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Member postings for Phil Whitley

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

Thread: Interesting??
23/05/2019 21:29:21

BTW, not intended as a "Tirade" just observations really. I don't get what quantum physics has to do with GPS, we were positioning accurately to a matter of a few feet shortly after ww2 using ground stations, in 2 dimensions, the ability to launch sattelites increased this to three dimensions, and meant that terrain did not get in the way. Turing was a genius mathmatician, but could not have built the computers he needed, but he was able to get his ideas over to a clever GPO telephone engineer, who built the first computer since Babbages attempt at the mechanical one.

23/05/2019 21:06:20

Basically, Wot Neil said!! But some observations. Edison invented nothing apart from his telegraph device, that was not already working somewhere in the world, he merely obtained the first American patent on that thing by getting his team to come up with a quick working prototype and rushing to the patent office! Maxwell was a mathmatician, Steinmetz was a mathmatician and experimental engineer. The lone inventor is all but extinct because of the patent system. It has become possible to patent ideas without any proof of concept, and so teams of company scientists are involved in this process daily, (IBM are one of the biggest) with the result that no company will fund research into any area that already has patents owned by another, and if anyone does come up with something that works, they can use their legal and financial clout to make your invention come under their patent. I have a friend deeply involved in traffic management systems, and he and collegues worked on an idea for several years, which they patented, for a bus navigation system, which they showed to a major european bus manufacturer. They changed a chip in it, stole the device, and said, ok so sue us! The possesion of a patent means nothing unless you can afford to defend it succesfully in two or three cases, and as Mr Dyson has found out, that costs millions. There is no such thing as Artifical intelligence, that is the hype that makes people believe it is clever. It is merely a machine functioning as it has been programmed, and you can program a machine to write its own program, but it is not capable of thought, it is just crunching zeros and ones very fast. The self driving car, like nuclear fusion, is only twenty years away, and always will be! It requires consciousness to drive a car, not just inttelligence. I have been looking for some proof of this for some time, and found it in some recent discoveries in Neuroscience. If you take a subject with a damaged visual cortex, who has no vision whatever, but has perfectly working eyes, and sit them in front of a screen, you would imagine that you could play anything on the screen and it would have no effect on them, and you can, except that if you show them an attacking predator, they immediately recoil from it, but when asked, say they saw nothing, and do not know why they recoiled. You need this sense to drive a car, how are they going to build that into a computer? By the way, whilst there are theories about magnetism and electricity (and gravity) no one has come up with an explanation of what they are and why they occur, they have merely been quantified Tesla, Heavyside, Steinmetz and Maxwell all denied the existence of the electron, and their calculations are no less correct for it.

Thread: Oh Dear, I've blown the chop saw...
23/05/2019 20:24:56

actually looking at the pics again, is that a bit of blackened field coil I can see through the lower gap? Field could have failed and caused the arcing at the armature. Armature failure is more common though.

23/05/2019 20:21:20

I see that the gaps between the commutator bars are wider in the middle, looks like the insulation has failed in the armature windings, test between the comm bars and the shaft of the armature, with an AVO, or a megger if you have one, any continuity, or a resistance of less than 1 Mohm and the armature is toast. Check the manual and get in touch with the spares supplier, then at least you can weigh the cost of a new armature against the cost of a new chopsaw.

Thread: Interesting??
23/05/2019 09:13:00
Posted by SillyOldDuffer on 20/05/2019 21:07:05:
Posted by Phil Whitley on 20/05/2019 20:07:54:

The steam engine was invented , built and used in many forms without any knowledge of thermodynamics, in fact the science of thermodynamics was based on the study of working steam engines. The electric motor was invented by Michael Faraday, who was a well trained book binder who was employed by Sir Humphry Davy to write up and bind his notes. Science and scientists have a very poor record of invention of anything in common use today. It is the people who constantly test the laws of physics and experiment that make the breakthroughs, those who stick within the orthodxy of science discover nothing.

A very unfair criticism of science because the goal of science is understanding, not inventing! It's other people, like engineers, who exploit scientific understanding by inventing new things or improving old ones.

Dave

I don't see it as unfair, pointedly accurate perhaps, science is often understanding for the personal satisfaction of the curiosity of an elite, who never put that understanding into practical use. It can also be the development of very efficient new poisons to kill pests and weeds without any consideration of the future effects. Our entire electrical system was brought to the point it is in today by a small group of brilliant engineers, Tesla, Heavyside, Maxwell and Steinmetz are the main ones, and their work has been advanced very little in the years since their passing, and also no one ever heard of them, except perhaps Tesla. Einstien on the other hand is universally known, and much of his work is theoretical and obscure (and possibly wrong, they are only theories!), he got his Nobel prize for a paper on the Photoelectric effect, which he neither discovered or put to use, he merely "quantified" it. Tesla called Einstein a "Fuzzy haired crackpot" Science, as in the "understanding of the universe" is important, but going to the moon "because we can" turned out to be a pointless waste of resources.

Thread: What do YOU call it?
23/05/2019 08:48:38

I call it work!

Thread: Oh Dear, I've blown the chop saw...
23/05/2019 08:46:14

When I buy any tools from Aldi/Lidl, first thing I do is staple the reciept inside the instruction manual that comes with the tool. You do after all get a 3 year warranty!. first off, is it a soft start motor, ie does it ramp up the speed after you have pulled the trigger? if it is, suspect the thyristor control failure, which is quite common. second, check the interference suppression capacitor bridge, they blow up very loudly and frequently, and the tool will work without it anyway. Parts are usually available from Kompernass, which is the german company that imports these tools, check in the manual. Strip it down, and find where the smoke came from, it will be fairly obvious. If the commutator slots are not parralell, and burnt, armature failure may make the repair not worthwhile, but check on the price anyway, I have many Aldi/Lidl tools, and have abused some of them to the point where I was not really suprised they broke, but by and large, they do the job, and if they quit within three years, you get a new one or a free repair provided you have the reciept!

Thread: Interesting??
20/05/2019 20:07:54

The steam engine was invented , built and used in many forms without any knowledge of thermodynamics, in fact the science of thermodynamics was based on the study of working steam engines. The electric motor was invented by Michael Faraday, who was a well trained book binder who was employed by Sir Humphry Davy to write up and bind his notes. Science and scientists have a very poor record of invention of anything in common use today. It is the people who constantly test the laws of physics and experiment that make the breakthroughs, those who stick within the orthodxy of science discover nothing.

Thread: A dynamo question: rotation direction?
11/05/2019 18:48:52

Tim, long time since I did a dynamo, so don't have the circuit in my head, but to reverse a universal or DC brush motor, you swap the wires connected to the brushes over. You have proved it as a motor, if you polarise it by sparking a battery lead onto the field terminal, then spin it in the right direction and see if it charges, or you get some output. I assume the car is positive earth, so flash the battery negative to the field to polarise it in the right direction and it should be fine. We used to swap over from + eart to - earth to install a stereo, which were mainly -earth, just swap the battery and coil terminals, repolarise the dynamo, and off we go! can you post up a circuit for the dynamo internal connections?

hope this helps

Phil

Thread: Bandsaw blade jig
11/05/2019 13:59:22

Brilliant, the use of the hinges is a bit of superb lateral thinking!

Thread: Sump Plug
08/05/2019 21:16:59

Had this problem on occasion, as a last resort, drill a snug fitting hole in the end of a piece of stout flat bar, place over the square, and mig weld it onto the plug. The heat from the welding will expand the whole shebang, and out it will come, fit a new sump plug, preferably something with a hex head!

Thread: CovMac Lathes
08/05/2019 21:01:05

Bored the five sheave pulley from 1.25" to1.5", or 38mm if yer metrically inclined! will need to drill and tap for a grub screw after I have recut the keyway, as in the previous fitment this pulley had a tanged key in it, and the new motor is an internal key. That's tomorrows job!

Edited By Phil Whitley on 08/05/2019 21:01:46

Thread: 3 phase to single phase wiring
08/05/2019 18:29:18

Provided the cables are labelled, this is not a problem. I assume you want to connect the motor in Delta, if the cables are marked you will have A1 B1 and C1, and A2 B2 and C2 will be connected together on the N terminal? if this is the case, you will need to use seperate connectors, and connect A1 to B2, B1 to C2 and C1 to A2. the motor is now connected in delta for 240v three phase running. put one phase from the vfd to each connection. If the cables are not marked, start by assuming that the A B and C are the "ones" and the three connected together are the "twos" test from A1 with a multimeter till you get continuity, that is A2, and so forth.

Hope this helps.

Phil

Thread: CovMac Lathes
07/05/2019 20:33:05

Glad to report some progress on the Covmac!! Yes I know it has been a long time, but I have been busy restoring other things in the workshop, and thanks to my mate Richard coming over to play for the day, the Covmac motor is fitted! Tomorrow I will bore the pulley from 1 1/4" to 38mm (or is it 1 1/2" and fit it. Pic is on its back! tried to turn it round, which I have already done on my computer, failed, gave up!

Thread: Turning Cast Iron question - Health & Cleaning Up
06/05/2019 17:35:11

Whilst I think that it is very unlikely that even the most avid model engineer will suffer from what is commonly known as turners lung, I have a good friend who was working as a precision engineer (and loving it) till his employers got a contract to turn a large number of iron castings, and after suffering the black dust, cough etc for a few months, he quit! It always makes sense to wear a dust mask whenever there is dust of any sort in the atmoshphere. Indeed, sweeping up in my workshop (one of my favourite jobs) will set off my sinuses for a couple of days, so I tend to use a vacuum ( double filtered Dyson that my neighbour chucked out). When I am turning cast, I sheet the bed down with dust sheets and magnets, and use a strategically placed vac nozzle to take the dust away before it gets chance to settle. Did a rush job the other day, two discs for a Mazda, 10 minutes work, followed by an hour of cleaning down!

Thread: Coil binding tape = Empire tape? Suppliers?
27/04/2019 16:54:11

I well know and have used the product of which you speak, Tim, but about 40 years ago, you could try them in Rotheram. http://www.empiretapes.com/Specialist-Tapes

Thread: Safety of phone chargers
24/04/2019 21:38:24

Martin 100

"Electrical correctness' is not a word I would use to describe significant parts of what is said above."

Holding the view that rewireable fuses are 'safer' is staggering, they are by nature always slower in operation, they are prone to abuse, unreliability and early failure.

Staggering eh? do you have any evidence for this, I did mention they are prone to abuse, and you certainly cant fight stupid, but the vast majority of the British housing stock that was wired or rewired between the late fifties to the eighties still has rewirable fuses, and is very unlikely to be upgraded unless extended. Since these rewires were done, the number of electrical housefires fell dramatically (Rospa figures)

The 3 to 5 times rated current for a type B MCB, and similarly for the other types is for a fault clearance time of 0.1 seconds. At around 2 x their rated current they will trip in around 2 minutes

Interesting, so why are they catching fire? Could it be because of the vast numbers of chinese made mcbs on the market?. the introduction of fully metalclad CU's and fire sealed cable entries means that already, there are serious problems. Incidentally 2x the rated current for a 2 minute trip is longer than a rewirable, even at 1.8 fusing factor!

A BS1362 plug top cartridge fuse rated at 13A requires around 150A to clear a fault in 0.1 seconds

It may require that to clear in 0.1 seconds, but requires much less than that to clear in 1 second. I have tested this at college many years ago under lab conditions. The IEE set the fusing factor for an HRC cartridge fuse at 1.2 times the rated current, are you saying they were wrong?

Rewireable fuses are long since deprecated. Cartridge fuses or MCB's are the norm worldwide because they are good sound reliable and dependable engineering practice.

Explain this "deprecation", lets hear some thoughful logical reasoning if you are going to comment at all. Is it "sound reliable and dependable engineering practice" to fit a device as sole means of overcurrent protection that has no failsafe capability and can, and does stay in the on position in the event of an internal failure, and will carry current till it literally catches fire because the next line of protection is the 100 amp service fuse, which (according to your calculations)will need 1153amps to blow in 0.1 seconds, here is the clear illustration of the reason for the introduction of the Metalclad CU. IEE regs used to state that "No mechanical device or circuit breaker shall be fitted in any final sub circuit as the SOLE means of protection" In other word, use an MCB or other circuit breaker by all means, as long as it is backed up by a similarly rated fuse, ok use a cartridge fuse if you must, but electrically they are only a little better than a rewirable, although harder to fit the wrong size. To say they are "the norm worldwide" is just silly, they may be the norm worldwide IN NEW INSTALLATIONS, but that is all. The UK has the safest and most modern system in the world, and we still have a majority of "legacy" installations. I have shown that MCB's, under certain circumstances, are much less safe than fuses, and the IET regulations upgrade to metalclad (which used to be common anyway in large domestic commercial and industrial installations) and their introduction of Potential fault current calculations shows that they are literally firefighting the problem!

I stand by what I said, which is based on 50 years of practical experience of a wide range of domestic, factory and heavy industrial installation, faultfinding and maintenance You are entitled to your opinion.

Phil

24/04/2019 20:28:54

t was a politicians son or daughter that died due to shoddy electrical work carried out by a builder that brought about PART P. Which in my opinion is a good thing, but would be better if it was ENFORCED, and not just a money making scam for the powers that be, and jobs for the boys.

Correct Paul, it was. but the reason (she) was killed was not shoddy work, but the removal of the requirement that "all extraeneous metalwork must be earthed" from the regs. A metal framed partition had been fitted and wired for lighting, then plasterboarded, and a pb screw had damaged a cable. If the metalwork had been earthed, the rcd would have tripped immediately the circuit was powered up, but it remained on, and the partition frame became live and went unknown till the unfortunae victin was mopping the concrete floor next to the partition. I had the report of this occurence sent to me by electrical review, and wrote a piece for them commenting on the problem highlighted by this unneccasary tragedy. The part p boys claimed that it was caused by a lack of proper testing, whereas it was actually caused by lack of proper earthing! A test is only valid on the day it is done, a properly fitted and earthed installation is always safe.

23/04/2019 09:24:41
Posted by duncan webster on 23/04/2019 08:42:38:

So how do you check that the ring is continuous? First thoughts are that you need to make it discontinuous at one socket and check that both ends are still live, but then you have to put it back together and so can't check this last connection

https://www.google.com/search?client=firefox-b-d&q=testing+a+ring+main#kpvalbx=1

There you go Duncan!

22/04/2019 21:29:55

Of course there is another factor in all this which I have not mentioned. I served a five year apprenticeship and spent three years at technical College to gain my qualifications, you may not believe this, but today you can go to a "college" tip up about £3500 and become a certified domestic electrician IN 5 WEEKS!! Is it any wonder that standards have fallen through the floor?

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