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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: Hi from Aldridge
12/09/2021 17:02:53

Welcome to the Forum!

Before doing anything drastic, or making a purchase, seek advice from those on here who are knowledgeable and have experience of the machine that you are contemplating.

You need to say how much space is available, and the uses to which the machine will be put; not to mention the budget. It would be helpful to know more about the site, for advice on moving the machine from point of delivery to final siting.. Pillar drills can be extremely top heavy and unstable whilst being moved!

Taking an extreme, a with a three phase motor machine would not be suitable for a workshop with only a single phase supply, unless you are prepared for the expense of repowering.

They will know the vulnerabilities, and how to fix problems that arise, so that you are less likely to by a machine that is unsuitable, or a real pup!.

Howard

 

Edited By Howard Lewis on 12/09/2021 17:03:28

Thread: General sharpening direction help
12/09/2021 13:31:23

Scissors, and garden shears, by their very name, are different from chisels, plane irons and drills, end mills or slotting drills.

These latter are ground with two reliefs. (In this context drills are meant be four facet ground )

The usual advice is to grind the larger secondary clearance first, followed by the smaller primary clearance. In this way a four facet ground drill shows a chisel point.

Scissors cut by shearing the material, so have only one clearance angle. If grinding / honing produces a slight burr (A "Wire Edge" ) the usual advice is to wipe the edge across a piece of wood to remove the burr without affecting the actual cutting edge. The same technique would be applied to a plane iron or wood chisel.

This should produce a set of shears which will cut paper, if not human hair!

Rotating cutters tend to be ground either along the edge or away from it so that no burr is produced.

Howard

Thread: cutting threads
12/09/2021 11:31:11

If you are unsure of what to use, or don't have the alternative gears, the safe method is to keep the half nuts engaged.

Withdraw the tool and reverse the motor to take the tool back, well past the start of the job.

Having reset the tool, the lathe can be restarted in the forward mode, and by the time that the tool contacts the work, the distance travelled before cutting, should have taken out the backlash.

Howard

Thread: in a mount fitting the Leica and with thread M 39x1
12/09/2021 11:23:12

In the hope of getting a definitive answer, I have taken Clive's advice and contacted the Leica Society.

There is a wealth of information available BUT no mention of the thread form or pitch!

The reply will be interesting.

Howard

12/09/2021 09:17:51

The Russian made Fed (Copy of the Leica 2f ) and Zorki used the 39 x 1 thread (I think that the Kiev was a copy of the Contax )

The "economy" lens was the Industar, f/2.8.

The Zenith 35 SLR used a 39 x 1 thread but the register, being a SLR was greater than the 28 mm of the Leica body.

So although "Leica thread" lenses and accessories would fit, it could then only be used for close up work.

The Periflex series, 1, 2, 3 and Gold Star used the same thread and register and provided a rangefinder which functioned with a lens of any focal length. It used the SLR technique of focussing on a small ground glass screen which was lowered onto the centre line of the lens (Manually for the 1, in-situ and automatically withdrawn for the 2 and subsequent models). The Corfield lenses were quite good.

There were also three Interplan models (A, B and C ) which accepted Exakta , Edixa/Pentax or Contax lenses, but were less popular, and short lived..

When the Zenith B and E SLRs were produced, most had the 58mm, f/2 Helios, which being a copy of the Sonnar in the new mounting, to suit the 42 mm "Pentax / Edixa" register, was a very good lens

Howard

Thread: new member
11/09/2021 19:37:59

If a machine is described as Metric, most on here would expect to find that the Leadscrews were metric pitch (and diameter ) with dials that are graduated in mm or parts thereof, such as 0.02 mm per division.

My lathe is really Metric having 3 mm pitch leadscrews., but is dual-dialled Each dial has two sets of graduations, 0.02 mm per division marked every 5, on one side, and 118 divisions, marked every 10, as 0.001" per division on the other.

An Imperial machine is more likely to have 10 tpi Leadscrews, but not necessarily, with dials carrying 100 mdivisions, marked every 10, giving 0.001" per division.

BUT some lathes have the Cross Slide dials graduated not in tool movement, but in metal removed from the diameter. In which case, although the dial may show say, 0.04, the actual tool movement will be 0.02. By removing 0.02 from each side, the diameter will reduce by 0.04.

As an Apprentice, it took a little while for me to learn that!

Howard

Thread: in a mount fitting the Leica and with thread M 39x1
11/09/2021 19:18:04

The early lenses for precision 35 mm cameras really were advanced, for their time. The Elmar and Sonnar were far in advance of anything available at the time, setting quite a goal to reach..

Present lenses are even better. The Vario Elmar on my Panasonic FZ50 performs incredibly against the light. Just shows how much progress has been made in lenses and their coatings since the 930s.

As for enlarging lenses, a prominent photographic lecturer did not think much of my 2"Taylor Taylor Hobson Ental 2, preferring a 50 mm EL Nikkor.

Until I told him that my TTH would resolve grain at full aperture, while the El Nikkor had to be stopped down considerably so to do, on the same negative!.

Howard

Thread: Cutting a 1/2" bsp thread on Harrison L5 help
11/09/2021 19:06:57

With a 4 tpi Leadscrew, for a 14 tpi thread, the reduction between Mandrel and Leadscrew needs to be 3.5 :1

(14 / 4 = 3.5 )

So, on the face of it a 20T - Idler - 70T would do the job, assuming that the intermediate settings are 1:1.

If there is a 2:1 Intermediate reduction then the 40 iDLER 70 set up will do the job..

Howard

Thread: in a mount fitting the Leica and with thread M 39x1
11/09/2021 18:56:26

Intriguing that the mention is not of 26 tpi Whit, but 39 x 1

So, the mystery deepens.

Has anyone used thread gauges on a male genuine Leitz lens?

Possibly. Michael and i will both then be able to sleep at night

Howard

Thread: 12volt three wire fan connections,
11/09/2021 18:12:25

Possibly a two speed fan.

One wire will be common, the others may connect to different field windings (Although likely to be a PM motor) to provide the low and high speeds.

Akin to the rear wiper motors that were used on some cars.

Howard

Thread: Help identifying some tools
11/09/2021 18:04:04

You may find all sorts of good things in the filing cabinet, possibly the dead weights for the Budenburg, and other instrument as W I P which might benefit from the addition of the Drum Micrometers.

Seek and ye shall find!

Howard

Thread: Lathe Vertical Milling Slide
10/09/2021 19:21:15

The carrier for the handle looks like as if came from Myford, and the body looks like a Cross slide, but neither for a ML7 nor a Super 7, unless my memory fails me.

With a suitable Angle Plate, it could be used as a Vertical Slide.

Maybe it was one, but the Base to adapt it to the lathe Cross Slide has been lost.

Howard,

Thread: Help identifying some tools
10/09/2021 19:12:45

The micrometers are Drum types. The large diameter barrel allows the graduations to be wide apart, so that they can be subdivided, probably into tenths of a thou instead of thous on an normal micrometer barrel.

Possibly, they came from Height Micrometers.

The Budenberg tester is used to calibrate pressure gauges.

The various pressures are obtained by loading a disc of known specific weight onto the plunger with the gauge to be calibrated fitted to the connection. The pump is then used to increase the pressure, until the weight just "floats"

This allows the gauge reading to be compared with what it should be, and corrected if need be..

This procedure is repeated for each increment of the gauge graduations; probably in 10 psi steps.

It is very good piece of kit, if all the weights are there. There should be at least ten, to cover from 10 psi upto 100 psi.

The electrical device, Pye Scientific Instruments is used to check Thermocouples, to measure their ouput, and again, to calibrate a electronic temperature measuring set up (Thermocouple connected to a sensitive moving coil meter, measuring milliVolts, but probably graduated in degrees C. )

All this stuff, including the Toolmakers cabinet should be quite valuable. Most of it would have come from a Standards Room, or Cakibration Room, and would have been very carefully looked after..

The kind of kit that one would be a joy to own, but have no actual immediate use for it! (On a shelf, I have two drum micrometers for which I have yet to find a use )

Howard  Fat fingers strike again!

Edited By Howard Lewis on 10/09/2021 19:14:55

Thread: Hole in tool post
10/09/2021 18:34:41

And I thought that you were going to make a faceplate for your lathe.

If you find the the Allen screws are a PITA, why not make nuts with a reduced shank (to fit into the counterbores ) and use studs instead of the Allen screws.

The choice of spanner to use, or the size of hexagon, is up to you.

Howard.

Thread: Steam engine toy with machines
09/09/2021 17:57:27

Mamod used to sell little machines, and a lineshaft to be driven by their steam engines.

Stuart certainly sell a little lathe, kit, fully machined, or complete and ready to run.

Howard

Thread: Hi
09/09/2021 17:53:43

Welcome!

We all have to learn. Experience is what lets you recognise the mistake the next time you make it. So, by that standard, I am experienced.

But you wouldn't think so seeing the simple things that I make. Little skill and even less patience!

I thought that the back of an envelop was for drawings!

My wife had a book by Monica Dickens on cooking. She said that what was important was not the dish, but how you recovered it when it went wrong!

Howard

Thread: Win 10 back t0 Win 7
08/09/2021 20:40:59

One of the first things that a friend said about W10 was that he could not load his older pictures.

Images from my now elderly TZ50 load to W7 without a problem, (Until a few days ago, during some copying, Bands starting appearing across the bottom of the recorded image ).

Clive, you will be leased to know that I bought the TZ50 because of the Leitz lens. A superb piece of optics!

(Too tight to spend the extra £90 to get the red dot! )

Maybe I released the shutter release too soon,,before writing was complete, because repeating the exercise, on the same memory card, worked perfectly!

But Clive's experience sounds another knell for W10 to my mind.

Howard

Thread: Lathe Move
08/09/2021 19:15:34

Have never needed ti use them, but Landylift seem to have a good reputation.

Weighing near enough a ton, it6 will need care in lifting, transporting and siting.

Howard

Thread: They see you coming
08/09/2021 09:59:23

A friend donated his late wife's car to his daughter. It developed a rattle.

"You need anew timing chain, sir" But the rattle was not from the engine, it was coming from underneath!

The heatshield around the catalytic converter had rusted through around one of the bolts.

Being a woodworker, my friend made and hammeredi into place a wooden wedge to stop the shield vibrating.

Silence!

Howard

Thread: Disposal of swarf
08/09/2021 09:53:15

Our council refused to empty the recycling bin "Because it contained metal" (two aluminium extrusions.

The chap at the council seemed surprised that baked bean tins were made of metal He thought Aluminium.

Even more surprised to be told, "No. Tin plated steel"

The cabinet member for refuse collection does not think that any of the operatives need further training!

Somewhere in the Bible it says "If the blind lead the blind, both shall fall into the ditch"

Howard

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