MattyB

Sorry, but I don't think adding a rudder and using coupled ail to rudder mix is going to cut it - you really need ailerons with a deeper chord. Personally I would cut the existing ones in two a third of the way out, glue the inner section back on as a fixed TE, relieve the TE on the outer portion to double the chord then make some ailerons to fit driven by a servo per side. I would be very surprised if that did not fix it.

Posted by cymaz on 14/11/2016 18:01:04: Cannot wait...great subject A bit more on " Bunty" Yep, it really is a pretty plane - reminds me a little of the original flying car in some respects, minus the additional set of wheels of course! Just one request though - please leave out the carbon dashboard surround that seems somehow to have made its way onto the plane during the restoration. What on earth were they thinking on such a graceful old bird!

Have to agree, given the symptoms and the fact they were preceded by a prop strike means it is far more likely to be a motor or connection issue than an ESC issue. Check all your external ESC to motor connections first and test with a spare ESC, but if you find nothing there you are going to need to disassemble the motor to find the cause.

Not really. Sorry, but if you are doing a B both should be trivially easy. If they are not you are probably not ready!

Posted by Geoff Sleath on 10/11/2016 11:09:04: Matty, I've already reflashed the firmware. I have 2 Taranises (sp?) and I've been using the 'disposable' one I repaired. I suppose I could try the 'serious' one but I'm not very hopeful. I was thinking of having another session today now I've cooled down a bit Just to be clear I was suggesting you upgrade the RF firmware in the TX, not reflash the Receiver firmware again. Have you tried that step? If your TX is one of the early ones and you have never flashed your internal RF module then it is conceivable that there may be an mismatch between two different versions of the Int'l RF firmware. Unlikely, but just about possible. Posted by Geoff Sleath on 10/11/2016 11:09:04: I just don't want to update to OpenTx v2.2 or whatever as it means sorting out yet another voice file. Having continually to update software is getting too much like being at work Yep, I get that - I used to keep up with every update, but I have been flying less recently due to my small people and having various works going on in the house so I am still on 2.0.19. Works great for me! Given you don't want to move to 2.2 though I think your only other options is to buy the STK cable and calibrate your RX from the PC - that should allow you to be confident that your calibration has worked correctly (or not if the RX is defective).

Mostly I agree with Gary, but I do have a couple of ESCs with flat top ends - they have needed custom curves to give a more linear response. In a number of my models I apply different throttle curves depending on flight mode (for instance limiting throttle to 75% max on launch for a hand launched EFX Racer to avoid excessive torque roll).

Posted by Gary Manuel on 10/11/2016 15:42:58: ...I may be a bit slow in catching on here, but the only way a roll can be away from the flight line is if the model is flying (with the nose pointing) away from the flight line. When you roll a model, it should roll about the centre of gravity, which should continue in a straight line. If the model is flying parallel to the flight line, whichever way you roll, one wing is rolling towards the flightline and the other is rolling away. I can't see that it makes any difference which way the first rolls are as long as the next pass in the opposite direction is rolling the opposite way. Hurrah, it is not just me that doesn't get this recommendation then...! Posted by Gary Manuel on 10/11/2016 15:42:58: ....Another point that's bugging me is that the roll test does not require the use of the rudder but it does require the use of the elevator to be demonstrated. A model can be trimmed so that it does not require any elevator input when inverted. I've never flown one that doesn't require any rudder when passing through the knife edge. How would the use of elevator be demonstrated when a model is trimmed for neutral elevator? I would say that the only reason for a model that is trimmed like this to need the elevator applied is because it has become nose down because the rudder was not used during the knife edge parts of the roll. I know that the B is not looking for perfection but a perfect roll (using rudder) of a perfectly balanced model, might not need any elevator input. Would this be a failure because the use of elevator was not demonstrated. I suspect as long as the roll is a) slow enough to require at least some correction, and b) the adjustments are not hideously uncoordinated it will not really matter - that will be good enough to pass. Personally I almost never input rudder during rolls unless I am trying (and failing, as always...!) to fly a rolling harrier.

I am still mystified as to this "rolls away from the flight line" bit... 50% of any roll is "towards" the flight line (i.e. some component of force acting towards the pilots position) whichever way you roll, so why would it be safer to start one way rather than the other? Sounds like an urban legend to me... Edited By MattyB on 10/11/2016 14:54:49

Remember if you get one of thee you must drill holes or remove the rubber seal to allow it to vent in the event of a fire, otherwise you have something that isn't really any less dangerous...

Posted by john stones 1 on 10/11/2016 10:33:21: No Matty if it's chosen to insist on a particular standard to the one manoeuvre, be consistent on the others. If the pilot can be asked to fly directly at himself during the eight, why penalise for stall turning inwards ? Now you are asking a different (though I agree valid) question. Originally you stated "Rolls/spins no mention of not rolling/spinning inwards to flight line and manoeuvre is in front of you....more likely to be dangerous if messed up?" - that is what I answered, in my eyes there is no increase or decrease in risk related to the direction of the spin or roll. I agree that the stall turning towards the flight line represents a negligible increase in risk overall and should probably be permissable, but that is the way the test was written - perhaps there is other thinking behind it we are missing. You should direct your question to the BMFA if you want the answer, not this forum. PS - The only way I can think of of never flying towards the flight line is by only using immelmans or split-s turns to change direction - I am not sure that would help a budding B candidate to pass!  Edited By MattyB on 10/11/2016 11:03:23

My recommendation to Geoff would be 1) try flashing the RF firmware in the TX to the latest Int'l version on the FrSky site, and if that does not work 2) find someone else with a Taranis on Int'l firmware and see if they can bind it and get the same issue. My hunch is that this may be some kind of RF firmware mismatch betweeen the TX and RX, so this test should at least enable that to be eliminated as an option.

Posted by john stones 1 on 10/11/2016 09:07:58: How i read it Rotation of the stall turn itself should be away from the flight line, if it's on your left it stalls to the right, only reason i can see, if for safety...away from people Rolls/spins no mention of not rolling/spinning inwards to flight line and manoeuvre is in front of you....more likely to be dangerous if messed up ? Not really. In a roll or spin you spend the exactly same amount of time pointing "towards" the flightline irrelevant of where in the sky you do it or whether you are spinning/rolling left or right. In a stall turn however you spend zero time pointing towards the flightline if you turn away (right at the LH end of the flightline, left at the RH end) which is not true the other way round. Frankly though if you are doing a B you should be capable of recovering safely from any position/orientation anyway, so the direction of turn seems rather a minor consideration to me. For a B standard pilot it could only cause a problem if you had a mechanical or radio issue at the exact moment the aircraft was pointing towards the flightline during the stall turn - that is a window of maybe 0.5s in the whole of the flight. That is nothing compared to the amount of time it will spend pointing at the flight line during the circuit and figure 8 based manoeuvres.

Posted by Geoff Sleath on 09/11/2016 17:32:31: I can get mine to bind (International firmware) but it doesn't do anything useful. The RF continually swamps the transmitter and gives the 'Telemetry Lost' /'telemetry regained' messages on and off continuously even when they are over a metre apart. I've given up. I just got totally frustrated after struggling for hours and getting nowhere. It's not in the bin ... yet - but it's close. Geoff Why not just send it back for replacement or refund?

I don't think the stall turn being 100 yards away is anything to do with safety - it is a turnaround manoeuvre so the pilot should be able to do it at some distance away from them. There is also nothing fundamentally dangerous about doing rolls or spins in front of you provided you enter at the right height and take account of the wind direction and speed when deciding your point of entry. Edited By MattyB on 10/11/2016 07:53:06

For those of you wanting to estimate the max amps for cheap motors from the like of HK, 4-max etc (more expensive ones from Hacker, Axi, OS etc. tend to have accurate specs provided that include this info) here is a rough method that should help... For your motor find out the mass in grams and nominal voltage for operation. Ignore any quoted max wattage. Instead take the mass in grams and multiply by 3. This is your (conservative) max power in watts. Take the calculated max wattage and divide by the nominal pack voltage*. This will give you the max current in amps. Size your ESC a minimum of 15% or 10A above this calculated max motor current, whichever is lower. Prop to give yourself slightly less than the max calculated MOTOR current. * - If the motor is quoted to be used on multiple pack sizes i.e. 3 or 4S always use the higher of the two voltages when doing this calculation, as it will give you a lower maximum current. Yes this method is conservative, but it works - you are almost certain never to burn out a motor or ESC if you use it. Besides, in most models we need a bit of weight up front to get it to balance, so running a larger motor rarely causes an issue and will be more efficient. Important point - the 3W/g rule of thumb only applies to prop models powered by cheap motors. Better quality items from Hacker etc will do more providing the cooling is right, and even cheap EDF motors can output far more watts/gram because of the enhanced cooling intrinsic to an EDF installation. I do not have a similar rule of thumb, but if forced to guess I would imagine it is at least 6W/g. Edited By MattyB on 09/11/2016 16:47:27

I'm not sure it is as simple as the pollsters asking "the wrong people" - after all if you are of voting age you are someone who will have an effect on the outcome and are one of the "right people", assuming you actually do vote. Yes they need to survey a representative sample of the demographic within that region/constituency/country to get an accurate result, but you would think that would be pretty easy to do given the amount of money and technology at their disposal. It would therefore seem to imply that people don't necessarily give a true answer to the question(s) posed when polled. Why? I have no idea, but you can bet there are plenty of pollsters in the US today wishing they knew... Edited By MattyB on 09/11/2016 16:24:55

So if you set it up to balance charge at 1C your packs will take 2-3 hrs before it tells you the charge is complete? Wow. What voltages is it saying the individual cells are coming off charge at, and what accuracy does it measure the voltages to? My cheaper i106b iCharger only measures to a 1/100 of a volt whilst the 406 measures to 3 decimal places. The actual accuracy of balance doesn't seem much different though if a pack off the 106 is measured on the 406 immediately after charging. Both terminate a 1C balance charge after about 45 mins if charging from a storage voltage of 3.75V/cell, though the 406 actually has multiple balance charge cycles of various different speeds (it has a much higher max balance charging current which I guess helps here).

This hobby is full of items that come with next to no instructions and require knowledge to be used correctly. Linkages, servos, engines, retracts, plans, even some ARTFs come with next to nothing. These are not mainstream commercial products like washing machines or computers, so you cannot expect them to be packaged as such - knowledge will always be required to use them correctly. Ps - I just checked a few, and all my batteries from HK and Gens Ace come with the nominal voltage, max discharge / charge rates in C and capacity marked reasonably clearly. I do agree that some packs do leave a bit to be desired on these fronts though.

Posted by Adrian Smith 1 on 08/11/2016 09:17:44: Now I know that the manual recommends this plane flies on a 6S 4500 -5000 mAh pack, but I have found some 5S 4500 mAh Lipos here. **LINK** Firstly, is the spec satisfactory to use in this case and will I notice any major difference in performance? Sorry, but with the motor you have (A50-16S is 365Kv) you have to use 6S; you will be very underpowered for aerobatic flying on 5S with the recommended prop, and I doubt you have the ground clearance to prop it up and get back the thrust you have lost. Even if you did you would be pulling more amps so duration would be down. Besides, you could by 6S 4500 Zippy Compacts from HK for hardly any more money. Stick with the factory recommendation - it works! Edited By MattyB on 08/11/2016 18:52:16

Posted by SuperNash on 08/11/2016 17:09:42: Posted by Percy Verance on 08/11/2016 14:17:56: I'm given to understand a normal (non balancing) fast charge will take the pack to about 90%, whereas a balance charge will get it fully topped up, assuming the pack is in good health. Depends how long your balance charge takes, my understanding is that a full 100% charge will take a good 2 or 3 hours, regardless of the speed of the fast charge phase. I don't know what charger you are using, but that is absolutely not the case with those I have used. Both my iChargers will balance charge any pack within their capability range at 1C in under an hour and at 2C in ~30 mins to an indicated 0.01-0.02V/cell variance. I'd call that fully balanced!

Posted by Biggles' Elder Brother - Moderator on 08/11/2016 16:25:53: To be honest - having done both - I do not think there is any major difference between 1C and 2C. I totally agree that charge rates significantly above 2C are questionable in terms of battery life. As stated above I regularly charge at 2C and my batteries certainly outlast most people's around me. I put that down to two facts (both of which I personally think are more important in the overall effect on battery life); first is the fact that I never discharge below 20% capacity - usually more like 25-30%. Secondly I always balance charge - only very, very, rarely doing otherwise. As I say I can get excellent battery longivity from these two and 2C charging. Completely agree on all points - with first generation lipos there was undoubtedly value in charging at lower rates, but I have not seen any appreciable heat build up/degradation in performance from charging at 2C with more modern (i.e. from the last 4-5 years) packs. They are a lot more resilient than those early examples!

It should tell you the max charge rate in C for your pack on the outside - most batteries now have a rating between 2 and 5C. Opinions vary greatly on this topic, but I generally never charge above 2C in order to preserve the cycle life of my packs; in your case 2C = 2x3200 = 6.4A. I would also recommend that when charging at home you balance charge every time, as this should of lengthen the life of your batteries and many of today's chargers rely on being able to see the cell voltages in order to utilise their more advanced safety features I.e stopping the charge if an issue is detected. Edited By MattyB on 07/11/2016 09:23:33

What you are describing is not a model or technology problem - there is lots of suitable setups available to buy or build for use in higher winds. This is all about the squidgy thing that holds the sticks... It's not the sole reason, but as the demographics of modelling steadily change more and more people are becoming fair weather fliers. As a result attendance levels at the patches where I am a member are dropping off, especially when it gets windy. Lots and lots of my peers have other hobbies or activities they do when the wind gets up, so they don't see any need to risk a crash by flying in more challenging conditions. That's absolutely fine, but there is no doubt that you can learn a lot by flying in a wide variety of conditions - coming from a background where I learnt to fly on the slope I find the conditions that some power fliers dismiss as "far too windy" rather innocuous!  Edited By MattyB on 06/11/2016 12:22:15

Posted by Bob Cotsford on 05/11/2016 19:22:45: The search is still a total farce, which means the site is pretty useless unless you are just browsing through a category. At least the search worked before the upgrade. If you want lipos from HK forget the search box or lipo finder. The best way currently is (ridiculously) to search directly from Google. It will take you straight to the page of the battery you are looking for, though obviously you need to input more or less the exact name (i.e 6S 4500 Zippy Compact) to find the right page.

Essentially the same as I described above for the separate RX pack and Digiswitch, but all fed from the main pack - 4-Max have a good explanation on their site.