Member postings for Robin Graham

That's fantastic Dave, thank you! I don't fully understand the pictures though - are the deflections in the plane, normal to the plane or what? The pattern certainly seems to correspond to my observation.

Unfortunately I now have a scenario in my mind: apprentice asks Foreman to check his setup. Foreman - " That's no good lad, you need a Bernard's bung in it. Run along to the stores and get one."

Good idea for the future though, thanks Bernard.

Robin.

This corresponds with my own observations/calculations. I was actually trying to prove my wife wrong when she insisted on buying a hob (gas) kettle to replace the electric one when it conked out. Gas turned out (measurement) to take ~0.24kWh to boil a litre of water, electric kettle (calculated assuming 90% efficiency) ~0.11 kWh. That gives an efficiency of ~42% for gas. So with gas about a quarter of the price of electricity, gas wins hands down.

Robin.

Thanks for replies. I should have said that when I noticed the effect I checked the spigots for witness marks showing where the chuck had gripped. They were there, and the jaws had gripped the spigot at (eyeball accuracy!) 60° to the depressed areas, so the front faces of the jaws were behind the 'raised' areas. That observation got incorporated in my thinking about the cause and was implicit in my speculative explanation, but I should have mentioned it explicitly. Sorry!

If I have understood the axial deflection explanation correctly the pattern should be the other way round if it is right.

The discs were faced using a fresh 0.4mm radius CCGT insert (Arc Euro Trade), so sharp(ish). Roughing cut ~0.5mm, finishing cut ~0.05mm. So very little axial cutting force for the finishing cut I would have thought?

I take old mart's point that it might have been better to make the hole last - sequencing of machining operations is an aspect of this hobby I find particularly challenging. I guess it comes with experience - I didn't anticipate this effect so no amount of planning would have helped. The reason for the steely appearance is that I had to adjust lighting to display the contrast between the areas, and that must have mucked up the colours on my phone camera.

Anyone out there with a finite element analysis program? Well above my pension grade, but it would be interesting to see the stress field for work held in this way.

Robin

Edited By Robin Graham on 06/09/2022 00:10:28

Edited By Robin Graham on 06/09/2022 00:11:19

Edited By Robin Graham on 06/09/2022 00:12:58

I faced off a batch of brass discs to 1.5mm thickness the other day holding the work by a 16mm 'spigot' on the rear of the work in the three-jaw:

When I started to polish the faced surface I was surprised to see:

The dark areas are 'low' with respect to the rest of the surface, probably by ~40µ at deepest.

I assume that the disc was distorted and 'bulged' in the areas between the chuck jaws, then relaxed and that's what caused the hollows.

I could have used a collet chuck, but being lazy I didn't want the faff of changing chucks. I have paid the price in time/elbow grease/sheets of wet'n'dry!

The point of this post is just to document one of the many things that don't work*.

Robin.

* "But the student will find that experience is the best teacher. The reason why I get along with comparative ease now is because I know from experience the enormous number of things that won’t work." 1882 June 15, The Christian Union, How to Succeed As An Inventor by Thomas A. Edison, Page 544, N.Y. and Brooklyn Publishing Co.,

I actually found a quote from Ecotricity (one of the three exempt from the cap) a couple of days ago, about 65p /KWh for electricity after Oct 1st. But today they won't give a price because of the "fluctuating market". So who knows!

Robin

Hi Dave. This is inevitably a bit hand-waving, but I hope it will answer some of your questions to some extent.

Let's start with "given electrons don't travel very far...". They don't need to.

DC case: You shove electrons in (slowly) at one end of the wire, they push the electrons which were 'sitting' there along (slowly), they push the next ones along and so one until the electrons at the other end get shoved and can be made to do work. Although the electrons are individually moving slowly, the 'shove effect' moves much faster - at something approaching the speed of light. An electron injected at the generator end may or may not make its way round the circuit back to the generator, but it doesn't need to in order to transfer energy to the 'work'. A physical example of this sort of thing is given by a Newton's cradle - energy is transmitted at the speed of sound from one end of the cradle to the other by a compression wave without the particles in the intermediate balls moving very far from their equilibrium positions at all.

AC case: It's not much different at this level. The electrons are just pushed and pulled in and out of wire at the generator end, and the effect propagates as a wave down the wire to the work end. Because the drift velocity is zero averaged over an AC cycle no electron makes its way around the circuit except by diffusion. The electrons at the other end are forced to jiggle back and forth and can be made to do work.

Does that help? Apologies if I've misunderstood your questions.

I don't know anything about the practicalities of energy distribution so can't comment on that.

This has now strayed a long way from my opening post, but it's all been interesting to me at least. I am now decided firmly against a smart meter and given that it looks like I'm going to be paying about 65p per kWh for electricity after 1st Oct I'll probably switch to a supplier bound by the price cap.

Robin.

Edited By Robin Graham on 03/09/2022 23:18:26

I'm not quite sure what you're asking Dave, but your understanding seems broadly correct to me. Certainly there is no direct path from a generator to a consumer, the electrons get mixed up in the grid. I don't think there is much storage capacity in the UK so the 'pot' in your analogy is fairly small. If I'm right (and I'm happy to be corrected - I'm only just starting on my quest to understand all this) the 'pot' is filled by supply taps fed from various sources - nuclear taps provides a steady stream, wind taps sometimes gush then sometimes drip and dry up, solar taps gush and drip in more predictable ways, and the demand taps at the bottom of the pot open and close in a fairly predictable ways. To balance supply and demand the flow from the Combined Cycle Gas Turbine supply tap is turned up or down as needed. That's my (no doubt over-simplified) understanding anyway.

More generally:

When companies generate carbon-neutral energy (ie everything except that from burning fossil fuels) they also generate Renewable Energy Certificates (RECs) in proportion to the amount of energy generated. These aren't attached to the electrons unfortunately! They are abstract representations of 'value' in the same way as money is an abstraction, and are traded speculatively just as money is.

For the most part, when you buy 'green energy', or indeed 'green' anything you are buying from a company who has bought enough RECs to cover their carbon footprint. The idea behind this system is that if consumers demand more 'green' products, REC prices will rise, so supply will follow and there will be an incentive to invest in renewable energy technologies because the price of the RECs will increase. This is what is called a 'market based solution' to the problems we face. Other solutions are available I expect.

Robin.

Edited By Robin Graham on 03/09/2022 00:40:24

Ian, in reply to your first question about 20% of UK energy (source We Own It ). In reply to your second, I have no idea. Well I do have some ideas actually, but they would take this thread into the realm of politics, which wouldn't be appropriate for this forum.

Dave W, your question about Shell's claim that all the energy they is from sustainable sources is interesting. I had been looking at this myself to try and understand where the premium I pay to Good Energy actually goes.

It seems that when energy providers generate 'carbon neutral' energy they also generate Renewable Energy Certificates (RECs), one per MWh. RECs are traded (effectively globally) - they have their own market. It is thus possible for a company to represent themselves as 100% carbon neutral by buying the requisite RECs. This muddies the waters - not least because (according to one source) "the market in RECs is not entirely transparent".

A criticism of the REC system is that it doesn't drive 'additonality' because a great many RECs are generated by legacy generators - for example nuclear stations built decades ago generate RECs. The claim made by the three cap-exempt companies is that they use the premium to drive additionality directly. So they might contract to buy directly from a start-up windfarm for example, thus making the project viable when it might otherwise not have been.

Probably more than you wanted to know, I'm getting interested in all this now though!

Robin.

If the silver steel is 'as bought' it will be in a 'soft' state, no need for any heat treatment before machining.

Robin.

Edited By Robin Graham on 01/09/2022 21:52:04

Thanks for further comments.

Gray - your experiences add more weight to the case for not going with a smart meter, at least at the moment.

Dave W - in my case, I have discovered that my supplier (Good Energy) along with two others (Ecotricity and Green Energy UK) were granted permanent exemptions from the price cap in 2020. This was because they persuaded Ofgem that "By consumers being on the tariff, support is given to generation and production of renewable energy to an extent that is materially greater than that which is brought about as result of subsidies, obligations or other mandatory mechanisms". In your case it might be that Economy 7 isn't deemed a 'Standard Variable Tariff', or that the cap is being applied to a weighted average of peak and off-peak rates - (7*18 + 17*34) ÷ 24 = ~29.

Regional variations in unit rates are tabulated here (Money Saving Expert) but don't amount to much: for electricity they vary from 27.13p (Yorkshire) to 29.39p (London) /kWh.

Robin.

Thanks for the link Michael. From the info DDC give it seems that with newer meters the gas meter 'talks' to what DDC call a "Comms Hub" which they say is "usually built-in to the electricity meter". This is now dual-band, 2.4Ghz and 868Mhz (apparently the older single-band systems are 2.4GHz only). However when it comes to the Hub sending the data to DDC they say only that is 'through radio waves', not giving any data about frequency. Nowhere do the give the Tx power of the transmitters.

My scepticism about the technical possibility of a smart meter working in my house was based on the observations that my mobile phone (EE 4G, which uses 1800 and 2600 Mhz bands) doesn't get any signal in either cellar, and my wireless router (2.4GHz, 100mW) , located on the ground floor, isn't 'visible' from the cellars either. Class 2 Bluetooth (2.4GHz 2.5mW) obviously hasn't a chance. However my (non-Bluetooth) wireless headphones with the base unit on the ground floor work fine. I have a dim recollection that they use something in the region of 800MHz, so it may be that the dual-band 'Comms Hub' would work, assuming the "radio waves" that the Hub uses to send data to the DDC use Band 20 (800MHz) or Band 8 (900Mhz) of the 4G network.

Anyway, I now understand the issues much better than I did before posting, and will be in a position to ask some sensible questions when I next get a nagging call from my energy supplier (Good Energy). Whether they will be able to give sensible answers is another question of course.

Regarding off topic posts, well I did say I my question was "mainly" about technical matters, so to that extent I invited wider discussion. For me it's been useful to read about people's experiences with smart meters, and given what 's been said and the fact that it's not a problem for me to submit readings monthly there doesn't seem to be any real advantage (for me) in going down that route at present. So maybe the whole technical thing is moot, but I still like to know how stuff works!

Going off topic myself now, in reviewing all things energy-related I have discovered that Good Energy are exempt from the price cap (because they're so Good) and have been charging me ~39p /kWh for electricity against a cap of ~28p/kWh. That's nearly 40% over the cap! They didn't mention that when they were wooing us! I don't mind doing my bit for the environment but if they maintain the differential when the cap goes up to 51p/kWh I'm off. The reason it took me so long to pick up on this is that the cap is normally expressed as 'annual cost for an average household' and I assumed that I was paying over par because mine was an abnormal household, which it is in some ways. It's a very vague and potentially misleading way of quantifying the cap.

My thanks to all for replies, Robin

This one is mainly about how the things work, rather than the pros and cons of having one.

We had a phone call from our energy supplier today inviting us to have a have a smart meter installed. I explained to the lass on the phone that it might be technically difficult because our gas and electricity meters are located in cellars and are about 1.5 metres below ground level. All I could get from her was 'WAN coverage is very good in your area'. She wasn't able to give me any info as to the frequency and power of the transmitters they use.

So far my researches suggest that the latest generation of these devices use a low-power battery operated (for safety reasons?) transmitter on the gas meter which beams readings to a unit attached to the electricity meter, which then sends both gas and electricity readings on to a government operated* facility for distribution to suppliers - by what mechanism isn't made clear on the gov.uk website. Don't worry your pretty little head about it love!

There is a potential problem with this scheme for me in that the gas and electricity meters are in separate cellars which are divided by a metre thick stone wall. 2.4Ghz photons struggle to get through. And mostly die - at least at Bluetooth Class 2 power levels.

The point of this post is to ask if anyone in a similar situation has got these things working, Whether I want to have a smart meter is another question, but if it's not technically feasible, well, that makes the decision for me.

Robin.

* Government operated means subcontracted to Capita who of course have have an impeccable record of delivering and aren't spooky in the least.

R.

I don't know if it's relevant to the OP's point, but as an aside a large part of that difference is due to taxation. In the US they pay around $0.09 per liter tax (combined Federal and average State tax), so the 'actual' cost of a liter of gas is around $1.09. AFAIK they don't have an additional 'sales tax', but I might be wrong. Here (UK) we pay £0.53 per litre duty, plus 20% VAT on the total ('actual' cost +duty - yes, we pay tax on tax!) which means that the 'actual' cost of a £2 litre of petrol is ~ £1.14. I guess the remaining difference is down to the UK being more dependent on oil imports than the US.

Just thought I'd share that midnight calculation!

Robin

I've been wondering why I was getting a barrage of notifications of new postings on this thread, then had a look and saw that I started it. At 01:23 on a Sunday morning six years ago. I was probably having my nightcap and feeling a bit discursive. Perhaps I should be banned from posting in the wee hours. But it seems to have had a function!

For the record my views have changed somewhat since my original gripe about restricting the availability of chemicals to the general public. I don't like not being to buy concentrated nitric or sulphuric acid on the internet, but accept that it probably had to happen. You can find a recipe for almost any anything on the internet now - when I was a kid it was the knowledge not the not the means which was restricted.

On a lighter note, in the spirit of Dave's supermarket related Commandments I would ban people who feel that they have to mash their payment card into the checkout machine - IT'S CALLED CONTACTLESS FOR A REASON shouts my inner voice. It bugs me out of all proportion to its importance. I want to follow them outside and 'have a word'.

Robin.

Thanks for further replies.

Peter Greene - thanks, though I had already realised that I have 192.168.xxx.xxx on 'my'side of the router and have set things up so each of my devices has a static address in that space - I needed to do that because I have Samba and NFS shares between devices.

Jouneyman - I'm coming round to your (and others' way of thinking, ie that it isn't worth the hassle of setting up 'private' server, largely because of security issues. Just something I was toying with because it would be a fun thing to do. I'm OK with setting up Apache oddly.

Peter Cook 6 - thanks for your explanation of how outgoing/incoming packages cross the router interface. I had a look at the router configuration and found that I could toggle DMZ 'on' (after dire warnings from the router!). I made a brief experiment and had a working server, but quickly shut it down because of security concerns. I'm not going to risk going that way.

Pretty much spot on. I'm satisfied (thanks to PeterC6's explanation of how the router works) that I can, in principle (and brief practical proof of principle testing) , set up a server on my computer. Sometimes proof of principle is enough. I'm not going to take on the risk of hosting on my home machine.

I suppose that at least part of my reason having a home workshop is like Dave's - learning and interest in the process of making things. For me personally it's also to do with demystification. Sometimes I make simple things for other people - a camera mount, an oven knob, whatever. Wow! how did you do that? By having a turny-roundy thing (as someone I know delightfully characterised my lathe), some bits of metal which can cut other bits of metal and a little skill. Same with computers - I like to know, at least in principle, how things work.

Robin

Edited By Robin Graham on 20/07/2022 01:07:32

Peter - thanks for the info re email addresses. That makes sense.

Bazyle - my connection is over copper to the exchange (over the road, about 70 metres away!) and fibre optic from there I think. ISP is TalkTalk. But I don't think that I've ever had as bad as a 10:1 down:up ratio - well, not recently for sure. Interesting, I take the points about running a server being outside T&C's and unfairness to neighbours, but if I go along this route it's likely be temporary (security issues) and I would be very surprised if anything I publish will generate bandwidth-challenging traffic. I shan't have any (ahem) 'tractor-related' pages or anything like that. A bit of lathe porn perhaps.

Dave - thanks for the numbers. Your calculations give some welcome perspective. I'm pretty sure I'm not going to get 22 people competing to see my stuff (which will be largely text based). I'll probably buy webspace in the end because of security if nothing else. Though I've just had a look and it seems that TalkTalk do a 'Business Package' which includes unlimited landline and a static IP address for £26 per month - which is less than I'm paying them now! Hmm.

I'm now trying to understand how my router works. It serves maybe eight or nine domestic devices, and I'd assumed that as communications with the 'outside world' are invariably initiated by those devices they give a port number or something which allows the router (which obviously has a single public IP address) to direct replies to individual devices. I can't yet understand how I could run a server on the machine I'm typing on and get packages initiated externally and directed to the public IP address of my router sent to the correct device. Perhaps the DNS allows for such things? The mists are gathering again! II don't need to know this stuff I'd just like to understand if possible.

I'll get there, but any info to speed the process would be welcome.

Robin.

Edited By Robin Graham on 19/07/2022 01:06:53

Around 32% RH at 25.5C indoors this evening here in Derbyshire - earlier around 24% at 32C outdoors. Daughter in London reports 44% at 27.5C indoors, so not too bad.

For once I'm pleased to have a semi-subterranean workshop (cellar of house on steep gradient) - 19.5C down there! That's the hottest it's ever been without heating I think -normally sits at 12-14C throughout the year.

Robin.

Thanks for further advice Dave. I didn't know that dynamic addresses were in fact (somewhat) stable - I had assumed that they were allocated pretty much 'on the fly', but it sounds like running a local server might be the way forward, initially at least. I'm well aware of the security risks though - I once arrived at work to find my ethernet cable unplugged and a note on my desk to contact the Computing Centre asap. It turned out that my machine had been used to launch a DoS attack on  a University in Israel - some blighter had managed install a rootkit despite the security of the Comp Centre's firewalls etc. If they couldn't stop that happening I don't think I have a hope of defending my home machine against global probings. It's quite scary actually - when I establish a wireless connection with 'my' router I see neighbours' routers as well - even with my limited knowledge I could easily get into their configuration pages (few people change factory set passwords) and reset DNS server info etc. I wouldn't do that, but some might. And I'm sure there are many people out there who are much more savvy than me!

Peter Greene makes a good point - a quick check reveals that my download speed is ~38Mb/s, upload a paltry 9Mb/s.

Journeyman - thanks for the info. I had thought that when providers said 'one email' they meant just myonename_at_domain, and it foxed me a bit - surely it must be trivial to make new mailboxes given a domain name? I'll investigate! On ,htaccess, perhaps better to avoid altogether and do what you need to do in the Apache configuration file? Assuming you have root/administrator status

.I doubt that I will need to learn SQL for what I have in mind, it would just complicate things.

Neil - thanks for the suggestion of 123-reg, had a quick look and it seems promising.

Robin.

Edited By Robin Graham on 18/07/2022 00:33:04

Edited By Robin Graham on 18/07/2022 00:35:02

Edited By Robin Graham on 18/07/2022 00:38:08

Thanks for replies - all very helpful. I'm sorry if I wasn't clear about what I'm looking for - I'd spent an hour or more trying to negotiate my way though 'advertising blurb' before posting so my brain was fried. And my temper short.

Thank you John (Journeyman) for the direct link to the Ionos page listing their packages - I gave up before finding it. That was what I wanted.

It'll take me a while to work through all the suggestions / links, but at the mo Fasthosts is looking good. I'll follow up other suggestions though. I'm looking for something pretty basic - I don't need website building tools at this stage, I'm OK with coding in HTML/Java and have pages which I've already developed and can run locally in my browser. If (and it's a big 'if' ) I get more ambitious I'm sure there is third party development software out there. I don't want to get locked into development tools provided by the hosting company, and I have no serious commercial ambitions.

Dave (SOD) - I wrote the above before reading your post. Thanks for your characteristically informative and clearly written contribution. It wasn't the Ionos start page that provoked the FFS reaction - I got through that OK and the domain name I wanted was available, I suppose I just got crabby - I wanted the bottom line and it seemed a hard trek to get there. Having backtracked I was only a click away from the page Jouneyman linked to, but had run out of steam. You're right, I should have persisted!

Ionos' opening page's 'Power your project with scalable hosting' sort of set the tone. For me that's not friendly. It's patronising . As is the knitting analogy. Perhaps that put me in a bad mood!

I wrote 'own' in inverted commas for a reason - I understand that I am buying something more akin to a lease than a freehold.

To give some background, in my working life I used to teach C/Unix programming inter alia and made web pages to allow students to access course materials. I had the luxury of a powerful computer with a static IP address in my office so I could use Apache to give me a "personal" website - [mycomputer].[uni].ac.uk . What I'm trying to do is replicate that in a home environment - it's more to do with understanding the way the commercial web hosting world works than the nuts and bolts of building webpages.

Thanks again to all for advice, the mist is beginning to clear.

Robin

[edited to get rid of unwanted  winkicon]

[and again and again to remove angle brackets which don't seem to be allowed]

Edited By Robin Graham on 17/07/2022 01:04:07

Edited By Robin Graham on 17/07/2022 01:10:34

Edited By Robin Graham on 17/07/2022 01:12:59

Edited By Robin Graham on 17/07/2022 01:22:24

Edited By Robin Graham on 17/07/2022 01:26:20

For various reasons I would like to register a domain name and buy a modicum of webspace together with a couple or three email addresses associated with the domain. So I could have space for content at www.mydomain.whatever and email addresses [email protected]. Should be simple I thought,

I've had a look at two providers - GoDaddy and Ionos - but I'm finding it difficult to understand what they're actually offering and at what price. For example, Ionos ask me for my preferred domain name (it takes them a whole page to ask this question - I'm told "Need a website? You own this!". "Knit up the perfect website in a flash. No experience needed." ) FFS. I don't want to knit anything and realise that I 'own' the domain name for the duration of my my contract, that's the deal isn't it? I just want a DNS registered website with some defined storage space and some linked email addresses with defined storage space. Not "all you need". Pretty much the the same with GoDaddy - it seems hard to know exactly what you're buying.

Can anyone recommend a 'package' which would meet my needs?

Robin.