By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Megawatt

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

Thread: Future balsa supplies in UK
12/12/2020 19:50:54
Posted by Michael Kulagin on 12/12/2020 18:41:36:

Just to put my two cents in on the shortage of balsa. I have had a conversation with my nephew who has been working in the off-shore power generation business for over a decade. When I mentioned the shortage of balsa we are facing and it's use for turbine blades, he has assured me that the turbine blades are hollow. Given the size of the things they cannot afford to have something that big made a solid. (waiting to be shot down in flames!)

Not all of them apparently

https://www.ft.com/content/315455ae-021f-11ea-be59-e49b2a136b8d

Thread: Flying through covid !
01/11/2020 16:49:23
Posted by Gary Murphy 1 on 01/11/2020 13:01:08:
Posted by Doc Marten on 01/11/2020 11:59:29:
Posted by BackinBlack on 01/11/2020 11:32:12:

Well said. People spread Coronavirus, so if you don't want it, keep away from other people wherever possible. If you HAVE to be close to others take precautions. Simple isn't it?

Yep....

Spot on.

Its like Peter`s mention of the 101 neighbour. She needs to have contact to get by. So precautions must be taken BUT needs people close to help.

It was said here that a family member has had covid 19 and had a nasty cough BUT that would be much worse for a 70 year old, yes so would the flu or such like.

The vast vast vast majority who get Covid have minor symptoms. We need to take care of the old and weak etc BUT get on with life. The way things are going no one will be able to afford any hobbies or pastimes soon.

All the rules and regs ARE NOT consistent. This will never go away, what are we all doing, waiting for a vaccine,good luck with that.

Look out for the next great depression because that's very likely.

The rules are designed to be not consistent - I am getting more and more irritated with the press who seem to immediately look for and highlight inconsistencies!

It is not about some things being safe and others not - it is about stopping doing some less important activities (like model flying) so that more important ones (like sending children to school) can continue - whilst keeping the infection rate to a level which can be dealt with by the hospitals.

Thread: New limit on groups in England from Monday?
10/09/2020 12:54:17

Ok so if there are 7 flyers at the field all social distancing by 2m - is this an illegal gathering of more than 6 or is it 7 legal groups of 1? If 2m is not enough what is? There will certainly be several groups of less than 6 on the golf course!

Thread: Dihedral
02/07/2020 21:44:15

Assuming the model has ailerons all of the above is true if, however, you are relying on the rudder then dihedral is essential for the model to roll.

Thread: CAP1915 UK Drone Corridors - Future impact on model flying?
09/05/2020 11:19:43

Hmm - as I understand it a NOTAM (NOtice To AirMan) is just that - a notice. It does not in itself create a danger or prohibited area or amend the classification of the airspace. It just informs the pilot of an activity so that he can take it into account. Of course a NOTAM can be used to notify the existence of a danger area which has been created for a particular reason.

Thread: The Gov't, CAA, BMFA & UAV legislation thread
19/02/2020 13:21:12

Might be worth mentioning that as the previous operator ID exemption has now been revoked we presumably need to print out the new one to put on the club wall / carry with us.

Thread: ARTF tail feathers - what glue do you use
28/05/2019 17:30:11
Re that accident - wasn't that the one where the covering film hadn't been removed before gluing the rudder in place?

Cant find the report right now but I believe you are right - there were other factors too from memory.

28/05/2019 12:43:34

Most ARTF instructions say you should use epoxy to fix the tailplane and fin to the fuselage - having removed the film to allow a wood to wood joint. I can't help but think it would be far easier and less messy to use PVA or aliphatic glue instead as we are constantly told that these glues produce a joint stronger than the surrounding wood. However I am very mindful of the tragic fatal accident some years ago where (I believe) a tailplane came adrift of a model and it was noted in the report that the wrong adhesive had been used. Now if I were ever to be in that horrible position I would at least like to think that the same report would say that the model was constructed in accordance with the manufacturers instructions. Does anyone know why they specify Epoxy (gap filling?) and what glue do you use?

Thread: Is this yet another scam
17/05/2019 10:45:04

Posted by Alex Ferguson 2 on 17/05/2019 10:20:44:

A year or so ago I had a call from IRD (tax dept) from an Indian. Hmmm??? So I asked for his name and said I'd ring back. I rang IRD and told the girl who answered. She laughed, said it was actually genuine but she'd handle it. Yes, it was genuine and she knew why I was doing what I was doing but you can't be too careful.

If it might be genuine, look it up in the phone book and ring. A number from the caller might not be correct.

And either use a different phone, your mobile perhaps, or dial a known number first to make sure that the call has cleared. The call does not shutdown until they hang up and there have been cases where they play a dial tone until they hear you redial and then pass the line to another scammer.

Edited By Megawatt on 17/05/2019 10:50:35

Thread: CAA registration consulation
26/04/2019 15:40:23

Has any information been published about the labelling requirements - Could impact severely on scale models

Thread: New Drone Laws from 30/5/2018
08/06/2018 11:45:31

I think I need to challenge the assumption that this legislation is to clear the airspace above 400' for commercial drone ops. Full size aircraft are subject to a 500' rule and it is quite legitimate for them to descend to that height for whatever reason and remain legal. IMO the 400' limit and 1KM from an airfield is to allow separation from full-size aircraft and ensure that any increase in commercial drone ops remains segregated from manned aircraft. We shall be sharing the 0-400' range with them.

Thread: A new possible scam
20/04/2017 17:57:04

If you receive an Email like this do not under any circumstance click on any of the links - these may take you to a fake login page set up just to "harvest" your login details. Always enter the URL into your web browser for any login screen. If you have followed a link then you should change your password ASAP.

Thread: Life Today and Customer "Choice".
19/10/2016 11:52:32

BEB

My problem with the Pizza shop is not the scale of choice but the limitations of what you can and cannot do (like no more that 3 toppings on a 9" )

This always makes me thing that they decide what they want to sell rather than me decide what I want to buy.

Your experience also smack a little of misrepresentation - their offer (should you really only want one 7" pizza) is really a One for the Price of Two offer !!

 

Edited By Megawatt on 19/10/2016 11:53:04

Edited By Megawatt on 19/10/2016 11:53:50

Thread: A question of bears.....
17/10/2016 09:43:47
Posted by The Wright Stuff on 17/10/2016 09:33:57:

Question. Sounds obvious, but best answer wins!

Why is there a North pole and a South pole, but no East or West poles?

Because the N & S Poles relate to the axis on which the Earth spins.

Im interested in how a mirror reverses your face left to right but not top to bottom - how does it know?

Edited By Megawatt on 17/10/2016 09:44:04

Edited By Megawatt on 17/10/2016 09:44:28

Thread: A question of physics.....
16/10/2016 20:29:57
Posted by Peter Beeney on 16/10/2016 18:31:38:

Megawatt @16/10/2016 11:11:22

Megawatt, I do apologise for the late reply, I’ve been out flying…

With respect, I’m afraid I’m still not yet convinced at all, so I guess we shall have to gently agree to disagree here.

Yes lets do that. I really have nothing further to add I have tried science, engineering and real world examples and failed to convince you. I am now certain that nothing else I can say will make any difference.

BTW I have just re read the whole thread from the start it is amazing how the "plane won't move" group have never answered a single question about how a low friction wheel has the ability to overcome the thrust of four jet engines despite being asked several times.

You are convinced that you are right and that I, Newton, Einstein and even BEB are all wrong. I will clearly never change your mind - as I said I am out of here.

16/10/2016 12:00:21
Posted by Gary Manuel on 16/10/2016 11:51:15:

A thought accurred to me while I was watching the Sunday Politics show, which was ironically about new runways at Gatwick and Heathrow.

Imagine our 747 had different sized front wheels to the rear wheels (they are actually all the same). Lets say the main tyres are 56 inches diameter and the front tyres are 40 inches diameter. If our plane accellerated to 150mph, would both sets of wheels be moving at the same speed or at different speeds? Bare in mind that they are all attached to the plane and all in contact with the belt.

This is actually the crux of the argument and both camps will give a different answer, but it will highlight where the difference of opinion comes from.

Ok I'll start the ball rolling

Both will have the same linear speeds but will have to rotate at different RPM to achieve them

16/10/2016 11:11:22

 

Posted by Peter Beeney on 16/10/2016 10:49:22:

I think I might argue with the same conviction that plane wouldn’t move forward, it would stand still. Relative to the observer and the surrounding air, that is. Belt moving backwards at 150 mph, that must now mean that the point of contact under the tyre is also moving backwards at 150 mph. The 150 mph worth of jet thrust is simply now holding the plane steady against that. The wheels are still turning at 150 mph. The belt is having to apply a similar worth of thrust backwards. Top kit, these Turnigy brushless motors!

The post implies that the plane takes off normally regardless of any sort of movement underneath the wheels. That being so, then how is our stalwart runner on the treadmill able maintain equilibrium between himself and the backwards moving belt? Why doesn’t he simply keep running into the stand in front of himself?

Eye of newt, and toe of frog, and all that… We should have a nice thick brew by Halloween…

PB

Ok One last time (this time I mean it)

Yes the bottom of the wheel is in contact with the belt and is moving back at 150mph relative to the air

No the axle is not stationary it is moving relative to the air at 150mph - and 300mph relative to the belt - it is revolving twice as fast as on a stationary runway remember

The top of the wheel is moving at 300 mph relative to the air and 450 mph relative to the belt

Draw it out if you want to - I did

Once again your man on the treadmill can only derive his thrust from the belt which reacts to his movement such as to keep him there - the 747 has no such constraint.

A final example - not that it will do any good if you do not believe your own eyes watching the mythbusters video - Consider a car, in neutral on a rolling road with the brakes off. The road is moving at 30mph and the car is held stationary by a rope attached to something off the rolling road in front of it. Now then the something it is attached to is a winch which begins to shorten the rope at 5mph - the rolling road compensates by increasing its speed to 35mph. Are you really saying that the car will not be winched off the road!

That really is it for me - I'm off back to lurking.

Edited By Megawatt on 16/10/2016 11:14:44

16/10/2016 09:38:43

Well I hope we're all still having fun because that's what this is about. Like Gary this is not about point scoring but the enjoyment of discussing logic and hopefully causing pennies to drop. Having said that I am beginning to suspect that one or two people are having a little fun at our expense so this is my last attempt - forgive the long post but I am going to try to cover it all.

I will assume that conditions are perfect throughout i.e. frictionless bearings, massless wheels and nil wind so as to show the concepts and because the real world effects are small or transitory - if you are unhappy with this approach then there are several youtube videos which deal with the real world issues and demonstrate that they do not affect the outcome - take a look if you can follow the maths.

This question all revolves (pun intended) around wheels - nothing else really.

So lets start with a car on a conveyor with a driven wheel at the rear axle and a free wheel at the front. If the Car starts moving the conveyor matches its speed and the car will not move relative to the air. This is because the car can only get its propulsion from the reaction between the rim of the wheel and the conveyor - if the conveyor moves backward then the car cannot move forward. Please note that the speed the conveyor must move at is the speed of the axle if the car is to remain stationary not the speed of the top of the wheel or the bottom but the axle which as it is rigidly attached to the car is the same speed as the car. Now think of the front free wheel it knows nothing about what is happening at the rear - it simply rotates at whatever rate is necessary for there to be no slip between the wheel and the belt. As I said before that is what wheels do - they are no good for making tea and cannot receive radio one or get the children ready for school but they are brilliant at moving something over a smooth surface with little (or in our example no) resistance.

Now think about our 747. Its propulsion is generated completely independently from the conveyor - the conveyor cannot influence its speed in any way as it is resting on frictionless bearing wheels - the belt could be moving at Mach 0.99 and not be able to influence the speed of the 747 (ignoring any small real world effects due to air disturbance). But its not even moving at Mach 0.99 - only at the same speed as the wheel axle/747. So the 747 accelerates which makes the belt accelerate to the same but opposite speed but the plane still moves through the air and takes off.

Mythbusters actually did a pretty good job of recreating this - if the plane won't move brigade were right I would have expected the plane to maybe move back and forth a little due to errors in speed but it didn't, it smoothly accelerated and took off - in the real world with the wheels rotating at twice the rpm they normally would.

Edited By Megawatt on 16/10/2016 10:05:07

15/10/2016 20:12:44

Ok what does the original question not say - it does not say that the conveyor moves in the opposite direction so as to render the plane stationary - because that would be impossible the conveyor has no means to achieve that.

What it says is that it will travel at an equal speed (note this implies that the 747 is moving, speed being distance moved over time) in the opposite direction, So the original question allows for the 747 to be moving in one direction whilst the conveyer moves in the other resulting in the rotation of the wheels at the correct rpm to result in no skidding. I really can't see why this is so difficult to grasp.

15/10/2016 19:50:24

Posted by Pete B - Moderator on 15/10/2016 18:50:17:

Posted by Megawatt on 15/10/2016 18:25:30:

Erfolg - please put me out of my misery and admit this is a wind up. I call Troll and suggest that if you want to indicate that I am wrong you reply to the simple direct closed questions I have asked without introducing yet more technobabble to obfuscate the issue.

No, Erf's his normal self - once you've read a thousand or two of his posts you'll realise that....teeth 2

Besides, we all love him and wouldn't want it any different....wink 2

Pete

Indeed -that is what makes the debate worthwhile

Latest Forum Posts
Support Our Partners
CML
Slec
Sussex Model Centre
Jetworks
Subscribe now
electricwingman 2017
Sarik
Advertise With Us
Latest "For Sale" Ads
NEW POLL - has the pandemic altered your event safety perceptions?
Q: Has the covid pandemic deterred you from attending shows and events in 2021?

 No, I'll be attending just as many as I usually do
 No, but I'll choose my event with greater care
 Yes, I'll attend fewer events going forward
 Yes, I wont attend any where previously I have

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!