Dave Hopkin

Whats the difference between a politician and a flying pig? The letter F

I learn from people who took my advice

Fair enough Steve................. Parachutist leaps out of plane, mail chute fails and to his horror so does the reserve... Plummeting down to earth he see's another bloke without a parachute passing him going the other way (as you do) "Hey Mate" he shouts... "know anything about Parachutes?" "No" replies the bloke "Know anything about gas boilers?"

A lady walked into a drug store and told the pharmacist she needed some cyanide. The pharmacist asked, "Why in the world do you need cyanide?" The lady then explained she needed it to poison her husband. The pharmacist's eyes got big and he said, "Lord have mercy, I can't give you cyanide to kill your husband! That's against the law! I'll lose my license... They'll throw both of us in jail and all kinds of bad things will happen! Absolutely not! You can NOT have any cyanide!" Then the lady reached into her purse and pulled out a picture of her husband having dinner in a restaurant with pharmacist's wife. The pharmacist looked at the picture and replied, "Well, now... You didn't tell me you had a prescription"

A child asked his father, "How were people born?" So his father said, "Adam and Eve made babies, then their babies became adults and made babies, and so on." The child then went to his mother, asked her the same question and she told him, "We were monkeys then we evolved to become like we are now." The child ran back to his father and said, "You lied to me!" His father replied, "No, your mom was talking about her side of the family."

A Blonde goes to Heaven A Blonde was sent on her way to Heaven. Upon arrival, a concerned St Peter met her at the Pearly Gates. 'I'm sorry,' St Peter said; 'But Heaven is suffering from an overload of godly souls and we have been forced to put up an Entrance Exam for new arrivals to ease the burden of Heavenly Arrivals.' 'That's cool' said the Blonde, 'What does the Entrance Exam consist of?' 'Just three questions' said St Peter. 'Which are?' asked the Blonde. 'The first,' said St Peter, 'is, which two days of the week start with the letter 'T' '? The second is 'How many seconds are there in a year?' The third is 'What was the name of the swagman in Waltzing Matilda?' 'Now,' said St Peter, 'Go away and think about those questions and when I call upon you, I shall expect you to have those answers for me.' So the Blonde went away and gave those three questions some considerable thought (I expect you to do the same). The following morning, St Peter called upon the Blonde and asked if she had considered the questions, to which she replied, 'I have.' 'Well then,' said St Peter, 'Which two days of the week start with the letter T?' The Blonde said, 'Today and Tomorrow.' St Peter pondered this answer for some time, and decided that indeed the answer can be applied to the question. 'Well then, could I have your answer to the second of the three questions?' St Peter went on, 'how many seconds in a year?' The Blonde replied, 'Twelve!' 'Only twelve?' exclaimed St Peter, 'How did you arrive at that figure?' 'Easy,' said the Blonde, 'there's the second of January, the second of February, right through to the second of December, giving a total of twelve seconds.' St Peter looked at the Blonde and said, 'I need some time to consider your answer before I can give you a decision.' And he walked away shaking his head. A short time later, St Peter returned to the Blonde. 'I'll allow the answer to stand, but you need to get the third and final question absolutely correct to be allowed into Heaven. Now, can you tell me the answer to the name of the swagman in Waltzing Matilda?' The blonde replied: 'Of the three questions, I found this the easiest to answer.' 'Really!' exclaimed St Peter, 'And what is the answer?' 'It's Andy.' 'Andy??' 'Yes, Andy,' said the Blonde. This totally floored St Peter, and he paced this way and that, deliberating the answer. Finally, he could not stand the suspense any longer, and turning to the blonde, and asked 'How in God's name did you arrive at THAT answer?' 'Easy' said the Blonde, 'Andy sat, Andy watched, Andy waited til his billy boiled.' And the Blonde entered Heaven... ... you're singing it now, aren't you?!

I wonder if Amazon are going to be using DSMx?

Mikes slot cutting method is also a good one that I have resorted to in the past, though I use the dremmel to cut the slot

I am assuming the culprit is the compression adaptor and that the motor is buried inside a cowl? You can try holding the prop and applying a slight twisting pressure so the prop barrel grips the shaft giving enough purchase to tighten the nut sufficiently tight for the adaptor to grip the shaft Failing than a dowel can be used to jam/wedge the motor can while you tighten the prop nut

Hmmmmmmmmmm Firstly the photo has only been reported on MSN and Yahoo news as far as I can see Secondly - Twin IC engines with no heat shielding at all? Going to be a big far Infra Red Target for the Phalanx guns on every US warship deployed in the gulf (and its pretty certain the enemy they have in mind is the US) Not at all convinced its anything other than a bit of propaganda

I felt so depressed when my wife left me - I ordered five ARTF's and went out and brought a dog - that didnt cheer me up, so I went and brought a motor bike, that didnt work either, so I spent a grand on loose women and booze She's going to be so mad when she comes home from work...................

Its very unlikely the instructions will tell you a great deal about the engine other then any offset angle it needs to be fitted at

Posted by Peter Beeney on 16/10/2016 18:33:20: Dave Hopkins @ 16/10/2016 12:10:02 Dave, I’ve just read this post and the comment I’d have to respectfully make is that just like Megawatt above all you’ve done is simply just changed the rules. You are now anchored to a fixed point, the 747 cannot do this because it’s free to go where it will. What ever the belt does, you will always be able to pull yourself forward. Although that’s within reason, of course, if the belt were clocking 200 mph rearwards the ride could get interesting; and don’t let go of the rope either, that might be a bit of a mistake, too! Still, at least you would see the way clearly by the glowing light emanating from the skate’s wheels. I’m always looking for the easy option, so why not clamp the skates to a folding chair, employ a winch as the far away anchor point, tie the rope to the cross bar and relax with a quick half and RCM&E as you are towed gently to the end of the belt. Stay cool! PB No, I have just replaced the planes jet engine with a pull rope - I could just as easily have said I have a mini turbine strapped to my back - and as I opened the throttle, I would move forwards - simply because unlike the treadmill runner my motive force is not generated from a reaction against the belt but against the air - so unless you can find a way of diverting the energy from the turbine on my back Newton's law says I have to go forwards... equal and opposite reaction and all that

So Jonn are you saying that I wouldn't be able to pull myself hand over hand along the rope because of an infinite amount of air pressure?

Posted by ted hughes on 16/10/2016 15:59:34: Posted by Dave Hopkin on 16/10/2016 12:10:02: Ok, lets try again I wear roller skates and stand on the conveyor belt there is a rope running up the length of the belt attached to something not on the belt. I hold the rope and start to pull myself along it allowing the roller skate wheels to rotate as they wish The belt speeds up in response to my movement as per the original question Now what is stopping me working my way up the rope hand over hand? Nothing at all..... The rope equates to the engine thrust acting on the surrounding air...... hence the belt will have no effect on take off which will occur normally It sounds plausible, but in actual fact you would be trying to pull against an infinite amount of pressure and it could not be done. And what "pressure" would that be? Energy cannot just appear miraculously so where is this force coming from so there must be a source of this "infinite pressure" ?????

Ok, lets try again I wear roller skates and stand on the conveyor belt there is a rope running up the length of the belt attached to something not on the belt. I hold the rope and start to pull myself along it allowing the roller skate wheels to rotate as they wish The belt speeds up in response to my movement as per the original question Now what is stopping me working my way up the rope hand over hand? Nothing at all..... The rope equates to the engine thrust acting on the surrounding air...... hence the belt will have no effect on take off which will occur normally

The crucial difference between the treadmill and the plane is where the opposing forces meet On a treadmill the runners legs react against the moving conveyor belt, so his forwards motion is counteracted by the belt (if the two are equal) The aircraft does not react against the conveyor its thrust reacts against the air As the engines will develop the same forwards propulsion force if the aircraft is on the conveyor or not the aircraft is forced forwards regardless of what the belt is doing The wheels of the aircraft are the only interface between the power of tge belt and the power of the plane, as they are free wheeling they are unable to prevent the aircraft moving forwards For the aircraft to remain stationary the wheels would have to absorb and disipate the entire force of the planes engines (as energy cannot be lost) how do they do that?

And the answer to this surreal question is...... A FISH

I've had a re-think............... I am now sure the plane stays perfectly still but the conveyor belt takes off...............

As BEB and others have said there are quite a few makes of compatible RXs on the marker sadly the levels of compatibility and component quality varies hugely - that variation makes it ermmmm "Interesting" to choose one! Some are outright fakes and best not touched with other peoples barge poles..... usually found selling at less than 50% of RRP on fleabay Some are genuine compatible RXs like Lemon or Orange - and many people use them outside of those two brands I would be VERY hesitant about using them.....

Posted by Erfolg on 15/10/2016 15:34:54: The question posed, is quite specific, there is a fundamental relationship between the speed of the conveyor and that of the aircraft. For the aircraft to go any faster than the speed of the conveyor belt, the wheels have to skid. We know that the question posed does not allow this. If the wheels are driven, or the power is provide by fairies is immaterial, to the question as posed. There is no requirement to explain the mechanics, of if this in reality is possible or practical. No! There is no "fundamental relationship" between the wheels and the airframe - the wheels are free wheeling and can rotate in total isolation from the airframe. The wheels will not skid, they are free wheeling as the speed of the conveyor increases they will just spin faster There is every reason to explain the mechanics because the question essentially pits two opposing forces together in opposition (the drive of the conveyor versus the propulsion of the airframe) - so ask yourself where do these two forces interact with each other? The only point of contact are the wheels! So are the wheels fixed (rotationally) to the airframe? No the freewheel....... and will adopt the combined speed induced by the two forces...... what the airframe does is totally isolated from what the conveyor does.....

Posted by Bob Burton on 15/10/2016 07:21:31: Posted by onetenor on 15/10/2016 01:28:29: The car and the plane get their thrust in different ways The car via driven wheels in contact with the road. The plane from jet/props which act upon the air not the conveyor.thus pushing the plane forward irrespective of belt speed. But in the case of the original question the conveyor moves at the same speed as the wheels, so if/when the plane speeds up so will the conveyor to compensate for it. Thus the plane will stay in the same position on the conveyor and have no airspeed so cannot take off. Lets ignore the trickery in the original question which makes no mention of the engines being on., lets assume they are functioning normally - if they are not of course the plane cant take off! Lets step through what happens.... Engine thrust pushed the airframe forwards..... Conveyor sense that and moves in the opposite direction at the same speed.... The wheels are now between two forces.... (lets ignore the tiny percentage of power lost to friction in the axles) The wheel axles are being propelled forwards by the airframe so the wheels would rotate on the axles at a rotational rate proportional the the airframe speed But the conveyor belt is also influencing the rotation of the wheels but acting in concert with the rotation created by the moving airframe, so the wheels end up turning as follows: RPM = RPM induced by Airframe + RPM inducted by conveyor As the conveyor matches the airframe speed it the RPM is double that it would be on stationary ground BUT no force is being applied to the airframe to prevent it accelerating, so as long as the engine pushes it forwards it will move forwards and take off...... If you think it cant do that, you have to have a reason where the power from the engines is countered to prevent it (yes friction losses will reduce that power by a tiny %age but not enough to stop it flying)

Posted by Peter Beeney on 15/10/2016 09:09:47: <snip> he’s stationary because the road is passing under his wheels in the other direction also at 50 which cancels out his forward speed.<end snip> No he's not stationary, he IS Geo-Stationary - i.e.. stationary in relationship to the Oak Tree BUT to maintain that geo static position the speed of the train in one direction would have to be exactly counter balanced by the same speed in the opposite direction, THEN he speed relative to the train would be the same speed as the train but in the opposite direction. But that analogy does not apply to an aircraft simply because the car propels itself by reacting against the ground surface via driven wheels, an aircraft obtains propulsion by displacing air from its propeller or jet Think of it this way, you model needs an airspeed of (say) 20 to lift off, if the wind is 10mph and you take off down wind, the airspeed you need is not changed but the ground speed you need is 30mph (an extra 10mph to counteract the following wind) taking off upwind and you will need a ground speed of 10mph as the air is already flowing over the wings at 10mph Apply that to the plane of the conveyor belt (and lets assume the engines are running - which the scenario does not specify) on normal ground the plane would simply accelerate away to rotation speed, on a conveyor belt the rearwards motion of the conveyor belt will interact with the (un-driven) wheels causing them to rotate at twice the ground speed, but the plane will still more forwards as the prop/jet thrust is still propelling the body of the aircraft forwards (yes there may be minute friction losses in the axles but nothing like enough to overcome the forwards motion induced from the engines) In this case the speed of the aircraft in relationship to the conveyor belt i(ground speed) s twice the speed of the the forwards motions of the craft in relationship to an observer who is NOT on the moving belt so the rotation speed of the craft would be identical to the observer and the plane would fly as normal A real life example of this are Geo-Stationary Satellites which maintain a fixed position in relationship to a point on the surface of the earth BUT are hurtling through space at many thousands of miles an hour to maintain that position

Posted by Erfolg on 14/10/2016 19:05:57: I do not think I agree with BEB, oh dear,whatever the trust from the engines to accelerate the aircraft, the question states that the conveyor supplies the opposite and equal acceleration. To keep the situation in equilibrium. In the real world that may not be true, although in the context of the question as posed, that is how i evaluate the model. Yes the belt would apply a force on the wheels, which would spin (driven by the belt) but apart from any friction loss in the axle it would hve no impact on the plane moving forwards as the jet/prop propels air backwards...

Posted by ted hughes on 13/10/2016 20:04:00: It would not fly. Imagine the conveyor belt started with the plane not using its engines for thrust. The plane would stay stationary, just the wheels would spin. As soon as the plane used thrust, it would move backwards if the conveyor belt was faster than the thrust could provide, but if they were balanced (as in the problem), the plane would be stationary. Edited By ted hughes on 13/10/2016 20:04:37 Apart from the facts a) the wheels of the plane are not driven so what happens at the wheel/ground interface is irrelevant b) Mythbusters put the conundrum into real life... guess what the plane flew.... **LINK** Now can we let this thread die ?