust a newly mounted tool slightly after facing to the centre to get exactly the right height.

Yes, a Centre Height Gauge really IS that useful.

In my shop it gets used every time that a tool is changed, or sharpened. Using a tool that is off centre does not give optimum cutting or surface finish.

Having measured the eccentricity, and maximum height of a round bar, (Silver Steel of known diameter) those doimensions are allowed for in setting up a pack of slips, to which the gauge is set.

Occasionally, I have even found that changing a carbide tip can mean that the edge is very slightly off centre, (with a clean holder).

Maybe I am too much of a perfectionist, but I do not want a pip of any size on a faced component. Where I was trained, and the other Companies for which I worked, "near enough" was not good enough.

Getting it right first time is usually a lot easier than putting it right later on after things have gone wrong.

Howard

I use a digital height gauge also. Using CNC with calibrated tools, all the tools need to be at centre height for the offsets to work properly at all radii. The only way I have found to do this accurately is to measure the height and keep adjusting it until it measures right.

If you have a gauge that has a gauge surface above the tool, it is difficult to guarantee that the tool isn't a bit too high and slightly lifting the gauge.

So I use the height gauge, lowering the measuring bit until it touches the cutting edge while holding the gauge firmly down to the bed.

To measure your exact centre height, turn a short length of bar to say ~12mm dia, measure with a micrometer whilst still in the chuck, divide by 2 to get radius, then use height gauge to measure to the top of the turned length from the bed and subtract the radius. For my Super 7 the answer was so close to 76.2 mm (3.5" as to make no difference.

Hi there, Clive,

As nobody else seems to have commented on spanners (aka 'wrenches' ), here's my two penneth:

The rule of thumb on most ML7 machines is that all threads below ¼" are B.A. and all threads of ¼" or bigger are B.S.F.

Best regards,

Swarf, Mostly!

Thanks Swarf,
That is handy to know.

I don't know how easily I will find BSF spanners in Canada, but hopefully will be able to find a combination of metric or AF inch wrenches that will fit the few bolts that need a spanner.
Regards,
Clive

(I used to know only one word for many things; bonnet/hood, boot/trunk, spanner/wrench etc. Now I can never remember which word to use where).

Ohh this is good! I saw that on an end before but did not know it could be done this way too.

I rummaged through all the bits in the box that came with the machine and found what looks like a home made height gauge. Need to calibrate that too.

Your normal inch spanners will work fine with BSF bolts.

It's Whitworth that you have to experiment with

Whitworth and BSF spanners are the same.AF spanners do not fit BSF , some metric ones might fit.

If all else fails, you could measure the A/F sizes of your hardware and then make your own. End Mill, or Slot Drill in Chuck, workpiece clamped in Toolpost, and away you go. (Even better if you have Milling facilities available)

My turning instructor made his rectangular cigarette lighter whilst working on capstan lathes, so it can be done.

As soon as I bought a ER25 Collet Chuck, I used the Rodney milling Attachment on the ML7 to make a spanner to hold the shank whilst the C spanner dealt with the clamp nut..

Engineers should be ingenious

Howard

Thanks for the replies Nicholas, Maurice and Howard,

To be honest, I don't really have much interest in trying to make something as utilitarian as a spanner, I would rather spend the time working on my loco. Besides which, even with considerable effort, I very much doubt that I could achieve anything nearly as durable as a cheap off the shelf drop forged spanner.

So It looks as if I will have to order the spanners from the UK. There are a few other things I am already planning on ordering so hopefully they will not add on too much to the postage.
The ML7 manual I have shows 2 spanners as part of the standard equipment but does not mention sizes. So please if anyone knows what sizes I need to order, I would very much appreciate it.

I guess that the allen keys are standard inch sizes ... or maybe not?

Thanks,
Clive

Edited By clivel on 12/12/2018 15:38:29

Unless it is a fairly recent Myford, I would expect all Allen screws and hardware to be Imperial, (BA for things like Gib adjusters) A 1/4 BSW spanner will fit a 5/16 BSF fixing, and so on. (Unless some previous owner has "done their own thing", in which case it could have been converted (Bodged in my book)to Unified, or Heaven forbid; to Metric!

If the machine has been modified in this way, it may be possible to return to original fixings by making bushings with the Imperial thread ID and non standard OD, such as an oversize Imperial thread.

You MAY find that some Metric spanners will fit Whitworth standard hexagons.

Howard