Martin Harris - Moderator

Posted by Erfolg on 04/11/2010 12:18:33: I both agree and totally disagree with Martin.    You've got me there, Erfolg,   What bits do you disagree with?  I don't think I've ever claimed that possession of a B certificate would make anyone a better flyer but the point I was trying to make was that when someone is standing up in court and is asked how they judged themselves sufficiently skillful to fly a large model, instead of a vague reference to x years of undocumented experience, they could state that they have passed a nationally recognised test of competence.   The simple answer to the original question is simple - 20 kg-  but the rest of the answers and comments are aimed at giving an enthusiastic but apparently inexperienced pilot some good advice.  Dan, I hope you can accept these bits of advice in better spirit in the future than your response to leccy.

Timbo posted a good link earlier but it's worth pointing out the BIG difference when flying a model over 7 kg is that it is subject to far more rigorous Air Law requirements - both regarding operating/ technical requirements and pilot competence.   For example, it is ILLEGAL to fly a 7 kg model more than 400 feet above launch height ANYWHERE in the country (and this DOES apply to gliders) without the express permission of an Air Traffic Control unit and at any height in controlled airspace without permission.  How high is 400 feet?  Not very high at all, is the answer - especially with a large model which appears nearer the ground than a small one at the same height.   Another example is that there is a LEGAL responsibility to satisfy yourself that both the model and pilot are fit and competent to fly - so if there should be an unfortunate incident that comes to the attention of the CAA it could be that you have to defend your decision to fly, in a court of law.   While there is no specific requirement in law to hold a B certificate (or equivalent) there is a school of thought that possession of one goes a long way towards defending a charge of not being competent to operate a larger model so it's well worth considering getting one before you fly a 7 kg model - and you don't even need to be a BMFA member to get one (and there's no charge).Edited By Martin Harris on 04/11/2010 11:40:02

Do you have a switching BEC in the new setup?  These can generate a lot of high frequency "noise". A lot of ESCs come with these incorporated nowadays as they are more efficient than the old linear devices but look identical.Edited By Martin Harris on 03/11/2010 12:36:40

We were told that we couldn't have it permanently because Scottish farmers objected.   Hmmm, it seems to me that it gets light when the sun comes up and dark around the time it disappears, animals don't usually wear watches and a farmer's day is his own to organise, unlike the majority of wage slaves.

Nothing personal - before I got back into modelling I had an active interest in car and bike restoration...

I don't think this is an issue with 6EXs in general - it seems like a problem with an individual transmitter.   I did find a dry joint on the crystal socket of a friend's one a few years ago (I think it was a 6EXA) caused by repeated small impacts when the transmitter was put down on its back - I built up the case under the crystal cover to stop it happening again.

I thought "everyone" already used Technoweld...it's very well known within my circles.

As I recall, the XL was claimed to have a specific formulation that allowed subsequent coats to bond properly which was unique to it within the Ronseal range.  This was supposed to make it ideal for our purposes and "ordinary" floor varnish wasn't supposed to work properly.

I'm probably guilty of bias towards my system of choice but I don't see Jeti as a second tier system!  They are reassuringly expensive...especially if you were to ignore Puffin's good service and fair prices and get them via the other importer!!! ...but this is the point of the thread, really.  You make a judgement based on reputation, reports, features and price and then "yer pays yer money".  Funnily enough, I'd be more inclined to put a popular system from your first tier list with a track record of problems in the second tier but I'm not looking to start a mine's better than yours war so I won't name it.Edited By Martin Harris on 02/11/2010 15:40:04

I think it's a fair bet that it's a 35 MHz set. "Range checked 30 metres aerial down all ok." "Tonight tried new tx crystal"

Also it might be worth checking that the aerial wire hasn't become detached from the connection at the base of the aerial inside the transmitter.

Leccy, your viewpoint is exactly what mine was but I'm happy to have been proved wrong so far at our club.  The 2.4 take up is fairly high at ours but this may differ between clubs.   As a dual user - I have my larger and more precious stuff on 2.4 and the lightweight and less often flown models on 35 as I gradually replace receivers - touching every lump of wood for yards about, I have not found myself forgetting my peg discipline yet.   What has happened is that my prime frequency has gone from being annoyingly popular to virtually my own but I'm sufficiently aware to assume someone might turn up with it though and always make the usual checks even when I know that everyone is using 2.4 as I would expect anyone else to do too.    

Where was the prop noise?  One of the features of turboprop models I've witnessed flying was the (fairly excessive) prop noise. Maybe it was the recording/my PC but it sounded more like a pure turbine which spoilt it rather, for me.

Here's a question for the statisticians amongst us - if there are 36 channels available and on a typical day 20 people turned up pre-2.4, how much does it affect the chances of a frequency clash if, say, only 10 people are using 35 MHz now? I suspect it may be less than the obvious halving? Edited By Martin Harris on 01/11/2010 14:20:51

I don't think anyone is advocating abandoning frequency control for 35 MHz! As I mentioned earlier, the chaos I had imagined from dual users forgetting to use the 35 MHz pegboard hasn't happened (yet!) although I have presented all your other points in the past - however democracy ruled and I was out-voted on the issue.Edited By Martin Harris on 01/11/2010 14:11:28

Craig, As with all these matters, each club may have local factors to take into account but I must say that despite my fears, the use of the pegboard for 35 MHz only has worked very well at our club. I do wonder whether there could be incidents in the future when people who have grown up with 2.4 GHz or got so used to switching on a radio without considering frequency control find themselves assisting or test flying a 35 MHz model but I'd guess that as the older systems get rarer, so do the chances of an inadvertent frequency clash.  

Can't agree more, Timbo.  I'd guess that our club operates in a similar manner than many others in that the committee is empowered to introduce rules as it sees fit but they are ratified at the next AGM.   This very subject triggered a lot of debate at our club and I have to admit that I felt quite strongly that we should retain the pegboard while both systems were in use so that occasional users of 35 MHz (instructors, test pilots etc.) would be less likely to forget about frequency control.  However, after an AGM proposal the membership voted to abandon the pegboard (and black flags) for 2.4 GHz operation.   The funny thing was that when we went to re-draft the rule it was realised that the actual wording of the proposal effectively prohibited any operation of 2.4 MHz equipment due to our peg on/peg off system - being a (hopefully) reasonably sensible committee we re-wrote the rule to reflect the intent of the vote.  This, of course, meant that we needed to rubber stamp the "new" rule at the next AGM and several members misinterpreted this as an attempt to reverse the original vote!  Thankfully it was all resolved without tears and we're happily operating a 35 MHz pegboard with 2.4 GHz switching on as and when required.   Re. Gaz's reference to BMFA "rules" remember that the handbook is only guidance and the only compulsory  aspects are the Air Law requirements. Our flying rules are based on the handbook and only really refer to exceptions and modifications to suit our site.

Keep a lookout for my Mother in Law's company car this afternoon!  

No - but using 5 minute epoxy for laminating is as near instant as makes not a lot of difference...

I've only used it for fuel proofing and for "instant" laminating for cowling repairs in a hurry with 5 minute epoxy.   I believe that you can thin it too far but small amounts are OK  - however, you'd really need to do your own tests if you were using it for structural purposes!

I use meths to thin epoxy for fuel proofing but I've found Skincrylic (no doubt the same or very similar to the other water based varnishes) to be a superb fuel proofer - and you can use it the next day unlike traditional fuel proofer that needs at least a week to cure. Being water based it's easy to work into corners in tank bays etc. and adds little weight.   Used externally it gives a semi-matt finish which is just right for warbirds which, I'm told, were often polished to a certain extent for performance reasons.

I'm afraid that makes no sense at all.  Can you upload a screen shot? I'd say it's either a misinterpretation or you have a faulty charger.

Use the biggest washers possible  or ideally a steel plate to spread the clamping force. Phil's advice is very sound - the lead WILL compress and fret with any vibrationand any plain nut will loosen. Nylocs are best but you could get away with properly applied locknuts.

I don't know about the talk but what was going on @ 5 minutes in!Edited By Martin Harris on 29/10/2010 00:43:57

And he's got all the hassle (or risk) associated with CE declarations and marking!Edited By Martin Harris on 25/10/2010 19:02:58