MattyB

On a different topic I was quite surprised how much this model got thrown about in the wind considering it's large size. I guess it is probably quite lightly loaded and obviously it's very draggy with a lot of front and side area. Certainly looked a bit of a handful on landing, especially the second flight.

Posted by ERIC CLAPHAM on 08/05/2017 13:28:57: Finale - A free plan in the April.88 Radio Modeller by Mike Freeman. The control movements are given as (both pitch and roll) 3/8 -5/8" at the wing root trailing edge. Original weight 18oz. C.G. at 2.75" from the root L.E. i.e. about 0.35" in front of the wing pivot. He had another more orthodox layout plan but still with wing twist, as a Interesting. I would say 5/8" aileron movement would really be a lot for a model like this - you may want to set up dual or variable rates on pot (if your TX can do that) to give you a better chance of success. Another alternative is to "fly" the model in your hand on the slope edge whilst having someone else move the controls to get a feeling for how much effect they are having. Edited By MattyB on 08/05/2017 17:55:09

Yes, HS81s are IMO not a good choice - the plain bearing develops slop over the flights and eventually they all double centre. The 85s do not suffer this, though to be honest any decent mini with a ball bearing on the output shaft should be fine. Edited By MattyB on 08/05/2017 17:44:41

Here you go...     Although I personally wouldn't do it myself, I can't see anything fundamentally unsafe in the roll that Robbie did shortly after takeoff. Yes I suppose he could have had a structural failure or discovered a snafu (reversed ailerons etc.) at that point, but if an issue had occured that brought the model down it would have been well away from spectators. I would have done a few nerve steadying passes first, but at some point with a model like this you have to start putting it through manoeuvres - there's no real reason that can't be on the first flight if you are happy with the trim. Edited By MattyB on 08/05/2017 17:41:02

Definitely 1 per wing is preferable, but 9g nylon gear servos are two small IMO for an IC of this size - the gear area just isn't big enough to cope with the vibration over long periods. Fit a bigger (15-25g) metal geared alternative and you will be fine - HS85MG or similar should be fine.

No idea what it is, but assuming it's a pitcheron (which looks the case from the pic) it will need as much pitch movement as you can get, and very little roll - 5mm or so should be fine. Edited By MattyB on 07/05/2017 16:19:16

Posted by Simon Chaddock on 06/05/2017 11:29:15: I really don't follow the logic on how generating a lower wattage by using a lower kV motor can increase the stress on a battery. Surely less watts means less amps and its amps that stresses a battery. Sorry, my original post was not that clear I admit. What I was trying to say was that the only other option if he doesn't change the motor is to go 3S and prop up to get the desired wattage. That should work, but pulling 600W out of a 3S setup is going to mean drawing 55-60A from his packs, a substantial increase in current draw over his existing 4S setup even though the maximum wattage on 3S will be lower. Edited By MattyB on 06/05/2017 14:11:21

Posted by Steve J on 06/05/2017 09:28:09: Posted by Andy Symons - BMFA on 05/05/2017 11:37:52: Day pass for flying is £6. Has the BMFA published an estimate for the annual running costs of the NFC? I am curious as to how many £6 day passes it would take to cover it. Steve No, but based on the limited figures they have released it is possible to make an estimate. Some rough calculations I posted in the main NFC thread... The BMFA are investing £335k within the first four year term of the lease (figures in this presentation). Lease costs are £18k in year 1, £27.4k year 2 onwards. You can probably add at least another £20-25k per annum to that for grass cutting, security, amenity charges etc (that is the only key figure they have missed out of their deck), so to stand still the project will have to generate revenues of ~£45-50k per annum at a minimum to be self funding. More than that will be needed if the proposed additional facilities are to be added. Edited By MattyB on 06/05/2017 13:47:19

You are unlikely have any short term problems limiting max throttle via an endpoint, but depending on the type of ESC you could cause an early death to the FETS which are working harder at part throttle than full. Adding an extra heat sink to improve cooling might help with that though. Ultimately you'd improve the whole setup with a lower Kv motor of the same size and weight - you could then turn bigger props that give more thrust at lower rpm, reducing noise and probably increasing duration too. Your only other option is to try 3S and bigger props, but you may need a larger esc and will be stressing your batteries more to generate a lower wattage.

The requirements to be a competent authority appear significant and complex (registration of operators and UAs, audit and oversight of operators, granting and oversight of the operational authorisations etc.). That is far more than the BMFA and LMA do now to oversee their members. IMO they will need a fair bit more manpower and far more advanced IT systems to do the job. Meeting those requirements is not going to be cheap or simple for the BMFA. Also worrying are the additional requirements on clubs to provide training and oversight of members. It is hard enough to get volunteers for committee positions as it is without all this red tape and a potential threat of being held liable if your paperwork or oversight procedures are deemed insufficient. This could really affect (legal) participation the hobby very significantly.

Nobody at the BMFA has stated that to my knowledge Phil. It is nowhere near big enough to run the power Nationals in their current format, but if they were prepared to split up the disciplines over a number of w/es it could be made to work if Barkston was unavailable. Would it attract the same audience if that was the case though?

Hmmm, plenty of nasties still in there - looks like registration of operators and models for the vast majority of us, 120m height limitations and the addition of technical height limiters and geofencing in certain situations. I've not been able to get to the bit where exceptions granted by overseeing authorities are detailed. However it's obvious that (as many suspected) users of public sites are going to have major issues unless their model is below 250g. Slope soaring in particular looks difficult to do legally given the expectation (pg15) that traditional models >250g can only be flown "...in an area where it is reasonably expected that no uninvolved person will be present". In addition privately built models in without all the fancy tech can only be flown "a safe distance from the boundaries of congested areas of cities, towns or settlements, or aerodromes" . Fly anywhere near an uninvolved person with a model between 900g and 4kg and you need geofencing - how the heck does that work on an unpowered glider!

Posted by John F on 05/05/2017 15:06:01: You said this, Matty, with regards to the initial efforts too! Can we not turn it into yet another MattyB opposition thread with yet more predictions of doom and gloom? Many people are perfectly happy with what they are doing and are quite happy to support this. Alternative viewpoint... Can we not turn it into yet another blind optimism thread with yet more predictions of a green and pleasant land despite the fact there is no funding plan beyond the use of £335k of reserves (60% of the Dev fund) to complete phase 1? Many people are uncertain about the financials and uncomfortable with how the project was given the green light. They are unlikely to support the significant fund raising efforts needed until they see a clear plan for phase 2 and beyond from the BMFA showing how the money will be raised to turn it into a true NFC. Seriously, last time I looked this is a free country. If you believe my post is against the CoC, please go ahead and report it. If not, leave it to the moderators. Edited By MattyB on 05/05/2017 16:36:39

As long as the charger is firmware upgradeable for other new battery chemistries I would not worry about it. Personally I have seen no reason to move to the LiHV batteries as unless you are involved in very demanding e-flight disciplines their benefits are negligible; there are likely to be negatives as well (charging to higher voltages must increase the speed of anode degradation, causing earlier capacity loss and higher IR).

Posted by Charles Smitheman on 05/05/2017 12:57:27: Well done what a remarkable achievement. It is commendable the BMFA have got this far, but let's not kid ourselves - compared to what needs to happen next, getting to this stage was still the easy bit. A truly remarkable achievement will be if they can raise the funding needed to develop the site in line with the later phases of the plan without requesting additional money from members. That was the stated aim at the EGM and the AGM that followed it, but to date there has been no communication on the multi-million pound fund raising initiative that will be needed to make this happen. I wish them luck, but I remain highly sceptical that sufficient funding can be generated to develop this from what is essentially a nice club flying field into the vision shared with members at the EGM and on the website.

Posted by Frank Skilbeck on 03/05/2017 08:30:39: I see Frsky are now launching long range 868 mhz systems with power outputs upto 1W with range in excess of 10km, not sure how this fits in the ESTI directives, but it would seem that if you are concerned about range this might be another alternative. I would be amazed if this module is marketed by U.K. distributors, but then this IS FrSky we are talking about...

How are ARTFs like this inspected Chris?

Posted by cymaz on 02/05/2017 17:30:28: There is a lot that goes into an over 20kg aeroplane....A little homework reading if anyone wants to Good link, but there is not much about ARTFs in there - the only bit I could see is this in the Q&A... Q What do you do about ARTF models A Obviously, quite a few of these are composite, and our Inspectors are usually able to look at the build quality. If you have any doubts contact us first. From what I can understand these Bill Hempel kits are built to order - perhaps they take photos in the factory along the way? Even if they did the provenance of those photos could not easily be proven without specialist forensic computing kit (my day job) which I sincerely doubt the LMA have at their disposal. Maybe they come with some areas of covering not applied so they can be inspected before being assembled?

That may well be true Mike, but irrelevant of whether the protocol is compliant technically it cannot be legally sold without a valid certificate of conformity. The only certificate that has ever been available for the D8 compatible kit is this one on the Frsky site - it explicitly states the earlier RXs were certificated against the 1.7.1 version of the ETSI regulations. From post 1 of the main ETSI thread on RCGroups... A revised version of the ETSI standard EN 300 328 (v1.8.1) has been published and will come into force in Jan 1st 2015. Version 1.8.1 has an effective date of December 31, 2014, so declarations of conformity with the Radio and Telecommunication Terminal Equipment (R&TTE) Directive based on testing against EN 300 328, v1.7.1 would need to be re-evaluated before the end of 2014 for devices going into the EU market after this date. Devices already in the market will be grandfathered in. However, at the same time as the v1.8.1 adoption, a note was added to v1.7.1 in the EU's Official Journal (OJ), stating that part of the new v1.8.1 requirements – medium utilization factors – needed to be immediately implemented and tested. The upshot: Radio modules tested and found compliant to v1.7.1 need to be retested due to the additional requirement – there is no longer a presumption of conformity with the R&TTE Directive. This has caused confusion and headache for manufacturers and some test labs. (Source)

Posted by Peter Christy on 02/05/2017 08:36:31: ...One other point, though: Those cut-off dates do have a loophole in them. If the equipment was already "in the supply chain" prior to the cut-off date, it is still legal to sell it! So if someone had a warehouse-full of (for instance) DSM-2 stuff prior to the cut-off date, it would still be legal to sell it! I am pretty sure there was an 18 month time limit on that loophole, but can't remember where I read it - the ETSI standard itself is not that clear on dates beyond the initial implementation in Jan 2015..

Posted by Matt Jones on 30/04/2017 22:49:39: Based on his previous models I'll be sure to hide if he displays it at any shows I go to. It's unlikely to end well. Indeed. Still, at least this time he fitted more than one aileron servo...     I'm with Philip, Rich, Percy and Ken - I'm not sure the world really needs a massively overpowered 65% ARF DR1. If it had been built from scratch, fitted out with lots of scale detail and flown in a realistic style I would be more partial, but clearly from the interview that is not his intent; he wants a WW1 3D machine to "wow" display crowds. He must have supreme confidence in the Chinese factory that put it together to do that; I just hope it does not end in tears. Edited By MattyB on 02/05/2017 08:43:15

Posted by Dave Bran on 02/05/2017 07:37:22: AFAIK it dates back to Cisco trying to grab all possible 2.4Ghz bandwidth for HD streaming video, and it was realised that with so much eqpt from all the disparate uses coming on 2.4GHz, simple rotation would be insufficient alone as the band became saturated. This near saturation could be seen when a lot (and it was a lot) of DSM2 non-spread sets were on at once. With regard why it might be an issue, and why you may want to do it if legal, well there's a lot of ARTF and RTF stuff (esp small multirotors) still being issued for protocols that Euro zone new Tx's do not inherently support, inc DSM2 and FrSky D8. Indeed, and some UK and EU vendors are still selling D8 RXs and modules despite the fact there is no valid certificate of conformity to go with them - I guess the authorities simply do not have the resources to enforce the regs...

Two useful guides - these can be used to flash the RF firmware in either direction... Guide - OpenTX 2.1 or later Guide - Pre OpenTX 2.1 Get a brew, read/watch them closely and work slowly and carefully - you can never completely wreck a Taranis through software updates, but it is possible to get yourself in a big old muddle and waste a lot of time if you do not follow the instructions studiously. Edited By MattyB on 01/05/2017 20:17:19

No, not at all. Well, not unless you have an axe to grind...

Just charge them singly every now and then (every 5-10 cycles) and you should be fine. However you should always check the cell voltages individually before you begin parallel charging to make sure you are not starting from a position where one or more cells in any pack is dramatically different to the rest. If it is, balance charge that pack singly at 0.5-1C to vice it a good shot at getting back into balance.