Neil R

Peter - you keep saying that Li-Ions are heavier than LiPos. I'll inverse your 'for the same capacity' caveat, and instead say that 'for the same weight' I'm personally seeing Li-Ions having up to 50% extra capacity. I'll put some numbers at the bottom of this post which you can check yourself. I've assumed for Li-Ion we're talking about twinned 18650 or 21700 cells, so typically 2500 / 3000 mah and 4500 / 5000 mAh respectively. For Rx packs of lower capacities I accept you'd probably still be looking at LiPo or LiFe, and in such cases the final weight will likely be less. My own thinking is that the main current disadvantage for Li-Ions is the poor availability of mass produced made-up packs and hence the current higher prices (noting that Nick Mann on the BMFA Classifieds is doing his bit in presumably smaller volumes). For actual electric flight packs the advantages of Li-Ion have started to win me over much more - I've just DIY built a couple of 4S Molicel packs, which like LiPos also charge to 4.2V, and for just a few extra grams I have replaced a 2800 mAh LiPo with a 4500 mAh Molicel pack. Given that these are essentially Electric Vehicle & Laptop cells I personally will have no qualms about charging in situ, and I'm going to worry less about returning them to storage charge if not used on any given day. It's the recent improvements in discharge 'C' rates for the Molicels in particular that have started to make these flight packs more viable. The data I just googled was: Li-Ion 18650: Molicel P30B 3000 mAh 48g ea; x2 and add ~10g for leads 106g Samsung 30Q 3000 mAh 46g 102g Samsung 25R 2500 mAh 44g 98g Li-Ion 21700 Samsung 50S 5000 mAh 65g ea; ditto 140g Moilcel P45B 4500 mAh 72g 154g LiPo: Nano-Tech 2s 2000 mAh 110g Turnigy 2s 3600 mAh 173g LiFe: Nano-Tech 2s 2100 mAh 115g Nano-Tech 2s 3000 mAh 183g

@Duncan Disorderly- many thanks for providing the inspiration, here's one I've put together over the last couple of weeks. It was finished earlier today, and so far the charging is keeping all the voltages nice and even, which gives me confidence I didn't kill anything when soldering. (I bought an ISDT Air 8 also). This is going to absolutely transform my flying, perhaps especially in terms of grabbing those last minute opportunities when nothing else has been charged. Thanks again!

Thanks v much DD for the interesting and inspiring post; I'm now very interested in putting one of these packs together. Which exact cell did you pick please? - was it the one of the LG M50 variants? I'm also really hoping you will post those extra piccies of the wiring within the case, I haven't quite worked out yet where the fuses would go. Thanks!

Although I subscribe, I'd binned my copy of the May '22 magazine before deciding to build a Gyroo. So I bought a back issue direct from this RCM&E website (link below, selecting the print copy option). It came complete with the free plan. Obviously you'll need to check out if they post overseas. Radio Control Models & Electronics | MAY 2022 (classicmagazines.co.uk)

In case it helps below are the notes I made and have used since for myself. I've got a Taranis and a Horus. Some may not be relevant to your own choices. I love the extra realism the gyro (in stabilisation mode) adds to scale models especially when it's a bit gusty. Looks like it might be quite hard to find these Rx now from new (I've seen the 'wanted' add on BMFA classifieds!), and I've not yet bitten the bullet to see if the new (Archer?) types are backward compatible. 1. Transmitter Binding and Set-Up: Bind in D16, at least 12 channels (?), 9 is gain, 10 and 11 are stab mode switches, 12 is self check. Also set a dedicated Rx number. Channel Order: A(L) E T R A2(R) E2 (first four are fixed). Ch 9 (Gain adjuster) set like this: Ch09 S1 Weight (+50%) NoTrim Offset (50%). Don’t use more than roughly 30% initially. Ch 10 (gyro on/off): use a curve +100 (on) to 0 (off). Ch 11 (mode): force to zero (assumes only stabilisation function required). Ch 12 (self check): needs to be default at either -100% (Up ^) OR +100% (Down v) either will work. 2. New Receiver Initial 6 Axis Calibration – Needs a Flat Surface: Use lua script on Tx. No cables needed. On Taranis it’s in Menu – long press – tab to SD card – S6R – S6R_Calibrate.lua Execute and follow instructions Needed once only 3. Set Model Type and Mounting Position: As above except use S6R.lua Note that new SxR receivers will come with quick (simple) mode enabled which should be disabled. Scroll between pages 1 and 2 to confirm that any changes have taken effect. Select the Aux2 box if you don’t want active stabilisation on that channel (e.g. tick Ele2, frees up that channel for use by another function). 4. Mount Rx in Model: Pins to rear, orientation as previously chosen. Servos connected as indicated on Rx 5. Set Normal Throws and Directions Leave in Max Rates 6. Chicken Dance and Attitude & Stick Calibrations: Ch 12 on SwF is currently set-up only to be active at mid SwG, where throttle also active. So Prop off! Then SwF needs to be flipped [equates to 0.0% (Mid) and then back to either +/- 100%] and repeated three times in three seconds before the Self Check Function will activate. You can also press the F/S, Bind Button on the receiver for a Self Check function. The Self Check Function: This function is performed to firstly to calibrate the Radio Stick movement endpoints to the receiver (it saves these values) and also it saves the current angle of Attitude (hold it steady) so it knows where it should keep the planes Attitude at during Level Flight. This Attitude should be set at very slightly Nose Up to prevent the plane going into a dive when in Auto Level Mode as this could result in a high speed dive and crash. The plane must be set at the correct attitude and not moved during this Self Check operation. Once Ch12 is activated, after a second or so the control surfaces will Twitch (Dance) then stop. Only after the dance (2 sec) has stopped do you start the Sticks calibration (use full rates!). The dance seems to need all servos connected. Depending on the Plane Type set you need to move the Aileron, Elevator and Rudder to the extreme endpoints of the Sticks travel, only a couple of times. Close by increasing throttle stick to max then depower (there is conflicting guidance on which of these actions saves the settings!). 7. Check Stabilising Directions S6r.lua allows for changes of directions and setting of individual gains. 8. Set Failsafe to Auto Level Mode (copy from PM or Avanti) 9. Fly and Adjust Gains as Required. Auto-Level: Stabilisation: Hover: Knife-Edge: Off: Ch10 (100); Ch11 (100) Ch10 (100); Ch11 (0) Ch10 (100); Ch11(-100) Ch10 (-100); Ch11 (0) Ch10 (0)

Although I strongly suspect that I fly alongside 100% BMFA members, I'm part of a 'group', not a club, and as such it isn't affiliated, nor do we have a committee. I also occasionally fly from other random places like a family member's farmland. And, perhaps on a less sound footing, from deserted beaches when on hols. So I'm a BMFA Country Member, and I sort of assumed that there will be quite a lot like me? I'm really hoping that the BMFA is going to give a strong voice (and guidance) on supporting all such flying / flying sites, and not just the 'easier' interests of those members in affiliated clubs. For the very first time in all this madness I am, however, beginning to fear the worst, and like Ron I am feeling the need to examine my own conscience. [Yes - I know - our group should affiliate - but that's not really my call]. This is getting ever more off the subs topic - but you won't find me bashing anyone who provides polite and well argued discussion points - it's always good to see both sides of any argument, and sensible adult discussion does make us better informed in the end.

So here it is. It's a fully 'stock' build, with the recommended motor, servos, etc. Even with the sharp leading edges, which I'll confess confounded all my instincts. It was especially rewarding to find all the cut parts went together perfectly - the magazine plan was spot on, well done to all involved. I'll probably not fly it until Spring - the last guy who tried to drive to our field got stuck in a waterlogged patch. I'm feeling slightly guilty that my last post was supposed to reinforce a question from 'Affair' - but I think I ended up pushing it to the background - apols to you Affair. With the covering and 5g tip weights I did finally get my own blades to 45g, hopefully this will be ok.

I have just reached the same stage myself, and my uncovered blades are also coming out coming out around 34g, so I'm watching this thread with interest. I haven't yet glued on the bottom plates so have been wondering about adding a full-length layer of 1/64th ply. I did take my scales to the model shop when buying the wood, and picked the heavier spruce: their stock 3ft lengths seemed to vary from about 45 to 65g, which surprised me. I also thought I'd found some good med/hard balsa, but didn't weigh that, maybe a target sheet weight might help others? I've really enjoyed this build though, which after nearly 40 years of flying is my first from a magazine free plan!

I did find some old stuff on the Acrowot and this pitch down tendency - in this very forum! - link below - scroll down slightly see the post from MattyB. The embedded quote also explains that the full size Miles Magister had a similar characteristic. I don't buy for one moment that this particular effect is due to rolling (change in bank angle), but it is of course a yaw (more correctly sideslip) effect. I've obviously no idea how well this translates to the Pitts in the original question though!

My Acrowot has always had quite a pronounced pitch down with (wings level) rudder inputs, with negligible noticeable roll. After speaking to a few aerodynamics bods, the best explanation seemed to be that the commanded sideslip causes the rear fuselage to blank part of the 'downwind' half of the tailplane, and since the tailplane is normally providing downforce, a reduction in same causes the aircraft to pitch down. I have a vague recollection that there was a known modification to the Acrowot, involving changing the vertical position of the tailplane, which I think (?) might have been related to this issue. For what it's worth the same bods also explained that you also need to think about tailplane vertical position - and how much it is thus influenced by the increased downwash rearwards of the wing when deploying flaps - to better understand the pitching effect of flaps. High wing with low tailplane (i.e. right in the downwash region) being most likely to pitch up, the opposite extreme being low wing with T-tail.

I had the same experience wrt the UK back-order sale sale showing only global options. I assumed that I was going for the popular choices, and that these had 'sold out' versus the initial shipment expectations. I did then also find certain other LiPos still offering the UK option, and have back-ordered a few. What really surprised me was that the first and cheapest shipping option offered was the Royal Mail, which I thought was a historic no-no for Lipos. I've hopefully de-risked my order by going for the slightly more expensive DPD option.

I've got one, from my old Taranis, exactly as your pic. I don't use neck-straps, so you'd be welcome to it. PM me your address and I'll put in the post. No charge, just pay it forward one day!

I'd suggest doing your homework on the analogue servos aspects. My understanding was that these converters require digital servos, and I think I remember confirming this with my own checks, admittedly with some low spec analogues. I think I've even read that some low end digitals might not work. On first buy of any such converter it's also likely you'd need to buy the channel changer gizmo. I've also been meaning to properly check how the fail-safe aspects work: on a recently completed model with a mix of both SBUS-converted and normally connected servos, only the SBUS ones twitch if I accidentally switch the Rx on first. I do like and use these converters by the way!

Brill, many thanks Ron.

I was a bit premature in binning this month's RCM&E - less than half a day after the bin lorry took it away I found a foam hinge which needs some attention. Could someone please remind me which of the two Deluxe glues featured this month was used to illustrate this exact repair. It was either Foam 2 Foam or Fix n Flex. (I already have both glues, so other options not needed. I also couldn't find this specific use mentioned on Deluxe's own website). Many thanks!

Ken - what do you mean by "deep" or "dark" red? I'm only seeing "red" or "antique red" in the Solartex colour charts. I have some old "red" offcuts you'd be welcome to if that's the right colour?

Mike, I have now flashed V57, because the SBUS stopped working as a servo output after cycling rx power. The flashing was confirmed by now seeing V57 on the Rstat lua. Unfortunately I still lose this functionality on power cycling - it only comes back if I use the RESET function (and set the 'Servo on SBUS' back to 'on'). In case it was a factor I went straight from V50 to V57.

Many thanks Mike for the amazingly quick reply, and for all your work in general on this stuff. My Rstat results - RX8R Pro, Ver 50, V2EU - all presumably good except perhaps not v57? Rset - 'Servo on SBUS' showed 'on', and 'servo outputs' as '1 to 8', which again is what I'd expected. Anyhow, I'm not sure what it did, but using screen 1's RESET option has fixed my problem! PS by bind in Ch 1 to 8 mode, I meant as per the 4 choices you get after hitting the bind button (so either 1-8 telem on/off, or 9-16 telem on/off). I did have the actual channel range set to 16. Now if only you could make the 'SBUS in' provide a Ch 10, I could also get my retracts to work in a staggered manner! 😂 (I'd use the sbus decoders more, but still have too many analogue servos). Thanks again.

A couple of quick questions please, I've just bought an RX8R Pro from T9HS with this new UNI firmware. It's for a gasser, and I want 9 easily accessed channels. So I bound it with Ch 3 and 4 signal pins jumped. And whilst the main channels are working fine, I can't get anything on the SBUS out. (An analogue servo just jitters, a digital servo does nothing). Do I still need to engage with a Lua script to achieve an activation and then Ch 9 on the SBUS with this ready-loaded Rx? Is Ch 9 the SBUS default when buying and binding like this? Am I probably just needing the fix in the previous post? And finally, what's the best way please to check I actually got sent a UNI and not a universal Rx? There was nothing on the outer packaging, only the standard FrSky instructions, and one of the first things I heard after binding was a telem lost warning. I can't actually repeat the latter, although it does occasionally swamp proper servo movements when too close. I am also seeing only a green Rx light on normal power on (and not the green and red mentioned in the UNI instructions). Horus X10S, EU Ver 2.1 bound in D16 Ch 1 to 8 mode. Many thanks!

I've done this once before, on a 2 x 3s Extra Slim Twin (7 servos), and it worked fine. (In my case with a BEC equipped ESCs, but with the red wires removed, and so with a separate stand-alone UBEC. It just made the wiring routes easier). If you've chosen an opto because you wanted true isolation, I do wonder if you are compromising this? But for me, on other models, I've used optos purely because I always knew I wanted the reliability offered by a separate UBEC. And then have powered said UBECs 'worry-free' from the main flight battery anyhow. I have also used balance leads to supply power to sound systems. Obviously in all cases taking power from the outer wires of the balance lead (to avoid cell imbalance), and make sure you are happy regarding the physical security of the new connectors.

I use - and love! - the FrSky current sensors, but yes they are only able to support the calculations and act on what you have taken out not what might be left. So >1650 is correct here. Since the sound pack I use has both 'Battery Low' and 'Battery Critical' options I create two different warnings e.g. at 70 and 85% usage. I suggest you also check out and understand the 'reset flight' options to ensure you take-off on any subsequent flight (with either a new or the same battery) at the right start point. I note the newer FAS40 ADV sensor can also monitor battery voltage - if at cell level (especially) I assume this could be used to give a truer indication of imminent battery expiry. Hopefully somebody can educate us both on this!

I also bought a second hand one a few years back. Strangely I've always found Baby Wipes to be a good way of cleaning off old muck. The former owner had written the throws etc on the underside of the cockpit floor. Plus there was a kit review (in two well illustrated parts) in the RCMW Nov and Dec 1997 magazines, the latter also covers the throws. Details as follows, with the RCMW version in brackets. CG: 13 cm from LE (5 1/8") Rudder: 75 mm each way (3" each way) Ail: 32 mm up, 16 mm down (1 1/4" up, 3/4" down) Elev: 28 mm up, 32 mm down (1" each way) Ail to Rud Mix: 30% (not mentioned in RCMW), I put this on a switch but can't remember whether I used it or not. Jon on here recommended that I fit a Laser 155, it flies beautifully with that.

Attempt to tag @Andy Symons - BMFA for possible comment on our discussions.

Chris, you are completely missing the point that I went for the postal option. I suspect from your comments that you haven’t actually seen what you get with same? The posted stuff normally provides everything you need, i.e membership card and insurance cert. The card was as expected, although contrary to the actual renewal date (mid Dec in my case), it actually shows a *valid from* date of 1st Jan 2022. All of the membership date preamble you have discussed / quoted above simply does not appear on the posted version of the confirmation of cover. Instead the one sent out just simply says: “This is to certify that holders of a current BMFA Membership card are covered (until 31 December 2021) by Liability and Personal Accident insurance held by the Society of Model Aeronautical Engineers Ltd. Details are given in the following schedule.” The rest (from Legal Liability downwards) is then as per the electronic version. So as supplied (in the post), with no included explanation of the mutually exclusive dates, I was confused. By adding the original question, I now understand that the postal offering is incomplete this time, and I’ll need to download an insurance cert later. Please don’t regard this as a complaint, rather an attempt to clarify my own initial confusion, and perhaps an attempt to help others in the same position. The benefit of the posted option is that you get the Vectis (discount) card. I assume the additional costs for this option are covered by the extra fee paid.

But that doesn’t explain why the electronic certificate attached to the renewal e-mail is dated to Dec 2022? (is that cert even valid after Jan 1st?). Why would they post me a cert for the residue of 2021 - was I not already covered by the previous year’s cert? Why are the posted and emailed versions not harmonised? And why does someone who has chosen and paid for the postal option not get sent any of the accompanying clarifications that were provided in the email? (Note also that the postal cert is different to the online one, without my name or membership dates, it just cross references to the membership card). Yes I know this is all down in the weeds, and the answer is to download the new cert after 1st Jan, but right now the position is that, in response to a timely renewal, I’ve been sent two certs, a posted one which definitely isn’t valid Jan onwards, and an e-mail one which appears questionable (?) for 2022. I bet I’m not the only one who finds this all a bit odd and confusing!