Member postings for Howard Lewis

Welcome to the Forum!

Some intersting projects to come.

Wish that I had your abilities with electronics.

Howard

Super work!

Great skill and patience.

Value the satisfaction, not the time spent.

How do you charge for pleasure?

The breather system is impressive, to brteathe withoutb oil going everywhere can be a major problem.

Howard

When I clean the scroll on my 6" 3 jaw, in situ, the tool used is a toothbrush, narrowed to fit into the slot for the jaws.

Rotating the scroll eventually works any swarf into centre so that it falls out and can be brushed away.

(A job for a bottle brush pushed through the spindle, from back towards the bed . )

But having cleaned the chuck, and got everything else as good as possible, remember that ikt a 3 jaw chuck.

So 0.012 - 0.013 mm is not too wildly out, especially if the chuck is not new.

A 3 jaw chuck is not, and by virtue?? of all the clearnances within it, cannot be a precision device capable of matching the concentricity produced by good collets, or a carefully adjusted independent 4 jaw chuck

If you can get down to 0.013mm eccentricity, I'd stop worrying and just get on with using it.

Howard

Edited By Howard Lewis on 11/08/2023 16:49:40

Presumably, the thread does notb have to stand much axial load?

So DOES it have to be fine, or is it to mate with an already existing fine thread?

But, a fine thread In a relatively weak material, being shallow, will not be particularly strong.

Many threads in composites are coarse pitch, probably for that reason. If the fitting is purely for connection or sealing, a coarse thread may well be better, being stronger and more difficult to cross thread.

If the thread is 1.125" OD, use an Imperial pitch ( Why produce a "bastard" connection, for the sake of it? )

I know that from time to time we do, often for covenience rather than absolute need, but not an ideal choice.

To my mind, with an 8 tpi Leadscrew, I would feel tempted to go for 10 or 12 tpi. (8 tpi is an easy choice of changewheels ) with the others not far behind. 16 tpi might be getting a bit too fine to have a decent thread depth, only 0.040"in Whit form.

8 tpi will be 0.080" deep while 12 tpi is 0.0534", and 10 tpi will be 0.064".

Howard

It might be posihble to fit the plunger and O ring by pushing htrough a suitabnle internall tapered dolly.

But as NDIY says, ensure that you have the correct sized O ring.

If the oil can is elderly, chances are that the O ring was Imperial, so you may have to do some sums to find the nearest Metric equivalent, which will either be a gnat's too small, or so too big that it does not self return easily!

You may get lucky and find someone supplying an assortment of Imperial sized rings, but don't hold your breath.

Hopefully nthe original ring was standard BS size, which might make things easier.

Howard

Roy, it always possiblke that my wi fi keyboard missed the 1 and /, so don't feel too sorry.

One of the few devices where i can beat a computerr for speed!

Howard

My tendency would be towards the GH600.

Ity might be a bity less versatile in terms of speeds, but is less complicated in electrical terms.

But, am a bit hypocritical in saying that, since my predessor to the GH600'is belt driven equivalent; but fitted with VFD, so the best of both worlds?

Instead of the original 12 speeds, I now have six, but each one has the speed range provided by the VFD.

Having said that a lot of the work, being bone idle, is done in mid gear (belt ) and with the VFD at max.

Has the VFD been unreliable? NO and it is coming up to 20 years next month.

The "jog" facility is invaluable when screwcutting, or using Taps or Dies. Back Gear and minimum speed or jog are very useful then.

Howard

Ventilation is important.

My roof is EPDM rubberover 12 mm plywith glass fibre between the 50mm frame and the internal 12 mm ply ceiling.

The shop itself has no windows, but two small fixed vents at floor level, and a 6" fan with a weatherproof external cowl.

In fine weathger used with the door open, with the door closed, occasionally the fan is switched on.

Heating is by a thermostatically controlled small 2 Kw fan heater.

Since it was built in 2003, just coming up to 20 years ago, no condensation or rust problems

Howard

To use the machine that Ady1 mentioned means that someone HAS to know and understand the basics.

The prize examples of what happens when the revesre is the state is visible as politicians making their "sound bites" to climb onto what they see as the latest popular band wagon

Gordon Brown - Diesel cars.

Blair - W M D

Electric cars - Technology catching up fast, but inadequate infrastructure.

Hydrogen as a fuel. Ditto.

Ditch your hydrocarbon boiler - Get a heatpump etc.

Or am I just so old that I have become cynical?

Howard

Roy,

To clarify matters.

I did NOT say that a ML7 had a 2 hp motor.

I had a ML7. The single phase motor was 3/4 hp. Three phase motors were 1/2 hp.

Don't get confused with my lathe which is oriental, bigger, and specified a 2 hp single phase as standard. I specified a 1.5 hp for the VFD conversion.

Belt changes, and Back Gear, are used to provide variations iu speed, in additiuon to the VFD.

Mini lathes tend to use 400 - 500 watts, brushed or brushless, motors.

Other lathes will use motors of different powers, depening upon what is required of the machine, and what can be accomodated within the overall envelope.

Howard.

Some races are in housings whereb vthere are two recesses behind the race where an extractor could be used.

Sykes Pickavant usewd to sell an extractor with "legs" for such events. The "legs" were forced outwards by means of a screw thread, so that they did not slip.

maybe you could make something similar thast you could then either punch out, or less violently use a screw therad to pull out.

The new races could then be pulled into place with a "dolly" in place of the legs.

Howard

Forgot to mention roofing!

Flat pitched roof, with 6" fall from front to back over a 7'6" length.

The original felt, lasted for 11 years before it began to show signs of deterioration. Replaced it before any chance of water ingress.

Material, was EPDM rubber from Rubber for Roofs.

Put the measurements into the on line calulator, speciafied where the gutter would be and ordered, mid afternoon

0800 next day rubber (ample! ) trims, adhesive, application roller, tray, and plenty of ring shank nails arrived.

It took two us with scrapers and a heat gun to remove the previous bitument adhesive, before laying one half of the sheet of rubber and then rolling it over to lay the other half.

Ring shank nails are almost impossiblke to remove, so do put them in the right place first time.

Final job was to trim off the excess rubber from below the trims. So much that bits are still being used for little jobs!

Adter nearly ten years still looks as good as new. The garge roof is also EPDM and has been ikn nplace for at leastbv thirty byears without any deterioration, so quite confident about the workshop.

Howard.

The Myford ML7, and its successors rely on the weight of the motor to tension the primary belt (A section )

My present lathe uses B section belts, and the again the weight of the motor provides the tension for the primary drive. The secondary belt, inside the Headstock is tensioned by an over centre arrangement, where the length of the connection between the external lever and the countershaft carrier is adjustable in half turn increments.

The original single phase motor was 2 hp, the three phase motor is 1.5 hp.

In cas of mishaps / over loads, the gravity tensioned primary belt can slip, reducing the risk of damage.

An A section V belt in conventional V pulleys can transmit quite a lot of power A single belt can easily transmit 3/4 hp.

For our usual hobby machines, a single A section belt usually suffices.

My Mill Drill transmits 1.5 hp through single A section belts. The secondary is over 20 years old, so well within its capacity!

Tension should be such that halfway along one side, the belt can be moved no more than 12 mm. without using undue force.

For years, private motor cars used a single A section belt to drive coolant pump, alternator and cooling fan.

All of which could require more than 3/4 hp!

If more power needs to be transmitted (As on higher horsepower industrial machines, the belts are duplicated or triplicated. The two cylinder air compressor for the brakes and suspension on Bristol buses was driven by triple A section belts, with the compressor having a screw adjustment to set the tension. )

Howard

FWIW

I only buy HSS Taps or Dies from Tracy or Tap and Die Company.

Problems?

One Tracy Dies was marked on the back instead ofn trhe front , another cracked. Both replaced without demur.

Tap and Die, again had one Die crack, replaced.FOC.

I set Dies, wherever possible, using a commercial bolt or setscrew as a gauge, before use. or open up and use the intended nut as a gauge for subsequent cuts, if needed.

Often cut under power, (Using the VFD "Jog" facility. or a Mandrel Handle for blind holes or shoulders ) dry for brass, lubricated for steel

HTH

Howard

Two gripes.

1 ) Our utilities should not be in the control of other countries. Does no one fear being held to ransom? (Note the problems from a certain "Military Operation" is having on energy and grain supplies

2 ) It seems that those running a company can set their own remuneration package, and not always to the benefit of the workers, shareholders, or customers.

Must stop before ik becomes political!

Too often, it seems that greed rules, rather than service.

Howard

Sadly, MANY of the skills that used to be indigenous in UK have been outsourced, and are being lost.

In the Rules, The Peterborough Society of Model Engineers, has one item which speciofically mentions retaining and promoting traditional skills.

Unless skills are kept alive by the various preservation movements, and model engineering, they will be lost for ever, and devices that could be repaired and preserved, will be sent for scrap. Historical atrefacts and their history will be lost.

Our skills need to be passed on to the newer, and younger, members of the hobby, or they will be lost for ever.

In 1977 I was told that in the US a Master Plumber could name his own price, so rare were his skills.

Do not let UK fall down ther same hole!

Howard

In Uk, and in many nbother countries, a manometer is, as said, often a U tube filled with a fluid.

The pressure is measured as the difference in height between the two columns The largest that I ever used was to mesure boost pressures of the orfer of 1.7 m of Mercury.

For lesser pressures our manometers were of a different, proprietary for, but still using Mrcury as the fluid.

For small pressures, water or light oil can be used.

To measure boiler pressures, what you need is a Bourdon tube type pressure gauge, as previously illustrated.

They should be available from model engineering suppliers, in Uk, such as Reeves.

Howard

Having recently received new glasses afetr the secind catarct, things are so much brighter, and more visible.

You now have an interesting project, and by the end will have a useable little machine.

If it is any help, when i had a Super Adept, I used a large O ring as drive belt,

Bringing it up to what you want, and then making things on it will provide SUCH satisfaction..

Go for it!

Howard

If everything else has minimal play, and the run out is only for work in the chuck, you have two choices, either live with it , or buy \a new one. But don't be disappointed if a new is no better!

(Run out of that magnitude is not uncommon with a used 3 jaw, or in some cases a new one! )

I have only seen one 3 jaw with minimal runn ot, all the otghers have had some, depending on how worn they are.

Run out of the magnitude that you are measuring is not that unusual, and might well vary according tghe diameter ofc the piece claped in the chuck(As I said scroll to body, scroll to each jaw,each jaw to body, dimensions / squareness of faces within each jaw )

If you think of all the clearances present in a 3 jaw chuck, just be surprised that run out is a small as it is.

If absolute concentricity is essential, you either turn the two or more diameters at one setting, without disturbing the chuck, or you use a four jaz\w and clock the work until it is concentric to within what you are prepared to accept.

If you reduce a 25 mmbar to 20 mm and elsewhere to 15 mm; the 20 mmand 25 mm diameters will be concentric, so the initial run out won't matter when you part off trhe job.

Howard         Why do the typos only become obnvious after pressing "send"

Edited By Howard Lewis on 09/08/2023 08:44:23

To an extent, a misaligned Tailstock may be caused by a twisted bed.

To cure this, use "Rollie's Dad's Method" (As told in Ian Bradley's "The Amateur's Workshop", and "Myford 7 Series Manual", and bu others elswhere  

For more serious mialignemnt more stringent methods might be required, such as machining the under side and fitting a plate to resoire the corrct vertical and horizontal alignment.

A friend bought a Myford ML4 which would not cut anything other than a taper.. One of the studs retaining the Headstock had been cross threaded and tightening the nut pulled things out of line. We made a crude jig (basaed on the centre distance of the other pair of "good" studs, and used it to open the damaged hole to tap it 3/8 BSF, before fitting a bush tapped 1/4 BSF. This allowed the correct alignment to be restored.

You may need to do something similar to bring things back into line.

Often, if there is enough metal, things can be corrected by opening up and bushing.

It might be possible that, with carefiul planning, the machine can "Pull itself up by int's own bootstraps" and produce the parts needed!

Howard