10-18-2012, 11:06 AM
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Thanked 439 Times in 432 Posts
Club: Founder Member Ventspils RC Club. Ex Waltham Chase and Meon Valley Soaring.
To design up and build an Avro Lancaster
First an intro as to why I need to do this ....
Hobby King Lancaster is refused on basis of size / weight via Latvian Post etc. - so my intended purchase is now cancelled.
I've built various over the years from plans etc. and I have a couple of traditional plans + a general of a foam block version.
I need help, ideas, thoughts as to putting this together in easiest way. I want to avoid hot-wire cutting if possible, at least avoid large sections as what generally happens there is ruts and divots ..
Size ? Somewhere between 1000 - 1500mm ... small ennough to be easily transported, but large enough to look part in the air. I also want to be able to hand-launch it at rough sites as well as have retracts for good paved areas ... Seriously !
My first ideas are that the Lanc has a relatively flat slab sided fuselage, the wings even though break-jointed at a nacelle are basically near flat bottomed.
This leads me to consider ;
Fuselage can be set up as slab side sheet with formers and folded sheet for top / bottom curved sections. Each side being laminated from two 6mm foam sheets to stiffen up such a long structure but keeping light. Top decking from 3mm, bottom from 6mm. All formers are laminated from 2 x 6mm or 3mm as appropriate.
Canopies and turrets can be foam block as I don't really need clear etc.
No need for bomb doors .. a slot in bottom would be good enough with removeable hatch for any 'sweet drop' at displays / meets etc.
Wing - this is the part that needs care as the wing has that break-joint plus has to carry 4 nacelles / motors ... plus retracts if I can squeeze them in. I want to avoid too much CF and weight to stiffen wings ... so reckon I might adapt the method I used on the SE5 I built ...
The Lanc wing is near clark Y, actually I believe the real wing is Clark YH ... so a flat 6mm sheet forms the basic shape. I can then cut 6mm strips to laminate into 12mm spars with width about 9mm ... these then resined onto the bottom sheet. A top 6mm sheet is then bent and resined to the spar and LE / TE to form an aerofoil shape. The wing would then be cut at the break dihedral point and extra infill made to strengthen for the nacelle and angled joint.
That's the barebones at moment in my mind ... so thoughts ladies and gents ...
If anyone wants to suggest inventory .. then please note that due to lack of LHS etc. - I'm pretty well forced to use Hobby King or ebay for most things. One area I'm undecided about is motors and props. I don't really want screaming high KV motors, but I cannopt fit low KV and big props .. not enough clearance between nacelles. So what to use ?
Battery ? Is it better to have a single large in bomb bay ? or split it to two batterys .. ie one battery powering inboard motors, other the outboard ? and carry them in wing ?
Controls ... unlike many who consider it too hard to connect up rudder ... I propose flexi snakes or stiff transverse rod to provide rudder control ... more on this later once I sketch up the idea.
Looking fwd to input ... I know it's only a planning stage on this thread at moment and I have about 2 weeks before I return home, but I hope this can become a group effort and others may jump on and build as well. Before anyone asks - I''m no good with CAD software - so plans will be based on sketches ... and eyeball work ... but I will try best to post up sketches ... anything I can for others to use / amend / modify etc.
Fingers crossed and wish me luck !
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