Peter Jenkins

Thank you GG. I must say I'd never heard of this but then I just fly precision aerobatics and not 3D aeros. Reading the article is sounds like the entry is identical to a negative snap or flick roll. However, in a negative snap the rudder goes in the opposite direction to the ailerons as it's now "underneath" so to speak. Having read through the instructions, it rather sounds like a sustained snap roll where the aircraft descends until controls are centred. I shall try this out but I suspect that for this to work you need much larger control deflections that we use in precision aerobatics. I will see how it goes. Thanks for the information.

How interesting. What is a KE spin and how do you enter it?

Of course, if you were flying electric, you could pick a motor with a suitable kv for a scale sized propellor. Not so easy with IC without having a physical gear box that the electric motor with a low kv represents. I know, it doesn't sound the same! But look at that scale size prop!

If your geared 61 is happy swinging the 16x 8 replace it with an APC of the same dimensions. It will be quieter and give more thrust for the same rpm. APC props are the best in terms of blade shape and give the highest rpm from most engines. If you want to spend on carbon fibre props, then some of them might be better but they are not a tolerant to damage as APCs.

That would be far better Toto. I should swap them over and you will instantly have much more power available with either of the two props. The 11x5 will provide more power but check on the wattmeter that it stays within the ESCs limit current wise. Don't exceed 980 W on the motor although in reality, once in the air then the power output drops as the prop will unload. It is load on an electric motor that makes it put out the power. Sounds like a cost free solution.

Exactly so leccyflyer. The problem is that Toto has been sold the wrong kv rated motor. His motor has a 500 kv with a note to say use 15 inch props whereas the one that DD pointed to has an 800 kv so getting on for 60% faster rotation speed per volt. That then can use a smaller diameter prop and produce far more power than he's currently getting. As an example, I bought a second hand aerobatic aircraft that was being flown by a beginner in aerobatics. He had a 425 kv motor that was really intended for a 6S setup but he was using a 5S setup and a 16x8 prop. The performance this setup gave was anaemic to say the least as it was impossible to maintain speed on a vertical climb. I had to resort to a 17x12 prop before I came close to the rated limit for the motor at which point all was fine except that there was almost no ground clearance now! Changing the motor to one with a 585 kv allowed the use of a 16x10 prop and gave the required 1200 W with the current draw just within bounds. It is rare to use full power for more than about 6 secs so that worked and still works fine. This is one of the problems with electric power as there are so many variables that newcomers have to ask and don't know which answer to believe as all answers, as we have seen, appear to conflict. The best thing you can do Toto is to go with your 6S packs and see how things work out. If you, or your instructor, feel you need more power, best solution is to swap out the motor for one with a kv or 800-900 and then you will probably be fine with the 4S pack. That's a cheaper option than buying 6S packs.

Toto Just record amps and watts. No other figures are necessary. Volts can be derived by dividing watts by amps. For a 4 lb all up weight 400 watts is good. 500 watts for a 5 lb model etc. If the 12x8 isn't producing the power try a 12x10 and even a 12 x 12. Unlike an IC engine an electric motor can turn off in flight or, better still, have a very low idle rpm of say 400. So having a high pitch prop won't cause landing difficulties as it would with an IC engine idling at 2,000+ rpm on a 40 size engine.

No float planes David?

I have to differ as 100 W/lb is a much better place to be even for a trainer. You can always turn down the throttle stick max movement to provide a lesser power rating but then again you should learn how to use the throttle from the word go. Full size is not taught on very low powered aircraft that are difficult to get a decent climb rate with full throttle. The throttle is not an on/off switch although I know quite a few who treat it that way. I hope your instructor tells you to keep both sticks under your thumbs, or finger and thumb, at all times when you are flying. You won't have the noise of an IC engine to help you decide how much power you have selected. To overcome this problem, I found that my Tx had a stick alert that allowed me to set a beep when I was at my "cruising speed" setting. That way, you know when you are at that setting without having to look down at the Tx.

Toto, that's what you use the watt meter for. Find out what the current draw is with your current prop then up the pitch and check again. As an example, I needed a 17x12 prop on a 425 Kv motor with a 5S pack but a 16x10 prop on a 585 Kv motor gave the same power but at a higher rpm. In both cases I had the same power, 1,200 W and with a 5.5 lb AUW the aircraft had 218 W/lb that gave the aircraft the ability to fly large loops at constant speed. With the 425 Kv motor and 16x10 prop the power was marginal for what was required of the aircraft hence the change to 17x10 snd eventuslly 17x12 to get the power out of the motor.

Toto, your friend is your wattmeter. What did it read at full throttle? You say you have a 60 A ESC and assuming that the motor can also take 60A then you are quite safe to have a full throttle current draw tethered on the ground of 60A. In flight, this will drop by 15%- 25% - I know as I have on-board telemetry and that was what I found. So, in flight the current draw willl be between 45A and 51A. Assuming your 4S pack voltage will be around 16 V at best at full throttle in the air that gives you a power output of 720 - 816 W. I don't know the weight of your model but let's say 4 lb this will give between 180 and 204 W/lb. Since a good W/lb figure is 100 W/lb which gives a sprightly performance. 180 W/lb should give a very sprightly vertical performance and will be the bottom of the power required for good aerobatic performance while 204 W/lb should give you unlimited vertical performance i.e. continue climbing at speed till its out of sight - my aerobatic biplane has 254 W/lb and its certainly got unlimited vertical performance! So, something is wrong in your set up and you are not getting the power out of the setup you have. Have you accidentally reduced the throttle channel output to the ESC? Is it at 100% in the ATV or whatever it's called in your Tx? It might just be that you need to increase the propeller pitch and, if the ground clearance will allow, diameter. You basically have to load up the motor until it produces its rated power. If you load it too much you will burn out the motor or ESC or both which is why you must check with your Wattmeter. I now check my systems when they are in the air to see what the true full throttle current draw is and that is how I found the motor drew 95 A and used 3,600 W on the ground tethered but a maximum of only 80 A and used 2,800 W in the air at full throttle. The motor is rated for 2,800 W. In normal aerobatic schedule flying I rarely see more than 2,750 W and 78 A at the end of the flight.

Don't forget to switc on the model and check your dual rates physically. Best to measure by angle of deflection. 10 deg each way on aileron and elevator and 25 for rudder is a good low rate.

Don't worry Toto, I was the wrong side of 60 when I started on electrics having been a diesel (teenager) and glow (50+ on) person. It's all very different when msking the change. The difference is that I only went electric after my first few aerobatic competitions. However, not having an IC engine noise to judge power settings I had to find another way of doing so and my JR Tranny could be set so with the throttle stick at the desired opening It emitted a beep. That was very helpful. I'm now well on the wrong side of 70 but still enjoying competing in aerobatic competitions.

Think of kv as gears in a car. A low kv means that power is generated at lower rpm so the prop goes round more slowly and can therefore, usually, be a larger diameter higher pitch one so equates to a high gear, say 5th or 6th. A high kv means the power is generated at higher rpm so the prop goes round much faster which means a smaller diameter and/or lower pitch, say 1st or 2nd gear. If you find that confusing just ignore my post.

Indeed.

I understood and Operators ID was required for anyone flying an aircraft weighing more than 250 g which is why the BMFA is offering us the service to register for and renew Op ID. Or have I got that wrong?

Well, I'd cover first, then cut the hinge slots otherwise it's the devils own job to find the slots you've made! Use a centring tool to get the hinge slots cut in the middle of the structure and control surface.

You can never have too many clamps!

As you can see Adrian, I have a good deal more space I can use than you have in the Capiche for moving battery packs around! That was why I decided not to electrify my Capiche 140 especially as it was a bit porky to begin with and tipped the scales at almost 6 Kg! When I put the DLE35RA in it, the weight climbed to 6.25 Kg and it just wasn't able to fly at a constant speed. Full throttle verticals always ran out of puff far too early!

I see you found the Anthem thread just before I posted it's location! The bottom of page 1 and top of page 2 shows the battery tray. Having assembled the model completely, I placed the the bits that were floating around into the fuselage and then used the complete flight pack and tray to get the CG where I wanted to start with. That gave the battery tray position. Subsequently, when I had to the batteries hanging off the back end of the tray(!) I measured where they had ended up and moved the battery tray supports to go under the batteries completely. I moved the tray about 70 mm aft IIRC.

Hi Adrian Even on my all electric 2 m, I left the final position of the flight pack strapped to the battery tray as the last items to position to get the CG in the desired place. The combined weight is 1.2 Kg so that's a pretty large weight to move around. Following the first few flights, I found the best CG position was 5 mm further aft and that necessitated moving the pack 70 mm aft! Luckily, with the setup I was using it only required 4 new ply supports that the bsttery tray sits in a new position. Unfortunately, when converting an IC engine design the best flight pack position is rsrely easy to reach but by using a sliding and locking mechanism might help. See my Anthem build for a photo of the arrangement.

Erf You have just set out what I call 'BGOs' - blinding glimpse of the obvious! Had you read the minutes of the EGM that was where the NFC was voted through you would hsve seen that there were a significant minority who did not want the NFC to proceed as it would not benefit them and as a result the decision was that no membership subs would be spent on supporting the NFC. The BMFA introduced a fund for members to donate to support the NFC. All this is clearly set out. If you haven't read all this information, I would suggest that you do instead of raising lots of points that have been covered. Of course, you are entitled to raise these points but they reflect more on your failure to properly acquaint yourself with the facts. A period of reflection by you that you could usefully use to read what has already been said and what fofmed the basis of the decision to allow the NFC to go ahead.

Yes, but it's just like in Clubs. The members rely on a few people to run their Committee.

Erf You do realise that those who drive the BMFA forward are, for the most part, involved in the competitive part of the sport. If they didn't give up their time to do it, no one else would. I see you recognise that but then you go on to raise all sortsbof issues about which I suspect you have little hard information. As regards the NFC, the use of Buckminster was agreed on a 35 year lease with reviews every 5 years. The old HQ building in Leicester has, I believe been sold, but we will need to keep those funds invested in suitably profitable areas lest we need to buy another HQ if we leave Buckminster. I am quite sure if doesn't need your long ramble to convince the Executive to keep the accounts to show how different costs relate to different activities - it's called management accounting. It is presented every year during the AGM. Have you ever attended an AGM? If not, and given the concerns you raise, perhaps you should. As for the impact of the commercial use of drones that is something the BMFA has been on top of from the beginning. Thank goodness for the efforts of Dave Phipps who has raised the profile of the BMFA up to Secretary of State level. I'm quite sure he will keep up his efforts on our behalf for as long as he remains the CEO. Now, go and lie down and relax.

Hi Toto It more than makes sense as that is how full size aeronautical engineering works. It's the same for today's cars that don't have a separate chassis. Which is why when you make a convertible you have to add extra structure to make up for the strength and rigidity lost by not having a roof. Think of how much weight a round drinking straw can support compared with a drinking straw squashed flat will.