1/4 Scale Tiger Moth build, a work very much in progress

[Ron Gray]

Respect! That is excellent work Richard.

[Richard Thornton 2]

Back to the Handley Page Slats. I had issues with making the slats ‘spring loaded’. On the full sized aircraft they have a lever in the cockpit that locks and unlocks them in place. When unlocked though, ie during takeoff and landing, they are unlocked to give extra lift but when the airspeed increases the slats are forced back into the wing by aerodynamics and remain in that position during flight. If aerobatics are to be performed they have to be locked in position so that they don’t ‘deploy’ during that process. Talking to the owner of the aircraft, he described the landing process where he gently bleeds of the speed on final approach and on approaching the stall, the slats deploy automatically. Apparently they are quite clunky and can be heard over the din of the engine. 
So the slats have two functions, lift generators and anti stall indicators. I asked what the other Moths do that aren’t fitted with these slats do? His response was a sly grin and comment, “you don’t see many of those anymore do you”. 
Back to the build, a micro servo drives the middle hinge on the slat, the outer hinges are simply spring loaded to resist the closed position. The middle servo arm has a sliding arm that allows the slat to be pulled closed against the outer springs but the return stroke is not fixed, the slat is actually pulled back out by the outer springs when the arm is moved. Sounds complicated and it was until the penny dropped!

[Richard Thornton 2]

2 hours ago, Ron Gray said:

Respect! That is excellent work Richard.

Many thanks Ron.

[Ron Gray]

Like the radiation shields on the servo cables 😎

[Richard Thornton 2]

2 minutes ago, Ron Gray said:

Like the radiation shields on the servo cables 😎

I am not sure this part of the build is a ‘feature’ or a ‘benefit’ but the servo leads and the wing tip nav light leads are soooooo long. I don’t confess to be electrically minded, Mechanical Engineering is my background but working on an MoD job several years ago, the Electrical Engineering Department shrouded all the signal cables in an attempt to prevent noise. My logic is noise and signal are similar?

It also keeps everything nice and tidy and stops the cables slapping the underside fabric.

 

[Manish Chandrayan]

The slats are working beautifully 👍. Don't forget to install the missing fourth bolt on the front interplane strut top plate😃

[Richard Thornton 2]

28 minutes ago, Manish Chandrayan said:

The slats are working beautifully 👍. Don't forget to install the missing fourth bolt on the front interplane strut top plate😃

The devil is in the detail, well spotted. That missing bolt is actually the hole where the inter wing strut pushes through both forward and aft, which then gets fixed in position one the covering has been done.

I followed the plan on this one as making independent brackets with pins as per the full size looked complicated.

The photo below shows the underside of the lower wing prior to the struts been fitted, marked with blue arrows.

[Manish Chandrayan]

Good amount of excellent metal work there Richard. I am sure these are neither supplied in the Traplet/Sarik package nor shown on the plans. 

[Richard Thornton 2]

3 hours ago, Manish Chandrayan said:

Good amount of excellent metal work there Richard. I am sure these are neither supplied in the Traplet/Sarik package nor shown on the plans. 

Thank you for the compliment. The plans show some metalwork detail but no are to scale. When I started this build it was about getting a Tigermoth into the air. After reading your build log and PeterF build log, it became more of a ‘scale build’ than  arc plane. I must confess to rather have enjoyed that change in mind set. I know from PeterF that the Falcon kit came with all brass bits nicely cut, Traplet/Sarik doesn’t but it seems to be the only 1/4 scale kit out there.

[Richard Thornton 2]

The Handley Page slats themselves, all bashed out of aluminium plate which wasn’t annealed as the first attempt was. First attempt bent fantastically easily into shape, but if you looked at them, they bent and warped. I even tried re hardening them but that didn’t go well.

I resorted to keeping them as they were cut from the sheet, and as per PeterF build log, rolled them on tubes of ever decreasing diameter.

The fixing positions are slightly not as per full size, but that was dictated by the model wing spar’s positioning. The cutouts in the starboard one seemed large but are from photos obtained from the owner of the aircraft. They were easier to do than I worried about, I sweated bullets trying not to oversize them whilst cutting the thin aluminium plate. 
Now, just a lick of paint which I hope will stop them scratching so easily.

Edited April 17 by Richard Thornton 2
Spelling mistake

[Manish Chandrayan]

The Falcon metal work was mostly steel with the shackles for horns being brass. All the control horns were out of G10.

Pity that Chris had to wind up. I had approached him for another set of parts but he expressed his inability 

[Richard Thornton 2]

Talking of metal bashing. Most Tigermoths are now fitted with domed inspection hatches.

apparently these are to save the cost of cutting open the fabric and resealing and paint matching an area that requires frequent internal thorough examination.

The aircraft I am modelling has 9 on the upper surfaces on the upper wings, none on the underside and 6 on the underside surface of the lower wings, but none on the upper surfaces.

I used litho plate and a circular card cutter to make the discs. Each one was then drilled out to take 2 rivets and a tiny screw. I then annealed each one and using a wooden ball and an upside down spray can, shaped the discs into dome shapes.

They might be a little to domed but I think the look ok. I did need to superglue a tiny 4mm strip of litho plate on the undersides as I kept creasing the domes due to them being soft. I tried making them without the annealing process, but the results were rubbish as the edges crinkled and the creases simply would not work flat.

What do you think?

No they are not some new drone swarm detector !

 

 

[Richard Thornton 2]

17 minutes ago, Manish Chandrayan said:

The Falcon metal work was mostly steel with the shackles for horns being brass. All the control horns were out of G10.

Pity that Chris had to wind up. I had approached him for another set of parts but he expressed his inability 

That really is a shame, the model looked fantastically supplied and scale like. I was very fortunate to buy a Falcon undercarriage kit which is spring loaded and looks fantastic. My silver soldering wasn’t upto scratch when I started building that part up, so I stopped and got the right tools and proper flux so feel more competent to take on that part now.

However…… shortly after buying the undercarriage I saw a photo of a Tigermoth in the USA fitted with floats, so mine has a part built set of floats. Thing is, that very aircraft is now flying again here in the UK and it has its wheels fitted!

At last I have an excuse for having both options.

 

[Manish Chandrayan]

I had been wondering about those inspection discs and had intended to ask how you shaped them. Thanks for showing. 

How are these attached to the fabric? Glued on or done like the full scale? 

[Richard Thornton 2]

Funny how things happen.

I painted my models cockpits with ‘cockpit green’ which was Matt and every tin seemed to have a slightly different colour tone to it. 
Taking photos of the cockpits of the aircraft I am modelling I noticed the colour was a lot lighter than I had used and also glossy. DAMN.

I read an article which suggested Vauxhall Reed Green, which is easier to find, finish is amazing and the colour tics all the boxes.

But how do I paint the inside surface of the cockpit now, specially once the covering is applied.

Do I spray it first where it is visible from the outside? 
Any suggestions?

 

 

[PeterF]

Richard, I have been away for a few days and missed these recent updates. I am glad you have got back to your Moth. Excellent modelling, puts some of my work in the shade, especially the slats, I simply screwed mine in place. I look forward to seeing your ongoing work and the plane flying.

[Richard Thornton 2]

16 minutes ago, Manish Chandrayan said:

I had been wondering about those inspection discs and had intended to ask how you shaped them. Thanks for showing. 

How are these attached to the fabric? Glued on or done like the full scale? 

There are 3 or 4 types of covers.

a/ just a simple dollar shaped supplied by Mick Reeves Models, ironed directly onto the fabric.

b/ a very thin disc is cutout and stuck to the fabric first with the ‘dollar shape’ iron on top of that. I found that card was too thick and simply used some 30gsm paper to make the rings, any thicker and the look TOO pronounced.

c/ the sort that have the domes fitted are as per option b/ above but they are glued to the fabric via the protruding rivets and the tiny screw, which allows the thing to flex. I think glueing it all the way round would work too but there is always the issue of the glue seeping out, just where you don’t want it.

d/ this Tigermoth has another type fitted to the tail. They have an outer ring with an internal ring also. It sort of makes it look like a target.

 

I have attached a photo but the one on the right is option d/ but in balsa which didn’t work out at all.

 

Several points to consider.

To stick the paper disc to the fabric I used Cover Grip and then used the cutout from the sheet to place the ‘dollar’ in exactly the right place. 
If you iron it from the centre of the dollar outwards, the inner edge is much neater and you don’t land up trapping air within the inner ring.

 

[Richard Thornton 2]

28 minutes ago, PeterF said:

Richard, I have been away for a few days and missed these recent updates. I am glad you have got back to your Moth. Excellent modelling, puts some of my work in the shade, especially the slats, I simply screwed mine in place. I look forward to seeing your ongoing work and the plane flying.

Thanks to you Peter and Manish, I got the bug again through both of your build logs.

[Richard Thornton 2]

So here are some of the bits that I used to add some original detail to the rear cockpit.

The hand pump is used to pump fuel from the spare tank located over the front passengers feet in the forward cockpit. Apparently putting the handle at 90° it opens the valve and fuel can then be pumped into the upper tank, all of which sounds fantastic until you realise this is all done in flight!

The grey board on the second photo is just a guide or mockup of the cockpit to ensure everything fitted in without having to remake the rear seat and to line everything up with the models pillars which are slightly off scale but this has helped, plumbing it all in place.

The transponder was a fiddle to build but the information on the internet regarding the size and shape and workings are all still available.

One thing that I do need to finish off though is the decals. All the writing is white and tiny wee. 
I have reproduced them all in Autocad but I can’t print ‘white’ on my printer.

Any suggestions? The radio in the central has similar issues (on the black surfaces) but the writing on the green surfaces are in black so I am hoping to try my luck at making some decal transfers but that is an area of exploration and yet to be resolved. 

 

[Richard Thornton 2]

So I turned some scrap aluminium from a skip and bits and bobs lying about into…..

[Manish Chandrayan]

That transponder looks 🙌

Are you planning to do the drain grommets as well 😉 

[Richard Thornton 2]

36 minutes ago, Manish Chandrayan said:

That transponder looks 🙌

Are you planning to do the drain grommets as well 😉 

I think the drain grommets might be a step to far for me, they are on the underside of the wings but the kit didn’t come with those and I know from your builds there are loads of them? What do you think?

[Simon Chaddock]

Richard

That is truly spectacular scale detail.

Any thoughts on how and what is going to power it? 

[Richard Thornton 2]

16 minutes ago, Richard Thornton 2 said:

I think the drain grommets might be a step to far for me, they are on the underside of the wings but the kit didn’t come with those and I know from your builds there are loads of them? What do you think?

Do you know if anyone has not used them from their Falcon kit build or are they easy to make?

[Richard Thornton 2]

19 minutes ago, Simon Chaddock said:

Richard

That is truly spectacular scale detail.

Any thoughts on how and what is going to power it? 

When I started the build, I was sure that electric was the way to go. After several disasters at electric flying I went back to the old faithful, fossil fuels. With that in mind I bought an NGH GF38 and have plumbed that in. Thought behind that was it’s a 4 stroke but petrol not that horrid glow fuel that all my other IC models have used. It always leaves a coating of gunk and varnish which gets everywhere.

That has issues all of its own though as the model club I used to fly at has been shut down and houses are now being built on the land. Other clubs now have a low tolerance to IC flying, not to mention that it’s quite a lump and I can’t find an exhaust to fit within the cowl. My silver soldering is much improved so that is actually going to be fun to resolve I hope