John Stainforth
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Posts posted by John Stainforth
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Each to their own (tea leaves, or whatever). Personally, I find the advice of experts such as Jon H very useful and heed what they have to say.
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I think this film clip was meant to be humorous. The finishing touch for me was the inadequate-looking elastic bands holding the wing on. I was expecting the wing to come off any moment during the aerobatics, as a grand finale!
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20 hours ago, PatMc said:
You're quite (W)right JD 8, my mistake. ?
I've seen & read a lot about their early flights & often there was reference &/or the tower used for their catapult system was either in the background or actually in use. Some how I came believe it had been used right from the earliest flight. I've just found this site's explanation of why it wasn't needed on the day & how it's construction & use did come about nearly a year later.
A really good book on the Wright Brothers, if you haven't read it, is David McCullough's "The Wright Brothers".
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6 hours ago, Cuban8 said:
Not so sure about the 'stabilizing' characteristics of a tailplane or fin given the definition of 'to stabilze'......make or become unlikely to change, fail, or decline. I've been in a few aeroplanes in bumpy weather where there wasn't much stabilisation in either pitch or yaw.
I assure you that the sole role of the vertical and horizontal stabilisers (fin and tailplane) is to stabilise - that is, maintain and bring back the plane back to an equilibrium position. That does not cut out small bumps, because it takes a finite time for the plane to respond. (Though quite how a kestrel maintains an absolutely fixed position in bumpy winds is a wonder to behold!.) Modern airliners have a great margin of stability built in, particularly in pitch. This stability comes at the cost of an enormous downward load on the tailplane (horizontal stabilizer).
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5 hours ago, Don Fry said:
Yer going to have to explain that one C8. A citizen of the higher half of the American continent would think that as an aircraft sticking out of an anus. Improbable, or even impossible, but such is the English language. Vive le difference
5 hours ago, Cuban8 said:Absolutely right. In this country the correct spelling and pronunciation is aeroplane. Similar thing with 'stabilizer', the correct and more accurate description being 'tailplane'.
The Americans use horizontal and vertical stabilizer for tailplane and fin, respectively. The former are at least as correct and accurate as the latter.
Incidentally, when I have used the term "undercarriage" in America, Americans generally think this is very quaint. They use "landing gear".
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2 hours ago, Cuban8 said:
The airplane V aeroplane thing is not so clearcut. I have US aviation books that refer to our spelling, but they do date from the 40s and 50s so maybe its something that's developed over the pond in the last few decades? Odd how some Americanisms catch on here easily while others never do. Trunk for the boot of a car, sidewalk/pavement.....plenty of others if you think about it.
No, the word "airplane" is much more than a few decades old. "According to Merriam-Webster, the word first known use of the word airplane was in 1906, about three years after the Wright brothers took to the air on the first successful flight with the 'flying machine.' "
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10 hours ago, Martin Harris - Moderator said:
Clarence is on the other side of the big wet bit just to the west of you John, where the corrupted version originated. I certainly don't hear the abbreviated word at my club and I don't think it's generally in use even by the internet generation.
I'm sure we were all educated properly by copious repeats of Reach for the Sky! 5 minutes 40ish....
Airplane is just the American spelling and is very widely used on the internet. It is not a corruption. The first airplane was invented by the Wright brothers, there was even a movie called Airplane etc etc.
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I've added an album to my profile called "S6b_construction", which shows the method I used for sheeting the wings of my S6b with a double set of jigs that conform to the shape of the ribs. I think pictures speak loader than words. The underside was sheeted first, so the first set of jigs (beneath every third rib) conform to the shape of the upper side of the wing without the sheeting. The jigging pieces, made of 1/4" balsa are glued straight to the glass building "board". The upperside was sheeted next with the wing supported by jigs that conform to the lower side of the wing plus sheeting. A combination of CA and aliphatic resin (mainly the latter) was used to glue the sheeting. The sheeting was held in place while the glue dried with weights (model magazines); and leading edge sheeting by a liberal use of masking tape. (The pictures show what I mean by liberal!) Note there is not a pin in sight. The benefit of this method is that the wings come out absolutely true. The sheeting cannot create warps: indeed, it locks the wing into the correct shape.
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3 minutes ago, Simon Chaddock said:
The final confirmation that everything that is now permanently built in actually still works!
https://www.youtube.com/watch?v=EXEC-Nl9rAg
From this 1955 'glamour' photo you can see why the Hunter's Sabrinas were so named.
You do have to do the research on your planes. Don't you??
That's not exactly a plane view!
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6 hours ago, Jon - Laser Engines said:
The VAT thing came as quite a shock to Laser and it was only because i noticed something i wanted to buy from Germany had dropped in price by the VAT amount that we knew anything about it. Consulting the various govt pages and our accounting people left us with 5 different answers on what we were supposed to do, all of which were contradictory.
We do drop the VAT on exports but as i have mentioned before Laser have had to pull out of the European market (which accounted for 30-40% of our sales) almost completely as its simply not viable.
Half of the packages either go missing completely or are returned for 'incorrect paperwork'. This latter point is rather sore as nobody seems to know which paperwork is actually correct as every variety we use gets rejected at some point.
The half that do get through sit around for 10-12 weeks and then the customer pays around 60% the value of the item in fees and taxes, they then take another 2-3 weeks to decide to post it on to the customer where it becomes apparent it is damaged as they took it all out of the box and didnt repack it correctly. That or the allen keys fall out and they dont bother to put them back in.
Add to this the added time wasted to fill out the paperwork, constant emails with the customer chasing their engine, chasing up tracking details etc means its simply not worth selling the engine.
its just a nightmare and its only going to get worse now the 'soft' customs rules of last year have lapsed into the full fat rules going forward.
While i cant say what the situation is at the company you used, i can say is that from my own experience dealing with it the whole thing is a complete shambles and i think we are going to have to set up an eu distributor as sending individual packages to individual people is simply not an option any more.
What a sad situation! But I remain hopeful that the current madness will eventually be reversed.
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Andy,
4.5 lbs for an 80" span model is an incredibly ambitious target. If you can achieve that it will be something of a record and you will have an amazing soarer!
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10 hours ago, Peter Miller said:
I like my CG at 25% chord. I want a model that is not at all twitchy on the controls and flies in a rock steady flight but which responds instantly to the controls. I have all incidences set at 0 degrees. That means that the datum line on the airfoil section runs from the centre of curvature of the leading edge to the point of the trailing edge. and is parallel to the thrust line.The tailplane is set at the same angle.
I have my controls set with low rates which varies with the model and are given on the data panel in the magazine and high rates for going wild with aerobatics
All I can say is that it works for me and most people find that my models fly well.
There was one person who complained that one with very twitchy and he found it horrible but he also said that once he moved the CG to where I had shown it on the plan the model was perfect....Funny that!!!
For aerobatic flying or "3D flying" one might need the CG fairly far back, although there are other criteria for optimising the CG position (such as the behaviour in vertical downlines and inverted flight). With an i.c. model one can get a feel for the twitchiness of the plane as the fuel tank (which is usually in front of the CG) empties, and then decide how much twitchiness can be tolerated. If the plane starts getting too twitchy, one needs to land pretty soon, because it gets worse each time one goes around for another landing attempt!
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Yes, Roman chariots that were designed to fit the hindquarters of two standard Roman horses. When the Romans came to Britain the chariot wheels created ruts in the roads - particularly their stone-paved roads - which made it awkward for any subsequent horse-drawn carriages to have different wheel gauges. Then, when railway lines were put in on the same routes it was only practical to place them over the ruts.
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Are you sure it is not M7? I had one model that had a nylon wing bolt of that size, which was not really satisfactory being on the short side: it only went into the plastic nut a few turns. M7 is a less common size, and I ended up replacing the nylon bolt with a longer M7 bolt made of beautiful titanium.
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I meant "normal" temperature and pressure (i.e., 20 C), not "standard".
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Don, I think you should tell me what does not impress you about my first paragraph, in which I have stated the facts as accurately as I am able to.
One has to assume that the stated proportion of oil is correct. In the case of the Optifuel I mentioned, the content of both the oil and the nitromethane have to be right up to the full amounts stated by the supplier in order to explain the weight of the fuel. The nitromethane content would only be seriously in error if the suppliers had inadvertently added a lot more oil than stated, which is unlikely. The weights are easily measured on digital scales that are accurate to fractions of a percent. The estimate of the volume of water (via weight and density of water) is accurate to within a few cc's in 5 litres, i.e., parts per thousand. The densities at standard temperature and pressure are obtained off the internet. The whole measurement procedure only takes a few minutes. With the assumptions above, only three measurements are necessary: the weight of the fuel+container, the empty weight of an identical container and the weight of the latter filled to the same level (as the fuel) with water.
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3 hours ago, Don Fry said:
Now John, I’m well oiled by, (beloved’s Birthday, champagne and rose hip syrup, red wine, nice dinner). I must state you may have hit the Bourbon early. That lot makes no sense whatsoever, even given my inebriated state.
Please elaborate on what does not make sense to you. I may have expressed myself badly.
(I am living an alcohol-free existence!)
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8 hours ago, Nigel R said:
I'd imagine that would be because the US market has suffered the cult of 20% castor oil (or death to the unbeliever) since about 2000BC.
This is your imagination. The majority of model flyers in the southern US use glow fuel with 18% oil and between 5 and 20 % nitromethane, depending on the engine and personal preference. The oil is typically synthetic or a blend of 80% synthetic and 20% castor. One of the most popular fuels there is VP PowerMaster, which uses the latter blend of oil. I have no idea what the benefit of 20% castor is meant to be; all I can say is engines using that blend did not gum up after 10 years of use.
One thing to watch out for on both sides of the pond is lousy fuel that does not contain what is says on the label. This may have contributed to the idea that nitro make no difference to power. I routinely check the fuel I buy by weighing it and doing a simple mass balance of methanol, nitromethane and oil, given the densities of these three ingredients. The first thing to check is the volume of fuel you've been sold, and the easiest way to do that is to weigh an identical container filled to the same level with water and subtract the weight of the dry empty container. The last batch of Optifuel I bought here in the UK (12% nitro, 18% nitromethane) passed this test with flying colours. Not only did the mass balance suggest the fuel contained exactly the proportions stated on the label, but the volume of fuel was very generous!
My own findings (in the US) re fuel consumption with different nitro percentages are at odds with some of the views that have been expressed on this site. I realise that the climatic conditions there, and the low altitude, and the fact that we took the baffles out of silencers to give the engines more power, were different to typical conditions in the UK. (I am very surprised by how much difference even modest differences in altitude make, but those can be largely compensated for by using propellors with different pitch or diameter.) I highly respect the views of Jon on this site - and follow all his advice wrt Lasers - so I intend to do some new tests myself in the UK in the coming year with different blends of fuel, particularly regarding fuel consumption.
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3 hours ago, Ron Gray said:
Yep, I know, I was there but I still kept my parallel motion board for many years even though I was also using CAD.
It’s the same with many things that we used to do, pre calculators and pre decimalisation- ready reckoners were the order of the day for £SD calculations.
Well off topic but can’t resist the odd plunge into nostalgia!
Continuing off topic, all pre-1950's planes and ships were designed and built using slide rules and log tables. The standard tolerance on the airframes of the Schneider trophy racers was 1/16th of an inches. The airframe dimensions were all in given in "tables of offsets and sixteenths" with respect to the fuselage stations, buttock lines and waterlines.
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Yes, Aero Modeller Of The Year!
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On 10/12/2021 at 22:27, dirk tinck said:
Thanks for the comments all !
This must be the first time i did not see my workshop for 3 days in a row !!...Thanks to , Yes... Covid.
The virus has finally got me , and my wife Diana...We think we got it from the grandchildren.
We both have mild symptons but work is out of order. Ten days quarantine now ...
I hope i'm over this soon and can restart working !! No work , no pay !
Keep safe ! Dirk
Best wishes for a rapid recovery!
If it's any consolation, I would vote for you as the AMOTY!
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I'm another fan of Optifuel 12. Frank, have you tried your OS55AX on 10, 12 or 15% nitro?
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5 hours ago, Paul De Tourtoulon said:
No never dabbled in drugs,,,?
... or as Keith Richards once put it: "I've never had a problem with drugs... only with the police!"
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Jon, it's easy for you to say that, as the world's expert in the language of Laserspeak! Most of us are still struggling with the basic vocabulary.
Weston UK Fuel
in IC Engines
Posted
Please can you have another go at your last sentence: I can't make head or tail of it.