Member postings for Paul Kemp

Interesting question. Not noticed that but then not usually trawling sale sites for models unsurprising maybe.

i would hazard a guess though that it is because commercial sellers do their certification on the commercial basis and commercial certification cannot be mixed with the 'club scheme'. For example if you have a 10 year hydraulic from a commercial inspection you can't get your annual steam test and cold exam done by a club inspector, they will need to do their own hydraulic also. So it really depends which regime the purchaser intends to follow after purchase, if he wants to do the continuing tests through his club it makes sense to take the boiler untested and get the club to do from the outset of ownership. If continuing on the commercial basis then you may as well take the certificate. I am not sure who pays though because there is a cost involved ie if the seller tacks the cost of certification on to the deal it will save the buyer money, if the seller absorbs the cost then by not doing the test he increases profit!

Either way if taking a model untested and even if not, make sure it comes with previous boiler history as if you take your new toy to a club with no previous evidence of boiler manufacture standards and previous tests they are well within their right to refuse a certificate!

One last point is I have seen boiler certificates issued by sellers / in conjunction with the sale that do not comply with either standard commercial (10 year hydraulic) or club (2 or 4 year hydraulic) periods! One boiler in particular came with a set of certificates for six months and the details on the certificate did not properly match the boiler! Made me wonder why the tester was not confident to issue a proper full term certificate! A commercial test certificate should be backed up with an inspection report, particularly on a steel boiler with records of ultrasound readings and extent of inspection carried out. So as always it's a case of buyer beware and be sure what you are getting!

Paul.

Don't forget to allow for any spigot protruding into the bore from the cylinder covers. As above will be fine for flat covers but if spigoted the piston will clout em if deeper than the 1mm allowed clearance.

Paul.

I think heat treatment to stress relieve is a fairly modern idea to speed up the job. Back when Stephenson was a lad (well maybe when his grandson was a lad anyway) new castings as you probably know we're chucked out in a field to weather, brought in and part machined and stuck back out to grass before final machining and finishing. All of this you are probably well aware of! This was still considered to be the way to do it when I worked for a large marine diesel manufacturer in the late 90's (probably though because there were few facilities big enough to take the castings anyway!) Obviously you want to use your camel back before you are too old to pick it up though, so that approach is probably not going to fly! I doubt though that the domestic oven will do the trick, better bet might be an aquaintance with a pottery kiln or similar. Best bet if you want a professional job is to find someone on the inside somewhere that can slip it in with something else. As you say most big companies view the likes of us as a pain in the backside so quote telephone number prices to discourage us!

Paul.

Michael,

I have absolutely no problem striving for accuracy and precision where it is necessary for the function of the output of the job. Certainly accuracy and precision in carrying out work is a mark of professionalism and craftsmanship and something I was taught in my apprenticeship. However I was also taught in subsequent years that tight tolerances cost money in the real world, may require a completely different machining process to achieve such as final precision grinding to gaurantee size and finish. It is also true as stated that some people derive satisfaction and pleasure purely by making something to the nearest 10th of a thou.

What often galls me though is the opposite attitude to the one you present where you suggest people are unable to appreciate scale of activities and the need for tight tolerances, that opposite being the people who indulge this activity commenting on the value, suitability, fitness for purpose of various machines and tooling from that perspective. The plain fact is outside micro biology and other fine engineering tasks like watchmaking is the steam engine fraternity, IC engine fraternity, motorcycle restorers and repairers and general back yard shed tinkerers who can turn out perfectly adequate jobs working to the nearest thou and be equally proud of them too.

It seems to me sometimes on this forum especially where outrage or surprise is expressed because there is half a thou play in say a rotary table that to an extent that attitude is encouraged and bred by the micro brigade sowing the seeds. A fair proportion of people and probably an increasing proportion in the future do not come from a background where they can recognise what is an appropriate tolerance to apply to a task and often the advice given on here errs on the finer side of the fine line!

We all have our own interests and reasons for doing what we do and come from different backgrounds with different levels of experience. It strikes me from several recent posts that perhaps all sides need to be a little more tolerant and have a slightly wider perspective.

Paul.

Well a cracking way of encouraging new people to the hobby I reckon. Guilty til proven innocent, very good. Absolutely first class P R.

Paul.

If you have a direct admission that it is the pattern that is at fault (not that it could really be much else if both castings were identical) and to their knowledge it has been so since 2001 then they have knowingly been selling goods not of merchantable quality for around 18 years. I doubt you would find the modern equivalent of trading standards would be the slightest bit interested in following it up though, especially as they gave you a refund on one and you chose to accept the other.

Looking at the other side, a lot of suppliers to this hobby are small businesses with limited staff that do not have a massive profit to distribute. It doesn't excuse poor service or knowingly selling drawings with errors or duff castings but corrections and patterns cost so it's understandable why issues do not get addressed when they only sell small numbers each year. It would be nice though if issues that are flagged up were addressed or even if not properly corrected, buyers were advised of potential issues..............

Look on the bright side though at least you got the casting, there are people out there that paid for castings months or years ago from suppliers that apparently have never recieved them, nor had a refund.

Paul

Lee,

Dont be put off lol. It seems like this topic in some form comes up a couple of times a month and it's not unreasonable to expect it will continue to do so. If you have not had a lathe or mill before, buying one to most people represents a significant expenditure so they want to get it right. Sadly though therein lies the problem, what is right for me may not be at all right to you! By the very nature of people they will likely give answers based on what is right for them based on their experience good and bad doing what may be a million miles away from what you envisage doing. Andrew's point about size is a fair one, if you want to make watches you don't want a Colchester and a Bridgeport! So a fair few will answer a vague question with another - what do you want to do?

FWIW I think given you don't know what you want to make, your mentioned choices of machine are not bad and will give you plenty of scope to find out (as long as you don't end up deciding you wanted to make a watch!). I was considering a Warco mill myself, as it happens I managed to get an old British machine which now I have it I am very happy with, appreciate its versatility of horizontal spindle and vertical head in one machine and I now realise I would have been frustrated by the Warco. But that is just me for my particular interest and I wouldn't spend time trying to convince you that you should do the same! It sounds like you have done some research and come up with a workable plan, so if you are happy with that, go for it.

Sadly I fear even if you had pitched your question in a different way and listed the machines you have identified from the start there would still have been negative comments, sucking of breath through teeth and comments "ohh I wouldn't buy one of those"! It's just a no win situation. Only caution I would sound if buying a Colchester is hear it running, bearings and headstock guts are expensive and try and make sure it has not been used in production for 20 years with the associated bed and slide wear. Other than that, go for it, you won't know really if they are right for you until you have them and use them! I have been using machine tools for 40 years on and off and even a poor one can turn out reasonable work if you know what you are about.

Paul.

Granted. But as I said in the context of what Neil said "In this case, I think reluctance to give an idea of what they want to do is rather like asking 'what guitar should I buy' without saying the genre of music." Coupled with the OP making no reference to size it was a fair analogy. Yes size is an obvious factor but the OP did state a budget of £5k for everything and I think you would be hard pushed to get a lathe with 500mm centre height, a mill (of similar size I would assume) plus the goodies, maybe a radial arm drill to match capacity and a shed as someone else mentioned for £5k?

Sorry if I am being a grumpy old git!

Paul.

Adam,

No not aluminium, silver solder. I have various grades kicking around the shed, a fair bit of the old easy flo No2 which apparently you are not supposed to use these days because of the Cadmium content. Also have some Cup alloys 434 and Johnson Mathey silver flo. Any of them will do pretty well. Use a high temp flux like Tenacity No 5 or I would think Cup HT5. For small jobs you can get away with the hand held DIY self contained torch with integral cylinder if you can arrange some fire bricks to concentrate / conserve the heat.

Paul.

What sort of temperature would you envisage running a vessel that boils water at? Are you talking flash steam generators here? Considering iron derivatives have been used for boilers since the industrial revolution and most full size boilers are steel, running at far higher loadings than proposed here I hardly think the material properties of the gas bottle will be a problem. It may be commercially un certifiable for other reasons such as traceability but as a small boiler operating at up to say 80psi temperature isn't going to be a factor.

Paul.

Ron,

Nice job on the cross slide and the tool post, well done. Particularly nice to see the progress you have made in a relatively short time in a modest shed, should inspire others hopefully to achieve similar. Back to the TE now?

Paul.

Or... Just accept it for what it is, a cheaply made bit of kit to provide an economical solution to the masses with a standard of accuracy commensurate with its cost. OP didn't state why he had bought it and what it's intended use is. If it's for the usual back yard engineering jobs like steam engines then bolt it on your machine and get using it. If it's for instrument making which requires extreme precision and formal calibration of the final product make sure your shop is kept at 20 degrees at all times, your measurement tools are only of the highest quality properly calibrated and buy a decent one. What else can be said? Seem to be a lot of people here chasing elusive microns where a couple of thou or in some cases 1/64" is perfectly adequate. Life and hence time allotted to us is finite so spend it getting on with the project and not chasing accuracy you don't really need! If you do need it don't buy your kit from purveyors of leisure grade equipment.

Paul.

Andrew,

While I tend to agree with most of your posts I am afraid your PS in the context of what Neil wrote is way off the mark. If some one wanted to play classical music for example they wouldn't want a strat! Technique for playing various styles is not successfully transferable across different instruments designed for different purposes. In the big picture it's a reasonable analogy.

To others busy adding up the value of their sheds - remember there is a big difference between perceived value and real value! For example try getting a dealer in to buy the contents from you and see what you get (or don't get!). For insurance to guard against your whole shed disappearing then new values are reasonable (which will probably be tweaked by the loss adjuster) if you have to pop out on Saturday afternoon to replace everything. The real value you can get on the open market for your treasures between willing buyer and seller is likely to be somewhat different!

Finally I agree these questions as per the OP are really unanswerable, an opinion I have posted before. Too many variables to even begin to quantify. It's natural I think that people with no previous experience will continue to post these questions as they don't have any knowledge of experience on which to base their choice. The correct polite response to encourage new people is to point out the top level considerations like size, accuracy desired and existing skill level and leave it there with no mention of brand names. Or politely suggest a search of previous posts as some do.

There is more than enough tosh on this forum on which lathe or mill is best, will hold microns of accuracy over 6', will take 6" cuts at 25million rpm with a bangood Carlos Fandango tool to drive anyone mad! Plain fact is there is a lot of very high quality stuff turned out by people on mediocre machines, buying the best machines in the world isn't going to gaurantee high quality if you don't know how to use them! The one thing that is guaranteed is you will learn a lot more about how to do stuff on a machine with a bit of wear which is a good idea because sooner or later your new machine will be worn too!

Paul.

I love this thread for a number of reasons; it's something different, not too serious, not seeking the last tenth of a thou, using machines to their 'full' capacity....... Great, well done, keep it up.

Paul.

Alternatively, save up your knackered carbide tips, machine a bit of ordinary steel bar to fit the head at one end and take a tip at the other and silver solder it on = free carbide tipped bar! Just need a green grit wheel to tickle it up ready to use. All my bars are home made with either HSS round or even old milling cutters and centre drills or repurposed carbide tips. Works fine for me so not about to be spending £'s on bought ones! (Yup, I'm tight!).

Paul.

I think if you reverse the spindle either under power or by hand cranking without retracting the tool you will have bigger problems than just breaking the tip! Any plain engine lathe will have backlash in the half nuts even if it's new. There is absolutely no need to reverse to break the chip when screw cutting. I am surprised any commercial shop would hand crank when screw cutting, time is money and the cost of threads would be astronomical.

Paul.

Matt,

Your method will work just fine as described but a good rule of thumb is 1 thou per inch, so your thou is a bit heavy, half a thou should be enough. I have just fitted a 3.5" cast iron liner to a cast iron cylinder the same way. Had 3 thou interference, cylinder on top of wood burner and heated to 150, liner in the freezer (about minus 10), dropped in a treat. When it cooled the bore had nipped in nearly 2 thou at the points of contact so I know it's tight and isn't coming out again any time soon! If you make your fit to tight all it will do is close down the bore (you can ream it after though). Or as Andrew says, glue it! Shrink fit is a lot more fun though.

Paul.

I really don't get the fixation with setting the top slide over to half the angle. When I did my time the method was mentioned but only to make me aware and was then told don't bother! Keeping it in the normal position has more advantages. If you are worried about cutting on both sides of the tool then put a few thou on the top slide every time you increase the depth of cut, has the same effect. It also allows you to pick up the thread again if you have to sharpen the tool or pick up a previously cut or partial thread if the work has had to be taken out of the machine etc etc. I like simple, all this back to front, upside down, inside out business does my brain in! Try cutting a three start square thread on a bar mounted between centres 3" in diameter, you don't need any other complications!

Paul.

Ron,

I have a very old and well used Kennedy stuck on a lump of nylon with an antique washing machine motor cobbled on the back to drive it. It's got a lot of wear, no belt guards and an H&S inspectors dream if it were in commercial use but it will sill sit outside on an extension lead and cut 2" steel round bar to a reasonable degree of squareness, unsupervised, while I get on with more interesting stuff! It does have limited capacity though and some of the band saws around now do look nice. I have recently been sawing up lumps of 3/4" and 1" plate up to 3" X 6" slabs by hand so that hand held Aldi saw looks attractive. But I then ask how many lumps that size have I cut in the last 10 years? The Kennedy I think was given to my dad, if he bought it he would not have paid more than £20! Owes me nothing and does most of the usual size bar, box and angle I cut so I think the £150 will stay in the bank and I can save any gym membership as well by doing the occasional big bits by hand lol.

Paul.

Pete,

A perfectly valid question but one that has been done to death many times in the past (which as an apparently new member you won't be aware of). It is though an unanswerable question because all the answers you will get will be swayed by personal opinions and experience! Also not unreasonable because that is what people base their advice on! First question you will get in return is what do you intend to do with it, ie how big are the bits you want to machine going to be. Then there will be a deluge of comments supporting old machinery and more supporting new machinery and even more comment on accuracy, cost and quality.

I should add based on today's developments I risk being banned from this happy group or having my post deleted by this reply!

The best thing you can do is to search all the historical threads on this subject and make up your own mind because end of the day it is only you that knows your own skill level, what you intend to make and what degree of accuracy you want to achieve and how fast you want to do it (10 thou cuts or 100 thou cuts!). Choice of machine really is a personal one based on many factors and if going for a used one particularly on a web auction site, seen or unseen can you spot if it's a dud that has been thrashed to death in production? My personal recommendation would be a used Holbrook or Harrison but just because it carries either of those names doesn't mean it's a good un! Could well be very knackered! You pay's your money and takes your choice as they say!

Welcome to the forum by the way, there is some very good advice and info to be gained from the collective.

Paul.