By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Nigel Graham 2

Here is a list of all the postings Nigel Graham 2 has made in our forums. Click on a thread name to jump to the thread.

Thread: Wall Chart
25/07/2021 15:52:47

I've now a few of these in various forms but I bought two of Tracey Tools' posters (tapping-sizes on the reverse). One hangs in the workshop, using an old trouser-hanger so I can turn it easily. The other floats around the front-room furniture for ready-reference when I'm using TurboCAD.

Oh, and both are complemented by copies of the Zeus book!.

Thread: Myford Gear Spacers
25/07/2021 15:48:20

Good idea. I must admit I'd never considered that.

Felt-tip pen mark on the wheel... Multiple thread?

Thread: Hydrogen
23/07/2021 08:52:06

The new "mining" for lithium proposed in Cornwall (in fact has work started) is not conventional rock-breaking.

It is extraction of lithium ore that has become dissolved naturally in deeply-circulating water, including that flooding old mines.

The brine is pumped out of boreholes, the minerals are extracted and the water returned (presumably down a different hole.)

Thread: Sourcing a Bolt
21/07/2021 23:26:52

Stainless-steel and aluminium-alloy can be a bad combination depending on the individual grades and the environmental conditions.

The alloys for marine use should be ones developed for the role. I have seen an assembly that had spent some time in the sea, in its intended use, whose stainless-steel thread inserts sat all smug and bright in craters filled with white sludge, in the aluminium end-plates.

I can't see it being a problem in something that is drenched in oil; but it certainly can be with any water about.

A non-metallic grease - mineral, silicone or petroleum-jelly - may be better than a copper-based anti-sieze compound.

I used to test experimental assemblies made typically from "ordinary" aluminium-alloy (HE30 - I don't know its modern moniker) held together with A2 or A4 grade stainless fastenings. Despite their designers' touching faith in anodising, the test-pieces' necessary immersion in a tank of fresh water kept sweet with only normal swimming-pool filters and additives soon started things fizzing.

I wonder if this could also be a problem for miniature railways using stainless-steel bolts with aluminium rails. It might not if the joints are always above the ballast and kept clean, but may be if vegetation or soil accumulates around the track.

Thread: Old lathe tools
21/07/2021 23:03:45

The holder with the light-coloured rust, to the right of the sping tool-holder, looks as if for holding small Coventry-type thread-chasers.

The large holder with the screw in a little hump (2nd from left, next to all those centres) is for parting-tools, and appears to have a blade in it.

Thread: E10 Petrol
21/07/2021 22:54:13

The compatibility-finder and other information on E10 fuel is on the site.

Thread: The beginnings of Mobile Telephony
21/07/2021 22:44:01

My employer had a security notice on its reception desk and that too, called the instruments correctly, portable telephones.

The wrong word probably comes from some big-name advertising company, and relied on enough people having not been taught to understand ordinary words in their own language!

I use "portable" and once puzzled someone enough for him to ask, "Don't you mean 'mobile' " ?

"No. Mine isn't mobile" , I replied. "It has neither motor nor wheels."

Thread: Vehicle reversing sensors
20/07/2021 15:21:01

Roy -

A very useful tip, a soft ball on string. I have seen that tip elsewhere a long time ago though if I recall correctly that motorist drove forwards into his garage.

Dave -

I would expect an ultrasonic transducer to be reciprocal as you suggest, i.e. capable of both transmitting and receiving. They can be calibrated effectively by making three of them ping at each other in turn, and apply the transmitting and receiving electrical signal levels, and the transducers' electrical characteristics, to complicated simultaneous equations. (It was easy for me. The sums lived in a computer programme written by them as know such things.) The method, "reciprocity calibrating", is roughly the sonar equivalent of making three surface-plates from each other without recourse to a reference-plate.

However, even if using a pair at their same resonant frequency, you may need know their receive and transmit sensitivities with their associated amplifier gains, in both modes, for the readings they give to make sense. It may be possible to calculate the results from purely relative signal levels, but you'd still need an optical or thermocouple pyrometer to calibrate the acoustic system, especially as it might not be linear with temperature.

The sound pressure-level emitted from a small transducer is fairly low and falls by inverse-square distance law plus absorption that rises with frequency; so although it is valuable for the sort of contact transmission and reception Pgk describes, in medicine and NDT of metal components, I would not to like to guess its likely efficiency though a turbulent gas cloud.

The sound might travel easily along a fire-tube well though. A metal tubes can be an effective acoustic wave-guide provided you can put enough of the total emitted energy into the tube's entrance. (Think of the speaking-tubes on old ships.) A single-piece sensor may be nearly omnidirectional so much of the radiated sound would miss the tube. If it is directional though, both transducers would need careful aiming for beam and tube concentricity. You could test for this by putting one sensor on a rotary table at one end of the milling-machine table, and the other on a fixed mount at the other: somewhat similar rigs are used in acoustics laboratories.

Also, although the electronics is safely away from the fire, the sensors would not be very happy too close to a high temperature heat source, whether facing through an open firebox door or in the smokebox.

Testing with a blowlamp flame would be interesting. I've sneaking suspicion the flame boundary would reflect and scatter much of the applied pulse back, due to the sharp density difference from the surrounding air. (Incidentally, whales call over long distances not only because they shout loudly and at high power, but also thanks to a natural wave-guide formed by the sea surface and a density boundary at some depth below the animals.)

All food for thought anyway... (No, not the whales.)

Pgk Pgk -

You could well be right about bats using doppler effects; and that combined with interference modulation might be what distinguishes a flying insect from a fluttering leaf.

I've tried to guess what certain enviroments may "sound" like. One study I read was of a pipstrelle colony in Holland, using a canal as guidance between their roost and their forest hunting-land. Although these bats hunt at dusk so probably helped by sight, when flying along the line of a calm waterway the sound impinging on the water at an angle ahead of the bat might be reflected ahead so lost (the canal would appear "black", or "dark"; bank vegetation such as rushes would probably give low-level, diffuse narrow-band noise; the hard ground each side give much more definite echoes.

Regarding your coming up behind tractors, I can say most I have followed have let traffic pass when possible.

The most irritating behaviour I find with cyclists is to play rabbits by trying to cycel as fast as they can, so are very hard to overtake safely, instead of pulling in to some refuge like a field gateway. Worst though was a big bunch, evidently a cycle-club, I once encountered on a rural road. Despite a half-mile of empty road ahead I could not pass, because they insisted on riding as a thrr-or four- abreast bunch taking the middle half of the road, even across the markings at a T-junction with a larger road where fortunately they and I were taking opposite directions.

I have no qualms about towed caravans as most I have seen, as a resident of a tourist-magnet county, are towed competently and at sensible speeds (I accept they have their own speed-limits). Some years ago the DoT studied traffic behaviour and found the largest number of slow vehicles causing long queues are not caravans but HGVs. There are far more of them, all year round and on all manner of roads.

The worst for discourtesy are a large proportion of drivers of horseboxes, both fixed-wheelbase and towed. I appreciate they have to be careful with a large, very heavy, unpredictably nervous animal forced to stand for a long time in a jolting wagon; (I feel sorry for the 'oss); but too many of the drivers seem to delight in ambling along at 40mph on all ordinary roads, and not pulling in where and when safe to let everyone else pass.

Thread: Bed stop clamp
20/07/2021 00:58:45

Owning an ML7...

all I found necessary was to cut a piece of 25mm X 6mm steel flat the width of the bed, and drill a hole through the middle. I secure it to the ways with the clamp and bolt borrowed from the fixed steady.

I did not need make any T-nuts etc as I use existing fittings.

Yes, it's a slightly crude set-up and gives only one stop position at a time but has amply repaid itself many times.

Actually, thinking about it, I did not make the bar specially for that. It is really a clamp-plate I made for holding one of my milling-vices to the table. Why make two items when you can make one item perform two duties?

Thread: Vehicle reversing sensors
20/07/2021 00:50:54

Dave -

Interesting idea, an acoustic pyrometer. Unfortunately:

"The speed of sound depends on temperature..."

To a point. It actually depends on density. Whilst the density of a gas is affected by its temperature, it also depends on pressure, so the confining conditions and gas flow. I think the variability of everything in a miniature boiler would be nighmarishly difficult to analyse to the depth necessary.

I don't presume to deny it would not work but could be far trickier than it seems.


A humbling little digression.......

By comparison with Nature's been up to for some millions of years...

... bats have been using sound in the some-tens of kHz for social calls, and typically around the 100kHz mark for hunting and close-in navigation, no problem. The hunting also needs high repetition-rate chirps to aid discriminating insect prey of low sound reflectivity, from acoustically very difficult backgrounds in constant but random change. It probably uses interference patterns between the call and insect wing-beat.

Except that their upper frequency distance range is necessarily very short by signal absorption in the air and by the animal's very low call power. This is to some compensated for by high voice pressure-levels; in some species, handsomely exceeding 90 or even 100 dB re 20µPa: levels dangerous for us if within our hearing-range and at larger powers.

Think of being a little pipistrelle or horseshoe homing in on a fluttering moth against the constantly moving acoustic clutter of foliage. Just part of a very few grammes of brain working flat-out on very rapid, very complicated signal-processing necessary to control the responding flight, calls and ear-damping, while synchronising breathing with wing-flap and call. That mechanism maximises system efficiency by combining the chest muscles' contribution to exhalation with assisting the wing power-stroke. While it's at it, the brain's other departments are continuing to monitor and control the rest of the animal's physiology generally. All by instinct.

(The horseshoe bats call through their nostrils! Their characteristic facial folds are for call beam-focussing.)

Oh, and some of that compact brain must be holding some form of acoustic map memory back to the roost, especially vital to a nursing mother bat. They do have fairly good sight but that won't work in a cellar, mine or cave with no light whatsoever. Yet these lovely little creatures recall their way through what must be fiendishly complex acoustic "scenery" to where they sometimes reach.

What are we doing with ultrasonic location and ranging? (Actually, light on my car - a camera.) Using steady pulses and a string of 'beeps' to help us ease a big steel box into a shop car-park bay to the nearest foot or so usually in broad daylight, whilst knowing our "prey" is sitting perfectly still in tins and packets on the shelves....


Thread: Midlands Model Engineering Exhibition 2021
19/07/2021 23:25:54

A sad do, but I agree wholeheartedly, John and Noel.

I've just circulated the news to my own society - no tthe entire post, just to announce the cancellation and cite the source (htis site). The members will understand, I am sure.

19/07/2021 22:12:08

Disappointing but not really surprising.

Some things are more important for we exhibitors and visitors, such as being healthy enough to enjoy our hobbies; and it's not as if most of our suppliers can't use postal and Internet mail-order. We should though think too of the organising company and host venues.

As one who had been down to help on a club stand, I admit I was becoming more worried how safe it would be.

I wondered too how the catering could be arranged as the balcony cafeteria is so cramped. (Excellent food though - I tell the dinner ladies I come to the show for my few decent meals of the year!)

Fingers crossed for 2022 then.....

Not just for "our own"; but also for the venues and their staff.

Thread: Garmin sat nav
16/07/2021 23:48:12

Chris - I don't know mt TomTom's model. It's sitting next to the computer but examining it reveals no designation. The most awkward thing about it, is having to remember it has no [Enter] key or equivalent. It took me a long time to discover it assumes you are entering the destination at the start if the journey itself, then you select [Drive].

It is accurate, but slow to react in heavy traffic in complicated areas giving no time or space to do anything but either take the correct turning immediately (if you can); or continue as the traffic dictates and try to correct the mistake within the next few miles.

It's often also slow and ambiguous on roundabouts, and never clear if it has counted as the first "exit", your entry road.

Best way is simply to avoid driving in cities! Luckily I do not need to.


Duncan - Encouraged by your and other's comments I've just examined mine. If it has an internal battery it is not replaceable. The case cannot be opened, and is probably glued together.

Thread: The last Gravity Ropeway
16/07/2021 23:25:03

Thank you John!

One of my old engineering text-books devotes a chapter to ropeway components and designs; and reveals as well as being transport machines (as at Caton) they were also used without buckets, for power-transmission. Basically a V-belt with a very long belt.

Seen the cliff-lift at Bridgenorth? Lynton and Lydmouth had installed a water-balanced one, fed from further up-valley; but at Bridgenorth the river's down at the bottom. Not to be outdone though, the late-19C builders installed pumps... Until they twigged it was rather more efficient simply to use an electric capstan.

Thread: Getting my Britannia No.13 into use
16/07/2021 23:13:59

The original treadlre-pulley was quite likely heavy enough to be flywheel as well, but I don't think mating the sewing-machine pulley with that round-rimmed flywheel will compromise things too much even if not original. It's good to see the lathe is back in good hands!

I had a Drummond early-B type for a while and wondered about making a foot-motor for it, only to discover some previous owner had gone to the trouble of hacksawing the treadle-shaft journals off the legs!

Thread: Chuck fitting
16/07/2021 23:06:31

Counter-sunk, Pete? Vic says his lathe uses counter-bores, which are not self-centering.

I have a small lathe with similar fittings, not yet set up and used, and I've wondered how easy changing the chuck would be. If there is very little room it may be as awkward to manipulate nuts on studs as socket-screws, so altering it might not gain much.

Thread: Garmin sat nav
16/07/2021 00:39:51

I can't remember when I last up-dated my Tom Tom, but I found it very difficult to do so - the thing is not easy to use anyway. In fact I think I had to abandon the effort. I am not sure if it has an internal battery but in view of the above perhaps I ought re-charge it so thanks to all above for reminding me.


I used it last in 2017 I think, to "find" Doncaster Racecourse, not actually turning it on until I had left the motorway at a junction bearing the one and only sign that indicates the Racecourse. If I can't find Yorkshire from Dorset with no more than a sheet of paper with A-road and junction numbers written in great big letters...

I'm not sure how I managed to reach the place, vowing never again. I didn't expect a racecourse to be practically in its city centre, and coralled by so many complicated and very busy junctions so close together the poor little box of electronics could not keep up. At one point it helpfully put me in the lorry queue for the rail-goods terminal....

Oh Harrogate, how easy thou wert!

No, sat-nags (as a friend calls them) are not always what they are cracked up to be. They are good though, for frightening motorhome and caravan owners leaving the camp-site near me, into ignoring a sign giving them a much easier route away than our very constricted, one-way street.

Thread: Making a miniature electric bell
16/07/2021 00:07:37

Won't reducing the bell size to 1/4, increase its pitch considerably? Or would that not matter?

Thread: Stone moving machine
16/07/2021 00:00:46

What are those smaller scars on it? Has someone been drilling holes in it?

Thread: The last Gravity Ropeway
15/07/2021 23:57:33

That the one near Caton? (Sorry, Google has made Youtube such a faff, and so stuffed it with idiotic ad breaks through the videos themselves, I've given up on it). I've driven under it quite a few times when driving back from the Dales via Ingleton.

Is the brickworks closing too?

In t'other county, one of the two limestone quarries at Horton-in-Ribblesdale now has a private siding built a few years ago, off the Leeds-Settle-Carlisle line. The other hasn't for some reason (cost?) though it used to, so its crushed rock still goes out by lorry, over the village's two narrow hump-backed bridges separated only by a very sharp bend.

Dow n the road a few miles from there, the Hoffman Kiln (for lime) at Langcliife is worth a look if you're driving through the area.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
walker midge
Eccentric July 5 2018
JD Metals
rapid Direct
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest