[Did I Just Imagine That? Or....]

Are you using Futaba extension leads or "JR" type without orientating lugs?

 

Best guess would be that they were both in upside down - while you're making one mistake why not make another - I know I have!

 

There's no other reason that you wouldn't have seen some response from the servos that I can think of.  Depending of course on the physical layout of the linkages, in most cases the servos will still travel in the correct directions (think Y lead) but may be out of trim.

Edited By Martin Harris on 06/09/2010 13:35:40

[Taking Off And Landing]

Posted by David Turner 5 on 05/09/2010 12:27:11:

Posted by Martin Harris on 04/09/2010 23:29:19:

Posted by Martin McIntosh on 04/09/2010 23:10:38:

 

 

Possibly allows for slightly finer judgement but at the expense of putting the pilots in a much more vulnerable position.

 

 

Interesting speculation. How do you justify that?

 Perhaps if you refer to my posts in conversation with you earlier in this thread on this very matter you will appreciate my justification. 

[Taking Off And Landing]

Posted by Martin McIntosh on 04/09/2010 23:10:38:

Most of these points have been covered at some length in the thread but to address some of them:

 

At a typical club site you will be at the downwind end of the patch, not midway.

 

Not in my experience - perhaps different parts of the country vary?

 

A trike u/c trainer will probably take off much by itself but something like a Spit. or a Mew Gull requires vision of both the direction and attitude at all times and this can only really be done from behind.

 

But this is just where you cannot judge the attitude properly from! A 3/4 view gives the best of both worlds.

 

Landing from a position at the downwind end allows a much better perception of the touchdown point allowing the full length for rolling to a stop and steering the model to the side if necessary.

 

Possibly allows for slightly finer judgement but at the expense of putting the pilots in a much more vulnerable position.

 

[BALANCE]

Although I don't know the plan, they usually show the C of G on the wing position (although the real point is some way down the fuselage) which I think is the case from your first post.  On this layout you'll need to balance it from under the top wing to maximise the pendulum effect.  Earlier you mentioned it balancing nose up - please make sure it's level or a little nose down.

 

If you had a low wing monoplane, you'd need to balance it inverted as the C of G would be above the balance point the right way up.

Edited By Martin Harris on 04/09/2010 23:19:34

[BALANCE]

I'd agree that these factors all affect the flight characteristics but I don't recall any C of G calculations taking them into account with the exception that radically different wing sections might affect movement of the centre of pressure with increasing angles of attack leading to a more critical stability margin but a proportional C of G position should work perfectly well in this case.

Edited By Martin Harris on 04/09/2010 20:08:27

[TH9X Transmitters]

Sorry if you think I shouldn't have truncated your quote but it's the first part that was significant to me.  I know you said the boards seemed fine but (along with the stick units etc.) they may be subject to the same quality controls - I don't know if that's the case but it's precisely because I don't know that I wouldn't use one for anything significant.

[Taking Off And Landing]

A preference for taking off from a particular place doesn't make you a poor pilot.  Inability to do so is maybe a different matter?

[TH9X Transmitters]

Posted by Steve W-O on 04/09/2010 13:21:44:

Quality control is a bit doubtful.

 

 I'm afraid that point would exclude them from my consideration for anything above a throwaway "toy".

[Using digital trims in-flight]

Posted by Martin Harris on 18/08/2010 21:14:10:

If anyone's interested, I've had a play and a mix for the slider trim control on an FF9 and similar Futaba transmitters can be done as follows:

~ 

Weather permitting, I'll try it out tomorrow...

 Reminds me, I did and it worked well...

[JR to relinquish DSM2]

As far as I'm aware it was that nice Mr Prescott's Office of the Deputy Prime Minister who decreed that any new work in a kitchen or bathroom of an Englishman's (or Welshman's) castle could only be completed by the holder of various certifications.

 

...and introduced new wiring colours at the same time to make it obvious that work had taken place.

Edited By Martin Harris on 04/09/2010 14:37:07

[seagull's or any richard the 3rd's (bird's)]

My Brother in Law is from North of the border and uses Scotney Rhyming Slang e.g. corned beef (deef) - for the hard of hearing...'

 

Not really a bird but on Thursday a red kite flew for some time at low level in close formation with a clubmate's electric Lazy Bee before deciding there was no food or threat involved and soaring off in search of something useful to do.

Edited By Martin Harris on 04/09/2010 14:26:51

[Taking Off And Landing]

Posted by David Turner 5 on 04/09/2010 13:22:53:

If your argument is that "a good pilot says stand mid-way along the runway, therefore it must be the right thing to do", how would you react to a video which shows another "good pilot" (Ali) standing behind his model for departure?

 

It's out there, on Youtube.  They can't both be "right" ... or can they?

Edited By David Turner 5 on 04/09/2010 13:23:33

Why not?

 

Without a better reference to the video it's impossible to guess at why Ali might have chosen to stand behind a particular model in a particular situation but he was happy enough to stand in our normal pilot's box when he came to our club to do a demo and that's where I've always seen him operate from at shows.

 

I'd say that the definition of a good pilot is one that is able to adapt to local procedures and circumstances having weighed up the options and applied the benefits of experience.

 

BTW I'd be interested to know who argued that: "a good pilot says stand mid-way along the runway, therefore it must be the right thing to do"   I don't recall anyone using these words or sentiments...surely this isn't a "Straw Man" argument?

Edited By Martin Harris on 04/09/2010 14:19:03

[Taking Off And Landing]

Posted by Steve W-O on 04/09/2010 13:26:03:

What about all the good pilots who sit behind the controls and travel down the runway with their aircraft?  Never seen one sitting looking out the side window

 Have you ever given an experienced full size pilot a go with a model - they are usually as confused as a total beginner when the model gets to the third turn in the circuit!

 

Actually, a great many full size pilots DO look out of the side window during the early stages of a taildragger take off! 

 

Charles Lindbergh looked nowhere else in the Spirit of St. Louis other than an occasional squint through his periscope! 

[Flair D7 undercarriage wires]

Sorry no-one was able to help - this forum is usually a mine of information.  Although most of the Flair scouts are very popular I have yet to see a D7 at our club so perhaps there's not so much experience around with this model?

[seagull's or any richard the 3rd's (bird's)]

As someone living fairly close to London and having some familiarity with Cockney rhyming slang, can I say that modelling a seagull's Richard the Third is maybe going a bit far in the direction of realism - and potentially rather messy!

[Hawker Nimrod Balance points?]

Remember that the C of G is a 3 dimensional point i.e. not just a point somewhere on a line along the longitudinal axis but also on the vertical and lateral axes.

 

What this means is that depending on the layout of the model, a small amount of nose up can mean the C of G actually being quite a long way back from the point it's hanging from so it is important that you set it level or slightly nose down.

[JR to relinquish DSM2]

Just back from flying this afternoon and a bit of socialising afterwards - what a lot of posts there have been!

 

David (Ashby) - would this thread make the basis of a useful article for the magazine?  I've learnt a lot from Pete's postings and I'm sure the greater modelling community could benefit from his clear explanations.

[JR to relinquish DSM2]

Pete,

 

Thanks - sounds like reassuring information for Spektrum owners and a great example of the work the BMFA does for us in addition to just being the "insurance provider" that many people seem to regard it as.

 

There are one or two things I wonder if you could clarify?

 

If I'm interpreting the information correctly I think this implies that the generally available FHSS systems only use100KHz from each of the 1 MHz channels as they hop around the waveband.

 

Does Spektrum use all of the 1 MHz channel bandwidth at 10 mW on it's 2 selected channels or are things not as simple as this?

 

Does the ERP mean (as it would seem if you interpret it literally) that the range will be the same for a lower powered but wider bandwidth signal or is there a benefit in the higher level but lower bandwidth of FHSS?

Edited By Martin Harris on 02/09/2010 12:59:42

[JR to relinquish DSM2]

It could be a concern.  Although we're only talking about relatively small power levels, there is a lot of low level exposure to microwave frequencies for all of us these days.

 

It may be co-incidence but a friend's father died of leukemia 30 years or so after being a radar mechanic during WW2 - and I understand that several of his former colleagues also contracted the same disease.

[JR to relinquish DSM2]

Pete,

 

I'm very aware that you've probably forgotten more about radio theory, design and application than I and most of us on the forum have ever known (you won't remember me but we were clubmates in the late 70s) and that you have direct involvement with the BMFA so I'd urge everyone to respect your opinions on this.

 

I do find that there is conflicting information about so perhaps you could clarify a few points?

 

I was under the impression that the relaxation of the 10mW ERP limit was subject to the proviso that FH was implemented over a minimum of 15 channels - was this correct and if so, has this been re-written as a consequence of the meeting referred to?

 

I don't dispute that wireless LANs operate on a single channel but they are legitimate users on that basis - as would be 10mW RC transmitters so there's no reason that any more rigorous enforcement of the existing regulation would ban their use.

 

 I'm sure I remember reading the "official" explanation from MacGregor's technical expert in a newsgroup explaining that scanning the entire band before allocating the 2 frequencies complied with the letter of the regulations requiring FH.  As I recall it appeared to be directly from him and not a quote. Was this issue addressed by the meeting participants?

Edited By Martin Harris on 01/09/2010 20:26:29

[2.4 Aerial Issue]

Once again people are saying they've had interference problems with 2.4

 

This was the subject of another thread recently where someone (BEB?) was proposing running a survey to dee if we could establish any patterns or common causes. Have I missed it or wasn't it practical?

 

I have to say that the only problems I've witnessed since the introduction of 2.4 at my club and any others I've been to have been battery related.

Edited By Martin Harris on 01/09/2010 19:48:12

[JR to relinquish DSM2]

Problem is that we are allowed more power than many other legitimate users on condition that FH is implemented.  At least one of the American multinational wireless LAN manufacturers has already made noises about getting peripheral users (that's us!) kicked off 2.4 GHz and if we're held to be habitual abusers of the regulations it could weaken our case.

 

On seeing David's last post it's reminded me that I'd say that with the rapid advances being made, the concept of buying into a particular system and remaining with it for decades is rapidly becoming outdated. We've already seen at least several manufacturers upgrade to non compatible systems from their first versions and another runs 2 systems in parallel with receivers only being compatible with certain transmitters/modules.

Edited By Martin Harris on 01/09/2010 17:29:02

[Reversing a O.S fs motor]

If it's a major consideration, I wouldn't worry too much about the inner parts of a prop being shielded by the spinner as that part does very little work.  I use 8" props on my 1/12 scale (OS15 CVA engined)  Me209s with 2 3/4" spinners so the proportions would be similar.

 

The silly looking little bits of prop left sticking out are very effective!

 

BTW, nice to see you working on such a beautifully proportioned aircraft instead of those ugly old Whirlwinds!   

[JR to relinquish DSM2]

David,

 

I'm certainly not a fan of the EU and its apparently wholesale embodiment of the nanny state mentality but as existing users of the 2.4 GHz band, would we be happy if another interest started disregarding protocols and launched equipment that could hazard our use of the waveband?

 

I'm not qualified to say whether the non-hopping operation of Spektrum equipment has any effect on existing or potential users but surely you can see that we do need some sort of protective organisation to legislate for the use of the band?

 

Of course, despite it's limitations, the 35 MHz band did at least have the advantage of being virtually exclusive (some very limited military usage was permitted) to model aircraft and because of this, such issues as bait boats on 35 MHz being sold to anglers were quickly resolved by the power of the law.

Edited By Martin Harris on 01/09/2010 13:17:05

[JR to relinquish DSM2]

As I understand it, any threat is to continued production rather than a retrospective ban. What happens outside Europe is another matter and could mean receivers being produced even if the new sales of DSM2 transmitters were stopped in the EU.

 

As to the problem, it's simply that the intent behind the regulations allowing us to use more than 10 mW (only sufficient for cars, boats and very close in airborne use) was that all systems would frequency hop over at least 15 channels constantly during operation. 

 

Spektrum chooses 2 free channels and does not vary from these for the duration of a session.  Spektrum have argued that the fact that they scan the band before locking on to these 2  frequencies is sufficient to satisfy the letter of the regulations if not the intent.

Edited By Martin Harris on 01/09/2010 13:00:53