Member postings for Trevor Crossman 1

Joe, your interesting exercise reminds me of long past times flying in Blackburn Beverleys and watching the numerous harmonic dampers, which consisted of a pair of heavy cylindrical weights with bonded rubber cores mounted on a shaft within open boxes fixed to the fuselage frames, all oscillating merrily and absorbing some of the vibration. Radial engines have harmonic dampers fitted into the crankweb, though how the design engineers arrive at the right mass and positioning is beyond my grasp of mathematics! You might find this article interesting___http://www.enginehistory.org/NoShortDays/TV.pdf

Trevor

I did this today...………………………….

but before doing that, I should have done this...……………………..

My concentration was centered on the cutter but as soon as the machine ran I noticed the vibration and hit the red button and immediately gave myself a good earful of abuse and considered myself lucky that I didn't get injured by the handle flinging itself into me nor damaged anything in the shop !. Just might fit an extra safety micro-switch to be tripped when the handle is fitted.

Trevor.

Rip-off prices? Possibly, it depends on how one judges value for one's money, comparing £15 for entry to spend all day at a show against spending the same £15 to squirt it down the porcelain and getting a headache!

Here are some reasonably current numbers to add reality to the suggestion made by Simon Williams and within the same interest group of his good lady.

A recent Knitting & Stitching Show at Alexandra Palace had 300 stands with minimum area of 4 sq.mtrs. priced at c£300+/ sq.mtr.+ £50 for each electric socket. There were 27,000 visitors over the 4 days who spent an average of 5.3 hours attending, their average family income was judged to be c£52,000 (nearly double then ational average!) and the average spend was c£115, though I'm not sure what this sum included. (A smaller show within the same interest group held say at Harrogate will only yield about 12,000 visitors, who are quite likely to be less affluent and probably will spend less. The exhibitor costs will not however be much lower, perhaps 20% or so).

So if selling the floor space at Ally Pally to exhibitors yields, say, £360,000 to the promoter who has to pay the venue costs and if the door price is to recoup that sum from those visitor numbers then the ticket price needs to be a minimum of £14. The average spend of £115 by the visitor numbers quoted would yield £310,00+ , but is impossible to apportion to the 300 exhibitors with any accuracy because I have no idea what 'the spend' covers, nor do I know how the Promoter got these figures, but I suspect that they are based on their survey of a limited number of respondents declared expenses which include ticket, travel, food and purchases, and limited surveys taken from a few exhibitors. My thoughts are that these very limited surveys are then extrapolated to make brochures and reports as glossy as possible to pull in next year's punters!

If floor space were to be free to the exhibitors, yes indeed some might profit from a show, but the numbers used here only give an average turnover of £1000 or so per exhibitor for 4 days work, and they still have their normal input costs plus, travel and accommodation, which in a major city like London isn't cheap. The only way that an exhibitor can make a serious reduction in their costs is to leave booking space until after the deadline when the promotor might? get desperate with unfilled space.

So although the idea might work for some exhibitions Simon, but I very much doubt that model engineering by itself is a large enough and, dare I say it, a 'spendy' enough, interest group to provide the footfall needed to make it work at major venues.

Trevor

Hello Jon,

A Raglan 5" was my first 'proper' lathe, much better than a Myford in my view. An easy machine to strip/reassemble and very capable especially if you can acquire some of the original accessories.Take some time to set up the variable speed mechanism accurately and it'll run very nicely. I had mine for many years until I replaced it with an M300. A guy John Ward, up your way makes some (good quality) parts for Raglans.

Trevor

This has been an interesting thread to follow, and although I have never been to a model engineering exhibition, I've attended other hobby shows both large and small both as a visitor since the 1960's and over 20 years ago as assistant to my wife's former business trade stand at major venues and small local shows.

The major shows are very different affairs compared to the club or local show. For the former, the costs back then were c£100- £200/ square metre of floor space, extra for (limited) power supply,shows were mostly 4 day affairs so 3 nights nearby accommodation was needed, B & B 20 miles away from a city center venue is no good when you've got to get the stand ready an hour before the doors open, city parking charges, stock 'losses' etc. We never, ever made a profit during the whole week that it took to set up / tear down/ recover from, a major show .

Our only perceived return from these major venue shows was that they widened her market base by acting as 'live' advertising for the product and services and provided a break from our workshops, but after 3 years or so few new leads were generated and so we stopped attending them with no loss in sales.

It may offend some folk, but my observation is that many hobbyists, not matter whether their model, flies, floats, goes round on wheels, runs on steam, is made of wood, metal, or fine fabrics - - - - are rather parsimonious who can see the cost but not the value, as noted by Dave Halford. Hobbies for anyone are expensive in the sense that the expenditure is not necessary for physical survival, though it may indeed benefit one's emotional and mental well being immensely, but I feel that sometimes, some people are pursuing interests, or perhaps projects, that they don't really have the financial resources for.

All (constructional) hobbies though seem to have been in a slow but steady decline since the mid 1950's when viewed through old issues of the various interest magazines, and so my view is that it is probably important that here in UK , certainly for the major venues, we should amalgamate them into broad spectrum shows rather than narrow single interest shows that can no longer hope to have high attendances. I think that many of the large shows in Germany are run like this and do seem well attended.

Club shows have their own problems, and the work is usually borne by the same few stalwarts year on year, but generally the costs are bearable and may yield a small but welcome financial return and a new member or two, but are always good PR and a chance to raise the local profile.

Trevor

A fantastic piece of work - - in all senses of the word! Artistry in metal and I almost expected one of Terry Pratchett's wizards to be lurking in the corner of the forge.

Trevor

I quite agree Nick ! When I ran my own small business customers requests were dealt with in the order that they were received without exception . To do otherwise, as has been suggested earlier, is to show that one considers the owner of a fat wallet to be a more important person than any other customer. The big-shot/big spender may think themselves important but in the great scale of things, they are not. Deferring to one person over another will not generate a loyal customer base which is essential for long term business survival.

Trevor

I agree with Jason about the use of manufactures sizing/groove charts, when I was making dive cylinders for my model submarines I found that when the grooves were cut accurately in pistons, the O-rings had too much drag for the motor size and gear train that I was using. It would have been different if the cylinder was pumping oil which is a better lubricator than water, as they worked okay when nicely lubed and on the bench just shifting air. I think that it depends on the operating pressure of your engine and the lubrication provided .

Trevor

Couldn't have been a visit to E.D. because their factory was in Kingston-on-Thames, or at least Surrey not Essex.

The crankcase of this engine seems to be modelled on some of the Fuji which had removeable front end, though this ones from solid instead of cast. I think that the carb is either Perry or Kavan, I've had both on the dozens of engines I've flown/crashed! but can't remember the differences. Head looks similar to K&B or 1960's style OS Max. but I can't remember an engine that had circular exhaust ports, so I think that it's 'home designed' based on general '60's features. Does it run well enough to fly? that's the important question!

Trevor.

Spelt is most certainly not gluten free, nor are another two ancient types such as Einkorn and Khorason, though the gluten is not as strong nor as abundant as in modern wheats which have been selectively bred with increased gluten for the benefit of the food industry to produce a stronger dough= lighter, wetter bread.

I use a large proportion of these low gluten flours in our baking because I too have a gluten intolerance which requires that I strictly limit my wheat intake, but that is an small inconvenience compared to my son-in-law who is coeliac and any gluten has a severe allergic reaction, potentially even anaphylactic shock.

The baking method, whether bread machine or trad oven doesn't affect gluten digestability, but studies have shown that raising the sourdough method does have some affect on the gluten and it's affect on the gut.

Trevor.

Hi Robonthemoor, that is a Vertex rotary table shown. Dividing discs are available from RDG/ Chronos and other sellers.

Trevor

Most probably because it is not easy to keep such small quantities of live yeast as would be used by a domestic baker working and maintaining a constant culture due to other wild yeasts present. It is much easier to start and maintain a sourdough culture in the kitchen environment, I started mine ages ago, some homes have them handed down from mother to daughter. I stopped baking yeasted breads ages ago and only bake sourdough which produces a more consistent, and to my mind, a better flavoured and more digestible loaf.

Regarding the OP's breadmaker, I don't have one nor see much benefit of them other than using them for the initial proving, and I, as others have mentioned prefer the oven for consistent results. However, perhaps the inconsistent results are due to temperature variation that particular kitchen, due to local air movement, sunshine, other heat sources.

Trevor

+ ! for that larry ! As one gets older the realization that lifetime is not infinite becomes ever more obvious so the sooner one gets started the better is my view. '' Action this day '' is one of my tenets .

Derek, it's not really necessary to buy machinery before you start the hobby, why not choose your starting project, study the drawings and research the processes and see what you can do with just the hand tools that you already have to get the show on the road, because machines by themselves are of limited use, it is often the tooling and accessories that release their potential and quite possibly will cost you more than the machine itself. Most model projects have some sheet metal and/or barstock which you could start first and hone your sawing and filing skills which are needed just as much as turning skills, maybe more so.

Trevor.

Yes tuned pipes are indeed effective, but remember that although whilst at cruise the rpm may be relatively constant, an aircraft engine requires instant response at the critical times such as take off and landing, aerobatic machines also require instant responses. Much of this can be overcome at little cost as is seen in modern sports bike road performances ( far beyond my motorcycling capabilities now I might add!) , but one is still left with the psychological aspects of aircraft enthusiasts, who, like many bikers and F1 watchers , link volume of noise with power, speed and excitement. On the other hand I used to enjoy burning of the ''racing striped, logo bearing, tunnel sized exhaust, over sized tyre type boy race'' with my pretty standard looking but well sorted machines. Just look at most car/bike ads where the ''macho-ness'' of the vehicle is exaggerated.

Although many production light aircraft have some sort of sound attenuating collector box within their exhaust system they do not make a massive difference , though the Avions Robin DR 400 types that I once helped maintain, were quieter than many.

Trevor

I quite agree Perko, many light aircraft do make a lot more noise than others, sometimes due to propeller sometimes largely from the engine, usually it's a combination though. Back in the later 30's some British light planes, I forget the manufacturers, were sold with a very long exhaust pipe along the bottom of the fuselage, maybe also some of the DH Moth series too.

Several years ago when I was member of, and an aircraft inspector for, the then Popular Flying Association (now Light Aircraft Association), the Chief Engineer asked members to forward ideas and designs for effective and practical silencing systems particularly for homebuilt type aircraft that were not under prescribed FAA/ CAA regulations. Despite some promising work ,both science based and home workshop style practical efforts, done by a few members, the whole idea fizzled out much to the delight of the more ''traditional'' light aircraft owners who were quite unsurprisingly by far the loudest in rubbishing the project before it even started, often equating noise with power/performance and scornful of the public's dislike of light aircraft droning slowly across the sky, usually citing' safety' concerns to support their negative views. I dare say that manufacturers of certificated aircraft would say the same, plus of course the ever important added costs.

Trevor.

I'm quite surprised that although concern is often voiced on these Forum pages about using various chemicals and other toxic substances in their workshops/sheds, folk seem to be quite happy to spray toxic stuff around in their houses! Flies can be dealt with by safer methods than by filling your air with poisonous aerosols, yes I know that the manufacturers say they're safe, just as so many other good old products were!!

At least Grandad's old Flitgun ( remember them!) and gallon can of DTD in his shed is long , long gone and good riddance too . It killed all known flies DEAD! and pretty much anything else that that was in the vicinity too.

Trevor.

When we moved to our present home 22+ years ago I built a 24ft x 16ft timber workshop, lined and insulated, and it was big enough then. Since then it has grown another 5ft on the pine end and a 4ft lean-to along one side, double door on one end and a single door on the other and in the middle of one side. It is warm, dry and well lit BUT, it seems to have shrunk over the past couple of decades!

Previous posts have listed some fantastic advise and if I were starting from scratch now, I would do as Muzzer, and a nearby friend of mine has done, and that is to build it as large as possible and to housing standards as part of the main house. It might cost more in the short term, but is more efficient to run and eventually becomes a more valuable asset than a stand alone building.

Trevor

Well BOB, having worked sheet metal for much of my working life, from aviation standards down to agricultural repairs and tried and rejected a large version of one of these some 20 years ago, I would suggest that you, as an ex professional will be sorely disappointed with these 3-in-1 devices.

I think that Baz sums them up quite well with the suggested use as a doorstop, or perhaps as a mooring weight.

I think that you'd be much better off buying used individual machines such as Edwards/Keetona/Crefco etc. If even the smallest, usually 2 foot type, are too big for your needs ( or workshop!) with your experience you'd most likely get better results from home brewed bend bars and rolls.

Trevor

Most epoxies cannot be relied on for long term 100% resistance against petrol based fuels with the exception of those which are specially formulated for the construction of composite fuel tanks and they tend to be more expensive than standard lay-up epoxies, MAS is one such resin available from www.ecfibreglasssupplies, though I doubt that you would want the stock quantity. A better alternative for such a small task would be to use an aviation standard fuel sealant PR 1440 which is a virtually indestructible synthetic rubber compound and will resist attack from all forms of gasoline and its additives, it can be obtained from Light Aero Spares or other aviation suppliers, maybe you might know an aircraft maintainer who could get you a small amount.

Trevor.

An aerial for airborne detection of partial discharge within underground high voltage transmission lines maybe?

Trevor