Coming along very well Capt. 

bell crank in favor of disc crank?

Hi Peter
Yes sometimes one does marvel how technology has progressed. May be we could design and print a true scale flying model in near future but I am sure that won't be as much fun as doing it with hands dirty. Your progress on the Moth has been prodding me to get this one moving too.
Given the limited metal working abilities, I settled to get the discs made, yes shorter length should have been perfect. But then the gears should solve the issue. (at least that is what I assume)   

Tanmay
No it will not cost in terms of flight characteristics, in fact it would be more true to the full scale behaviour. Weight penalty is definitely yes. But then scale details do add weight, can not escape that, other than make it as much light as possible.

Iyer sir
Thanks, that is the intent, to replicate the full size as far as practical and within my capabilities.

Girish
Whether bell or disc, as long as the crank cranks the aileron to the required throws, this cranky chap would be happy     

@flyingboxcar

I don't see a reason for you to discard the arrangement shown in your reply #244 and add additional gears.

In the link that you have provided below, a hint to the solution is shown in DK's Reply #183

Quote from: flyingboxcar on March 24, 2016, 03:55:04 PM
So not being happy with that, I will try another idea that has been borrowed from this build loghttp://www.rcmf.co.uk/4um/plan-scratch-builds/dennis-bryant-15th-scale-tiger-moth/160/

You just need to change the position where the pushrod is attached............see the attached picture......
Hope it gives you the unequal throw that you require.

Haha captain, we're indeed a bunch of cranky gents. Almost all of us.

moment arm of the servo side on the disc is greater than moment arm of the aileron linkage, causing a reduction in throw. maybe flip the disc, and swap the control linkages? Hmmm, you may have to move servos!

Prasad
Will try and see if I can drill a new hole on the disc and attach the aileron push rod. That metal disc is one tough material to drill. The order for gear sets is already in order so will wait to see which solution works best  

Girish
The disc location is scale so can not change that.

Gearing option for the ailerons turned out not satisfactory. I was either getting too tight a mesh or sloppy. So that idea was binned too and help requested from another builder of the same model overseas. Will post a picture or two (or three or four if folks want ). But this would also mean opening up the bottom ply sheeting on the fuse and also some surgery to the control tunnel too to install a servo there. But the up side of all this is going to be that the mechanism for aileron operation would be very very near to scale  .  

Meanwhile also outourced design and cutting of some scale horns and windshield frames and brackets. I had contacted Pline last year and had given the dimensions etc but guess small orders do not make economical sense. Hmm never mind. Onward with my search. And search and you will find is so true. Money worth spent and results are here to see

1. Just one sheet of 0.4mm brass horns and frame cut with waterjet
2. One pair of elevator horns bent. One pair was bent cold, and the one with multiple hue was annealed prior to bending
3. Third and fourth one set of Rudder horns bent and silver soldered together. Needs cleaning and polishing.

One more picture of the Brass sheet cut with water jet for the various parts.
The other three pictures are of the aileron activation mechanism. Basically it has pulley on to which runs a metal cable that is operated in closed loop manner by a servo fitted in the fuse. The metal crank with threaded strut is where the aileron pushrod will be attached.
The idea and assembly is by kind courtsey of Peter F from UK who has used the same asssembly on his build of the same model. So big thank you to Peter. The L shaped thingy you see in second picture is the idler assembly for the aileron closed loop      

In case some one is interested to see how this assembly works, please do visit the UK forum and see for yourself the fantastic work Peter s doing on his Tiggy
http://www.modelflying.co.uk/forums/postings.asp?th=103321&p=14
A you tube video of the working aileron assembly posted by Peter

Bit difficult to make out the entire assembly from the video. Bell crank with push-pull?

Anyway, the movement seems perfect and very scale-like    Kudos, Captain 

Sanjay
That is not my Tiggy, that is a video posted by Peter of his build. The mechanism is same. There is no bell crank. If you visit the build on UK forum you will see a servo operated crank and the idler under the fuse (seen even in the video). A cable (each side) runs from fuse crank through the wing to the pulley mechanism.  The pulley has another crank attached that is in turn affixed to the aileron push rods. The other end of the cable from pulleyes on both wings routes back through the wing to be affixed to the idler. The idler does nothing except keep the loop closed to be called a closed loop    

If you observe the G10 crank under the fuse is doing the pull - pull while the L shaped idler bar just moves to and fro as it is connected in a closed loop

Not sure what your question was about Bell cranks with push pull? Could you shine some light on that?   

Here is a picture of the full scale Elevator horn just for comparing the ones being put on the model

A visitor dropped in today to inspect and inquire about the progress. On being questioned the bloke stated he is supposed to be flying this Tiggy
He did look suitably attired for a flight, with boots, leather helmet, googles, harness and the works. He was pretty disappointed to see his mount not yet ready for flight. But on the positive side he did seem happy with the quality thus far.
He has been earnestly assured that his much beloved mount would be given all impetus towards completion and he can air it soon.

The gent took a look around, settled in the cockpit (did say it was a bit cramped) and then went back to the cupboard.

Ohh! on being queried he did say his name as Tiger Terry

Looks pretty happy 

Quote from: sanjayrai55 on August 23, 2016, 05:53:40 PM
Looks pretty happy  

Ohh! no, you should have heard him voice his displeasure with the progress. 
But then his demeanor changed the moment he saw a camera come out.

In case anyone is interested the pilot was sourced from
http://www.mickreevesmodels.co.uk/~mickreev/Access/accessories.htm

With passage of time the mild steel items have taken a beating in terms of rust. So a fair amount of time was devoted in cleaning up the parts that are not yet mounted or those mounted but could be easily taken off.
These were given a nice sanding with 180 and then 400 grit wet and dry and washed off in acetone to degrease, and dried up. Followed by a coat of silver paint.
Here is a picture of the initial process

While researching the subject, I came across another fact that I have not seen captured by any one anywhere (to my limited knowledge).
This pertains to ingenious way of providing differential throw on elevators on the full scale. Did you know that the elevator horns on top and bottom surfaces are not equal height. Yes they differ. The first indication was when I saw a picture where these appeared unequal and I put it down as optical illusion.
But further research led me to the discovery that they are indeed sized differently. where the top lever is full 15 mm shorter than the bottom one. While the top is 2 13/32 " the bottom is 3".   

And in case any one was wondering, the recent times were not just spent de-rusting and researching the subject. Some progress has been made on the construction as well. Here is a list of what has been done on the port wing side
Interplane struts glued together and rough shaped/sanded (all four)
4BA studding glued in the struts ready to be trial fitted (on all four struts)
Metal fittings that will be used in conjugation with the flying, landing and incidence wires were trial fitted.
The above said wires themselves were prepared and tried on
Wing root fitting on the lower port wing finally glued in (after a long breath and a prayer)
And today the port wings were tried on the fuse. Both the wings were attached with the landing wires and interplane struts to the required dihedral of 4.5 degrees on the lower wing and the top wing was automatically rigged to 2.5 degrees. Will have to later fine tune the wire tension and ensure that incidences remain same. Since the construction started today was the first time when the wings were fixed and and trestle support removed. The the entire setup was supporting it's own weight. The other side should now go ahead quicker
 


 

Hello, Manish. Thank you for the advice that the rcindia forum was up & running again!

I'm glad to see that you're back in harness for this build. By way of encouragement and to keep your juices flowing here's a picture of my 'PK on an evening flight...

That's a lovely and evocative shot of AGPK Don, thanks for popping in and checking the thread

Earlier I had shown and explained the aileron crank mechanism that was very kindly made by Peter in UK. I got around to installing these on to  the wings of my DH 82 and laid out the wires etc through the wing ribs. I will not be using full length plastic tube but merely provide tube bushing at each rib. Did a dry run by pulling the cables by hand at the wing root and the mechanism worked perfect exactly like the full scale.
I have much much more up travel of the aileron now and the down ward travel is just a little and if the cable is pulled any further the aileron starts going back to neutral and full up on one side gives neutral ailerons on the other wing. Just like the full scale.
Here are few pictures  
In fact the picture titled down is more when the push rod has travelled beyond the max down throw and starting to move down to bring the aileron back towards neutral.   

Brilliant, Manesh. It's looking good 

Today was also the day when all four wings were mounted on to the fuse and stood on their own without any external supports.
This was done to work on all the flying and landing wires (four each side) and the four incidence wires.
Once the wings were mounted it was also time to check for alignment, dihedral, and incidences.
Setting of dihedral is simplicity itself. These are set on lower wings by adjusting the landing wires so that the main spar is at 4.5 degrees (after the fuselage is set to zero degrees and now acts as datum).
Once the lower wings are at correct dihedral the inter-plane struts ensure that the upper wings are at required 2.5 degrees.
The wires need to be just right not tight else they start distorting the wing structure.
Once all wires are set the wing sides are pretty rigid.
Measurement of sweep back on each side did reveal some difference that would need fettling to ensure  that both sides are equal.
Assembling and checking takes lot of time and I needed to do all this in the hall when folks at home were away  

Here are some pictures of the Tiggy with all her wings

Thanks Don. Good to know I have you watching and can reach out for help if I get stuck.
While there have been some good progress, there is still a lot to be done