Member postings for Bubble

Hi all

Re:

when I served my apprenticeship I was also taught to aim for 1 thou' per inch shaft diameter

One of the few things I retain from 40 years in BR Rail Research was that for wheels on solid axles the design interference was one-and-a quarter thou per inch of diameter.This was enshrined in British Rail Technical Note T72.

Jim

Edited By JasonB on 29/07/2014 20:47:29

Hi Matt

I used to help a friend out, turning tungsten alloy for darts bodies. I don't recall any problems, used HSS and including screwcutting the thread for the flights, probably 2 BA

Jim

Hello all

Tony Griffiths' site has a photo of an ML4 fitted with an ML7 tumbler reverse, including the reverse lever/gear carrier.

Jim

Hello Brian et al

Thanks for that. The test pilots at RR Hucknall flew the Spitfire a lot, they reckoned landing it was good practice for landing a Lightning, nose up and crabbed sideways to see where you were going. I well remember the Spitfire on take-off, the tail was in the air as soon as the throttle was opened, lifted by the wash from that fearsome five-blade propeller.

Speaking of the Lightning, they lost one and the pilot's R/T was sent round the squadrons as an example of how to behave in an emergency:

(in clipped voice)

"Smoke in the cockpit"

" I don't think I can stay with this aeroplane much longer"

"Eee-jecting"

They don't make them like that any more.

Or maybe they do.

Jim

Hello all

I was working at Rolls Royce Hucknall in the late 60's. The company's Spitfire (Mk X1V, Griffon, 5 blade prop.) was loaned for the making of the Battle of Britain film. Being a clip-wing variant from 1944, it was disguised by adding elliptical tips. When the aircraft was returned to Royces it looked a right mess, camouflage paint and dummy bullet holes. It was hastily rebuilt and re-painted in light blue. Tragically later destroyed in fatal accident, but I did hear from somewhere that it was subsequently rebuilt.

Jim

Hello all

When single-point cutting threads, I find that the crests can be rounded off using one of my thread files.

They are designed to be used manually to clean up bruised threads, but I use them in the lathe with the lathe rotating under power at slowest back gear speed.

The file is applied to the threads and not moved, but with the work located on one of the cross-grooves in the file.

The file then acts just like a chaser. (I am a grown-up so please don't anyone tell me its dangerous. I know it's frowned upon, but many time-served machinists used files in the lathe, they just didn't boast about it. If you are not sure about it don't do it.)

The advantage is that each file has 8 different pitches. I have three files, BSF,Whitworth and BSP so 24 chasers although there is overlapping of pitches, all being 55 degree thread angle.

Works for me.

Jim

Hi Ian

The O-rings used in screw-on buoyancy-tank hatches for sailing dinghies are a soft porous rubber with a skin.

Any sailing shop would supply, I would think. About the size you need, too.

Jim

Hi Gordon

My KSS had a McCandless-converted rear and BSA front forks and handled very well.

Not like a Featherbed but better than my Garden Gate ES2 presently in bits.

Did you see Ken Sprayson on the programme, he must be 100 by now!

Jim

Hi Jqmes

Alocrom is unaffected by steel, brass or copper inserts in the articles being processed

extract from anochrome.com/ alocrom website

Jim

Hello all

My best guess is that the lathe is an American Atlas supplied on lease-lend.

Compare the distinctive tailstock style with pics on Tony Griffiths' site, also seen on the

UK licensed versions by Halifax and Sphere.

JIm

Hello all

In the 1950's, astronaut John Glenn experienced a total lack of instrument illumination when flying a fighter at night, over the sea during the Korean war. He found the aircraft carrier by following phosphorescence from the carrier's prop.wash for several hundred miles, and landed safely.

Jim

Hi all

At the end of the you-tube footage (Carl's link above), Ruby operates the control lever referred to by Andrew.

Looks a bit like engaging half-nuts on a lead screw. It's operated while the lathe mandrel is stationary but seems to engage easily enough.

Jim

Hello Allen

Some years ago I made a complete fuel system for the Avro 504 at Shuttleworth.

One item was a pressure relief valve for the fuel tank. This needed a part-hemispherical cork seal about 20 mm diameter to replicate the original item.

I will skip the details of making this (unless anyone is interested). The main point was that all of the machining of the cork was done using a grinder, with a 60 grit grey stone. This produced a very good finish. Try it with a bottle cork on your bench grinder!

regards

Jim

Anthony

True, I can "only" go to 80 degrees. I did say it was fine for screwcutting.

In 50+ years with an ML7 I have never needed to go "squarer", that's what the cross slide is for!

I think the loss of 3/8" height is a bigger limitation, especially with quick-change toolposts.

Jim

ps please take your caps lock off!

Hello Michael

This solution was described by a Mr Beecroft in ME in about 1955

It works fine for screwcutting but watch-out for excessive tool overhang on the top slide which can give an upward force on the assembly.

A refinement would be two long tee-nuts in the cross slide slots, with the two side- bars attached to them with studs, this would provide vertical location.

Jim

Martin

Emkay supplies www.emkaysupplies.co.uk/ list 3/8" BSF x 1/2" at 0.83p each.

First class firm, I would use no other, no connection to them except as satisfied customer!

Jim

Hello Interestin

Ringwood www.ringwoodmetal.com have seamless steel tube in 15.88 (5/8" )  by 1.22 mm thick which is 8 thou over 19 gauge

Fairly expensive but so are Jowetts these days

Jim

Edited By Bubble on 29/10/2013 22:04:09

What does make it boring is posts about non ME related stuff.

JasonB

Not everyone is a model engineer! Surely there is space on a forum like this for ideas outside strictly model engineering?

And this website covers MEW as well as ME.

It has been noted before, by at least two previous MEW editors among others, that quite a lot of people who take the mags are into engineering but not specifically the making of engineering models.

Well, if I have to report in on today's activity in order to qualify, I spent the day machining tongue & groove joints on boards for my new (wooden) garage doors.

Jim

Re the VC factory Chilwell

The politicians weaselled-on about this for 40 odd years, and finally Roy Mason, defence minister, decided in 1968 that as the shell filling factory had metamorphosed into the Ordnance Depot there was no-one left from the shell filling factory to award the VC to, and that it couldn't be awarded to a successor establishment as opposed to a person or persons. They agreed to put up a plaque instead.

However, there were still plenty of the old employees around in the 60s and 70s, including Alec Clark who won the OBE at age 17 for heroically going back into the explosion site to shut down the steam boilers, and Sid Oldham who at the age of 90 didn't know what day it was, but could remember in intricate detail the names of the chemicals used in 1918 to produce the amatol explosive.

Jim

Hello Neil

I used to live in Attenborough, near Chilwell, my house being the original pub in the village.

According to the old lady next door, who was 12 at the time of the explosion, all the windows in our house were blown out, at a distance of over a mile away. There is a mass burial grave in Attenborough churchyard.

I have a copy of "The Chilwell Story" compiled by Captain MJ Haslam and published by the RAOC , probably long out of print. You are welcome to borrow this if it would be of interest (if so PM me).

Jim