20%VULCAN

[DAVE JOHNSON]

Another week gone by,and even though i have worked on the project at some point every day,there isnt a lot to show for the time spent.I have been thinking of how i was going to transport the model to the forthcoming Wigan seminar,because its at the stage where its still easily damaged if picked up in the wrong place,so the last few days have been spent capping the Wing ribs on one wing and i have started the epoxy sheeting---the wing tip and outboard of one wing is now covered ,and i intend carrying on to try and at least get one wing so i can transport without too much chance of damage,the large Elevators have also been made and i should start covering these tonight

9bFKS1g8lz WINGTIP COVERING.jpg (38.35 KiB) Viewed 15641 times

[DAVE JOHNSON]

Not had much chance to update over the last few weeks with LMA committee business meetings etc,but still plenty of work done on the wing/tail and Nose.The first wing is now covered as far as can be untill the retract units are test fitted and woodwork installed--should happen in the next few weeks

c8C56cwbKnHALF WING.jpg (32.37 KiB) Viewed 15528 times

[DAVE JOHNSON]

While awaiting retracts,i have started building the nose section,this alone is 5ft long,and after offering all the cut formers on the bottom stringer--as can be seen.the rest was jigged up and locked in place

EncxBR81VE BASIC NOSE.jpg (40.15 KiB) Viewed 15529 times

[DAVE JOHNSON]

After a full days work today,the Nose is now fully stringered and ready for planking.Also the Tail has been partially balsa planked,and over the next couple of weeks before the Wigan seminar,i will hopefully finish these and have fitting to the Fuz for display

iYhUnIlFWxNOSE STRINGERED.jpg (46.56 KiB) Viewed 15530 times

[Stuart Solomon]

Dave, 12ft Cyparis ready, Maple u/c blocks ready, birch ply ready so what are you hanging around for? See you at Wigan, Solly

[Stuart Solomon]

Dave, 12ft Cyparis ready, Maple u/c blocks ready, birch ply ready so what are you hanging around for? See you at Wigan, Solly

Safe flying is no accident!

[robbieskipton]

Hi Dave,
Looks like a brilliant project.

However, i have a little bad news....

When we were building the 60% yak 54, i also used depron for every other rib ( from 1/2 way up the wing).. After speaking to my Inspector peter siggins (unsure of spelling), i was told that i could not use depron as
a) it would not be passed off
b) Depron is not strong enough under load, and does break easily
c) if any petrol/nitro/diesel gets on to it, it does indeed melt it...

Just a little heads up there., but i guess that each inspector has there own styles and thoughts.

I see you are using pro skin as well.. very nice material to work with.. that is what i was going to use on yak, but after working out weight of material.. it was going to add 30lbs to our model plus spraying, putting the yak to over 150 lbs!!!

Looking forward to seeing this fly

Regards

Robbie

[DAVE JOHNSON]

Morning Robbie--thanks for your comments--i would agree with Pete if depron was used on all the ribs----this is a black depron,much stronger than the normal,and its only there as extra support in between the normal ply ribs---on the original plan which the smaller Vulcan is built from,there were only half the number of ribs,but because i decided to use the epoxy sheet,i thought we needed extra ,and these have been capped in wood as well,so i have no worries at all.As for your thoughts on weight of the epoxy,that surprises me,i sat down with several who had used it ,and we worked out the comparisons of balsa/glass cloth/filler/etc aginst this epoxy,and it came out favourably.I have no worries about weight on this model,if it came out too light with this wing area,it would be unflyable in any wind,my present Vulcan is one of the few big models that flies well in strong winds because of the heavy build,i am working on 150lbs minimum for the new build,but if it crept up to 200lbs,i would have no concerns about the power/weight and wing loading,in fact everyone keeps telling me i should head for a more realistic 200 lbs to copy the flying characteristics of the full size---so time will tell hopefully later this year.Regards your other comment about fuel on the depron---i can understand that with a big petrol motor and fuel tank up front--my 4 turbines and fuel pipes etc are stuck right at the back end of the wing,so any leakage will exit in the airflow behind the model.DAVE
ps i need to speak with you at some time with regards to a suggestion you made at the AGM of journal distribution on e/mail

[robbieskipton]

Hi Dave.

i was not using depron for all the ribs.. prob what you are doing using them for added light weight ribs to make the shape easier to bend round with proskin ( when we were going down that root anyway).

I guess with your Vulcan, weight is almost immaterial as you will not be doing 3d aerobatics with it.......... (.. Thinking out loud..... can i have a do with the Vulcan , could be fun )

Sent you my number and email address dave..

speak to you later on hopefully..
Robbie

[Mike Booth]

Looks superb Dave, I cant wait to this one fly.

I imagine the bonding on Proskin material is critical on the leading edges of the wings, as i read of a catastophic failure on a Mick Reeves Spitfire wing regarding de-lamination.

Just a thought .

Mike.

[DAVE JOHNSON]

Evening Mike--yes you are right--it is critical to get the bonding right on this epoxy,especially at the leading edge.I covered the wing of my airbus the same a couple of years back,and once the bottom and top skins have been fitted and bonded onto the Balsa leading edge,i then wrap a .2m epoxy sheet---just like a deicing boot---around the leading edge and bond it to top/bottom sheet,this way it keeps any airflow away from the joints so no chance of lifting--it also make for a really strong leading edge as well.I wonder how Mick covers his spit wing??obviously different to me if it has de laminated in the air .DAVE

[Mike Booth]

Sounds ideal Dave, great, I can here the thunder of the flypast now.

I always remember a Vulcan flypast at RAF Halton where I lived in the 80s, as she throttled up a bit too much, the vibration broke all the glass in the green houses next to my property mine!!

Mike.

[DAVE JOHNSON]

Another few days work,and this week i have concentrated on the tail cone and brake parachute cover---the tail was first balsa sheeted and rubbed into shape,then the shute cover was then constructed in soft balsa and rubbed into shape---this will have a couple of layers of glasscloth now,then once all rubbed down,i will cut out ready for hinging---extra woodwork has already been fitted inside so when ready,a cut around the outside will release it---with the weather forecast being poor tommorrow,i am hoping to get some glasscloth on and maybe rubbed into shape-----

DuXjvzfTHCVULC Tail.jpg (40.01 KiB) Viewed 15356 times

m85Hf90W7t para cover.jpg (21.09 KiB) Viewed 15356 times

[Denis Brown]

Another few days work,and this week i have concentrated on the tail cone and brake parachute cover---the tail was first balsa sheeted and rubbed into shape,then the shute cover was then constructed in soft balsa and rubbed into shape---this will have a couple of layers of glasscloth now,then once all rubbed down,i will cut out ready for hinging---extra woodwork has already been fitted inside so when ready,a cut around the outside will release it---with the weather forecast being poor tommorrow,i am hoping to get some glasscloth on and maybe rubbed into shape-----

DuXjvzfTHCVULC Tail.jpg

m85Hf90W7t para cover.jpg

Time you got the hoover out on that floor

[DAVE JOHNSON]

DEN--my shed hoover is broken--do you know anyone who can fix it !!!!!

[Simon Wright]

Dave,
that is a really impressive build and seems to be moving along very quickly.

Proskin looks good as a skinning material, how thick is it and how many sq ft or meters will the airframe use?

[DAVE JOHNSON]

Simon--thanks for the comments---Proskin comes in several thickness sizes---i have used .3mm for the main wing surfaces,and some .2mm for covering surfaces that i have pree covered in Balsa such as the Ailerons/Elevators.The front end and Tail cone are being coverd in Balsa,because one problem with Proskin is it doesnt like double curvatures--so i will also Balsa cover some other parts of the airframe as well for this reason,so i am not too sure yet what amount i will use---i ordered 10 sheets of 4ft by 3 ft initially,hoping this may cover the wings,one is already done---DAVE

[DAVE JOHNSON]

With the LMA Wigan event now behind us,i decided to have a week away from the Vulcan,and spend a few days servicing a couple of display models ready for the East Kirkby show in 3 weeks.At Wigan--i spoke to several inspectors who looked at the build,and one concern was in the nose area if several pounds of Lead has to be added.On my existing Vulcan,the balance was acheived with very little nose weight,but this new one will have 4 turbines stuck right at the back--as aginst two on the existing one,so to be on the safe side,i decided to re-enforce the joint where the Nose will bolt onto the Fuz,and today i made a new birch ply former and glued to the existing ply one,and this will be tied in with several Cyparis stringers and ply quadrants as per photo--tonight i will start the planking on the nose.

peKogsSrvj Nose.jpg (43.75 KiB) Viewed 15215 times

[Stuart Solomon]

Dave, looking good but go to the back of the class for spelling, CYPARIS is how you spell the word and not Cyprus. Solly.

[DAVE JOHNSON]

Stu--the deliberate mistake made you look and read thro tho didnt it !!!