Mossie

[Martin McIntosh]

Thanks both.

[Steve Adams]

That's blooming Gorgeous Martin!

Looks like it has working navigation lights as well. I really wish I had your talent and patients to produce something this spectacular, it really is a work of art! So how many hours of time from start to finish have you put into this labour of love?

Cheers

Steve

[Martin McIntosh]

Hi Steve, I started about when the plan came out and other than having to go to work for three days a week until the 28th Jan. when I retired and a week incapacitated with flu I suppose that the rest of the time was spent building this until I got fed up with it each day. Not as many hours per day as I used to do on a model but I have found that it is best to see a project through to its conclusion and ignore everything else as far as possible otherwise it tends to be put on the sidelines and is a struggle to re start.

I tried to capture a tip light on but did not quite make it. If anyone wants a copy of the very simple strobe circuitry I can do it on here (Or maybe even make up some units. I needed two of these because the red high intensity LED drew more current than the green and white together). The original was a Vellman kit from CPC but the actual PCB was flimsy so I just made my own in the end.

Not quite happy with the finish because even though it came from the same tin as my 72" Spit. and Vulcan it has turned out glossier. Another coat with some flatting agent added would sort that.

[_AL_]

That looks fantastic Martin.

Great work.

Al

[Dennis Holmes]

Hi Martin it's looking great nice job, what's the all up flying weight now she's finished. Looking forward to hearing how it performs in the air, I'm nervous for you because I know how much work and time as gone into the project, all the best

[Martin McIntosh]

Hi Dennis, the best AUW guess at the moment is 14.6 lbs but this is not with the alloy spinners so I shall not really know until they arrive and are fitted.

You are nervous, how do you think I feel! The only thing that I am a little worried about is the rather complex wiring and unflown electronics but the Rx has been well test flown and the main servos are of good quality. A similar fail over switch and LiFe batteries have been test flown so there should be no problems with those and a lot of bench testing has been done to ensure that the retracts and doors should not give any problems. Most certainly a lot less work in this than my 96" Hurri for instance but the adrenaline will be pumping at a feverish rate when I eventually pluck up enough courage to commit it to the air.

[Colin Leighfield]

Good luck Martin. If anyone can make a success of it, you will.

[howie]

Hi All.

I have been reading this thread with some interest now. I have started the 72" TN Mosquito by building the tail plane .

The problem I have encountered is that with the dihedral of the tailplane the elevators are on the same angle so when I join them with the suggested wire joiner the hinges are not aligned correctly to allow the elevators to work together.

Most models I have built previously have the elevators and tailplane in the same plane. (no pun intended). How do I synchronise these elevators so the engineering principle will allow them to move without binding.

Cheers Howie.

[Allan Bennett]

Good point howie. I haven't got as far as assembling my bits and pieces yet but, thinking about your question, it seems that if the "arms" of the wire joiner go into slots in the elevator halves, instead of being glued in solidly, that would allow the correct movement. But the trouble is it would also potentially introduce some slop.

Of course, with the joiner glued solidly in to each elevator half, things will work okay if there's enough flex in the joiner, though the joiner trying to straighten itself out will provide a degree of self-centering.

I think I read that someone was planning to use two separate pushrods, and no joiner, to get over the problem. It's quite often done on larger models. I see from his photos that Martin hasn't gone that route, so it will be interesting to hear if he perceives any problem there.

[Martin McIntosh]

I cannot see where your problem is. Building a tail upside down is quite normal and the joiner can be glued in because if you think about it it will be more or less in line since the dihedral angle is very small and can be disregarded since the actual elevator movement is minimal.

I did consider using a `Y` pushrod but only because the elevators are quite flexible and this would have introduced more problems than it would have cured.

Edited By Martin McIntosh on 17/02/2016 23:37:39

[Allan Bennett]

I've just finished fitting the bits and pieces in the wing halves. Prior to closing them up by installing the bottom sheeting I decided to check that the joiner tubes are in good alignment. I cut the SLEC aluminium tubes to the lengths given on the plan, but then realised that this wasn't long enough for the main one to go as far into the tubes as shown on the plan.

The plan shows it going to the ends of the resin tubes, but at 460mm long it only goes as far as rib W3 on each side. If someone here has bought the wood pack from TN, can you confirm please that 460mm is all that's needed for the main joiner.

[Martin McIntosh]

I extended my large tube to W4 but this was just personal preference and possible only because mine is smaller than those supplied in the pack.

The rear tube length is not critical as long as it goes to W2 at least.

[Allan Bennett]

So going only to W3 with the ali main tube, not beyond like the sleeve does, is okay? No problem with the rear tube.

I didn't twig previously that your main tube is smaller diameter than specified. Unfortunately, from an engineering point of view, lengthening its connection to the main spar will not compensate for its lesser strength at the join between wing and fuselage, where the stress is the greatest.

[Martin McIntosh]

True, but mine also has another, shorter, tube fitted inside it to vastly increase the strength. I extended them just to give more gluing area.

[Allan Bennett]

Sounds good Martin.

[Martin McIntosh]

The alloy spinners from HK have arrived at last after a month. They are of course not to scale profile but at least run true. Only a little cutting was required for the l/h prop. The useless JP ones could be fitted for scale judging at the local comp. if it ever gets that far. I quite like the alloy look and shall not paint them until it has flown.

The prop shafts have a radius at the root which needed to be removed so that the spinner centre piece would fit flush. I started to do this on the lathe but had to resort to filing in the end.

The l/h props for some reason have a raised flange at the centre and this needs to be filed off or the prop washer will not grip properly. The pics to follow show this.

Some pics of it as is in the dark. The lights look great and should show up in daylight quite well but I could not capture them with a stills camera. With the new spinners and the batteries well forward the cg should be good to go.

Other than the weather and the state of the patch I am now running out of excuses not to fly it.

[Martin McIntosh]

[Danny Fenton]

Be careful Martin that radius is to increase the strength and remove a weak point. I leave the radius and relieve the spinner backplate centre hole.
Mossie looks stunning you have done a great job

[Colin Leighfield]

That was the problem that caused me to scratch my head for ages over prop balance on the Seafang. I was too stupid to notice that the radius was holding the spinner backplate off and causing it to run slightly off-centre. When it finally sank in I sorted it by slightly relieving the radius of the hole in the backplate to make sure that it fitted down completely square on the prop-driver. Anyone with brains would have seen it straight away, sadly there are times when I'm severely lacking in that respect.

You've done a brilliant job of that Mosquito Martin, it's going to turn some heads at the field.

[john stones 1 - Moderator]

Yep i'll echo that, very nice

John

[Martin McIntosh]

I would normally relieve the spinner centre but it was not possible in this case because there is an alloy insert which would distort if I had tried to radius it. An alternative, which I used on the original plastic spinners, is to carefully bore out the centre of a cut off disc and glue this to to rear of the backplate to form a spacer. I have one or two spare shafts so could try this but the motors have been run up to speed and so far so good.

[Martin McIntosh]

Had another look at this. It is in fact possible to radius the spinner backplate insert using a quality countersink tool either by hand or by gripping lightly in a mole wrench and applying it with an electric drill.

[Allan Bennett]

My build is going slower than yours did -- wings basically finished and nacelles still needing underside planking and doors. Everything else is built, but needs filling and sanding to an acceptable finish before glassing and assembling.

I've started thinking about the spinners though, and I've read again about the problem you had with yours. I suppose I should really try to use the ones supplied by TN, but the Perkins uncut ones certainly look tempting, and almost the right profile. What exactly did you find wrong with them? I've used Perkins' spinners before, though not that model, without any problems.

Edited By Allan Bennett on 19/03/2016 21:37:14

[Martin McIntosh]

Hi Allan,

Don`t touch the Perkins ones. As soon as the screws are tightened they splay out and will not run true (by a long way). As shown in one of my pics the design of these has changed from the originals which were just fine. I do not know of an alternative in that size. I would be interested to see if anyone has made up the ABS ones and run them.

Some pics of it at the field:

[Allan Bennett]

Posted by Martin McIntosh on 20/03/2016 15:53:16:

Hi Allan,

Don`t touch the Perkins ones. As soon as the screws are tightened they splay out and will not run true (by a long way). As shown in one of my pics the design of these has changed from the originals which were just fine. I do not know of an alternative in that size. I would be interested to see if anyone has made up the ABS ones and run them.

OK. When I looked at your picture a few posts back, you said the old model Perkins spinner is on the left, yet to me that looks like the one that's been squished out of shape. Anyway, probably I should give TN's spinners a chance before I go hunting for a better alternative.

Nice to see your Mossie in the open air. So, did you fly it yet?