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Member postings for Paul Kemp

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

Thread: DTI base
02/04/2020 00:15:17

Henry,

i bought a Noga style small mag base for my mill from RDG's stand at Ally Pally about 3 years ago. I turned up an adaptor to fit it that goes in the lug on the clock (it's a nothing special clock, only reads to a thou) but it does fine for general set ups squaring the vice on the Omnimill and I also use it on the lathes, it's become a sort of workshop go to where no fine accuracy is required. I wasn't expecting great things of it when I bought it but I have to say it's been great. I even use it as a quick and dirty tram of the mill vertical head by sticking it on the spindle. Very good value in my opinion, it's not a Rolls Royce of mag bases to be sure but it works plenty good enough for me.

Paul.

Thread: Manual for Elliott / Victoria / Gate Omnimill 00
28/03/2020 00:33:43

Peter,

No worries, just let me know if you don't get sorted. You won't be disappointed with the machine if it's a good one, wouldn't be without mine! Very versatile bit of kit that opens up many possibilities for the home workshop.

Paul.

25/03/2020 23:28:24

Peter,

I have what I believe to be an ordinal copy kindly posted to me by a forum member that I would be happy to scan for you (in the fullness of time when I can sort out the scanner connection screwed by a new router!).

If you want to pm your email address Inwill see what I can do in the next couple of days.

Paul.

Thread: Coronavirus
16/03/2020 23:48:55
Posted by Kiwi Bloke on 16/03/2020 23:38:47:
In a panic situation, logic is the first thing to go absent

Previous panic episodes, bread/petrol/sugar, and now loo-rolls. I despair.
DaveD

... and in the States, panic buying of guns. Probably as much at risk of being shot by some idiot in a state of panic as from the virus.

Doh, how else are they going to guard their stocks of toilet rolls? They don't call it the Wild West for nowt!

Paul.

Thread: safety valve problem
09/03/2020 21:42:03

Chris,

As others have said Gordon's work is a very good reference on these valves. Also if you can get a copy an article written by Ross Bishop in Australia. I designed a pair of valves for my traction engine with guts as per their advise and they took a little tuning, but work just fine.

The problem you describe is unlikely to be a high water level especially if all you see is steam coming from the valve, if it was picking up the water you would A, get very wet. B the water level would drop in the glass very quickly!

Sounds like the hysteresis of your valve is wrong. Basically to get the valve to open at a predetermined pressure is quite a simple task of balancing the force on the 'valve' (ball) exposed to the boiler pressure by the seat area against the static load of the spring at that point. However as soon as the valve opens you get a larger area presented to the steam pressure and you now also have a dynamic component due to the flow / velocity of the steam past the seat. Thus to get it to reseat quickly with minimal pressure loss you need a good spring rate (load / extension) and the correct annular area around the valve for the steam to escape.

To fix your valve you may need either a higher rate Spring, an increase in annular area or a combination of both. Making and tuning your own valves is not difficult just fiddly on adjustments (no point tuning on air as it doesn't react the same with steam) and it can be a challange to get the correct / ideal springs.

Paul.

Thread: Too large overlap = more high compression?
07/03/2020 18:29:55

Jens,

A little difficult to be definitive on the small amount of info provided. However assuming the port face is conventional with 2 inlets one either end and the exhaust in the middle (rather than some balanced type of valve that sends the exhaust through the valve and out the top) try measuring the recess in the valves (exhaust recess) and comparing the width of the recess to the distance between the inner edges of the cylinder ports, it should be the same or a little more (exhaust clearance or negative exhaust lap). If the distance is less (not uncommon on fast running engines) you will be developing compression in the ends of the cylinders because the exhaust will close before the piston reaches TDC. With a compound it may be designed as such to maintain a higher exhaust pressure from the HP to deliver to the LP, I would expect the LP valve cavity to have clearance though to get the spent steam out as easily as possible.

Hope that makes sense and gives you some ideas?

Paul.

Thread: Coal being phased out
25/02/2020 23:31:59
Posted by Hopper on 24/02/2020 23:05:22:

I dont have an opinion on it. Its not a matter of opinion. Its science. I dont claim to have gleaned enough scientific knowledge from google to know more about it than 97 percet of the 10,000-plus scientists who specialise in the field. That would be plain stupid of me, a perfect example of the Dunning Kruger effect at work.

I might as well go and tell the nuclear physicists how to run a power station or particle collider or tell the cardiac surgeons how to do a triple bypass or tell Einstein his theory of relativity etc is wrong because you cant bend light or see gravity.

Edited By Hopper on 24/02/2020 23:06:18

Edited By Hopper on 24/02/2020 23:33:17

There is a really good example (Einstien) who in his day was in the 3%. Trouble is he was subsequently shown to be right. So those that chose to follow and support the 97% were hoodwinked! Exactly why I would prefer to weigh up the balance of the evidence and form my own opinion even if I don't have the expertise to follow the detailed complexities. In my experience those that refuse to answer questions but evade or deflect or has often been the case on this difficult subject become aggressive or belittling are following the crowd or are politicians.

Paul.

24/02/2020 21:34:26
Posted by Hopper on 24/02/2020 03:24:56:
Posted by Paul Kemp on 24/02/2020 00:36:49:
,,,

Well if you read what I said.......... In fact relatively recently spans back to the beginning of this year (ie not decades!) and doesn't amount to a few minutes or hours on google but includes abstracts and some full papers. If you do the same looking at both sides you will see why I am asking the question, I haven't professed to know the answer I am asking if there is anyone who does and has specific undisputed evidence. As you seem to, maybe you would care to share? Can you list the 96 percent who are sure or even the alleged 4% that are not? With your obviously superior knowledge can you point me to a piece of authoritive research that includes explanations of the questions I asked?

What hard evidence convinced you?

Paul.

The 96 (actually it's 97, I stand corrected) per cent consensus among the relevant published scientific work has been the subject of numerous meta-studies and has been confirmed beyond doubt. You ask if there is anyone who knows the answer? These guys do.

Like I said in my intiial post I'm not going to argue the points of science. I leave that to the scientific experts, the 97 per cent of highly qualified scientists who actually know about this stuff at expert level and say manmade climate change is a serious problem. If you want confirmation of the 97 per cent consensus that you are wrong, look at this study: Consensus Confirmed

Which concludes:

"1) Depending on exactly how you measure the expert consensus, it’s somewhere between 90% and 100% that agree humans are responsible for climate change, with most of our studies finding 97% consensus among publishing climate scientists."

Thanks for that, that gives me a reference against those credited in the IPCC report and some further info to look at. As regards your statement "that you are wrong" what pray am I wrong about? I have not made any reference to an opinion either for or against and in my first post clearly stated up til recently I have no opinion, that has not changed. I will form an opinion eventually based on looking at all the arguments on both sides. There I think lies the problem firstly with your 'assumption' that by asking questions I have committed to denying climate change! Secondly with your statement "I'm not going to argue the points of Science. I leave that to the Scientific experts" so it seems to me you are quite happy to accept a study proclaiming 97% of those experts are right (and I am sure the study is perfectly valid) without even examining any of the evidence they offer to support their conclusions!

Neil's link later to critical thinking is more the process I wish to adopt. There is no need to argue with the experts but a critical review and broad understanding of the reasons for their conclusions doesn't as the article states require a PHD in climate science. I am afraid I was born awkward and not prepared to accept the opinion of 97% of my neighbour's that if I go past the top of the hill out of our town I will fall off the edge of the world! The first two para's on Niel's link and particularly the second really highlight the situation for me.

There is a lot to be gained and lost on following the current course, I am not yet ready to jump on any bandwagon.

So I will repeat my last question to you in a different way, is there anything else that really convinced you in your opinion (evidence based and referenced and not presented in the media) apart from the consensus of the 97%?

Paul.

24/02/2020 00:36:49
Posted by Hopper on 23/02/2020 23:41:17:
Posted by Paul Kemp on 23/02/2020 19:03:59:

...

Until very recently I have held little opinion on this subject and recieved no information outside the various media stories. Now having been put in a position professionally that is directly affected by current and potential pending legislation I decided some research was in order. Sadly that has left me more convinced that no-one actually knows and a lot of the 'evidence' is based on model predictions (both historical and future).

So now after a few minutes/hours of googling around you know more about it than the 96 per cent of scientists whose lifelong research leads them to say that manmade climate change is a very real problem? Really?

Next time, try googling "Dunning-Kruger Effect".

Edited By Hopper on 23/02/2020 23:43:53

Well if you read what I said.......... In fact relatively recently spans back to the beginning of this year (ie not decades!) and doesn't amount to a few minutes or hours on google but includes abstracts and some full papers. If you do the same looking at both sides you will see why I am asking the question, I haven't professed to know the answer I am asking if there is anyone who does and has specific undisputed evidence. As you seem to, maybe you would care to share? Can you list the 96 percent who are sure or even the alleged 4% that are not? With your obviously superior knowledge can you point me to a piece of authoritive research that includes explanations of the questions I asked?

What hard evidence convinced you?

Paul.

23/02/2020 23:15:06
Posted by SillyOldDuffer on 23/02/2020 19:23:09:

To me the clincher is that theory as expressed 10 years ago predicted what we are experiencing today. A general warming of the whole planet, increased frequency of unusual weather effects, loss of glaciers and a reducing ice-cap, and environmental conditions sufficient to shift lifeforms on a large scale. Depletion of temperature sensitive fish stocks in the North Atlantic is one example, desertification is another, and something bad is happening to plankton.

Thought the effects are complex the root cause is simple - man-made greenhouse gases cause the atmosphere to trap heat at the surface, especially in the sea. The extra energy is unwelcome because it fuels the weather - all of of it. Carbon Dioxide is the main problem gas because 250 years of industrial activity has put so much into the air, where it stays longer than previously believed possible. Methane is also a serious problem.

Personally I believe it is already too late; people are in for an increasingly rough ride. I believe it's possible to reduce the impact, but it's going to be tough. It's not just Academia who understand there's a problem, governments and big business are also reacting. The investment report this month from JP Morgan (hardly radical environmentalists!) is blunt. Forum members who manage to survive the next 3 decades will know the answer for sure: I shall probably miss out due to advancing old age, another unavoidable hazard!

Dave

Sorry had to edit as too long to post!

Dave,

I have long held your logic and evidenced based responses in high regard but on this subject I think you are a little wide of the mark.

I like your analogy with smoking as like climate change the initial suppositions were based on suppositions, personal experiences and opinion, later supported by definitive research and evidence. My feeling is with climate change we are still well in the supposition stage. During that stage with smoking there was no real government intervention into the activity until much later when research supported, even then there was no appetite to ban the activity altogether just tax it to the hilt (maybe justifiably on the basis of covering the cost to the NHS while still allowing a degree of choice) but that is an argument for another day!

The question I pose is beyond the suggestion and supposition that CO2 is definitively the culprit in this is there any actual verifiable evidence to back that up that definitively justifies taxing carbon to the hilt? Looking at your link it is to BBC news who have seen the JP Morgan report, quoting sound bites that support the story, I didn't see the whole report reproduced in full to allow the reader to form an opinion either way? Unfortunately I don't think even BBC news is free from bias. Also it needs to be considered that JP Morgan is a business and likely to bend to public opinion to protect its interests.

I am afraid I am not so adept at links as yourself but see if you can get this to work;

https://www.climate.gov/news-features/climate-qa/why-did-earth’s-surface-temperature-stop-rising-past-decade

This is a supposedly (we have to trust it is anyway) independent source of information. It concentrates on explaining the 'recent' often quoted by sceptics, slow down in temperature rise. This was an anomaly from the IPCC model and I am particularly interested in the line the model was re-calibrated. I have seen the temperature graph in other papers over a longer time span with CO2 overlaid and shows CO2 levels lagging temperature. Has this been falsified by the researchers presenting or is it true? I don't know! However if it is true and valid information if CO2 is the cause how can temperature be affected by a CO2 level not yet achieved? Are these versions of CO2 versus temperature also 'recalibrated'?

As I stated before I don't deny climate is changing but do we really know the reason? What has caused it to change before when CO2 levels were relatively stable? The above example of a pause over a decade or a slowing of the rate of rise is but a nano second when examining the history of the earth so hardly representative overall of a trend. When Greenland was green CO2 was lower, so why was it green?

The use of renewable energy is also to be encouraged, sustainability is of course essential but the pace at which change is being driven may still be felt by you in your lifetime. From November 2019 to date there has been a significant target suggested in my industry that cannot be met currently in the 10 years allowed by existing proven technology without adopting bio fuel (already noted as being land wasteful) and as demand increases that will get more expensive. The costs will inevitably be passed down the line. I am just looking for reassurance the world is still flat and it's not going to turn out its round! Whether people like it or not the notion of cheap renewable energy is a myth. Recouping the capital invested in a wind farm for example is a long term return and maintaining / overhauling the equipment to keep it going is still not cheap! Those putting their money in to any energy project, sustainable or not will want their returns in spades! I suspect JPM will be keeping a foot in all camps although not so prepared to advertise some of them!

Paul.

Thread: Boiler pressure
23/02/2020 19:14:40

Mine runs at 90psi too. Should be dictated by the pressure test cert but what if it's not got a cert! Another of the vagaries of model drawings! I seem to remember the only indication of WP on my Juliet drawings purchased 40 odd years ago and now too faded to read was a sketch of the pressure gauge with the needle at 90!

Paul.

Thread: Best Milling Machine Ever????
23/02/2020 19:09:13

Easy, the best one is mine!

Paul.

Thread: Coal being phased out
23/02/2020 19:03:59

OK........

So can anyone direct me to a credible source of data that links CO2 directly with temperature change?

There have been various comments on this thread suggesting we should trust the scientists that know far more about this subject than you or I.

Until very recently I have held little opinion on this subject and recieved no information outside the various media stories. Now having been put in a position professionally that is directly affected by current and potential pending legislation I decided some research was in order. Sadly that has left me more convinced that no-one actually knows and a lot of the 'evidence' is based on model predictions (both historical and future).

The latest IPCC report seems to be littered with words such as likely, highly likely and error without quantifying an accuracy level to likely or highly likely or giving a percentage range to error? While science should be opinion based on verifiable evidence there is so much conflicting evidence and journalistic hype on selective reading and report of evidence I have great doubt there is any definitive and verifiable opinion on the question?

I read an article from the Smithsonian (a supposedly upstanding and independent institution) today that stated we are currently at the highest concentration of CO2 in the atmosphere since 'records' begin 800 million years ago, currently over 400ppm (agreeing with figures quoted here) and back then a broad average of 200ppm (fluctuated a bit) but in the past the average global temperature was 14 degree Celsius higher than now. Is that statement verifiable? If it is why are we now 14 degrees cooler with potentialy more than double the CO2?

Plenty of other sources of conflicting information and speculation but seemingly few hard and fast facts or data based on verifiable and repeatable models. It seems even the referenced list of names on the IPCC report are not all scientist but some are journalists, activists and politicians? So is the claimed 90 odd percent consensus just between scientists or does it include the other hangers on? Should I believe the masses without seeing the underpinning knowledge? I believe there was a similar balance of opinion that the world was flat?

For questioning the theory am I a climate change denier? Surely the principle of science is to question results and verify in different ways to achieve certainty? I have no doubt climate will change, seemingly throughout the history of the earth it has changed many times. I can see the wisdom of clean air and the health benefits. I can't see the wisdom of the current knee jerk panic. I can see though that there is a lot of money to be redistributed!

Paul.

Thread: marine steam engines
17/02/2020 22:04:38

Under Classification Society rules it has been a requirement for many years now to fit over speed trips to main propulsion machinery many were "miniature" centrifugal governors that only had a maximum speed rating, when they reach that they trip the fuel racks to zero and shut the engine down, they then have to be reset before restart. A real PITA! Modern engines usually have this function fulfilled electronically. I have spent a few "happy" hours in the past setting these trips up driving them from a drilling machine at the correct speed to get them to trip. I have a vague recollection in the past of seeing a trip operated stop valve in the steam supply to a steam engine, probably in a book, never worked on a steam ship apart from a triple expansion engine powered vessel for 2 days 40 odd years ago.

Paul.

Thread: Jaws in the chuck
13/02/2020 08:41:12
Posted by Steviegtr on 13/02/2020 00:40:39:
Posted by ega on 13/02/2020 00:30:22:
Posted by Paul Kemp on 12/02/2020 22:28:58:

Steve,

Second picture with the jaws in is the best for the reason you stated (safer) and also because more of the scroll is in contact so less likely to damage the chuck if you horse it up.

Paul.

Isn't there a trade-off between depth of engagement with the scroll and the distance between the work and the face of the chuck? Neither setting is ideal in my opinion.

The chuck is apparently a Grip Tru and if it is in good condition it would be a shame to overtighten it.

The chuck is a Pratt & something. Yes I would have liked the work to be flat against the chuck face ideally. I checked the true with a digital dial gauge & it was slightly out. I refaced it & centre drilled & all seems pretty good so far. Lesson learned was not to remove the work until all operations finished. Once I have the hole to the correct size for the 9 1/6" fly press punches, I will start to turn the taper. I have watched the Geordie guy on you tube tonight he is called double boost & has a lathe with a chuck heavier than my lathe, & he turned the taper with a boring bar the wrong way round from the back of the job. Why is that. Does anyone know. Or is it just so you can see better.

Steve.

Steve,

One reason for the way he did the internal taper may be he was trying to get a matching taper - turned the male taper first and then wanted to do the female at the same setting? Saves a lot of faffing around resetting the compound to pick up the correct angle again!

ega,

As to what is ideal, that is a matter of opinion. If you feel so, perhaps you can share the benefit of your experience and tell us a better way? In my limited 40 odd years of experience the best way to do an awkward job is the one that works and gets it done. There are many compromises that have to be made when deciding on a method of work holding, not least the size of the machine and the available kit.

Paul.

12/02/2020 23:45:43
Posted by Clive Brown 1 on 12/02/2020 23:05:46:

If the 9/16" hole is through-drilled, there could be a risk of hitting the chuck jaws if they are as shown in photo no. 2. Best to check.

3 step jaws, he is on middle step so a step worth of clearance behind at 9/16" should be plenty of room. When it's spinning you should be able to see the drill breaking through.

Paul.

Thread: Fast bit of engineering work.
12/02/2020 23:39:26

Well talking about fast engineering the GWR (just under 119 miles) was built in 6 years mainly by itinerants with shovels and wheelbarrows. Now, 179 years later we are embarking on a new railway blessed with modern machinery and methods and the estimate for completion is 20 years........

Paul.

Thread: Jaws in the chuck
12/02/2020 22:28:58

Steve,

Second picture with the jaws in is the best for the reason you stated (safer) and also because more of the scroll is in contact so less likely to damage the chuck if you horse it up.

Paul.

Thread: My First Stationary Engine
12/02/2020 22:24:42

Ron,

Manganese bronze is typically a high strength high hardness material, it's not really suitable for high speed bearings as although it is relatively low friction its hardness will make it more likely to wear the shaft if the the shaft is unhardene than PB. It's typically used for marine propellers, sometimes prop shafts in smaller sizes, worm gears and the like. Can be used for slow speed bearings such as bridge trunnions or rudder bearings where the shaft speed is low and the bearing load high - with good lubrication!

Have to add how great it is that you have made such progress from the first time you popped up on here asking about lathes, to setting up your shop, getting your mill and now turning out some nice work. Well done!

Paul.

Thread: How to set up a rotary table tailstock
08/02/2020 19:37:11

Brian,

i have a similar set up. Turned a short slug of bar with a centre hole in it, held in chuck on RT (clocking concentric) and set the centre of the tailstock in it and nipped up. On my crank for example I mounted that in chuck and on the tailstock centre then clocked along the top to verify, if I remember right it was about 5 thou high so tapped it into line and locked up solid. Then repeated on the side tapping side to side to bring it spot on and fully tightend down. Other ways to do it particularly height using vernier height gage etc but it worked for me and it wasn't difficult.

Paul.

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