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Member postings for Howard Lewis

Here is a list of all the postings Howard Lewis has made in our forums. Click on a thread name to jump to the thread.

Thread: Colchester Student Mk1 Won't Start
07/04/2020 22:58:49

Being bone idle, I just grind the front face by approaching the grinding wheel head on. Hopefully, your parting blade already has clearance built in on both sides. If it hasn't, you need to grind some, but not too much.

You only need to produce some front clearance, effectively about 5 degrees. Too much takes away support from the cutting edge and weakens it.

Stating the painfully obvious, it is important that the cutting edge is on the centreline , and not above it. Tool rubs if you mdo.

Below and it will leave a pip in the middle of the job.

There are arguments as why a rear toolpost is better for parting off, all about the thrust being upward or downward on the dovetails. Have not followed the fight, just found that more dig ins and broken tools happen in the front toolpost. Am now getting so brave that power cross feed of about 0.0022"/rev gets used!

Speeds:

I tend to be cautious and run slower that for turning, about half usual surface speed.  Don't let the swarf build up for fear of jamming the tool on a deep parting cut..

HTH

Howard

Edited By Howard Lewis on 07/04/2020 23:01:45

Thread: Cutting long tapers using homemade top/compound slide
07/04/2020 22:47:57

If you want to turn a long taper, you can offsetb the tailstock (Don't forget to realign it afterwards )

Or you could fit a Boring head in then Tailstock With the slide horizontal ) and use the adjuster to offset a small, specially made centre. No Boring Head,? There have been designs for a Tailstock mounted slide which does the same thing. I think that Dave Clark made one up for his mini lathe and featured it in an narticle in MEW, some time ago.

It might be worth doing a dummy run to ensure that the offset is correct to produce the taper that you require.

Howard

Thread: Colchester Student Mk1 Won't Start
07/04/2020 21:57:39

Glad to see that you are making progress!

Parting off can be a problem. FWIW, I would suggest:

Minimum tool over hang

Plenty of lubrication

I cheat and use a rear toolpost, and being a cheapskate who hates grinding away good HSS, use Zero top rake.

This reduces the chances of a dig in.

For some reason, parting with a back toolpost seems to produce fewer problems that with the tool mounted in the front toolpost. But it may not be possible to fit a back toolpost to your lathe.

Keep a steady, but not hard feed. Don't let the tool rub.

Also, lock the Saddle to minimise any side load on the tool.

HTH

Howard

Thread: Dividing head problem with angles.
07/04/2020 21:46:04

If you need to rotate the table by a set number of degrees, I would suggest that you do not try mixing degrees and use of division plates, for fear of confusing yourself.

The Division Plates and an accurate chart will make it easy to produce the number of divisions that you want, IF it is possible with the three plates supplied with the HV6.

Use one of two methods.

Either use the vernier scale on the handlewheel, and work in degrees;

OR

Divide the required number of degrees into 360. That will tell you how many divisions are required. Then use the Division Plates to produce that number of divisions (Angular spacing )

I made up an EXCEL spreadsheet which tells me if that number of divisions is possible with the Division Plates for the HV6. When an extra number of divisions is needed, the required number is added to the spreadsheet, and hopefully a set number of Turns and a whole number of Holes results. If this does not happen, then that number of divisions is not possible with any of the three plates supplied.

One day I will get around to making at least one extra plate to increase the number of divisions possible.The road to hell is paved with good intentions!

Recently I needed a whole number of turns and 10.04 holes for a job. I decided that when the error had been reduced by a factor 90, I could live with the discrepancy!

ONE WORD OF WARNING

If you have a fairly old HV6, the supplied chart contains errors, and omissions. I found 8, hence the spreadsheet. I wasted a week trying to produce a 13T gear, but kept getting 12 thin teeth and one fat one. For a while it seemed that I could not count. Eventually, I made up the spreadsheet, and the errors came to light.

Needless to say, one of the errors was for the 13 divisions that I wanted!

H T H

Howard

 

Edited By Howard Lewis on 07/04/2020 21:48:10

Thread: Which Lathe???
07/04/2020 11:49:01

Do allow cash for tooling, both for the machines, and for hand tools, Taps and Dies, Drill Chucks, Collet Chucks, Reamers, a bench grinder, a good bench vice, if these are not already in stock.

A cheap vice will be useless, possibly not accurate and will probably break at the least opportune moment. A steel vice will be expensive, but you will only need to buy it once.

You will,be surprised how much you finish up spending on tooling. But you don't have to buy it all at the same time.

Power supply and lighting for the shop and benches can take up capital, if not already in place.

Howard

06/04/2020 20:53:38

For those having problems holding the M6 nuts on mini lathes, DannyM2Z wrote a short article in MEW on making a widget to hold the nuts while they are removed or fitted. It is just a strip of thin steel, with two slits with tin snios, and a little bending.. Easy to scale up for larger nuts.

I made one and it works, so more searching for nuts dropped behind the chuck and into the swarf!

Howard

06/04/2020 12:55:49

Making accessories not only adds to the usefulness of the machine, but greatly expands one's knowledge and experience.

Without a micrometer dial, the old machinists were skilled at knowing how hard and how much to nudge the handle to take a cut.

My old turning instructor could work to within a few thous with a worn 6 inch rule, far better than i could as an inexperienced Apprentice armed with a depth mic!

Howard.

Thread: I once built a go cart
06/04/2020 12:50:56

Do "Elfin Safety" approve of such unapproved, untested and patently unsafe vehicles and practices?

You might hurt yourself! But possibly acquired a better sense of speed and distance in the process?

Howard

Thread: Which Lathe???
06/04/2020 12:45:23

Fitness for purpose will do the job, but not necessarily please the eye. Land Rover Series, 1 and 2 spring to mind.

But a highly polished part will take a lot longer, and may not not work any better than the less refined version.

A Reliant Robin will take you from place to place less speedily and comfortably than a Rolls Royce Corniche, but you should get there.

A machine with a beautiful shiny paint job may not turn any better, (possibly even worse, if the labour has been spent on polishing rather than accuracy ) than a rough looking machine. People produce good work on hundred year old Drummonds, better than a shiny new "built down to rock bottom price" machine.

Ultimately, the criterion, surely, has to be accuracy rather than a high gloss finish in seventeen glorious colours.

Howard

Thread: Overwhelmed!
06/04/2020 12:33:16

Sparey's detail tended to be around the most prevalent hobby lathe, at the time, the Myford ML7. Whilst the details may differ, the underlying principles do not.

It is still a good foundation book.

To it, I would add Tubal Cain's "Model Engineers Handbook". This is a splendid reference book on many aspects of model engineering, and a set of Zeus charts.

As time goes on, you will find a use for many of the Workshop Practice series. Buy each one as the need arises. Over the years, I have accumulated a dozen!

When you get into screwcutting, you may find Brian Wood's " Gearing of Lathes for Screwcutting" a useful addition to the library.

You won't be using the books all the time, but they will be an invaluable reference for all sorts of jobs.

As in making or buying tools, the motto is "Slowly, slowly catchee monkey" Otherwise you will end like me at least one purchase that you never ever use! We all learned to walk before we began to run, and only sprinted later on.

Some accessories will be little used, but invaluable for the odd special job.

Howard

fat fingers strike again

Edited By Howard Lewis on 06/04/2020 12:33:48

Edited By Howard Lewis on 06/04/2020 12:34:52

Edited By Howard Lewis on 06/04/2020 13:01:11

Thread: I once built a go cart
06/04/2020 12:15:56

Two incomplete Stirling engines are not in the same ball park!

Howard

Thread: Homemade Lathe Tools
06/04/2020 12:12:45

Look in back numbers of M E W for the two articles (at least ) on making a Tangential Turning Tool.

A very useful tool, and with only face to grind, easy to sharpen.

By hacksawing off the flutes, suitable MT shank drills can be turned, quite literally, into centres.

An extra, double ended (One male, the other female ) centre will be extremely useful for centering work in a Four Jaw Chuck. Bit of a chicken and egg job to get it accurately centred, perhaps?

You can make yourself a tool for turning radii, balls or concaves .

Every one of these projects will add to your store of confidence and knowledge.

Howard

Thread: Which Lathe???
06/04/2020 12:02:52

For many years my ambition was to own a Myford (mainly because it was the only hobby lathe of which I was aware. I had operated DSG, Edgwick, herbert and Ward in Industry )

Finally I got one, but the design was over forty years old, and I found limitations, for what I wanted to do. So, perhaps it was not the best choice. Before it went, it had been fitted with Long Cross Slide, Fourway Toolpost, Swivelling Vertical Slide, Rear Toolpost, Micrometer Dials, a new countershaft and bushes.

On retiring I bought a larger far eastern machine. It has a number of features that the ML7 lacked, and came fully equipped, fitted with a VFD, at a quarter of the price of a new equivalent Super 7 Sigma, which lacked power cross.feed.

Over the last 16 years it has done all that I asked of it, and some things that were imagined to be beyond it.

Yes, there were a couple of silly minor, not insuperable, problems, and I have made one or two small mods, but overall it it suits me.

It will not command the price premium of a 7 Series, but does what is required. A carthorse perhaps rather than a steeplechaser?

Most of what I do could still be done on a ML7, but at the expense of wasted chucking pieces, and less conveniently.

Fantastic work has been, and is still, done on Myford 7 Series lathes but I have few regrets over my choice.

Everyone must decide what is most important and buy the machine that seems most fit for their purpose.

Howard

06/04/2020 10:03:52

STEVEIGTR

If you are looking for extra chucks for your ML7 the chuck, or its backplate should have a thread 1.125 x 12 tpi Whit form.

When things return to normal, you should be able find a backplate to fit a ML7 quite easily (Arc Euro certainly sell them).

Hope that you did not lose / misplace any shims when you removed the mandrel to take it to the auto jumble.

Personally would not have done it that way, but hopefully, no harm done.

If it broke, don't fix. Disturbing things without good reason could cause more harm than good.

Howard

Edited By Howard Lewis on 06/04/2020 10:06:06

Thread: Hobbymat MD65 Tailstock - Set Screws for Adjustment
05/04/2020 19:57:13

I would feel inclined to try make two "wedges" that can be thrust against the blue plastic part. Tap the block, so that tightening the screw on each side forces down the plastic, to act a brake to prevent the Tailstock from moving along the bedway.

Howard

Thread: Todays news -- well done
05/04/2020 18:34:23

Yes0, it was nice to be welcomed in the supermarket, ahead of everyone else, as Elderly (We are, combined age of 160!) But did he have to shout it out quite so loudly?

Have to admit, that in my 20s mortality never entered my mind. Now am sure that the future is shorter than it used to be. So make the most of it, if you can!  Just pleased not need a Zimmer frame yet!

Howard

maths never was my strong point

Edited By Howard Lewis on 05/04/2020 18:36:00

Thread: Overwhelmed!
05/04/2020 18:28:26

Nothing succeeds like success.

No experience is ever wasted, even if it only teaches you not to do it again.(As long as you survive! )

Howard

Thread: Todays news -- well done
05/04/2020 18:26:33

BCPROF.

FYI my wife and I practice social distancing and only visit shops to buy essentials.

We are using common sense in our approach.

I have NO time for idiot box tickers and jobsworths.

As I said, common sense is not that common.

Howard

Thread: Myford Super 7 with 'Big Bore Conversion'
05/04/2020 17:57:20

On the face of it, holding a MT sleeve in an ER collet is merely involving another possible source of error.

Although would it be as great as using a 4MT / 3MT sleeve?

I have to use a 5MT / 3MT sleeve in my mandrel, and am unaware of problems.

Maybe that's what comes of not looking for them!

Howard

Thread: Todays news -- well done
05/04/2020 17:47:29

Looks like the officers had been seconded from Derbyshire

We are allowed to exercise as couples, so OTT in my view

Couples can go to the supermarket so what risk did they pose?

The couple were not within 2 metres of anyone else, until the Police came and failed to social distance themselves. Thus changing a safe situation to one causing risk to everyone concerned.

Common sense is not that common any more!

Howard

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