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: Lathe facing convex or concave|
`Ok lets turn this question round(lol) How would all you concave dwellers out there "adjust" a lathe to make it turn slightly concave Without affecting the accuracy of the lathe in any other plane? I think you will find that a lathe should face completely flat, which is about as possible as a slide or a leadscrew with zero backlash. All that is being said in the ancient lore of magical machine tools is " in the time we have got to set up a lathe which retails at this price, get it facing as near to flat as possible, but it is better for the lathe to turn slightly concave, rather than convex. How near you get to flat depends on whether its a harbour freight or a Hardinge. I don't honestly know if my Colchester student roundhead faces slightly convex or concave because it is not important in 100% of the work I use it for. Although thinking about it, A T shirt emblazoned with the slogan "my lathe faces concave" would have a certain appeal to some sections of the home machining fraternity. (pulls on tin hat and heads for the Anderson shelter).
|Thread: Efficient Workshop Heating|
Just cap one end of a copper tube put a wick it from end to end,
Hi Russ B,
I assume you mean put a wick IN it from end to end? Just interested in the heat pipe theory, and you have also educated me as to what GPGPU Is!! very interesting, and a concept I had not considered, although I am not as involved with the computing world as I used to be!
|Thread: Lathe facing convex or concave|
At the risk of starting an international incident, a lathe should face at exactly 90 deg to it's axis, and the face turned should be perfectly flat. How close the manufacturers get to this will depend on whether it is a Harbor Freight or a Hardinge. When we face bar off for appearance, we do not lock the saddle, when we are going for more accuracy we lock the saddle, perhaps check and adjust the cross slide gibs (gybs) a little on the tight side. When we have done this we have taken the machine tolerance and clearances as far back to the manufacturers tolerances plus the wear, that we can. We then face off at the smallest tolerance that particular machine can achieve, without going to huge lengths to achieve the last few (some would say irrelavant) tenths of a thou. It is pontless to continue this type of argument unless someone can come up with a reasoned argument as to WHY a lathe should face slightly convex (or concave). In a wearing situation the faced part will present its outer edge for wear first if concave, and it's centre if convex, but in the long run, it will make no difference. A flat surface will present all to a wear face, and thus wear less. The ideal of precision machine tool manufacture is to make a mchine that is PRECISE, and able to maintain that precision by adjustment as it wears. How near manufacturers get to this is generally reflected in the price of their products.
|Thread: Cost to build in brick?|
Try this brick, block and mortat calculator.
|Thread: Machining Cork|
Could you use one of the synthetic corks that are appearing in our wine bottles?
|Thread: Servicing Machinery Bearings Properly|
In fact, if you open up brand new sealed bearings you will see the manufacturers use the barest skerrick of grease, less than 50 per cent full by far.
There is a reason for this, and it is not to extend the life of the bearing!!! I have fitted many thousands of bearings in automotive , electrical and mechanical equipment. I have always packed the bearing full, rotated it by hand, and then removed any excess. I only began to notice premature failures of bearings when the "sealed for life" junk came out. not putting enough grease in a bearing is a sure fire way of increasing sales. If I cannot get an unsealed bearing, I pop out one of the seals ( they are not actually dust tight anyway, most are all metal) and repack the bearing FULL. after all, a bearing with a grease nipple (Zerk to our overseas cousins) will be greased until grease is seen issuing from the relief hole, or the seal, and this means the bearing, and the surrounding casing is absolutely full. When I started my apprenticeship in 1967 one of the first jobs I had to do was recondition a huge pile of electric motors which had been removed from an old powdered milk plant. They were all between 2 and about 10hp and had been in continuous use since 1937 when the plant was built. They were greased daily, and the air vents and windings blown out weekly. They were stripped, washed out, bearings repacked, and put back into service. very few if any of the bearings needed replacing. Granted they were all Brooks of Huddersfield cast iron framed industrial motors, but they had seen 30 years virtually continuous use! I have seen bearings fail with over greasing with a grease gun, because the grease finds its way into the inside of the machine, where it tracks dust back into the bearings, but this is rare. There is no surer way of making a bearing fail than not putting enough grease in it.
|Thread: Open thoughts|
I call my self an Electrical engineer, because I passed an OND in Electrical engineering. OND/HND and ONC/ HNC tend to be taken as part of an apprenticeship style training in an engineering discipline. In other words, they tend to be based on the practice of a skill, as well as theory. Degrees tend to be academic, ie, based solely on theory and rules "laws" etc. The practical approach seems to produce a more rounded "engineer" who can cope with a wider variety of problems . The Phd without practical experience is of purely "academic" value. It is however the fault of the training, not the man! In the UK today we have more graduates asking "do you want fries with that" than working in the areas they were trained for. Whatever good engineers are, you ignore them at your peril!
What we have to fight against is the wave of political correctness, sweeping across the Atlantic from America, which states that you may not call yourself an "engineer" of any sort unless you have a degree. These people need to remember that the laws of thermodynamics were based on the study and measurement of steam engines. Luckily for messrs Thomson and Carnot, Messrs Trevithick ,Watt Et Al who were practical engineers and blacksmiths, had designed, built and operated steam engines long before the "lawmakers" arrived on the scene. Michael Faradays only qualification was an apprenticeship in bookbinding, he got the job as Humphry Davy's secratary on the strenght of presenting Davy with a bound set of lecture notebooks. Regardless of the field of engineering, if you can do it, you don't need paper qualifications, if you can't, paper qualifications will not help!
Phil, 5 year appreticeship, 3 years at technical college, National Diploma in Electrical ENGINEERING
61 years young, Dreadlocks down to my Ar*e, still learning.
|Thread: Could Concorde ever fly again? No, says British Airways|
remember going to Reading rock festival in 1978 and 1979, and experiencing the awesome sight and sound of Concorde which seemed to pass right over the riverside site as it climbed out after take off. It was one of those WOW moments you never forget.
East Yorks, UK
|Thread: electrical bonding aluminium track|
Use Densogrease (if you can still get it) aluminium cam also be soft soldered with the correct flux and wire, but use aluminium for the jumpers as well, then wash the joint and apply the Denso.
|Thread: Portrait of an engineer|
Vulcan Foundry produced a new locomotive every two weeks for 100 years!! they were exported all over the world. What has happened to our engineering industry?
|Thread: Force on welding cables|
Sorry Andrew, I didnt explain myself very well. Because the live and neutral in a three core cable are in close proximity to one another, and the current being carried by them is equal and opposite, the induction effect is cancelled out. with a welder there are two single core cables, not in close proximity to one another, so the inductance effect operates. If you have ever used a clip on ammeter you will know that it has to be placed round the individual cores of a cable to make a reading. It works on the inductance effect, and if you place it round a three core extension, or similar, you will get no current reading because of the above.
The current in a welder electrode holder and earth/work leads will be the same value in amps, but will be traveling in opposite directions. You can actually look for inductance effects using an ordinary compass held near a conductor. In a perfect world, you would get no reading near an extension lead, but a massive swing of the needle near a welder lead or other single core current carrying conductor.
The current in the welder cables will only be equal and opposite if you coil the electrode holder and earth cables together, and even then it would not be as perfect as a three core cable on an extension., The heating effect quoted on your extension lead is due to the fact that a coiled lead is unable to radiate heat due to load, whereas an extende cable is. There is no heating effect due to inductance or the fact that it is a coil.
|Thread: Glass/metal joining?|
Google Sikaflex, and see if it will meet the temperature range, I have fitted windscreens with this stuff (volvo estate) and they don't budge!
|Thread: Force on welding cables|
"Have you never wondered why the screws in Mains sockets get loose?. 50 Hz vibration from field interactions."
This is a complete myth, although I have seen it reported in a letter to a trade magazine, who should have known better, and not published it. The twitch effect in welding cables is caused by the cables coiled on the floor assuming (or trying to) the shape of the magnetic field they are creating. try putting a piece of string round one cable in a coil of welding cable, lift it to test the weight, then get an assistant to strike and maintain an arc, and try lifting it again, you should be able to feel the magnetic attraction to the other coils. It is not a good idea to leave welder cables coiled while you are working, as they can overheat. This is not the case with extension leads however, as the current in the live conductor equals that in the neutral, but they are traveling in opposing directions, and so cancel each other out. If your extension lead overheats, you're overloading it!
|Thread: Another motor wiring question|
also should have said from the readings it looks like ehite wires are the field and the red are the brushes/armature, to reverse swap over the field connections
Sounds like you should run this motor in series for AC and in shunt for DC, if you connect one red and one white together , and put the supply to the other red and white it will be running in series.
Something that strikes me here is we could do with a "sketch" facility on these sites, as well as a text box, Is that possible moderators?
|Thread: Churchill Redman Cub lathe Mk1|
www.lathes.co.uk has a manual for "later versions" contact firstname.lastname@example.org
|Thread: "Engineering" brilliance?|
For future reference chaps, there is an answer to this in the legal term (UK) "Repairers Lien" It basically means that you can collect the repaired item when you pay for it in cash, and not untill!
I had a sign in my workshop which said:
" All repairs must be paid for cash on collection. No credit will be entered into. Uncollected repairs will be kept for 3 months, then may be sold to ofset costs. Storage will be charged after 1 week."
I actually won a Jaguar XJ6 with this, so I know it works (in the UK anyway, other areas must check their local laws.)
|Thread: Rapidor Saw|
As an aside to this thread, I know that the Rapidor saw is specifically designed to lift slightlyon the back stroke, and because of this, must be run in one direction (rotation) only. Can anyone tell me what the correct rotation is? Mine is running clockwise looking at the belt pulley side, Is that correct?
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