Member postings for David Littlewood

JP,

The Q-Cut has a 12 mm shank, but it is quite easy to get the right height in my S00 (Myford size) Dickson setup.

I have a number of Glanze tools, including a slightly larger version of the Q-Cut, on my M300. They are OK, but don't have quite the same quality. The toolholders are not bad, but the normal turning tips seem to break more easily. Having said that, my Glanze parting tool parts off fine under power XF on the M300, which is of course a much bigger and more rigid machine.

Any parting tool will leave a pip somewhere. With HSS tools, you can make it be on the stock side by grinding the front of the tool at a slight angle - but then you will have far more problems as the tool will be pushed sideways on its way in.

Parting off with a tailstock support is not recomended; you can use one part way into the cut, but don't forget to remove it for the last bit.

David

Edited By David Littlewood on 21/01/2013 23:05:17

I'm not sure a milled finish will ever be the best for anodising; it therefore could be worth taping a large sheet of very fine silicon carbide paper to the bench and cleaning up the surface on that. This should remove any very minor discontinuity mark on the finish. Won't remove a palpable step, but with care you shouldn't get that.

David

JP,

Assuming your ML7 is not completely clapped-out, you should have no difficulty parting off if you follow these simple steps:

(1) Buy one of these: **LINK** This is by a large margin the best parting tool I have found at this size, and I tried quite a lot before I found it. The shape of the tip is the vital thing, it curls the chip so it is narrower than the gap, which totally avoids it jamming in the gap (the cause of many of the problems, especially with steel).

(2) Set the tool up in whatever you use as a toolpost - it ought to be as rigid as possible. And - this is most important - make sure the tool is exactly square on to the lathe axis.

(3) Locate the tool where you want the cut to be.

(4) Lock all the slides you can, other than the cross slide.

(5) Select a fairly low speed. In the bad old days, using old-style tools, I used backgear, now I just use a low direct drive speed.

(6) Switch on and advance the tool into the work. Don't hesitate, feed slowly but firmly (having the tool rub does nothing any good - and for work-hardening materials like stainless steel or titanium it is disastrous). For mild steel, drip feed neat cutting oil on to the work - every few mm of cut should be enough. For other materials, use oil or not as suits the material (dry for cast iron or brass, paraffin for aluminum, neat cutting oil for most others).

If this does not work well, your lathe may need a check-up.

I have a rear toolpost, but with this set-up I have never found it necassary, and it is a PITA to have to use it so best avoided. Incidentally I use a (genuine) Dickson QC toolpost, and although some people worry about the rigidity of these for parting off, I find it works fine. I don't have power cross-feed on my Myford, but I do on my Harrison - and with a larger version of the above set-up I regularly use PXF for parting off; works like a charm.

David

Edited By David Littlewood on 21/01/2013 12:56:18

Well, steam is still water (H2O), and I imagine the writer of the regulations had to use some figure which was capable of measurement. If you fill the boiler with liquid water it is easy to determine its capacity, but if you try to define some arbitrary typical usage level it would be impossible to have a useful definition.

David

Edited By David Littlewood on 20/01/2013 19:15:39

It is my understanding that the 600 Group still makes machines in the UK, including Harrison lathes. They did move production to China a couple of decades ago but there were quality control problems and they brought production back here. Mind you, if you need to ask the price you probably can't afford it!

David

Ron,

I have taken ME for about 40 years, and also MEW and EIM since their first issues. I would say that over the last 10-15 years there has been far more in MEW to interest me compared with the other two; MEW covers general workshop techniques, and the making or improving of workshop equipment. ME, since the start of MEW, has concentrated almost exclusively on projects, most of which you will skim through but get little from. EIM is rather similar, but with a few general workshop articles.

I think the problem from the beginner's point of view is that most of the "good" stuff is in MEW's past, and quite a lot of the articles now are on rather abstruse projects you will not be equipped to do. There are however some quite good series for beginners. Personally I think your best bet would be to watch eBay for a set of MEW and read the back issues, and start a planned program of buying key books.

On books, I can't really comment on the basic ones of recent years as I progressed beyond them before they came out. A basic lathework book and a basic milling book would be good. I agree with Peter that anything by Tubal Cain (Tom Walshaw) is worth reading, and recommend his books in the Workshop Practice series (Drills Taps and Dies, Soldering and Brazing, and Workholding in the Lathe spring to mind). I disagree with Peter about the G H Thomas books; they have probably been the ones having the most influence on me, at least, and I go back to them time and time again. True, the Workshop Manual is mostly based on Myford 7 lathes (which is what GHT used) but the consummate engineering expertise in there is worth anyone's time.

But, whatever you choose to do, have fun, find out what you enjoy doing most, and learn to do it better. To paraphrase Dumbledore, help will always be given here for those who ask for it.

David

Edited By David Littlewood on 18/01/2013 23:28:10

Jason,

The deflection of a solid round beam fixed at one end and loaded at the other is proportional to L^3, so doubling its length will increase the deflection by a factor of 8.

The formula is Y = 64*F*L^3/(3*pi*D^4) where Y is deflection, F is applied force, L is length and D is diameter.

For a hollow round beam, replace D^4 with (D^4 - d^4) where D is outside diameter and d is inside diameter.

The formula is different for other cross sections; a Google search should lead to the answer for anyone interested.

Incidentally, this shows why (a) stub length drills are so much stiffer than standard length ones, and (b) it's always worth swapping your small boring tool for one of even slightly greater diameter as soon as it will fit the hole.

David

Edited By David Littlewood on 17/01/2013 01:46:09

Phil,

Try Lee Springs: **LINK**

David

Jason (B),

Very neat piece of work! I take it you made them in one piece, so no soldering will be necessary. How did you get the splendid elliptical shape so neatly, CNC?

David

Ray,

Please post your photos one per line; if you post them side by side this stupid forum software stretches out the text on everyone's popst and takes it under the pesky advert strip on the right.

Jon,

The FB" has a gib strip bearing on the side of the locating bar and is adjustable by screws in the normal way; the column, being round, provides lateral location, and in the (unlikely) event of wear can be adjusted by means of a vertical slit and two stout clamping bolts.

It works!

David

I mounted an AET diamond wheel in my Clarkson a couple of years ago and it ran true without any adjustment. Worth a try!

David

Jon,

The FB2 has a rectangular guide on the LH side of the column, with a corresponding groove in the head, which is fitted with a proper gib strip. In over 25 years of using it I have found it remarkably good at maintaining the head alignment on moving the head up or down.

Not sure I understand your other question. There is fine feed, by which the entire head is moved up or down the column (and to which the DRO scale is attached), and a hand-feed quill for drilling, the handle for which can be seen on the last photograph. The latter has a movement of 40 mm and can be locked with a lever when miling.

David

As promised, a picture of the Z-axis scale on my FB2.

Unfortunately it doesn't show the fixing of the read head very well, and it's a bit hard to get a camera round there. I'll try again later.

David

I mostly disagree. A set of drills will cost you less than buying them individually, and you will always find you need a size you do not have if you follow this advice. Personally I'd go for metric drills, start with 1.0-6.0 x 0.1 mm (important - don't go for the x 0.5 mm sets, the gaps are too large) as you can do almost anything with them, within that size range. For collets, perhaps the position is less definite, but I'd still recommend you go for a complete set of ER collets in the size appropriate to your machinery (usually ER25 or ER32) plus appropriate chucks.

I do agree though on the lathe tools.

David

Like many others among you, I bought a couple of lengths of the excellent bronze bar from Jason Udall. I thought it might be interesting to invite you to share any interesting things you did with it - if nothing else, it would be nice for Jason to know that he wasn't wasting his time.

In fairness, I'd better start. The only thing I have had time to do so far was to make a roller for an anomalous climbing novelty.

The double cone was of course made by sticking two cones together. The cones have an included angle of 40 degrees. I was a little concerned about how to locate them; then I realised that there was a nice 1.03 mm pip left from parting off. I drilled a 25 mm hole in a piece of softwood with a wood bit, which was just enough to hold one cone to drill a 1.1 mm hole. Glued with Araldite, baked in oven at 65 degrees for an hour, which made it harder than I would have wished and was a b****r to clean off.

The lash up in the first picture is just to work out the necessary settings to enable the cones to roll "upwards"; broadly making the two bars (silver steel in this rig)  diverge more is positive, increasing the slope is obviously negative. You either have to work out the maths or do it by trial and error. I have embarked on making a nice oak stand with stainless steel bars.

Bronze is ideal for this purpose; it turns well, looks nice and does not stain badly. Brass would need to be varnished to avoid this, or be polished every few days, and I think varnish would not help the rolling.

David

Edited By David Littlewood on 09/01/2013 19:41:18

David,

Sorry to see you go, it has been good to have an editor who put so much effort into keeping in touch with their readers. Is this (near) retirement? Whatever, best of luck in it.

David

Colin,

As requested; let me know if you would like bigger copies PM'd to you.

Y-axis scale

X-axis scale

Note the stop at the base of the column, which is to protect the X-axis scale from contacting the base and possibly suffering damage. It does limit the Y-axis travel slightly, but I have only found this a very minor inconvenience which I have always been able to work around.

Though I bought a 3-axis system, I didn't fit the Z-axis scale until a few months later, so I don't have a decent photograph of it; I'll try to get one posted later. It was a little more fiddly to fit as I had to fabricate brackets at top and bottom, but I was able to do this fairly easily from the generous supply of Al brackets supplied by Allendale/Machine DRO.

BTW, although the Z-axis is (obviously) of little use when drilling, it is invaluable when milling, and I would say that without it the system is missing half its functionality. I recommend anyone to get the proper 3rd axis scale; it is better to have them all visible on the same monitor, and the position of a Z-axis scale is necessarily a little exposed - at least on this machine - and it needs to be robust and well protected.

David

Edited By David Littlewood on 08/01/2013 16:39:33

Paul,

I fitted a Sino 3-axis DRO (from Allendale) to my FB2 mill a few years ago; it has worked faultlessly and has transformed my ability to do precision work. I would personally never bother with those cobbled-together systems using recycled digital calipers and the like, but I appreciate not everyone can afford the proper stuff.

My own feeling is that a DRO is far more useful on a milling machine (for both milling and drilling) than on a lathe, since when one needs a precise diameter on a lathe one normally approaches slowly and checks with a micrometer.

David

Edited By David Littlewood on 08/01/2013 02:30:36

KWIL,

OK. I think was confused by Brian's reference to a "tailstock foot adjusting screw" as I thought that meant the bed had two feet. The danger, I suppose, of commenting when I don't know the machine in question. The advice (corrected!) is good for bipedal lathes.

BTW, there is no guarantee that a cantilever lathe bed is not twisted - maybe through use of unseasoned castings - though how one corrects it is a different matter.

David

Thor,

You are quite right, I said it the wrong way round. If the cut at the tailstock end is larger, the front of the tailstock foot needs to be shimmed up, to bring the tool nearer the piece. Thanks for correcting me.

Serves me right for writing late at night after sharing a bottle of wine with dinner!

Brian,

If the ML4 has two mounting feet, then I disagree with you; it is IMO far more important to remove twist from the bed than it is to align the tailstock by twisting the bed. The former affects everything, the latter only when you use the tailstock. It is in any case hard to see how a non-adjustable tailstock could get out of adjustment, but if it is out I believe it would be far better to put it right properly by scraping and shimming the locating part. Correcting one fault by deliberately introducing another (twist) is hardly the way to getting things right.

David

Edited By David Littlewood on 06/01/2013 12:06:06