Martin Harris - Moderator

This is from the same site as BEB's canard one but for conventional layouts - takes the tail moment into consideration so is an improvement on the ones which simply calculate the C of G for a wing and assume an average tailplane configuration.Edited By Martin Harris on 06/12/2010 13:33:37

1. Mainly Models, Hitchin   2. Cod   3. Extreme Flight Extra 300   4. Ripmax

If you're within reach of Northamptonshire, Club 2000 (click the fairly well hidden "enter" button) is a great way to get started without getting involved in exotic motors and models   I did a couple of meetings with a borrowed model a couple of years ago but it appeared that committing myself to the time might not be diplomatic with SWMBO on top of my other modelling excesses so I didn't carry on, but they seemed a very friendly bunch and keen to give a new pilot plenty of advice and help.   The structure is that you work your way up the 3 classes so you're not directly competing with the experts - although you will fly with/against them in the heats and as the day's flying is virtually non-stop with the non-flying competitors being occupied with various calling, timekeeping and flagging activities, there's no chance of getting bored!   Well worth a try!Edited By Martin Harris on 01/12/2010 00:25:58

Sure it's for two 15 cc motors?  I'd imagine they're more likely to be .15 cu in?  Otherwise it would be a rather lively performer!!!    You'll need to emulate Bob Hoover's display routine with both engines stopped when it's finished!  The full size was superbly demonstrated in his hands - including a deadstick 8 point roll.Edited By Martin Harris on 29/11/2010 21:30:34

I'd start to get worried if the box was around my height and width...

Watch out though - a lot of the cheap stalls stock very inferior ones which aren't self healing.

Same for me - only 2 other fliers turned up while I was there.  The snow was only a frosting but the skis on my Limbo Dancer worked fine on the icy grass.   My solution to the cold fingers problem is to use RAF aircrew gloves (found some on Ebay a couple of years ago) which are close fitting and very soft and thin (kid?) leather designed to operate switches and knobs in the cockpit. They won't keep your hands warm indefinitely but take the edge off for the duration of a flight and give plenty of feel - you can almost forget you're wearing them.Edited By Martin Harris on 27/11/2010 22:39:40

 "Your" in its various forms is another one - thanks for the reminder BEB!!! Correct usage:You're wrong. Your teacher failed. Vecchio, you might need to load a dictionary - I just did (I'm using Firefox) and now you're a spelling mistake as I type!  There is an option to do this when you right click as advised by Timbo.Edited By Martin Harris on 24/11/2010 13:28:09

Never heard of none of that, Mal!Edited By Martin Harris on 24/11/2010 12:36:10

Sorry Bruce, but it's the 'tex that I'd like.   Thanks David.

Airelons - and apostrophes (used incorrectly).  

I could use the other Oratex, David.

I've used it for rapid repairs of cowlings and spats where I've laminated glass cloth by thinning 5 minute epoxy with a small amount of meths. I have to admit I've never done any comparative strength tests.   Southern Modelcraft supply (or supplied) epoxy thinners which was a fetching shade of pink but I know no more about its formulation. There was a warning about not over thinning on the bottle or the strength would be compromised.Edited By Martin Harris on 23/11/2010 01:24:46

I use ordinary meths - seems to work very well...

Posted by Bruce Richards - Moderator on 22/11/2010 10:27:40: . Don't forget to get some flux I use Laco. Edited By Bruce Richards - Moderator on 22/11/2010 10:30:15  I haven't used Laco flux but it's usually very important to clean the flux residue properly otherwise you're likely to suffer from corrosion in the future

I've yet to read the article so this may have been covered and if so, please accept my apologies but modern thinking seems to be inclined towards lift being generated by the opposite reaction to air being deflected downwards - which goes a long way to explaining why a flat plate wing can fly - and is usually known as the Newtonian explanation or similar.   Opinions seem to range from Bernoulli explains all to Newton rules...   Personally, and for no deep scientific reason than common sense and empirical judgement I'm quite convinced that they both have a part to play.   Of course, if you accept the Newtonian theory the need to explain symetrical wing theory you refer to doesn't exist...although Bernoulli also has a part to play as I'm sure you'll agree.   As Steve says, good luck - and if you start explaining stalling off a downwind turn you'll need a bunker!

Car  in front of me today had 8 aerials of various shapes on its roof - one of your lot?

You'd need washers under the top as you've realised to give downthrust.   Thrustline adjustments primarily affect trim changes with power adjustments - the likely "proper" cure is to raise the wing trailing edge fractionally if the elevator trim isn't changing adversely with power changes.     With a typical trainer you should expect a gentle climb under power and settling into a slightly nose down descent when you throttle back with a neutral trim at cruising power.Edited By Martin Harris on 17/11/2010 22:05:56

How about a SIAI Marchetti SF260 ...large enough for functioning retracts. It could be finished as either a military or civilian version to suit most tastes...  Alternatively,Short SkyvanWright Flyer (that does!)  P.S. I wonder what AA Barry's choice will be when the sun rises in Oz?   Edited By Martin Harris on 17/11/2010 17:14:07

...and if you are serious about tasting them, ingesting methanol will send you blind and mad.  It is not stuff to be messed with...Edited By Martin Harris on 17/11/2010 09:52:02

You could do - but apart from the convenience of "fire and forget" charging of all four at the same time ther'e's no real advantage in parallel charging if you don't up the current.

Thought I'd poke around on the net and found this  (click on the long link within the page for their test details) which seems to suggest a maximum of considerably less than a 2C rate when charging a completely discharged cell from a 4.2V supply (i.e. a fully charged cell). Whether a high discharge rated cell would differ may possibly have some significance though.   In practice I'd say it's unlikely that any great current would flow between 2 partially discharged cells even with a considerable difference in charge state. Perhaps Peter's proposed testing will confirm (or disprove!) the theory.   The HK board appears to be good to 30A according to the website!   One thing that no-one has pointed out is the limitations of the average charger when charging multiple packs - charging 6 2200mA/h packs at somewhere approaching 1C needs at least a 150 W charger...Edited By Martin Harris on 17/11/2010 01:33:45

Mine lives in my car's boot from purchase to empty - only comes out during flying sessions in all weather.   Warming it may help start an engine in cold weather but it will soon cool back down again on a typical cold club field.

Posted by Chris Bott on 16/11/2010 20:28:05: Brian I beg to differ. If there is one volt difference, and the connection between the two is one hundredth of an ohm, then in theory 100 amps could flow.    OK that is extreme, but a current could flow that is greater than the current rating of something in the system. Batteries, wire or connectors.  @import url(http://www.modelflying.co.uk/CuteEditor_Files/Style/SyntaxHighlighter.css); @import url(/CuteEditor_Files/public_forums.css);    Is it as simple as that?  I thought you needed a larger PD than the difference between a charged and a discharged cell to initiate charging from one to the other - or does this only apply to Ni technology cells?   I've been parallel charging pairs of LiPos for some time - usually with similarly discharged packs but I have done a few charges from dissimilar states.  On one such occasion, to check how the cells had equalised, I then put each pack on charge again seperately and they took the same (small) charge - to the milliamp - each.Edited By Martin Harris on 16/11/2010 23:02:19

The amount of moisture in a sealed canister is miniscule.  I wouldn't worry about it. Even in a worst case scenario if the air was fully saturated on a warm summer's day when the bottle was sealed, there would be less than 0.1 of a gram of water contained in an empty gallon container.  Don't leave the top off though - then you might get significant water absorption over time.