HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 12, 2013, 06:29 PM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Build Log
Britplan Build Log Vic Smeeds Debutante scaled from 40 to 80” Span

At long last I have managed to clear both bench and backlog of family work and can start the Debutante, although Eric Fearnley’s Luton Minor came a close contender for this build.

Having built a 60” span version for electric, I am moving on up to an 80” version while my memory holds onto the mods made for the 60”.

Starting with the wings, I decided to build three separate sections –
The centre section which will be dowel plugged into the front cabin former and 2 nylon bolts holding down at the rear cabin former. This section will generally be left in place after all the radio fitted and trimming completed, so that to dismantle the model, it is only necessary to pull the 2 wing halves off. Note that there will be no rubber bands needed across the 12” chord wings.

A single 1/4” carbon rod will join the 3 parts together at the main spars to carry the loading and a 1/8” carbon rod at the rear spars to set the wing incidence on each wing half.

The single main and rear spars have been replaced by 4 off ¼” spars. The carbon rods will slide into balsa “tubes” built up between each pair of ¼” spars and extend into the first 2 bays in each wing. See sketch below for X section. Note that the triangular ¼ sheet fillers are grooved to take the ¼ rod and maximise surface contact for friction fit and absorb the wing loading.

The number of ribs has been increased to give spacing of 2.5” and these will be capped with ½” sheeting. L/E is 3/8 sq and T/E is 5/16 by 1.25”, the latter notched to take the 1/8 thick ribs

All wood will be balsa except for 1/8” liteply facing on the 4 root ribs.

I have built the centre section first. Each wing half is then built lining up onto the centre section to ensure the spars line up for the wing joining rods.

Photos show progress to date – the centre section and one wing half lined up with dihedral set to enable postion of holes in ribs to be established. The ¼” sheet filler can be seen under the ¼ rod in the centre section. The fillers have still to be cut and fitted on the wings
John38 is offline Find More Posts by John38
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 12, 2013, 09:19 PM
Registered User
Teals1's Avatar
New Zealand, Auckland, Papakura
Joined Nov 2006
362 Posts
Debutante

Hi, The Debutante is a model with very nice appealing lines and scaled up to 80inches will just make it that much nicer! You have got off to a good start. The 3 piece wing is a good idea for a model of this size - what are you using to hold the wings in place on the carbon rods? - ie: to stop them sliding out in flight.
You say the ribs "will be capped with ½” sheeting". Might be a little overkill.......unless you mean the cap strips are ½inch wide by 1/16" thick. Even then, ½" is about double the width I would use. Perhaps a typo maybe.
What are you using for power in the model?
Will continue to follow with interest.
Allen
Teals1 is offline Find More Posts by Teals1
Reply With Quote
Old Mar 13, 2013, 03:29 AM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
Joined Sep 2007
4,424 Posts
Subscribed and watching with interest. I've added a link to your build log to the build off thread post #1
Sundancer is offline Find More Posts by Sundancer
RCG Plus Member
Old Mar 13, 2013, 04:04 AM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Quote:
Originally Posted by Teals1 View Post
Hi, The Debutante is a model with very nice appealing lines and scaled up to 80inches will just make it that much nicer! You have got off to a good start. The 3 piece wing is a good idea for a model of this size - what are you using to hold the wings in place on the carbon rods? - ie: to stop them sliding out in flight.
You say the ribs "will be capped with ½” sheeting". Might be a little overkill.......unless you mean the cap strips are ½inch wide by 1/16" thick. Even then, ½" is about double the width I would use. Perhaps a typo maybe.
What are you using for power in the model?
Will continue to follow with interest.
Allen
teals1,
thanks for comments.

1/16" capping off course - I would hate trying to bend 1/2" sheeting round the ribs.
I dont normally cap but I am hoping to cover with doped tissue over mylar again and as the shrinkage on the 60" model ribs has over time introduced some wonderfully wavy ribs ( balsa too soft ) I am playing safe by capping.

If you saw the effort to pull off the wings on some of my other models with same carbon rod / balsa tubing, you wouldn't need to ask that question. Tight fitting blocking around the rods which have been grooved around the rods followed by - before putting on the last side web - a little thin cyano down the grooves - raises grain slightly and hardens the groove to minimise wear. After sufficient time for this cyano to dry, work the rods back in and make sure not too tight - ie you can get them back out -( or too slack - more cyano ) and then glue final web in place. However as a precaution - belt and braces - I will put a piano wire hook on each wing between main spars and L/Edge which will be rubberbanded thru tube in centre section.

Re power, the model will be lighter if fitted with a 400/600 Watt motor and 2300 / 3000 3 cell lipo ( and finished withe tissue/mylar and minimum of dope) than fitting with a 50 size 4 stroke and fuel tank and the necessary fuel proofing BUT I do like the sound of an idling 4 stroke in a vintage model puttering around so I will be leaving provision at front end for both until I see where the weight is heading then I will come off the fence and make a DECISION. ( life gets onerous when you are over 21 )

Target weight is under 5 lbs.

John
John38 is offline Find More Posts by John38
Reply With Quote
Old Mar 15, 2013, 07:16 PM
Registered User
United States, NY, Ithaca
Joined Sep 2007
874 Posts
If you want a four stroke but you're concerned about weight, a Saito 40a would power it just fine. Weighs less than 11 oz. Use a 4 oz tank and a 12x4 prop. Wonderful engine.
buzzard bait is online now Find More Posts by buzzard bait
Reply With Quote
Old Mar 16, 2013, 09:49 AM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Quote:
Originally Posted by buzzard bait View Post
If you want a four stroke but you're concerned about weight, a Saito 40a would power it just fine. Weighs less than 11 oz. Use a 4 oz tank and a 12x4 prop. Wonderful engine.
Hi BB,
unfortunately my saito 40 is hauling my 72" span Mamselle around the sky and its not ready for pensioning off yet.
Checked my Saito 40's weight on the Saito spec sheet and it comes out at 14 oz which with 6 or 8 oz tank puts it over 20 ozs not counting the extra construction weight and the need to fuel proof.
I am not short of 4 strokes - 2 magnum 52's, a saito 56 ( all 3 new ) and an old laser 60 run by someone once and then put on the shelf to glue up , and a nice and quiet LA40 2 stroke but all of these heavier than my Scorpion 400/600 Watt motor with a 3000 2S/3S lipo, no fuel proofing and simpler construction around the power bay.

So, I am spoilt for choice but it will still come down to whether I want really quiet and convenience of electric or the magic of an idling engine puttering around in a big vintage model and like all good procrastinators, I will leave the decision till the last possible moment.

john
John38 is offline Find More Posts by John38
Reply With Quote
Old Mar 16, 2013, 06:21 PM
Registered User
Teals1's Avatar
New Zealand, Auckland, Papakura
Joined Nov 2006
362 Posts
Debutante

I have hesitated a couple of times to respond here but I would think that electric would suit this light weight model better. This is coming from someone who only has 'wet' motors in his models! However, I have the plan, all the wood and necessary electrics for a battery powered scratch built model! Poised ready for action.

It basically comes down to two things: 1. Personal preference and 2. field location and noise restrictions. That said, I have to agree that the sound of a four stroke purring along is wonderful.

John, I am looking forward to seeing more of the build as it takes place. No pressure, this is a hobby after all! Enjoy the build.
Allen
Teals1 is offline Find More Posts by Teals1
Reply With Quote
Old Mar 17, 2013, 03:37 AM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Allen,
thanks for comments - its nice to know I am not alone in the dilemma of wet vs dry. Electric and light would be nice but our weather here tends to be windy and we all generally fly daytime when wind at its greatest - sod's law prevails as usual
no pressure applied - restarted last night and other wing 1/2 coming along
john
John38 is offline Find More Posts by John38
Reply With Quote
Old Mar 17, 2013, 04:33 AM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
Joined Sep 2007
4,424 Posts
Quote:
Originally Posted by John38 View Post
Allen,
thanks for comments - its nice to know I am not alone in the dilemma of wet vs dry. Electric and light would be nice but our weather here tends to be windy and we all generally fly daytime when wind at its greatest - sod's law prevails as usual
no pressure applied - restarted last night and other wing 1/2 coming along
john
I have to declare an interest since, for many years now, I have only flown electric - yes, yes, I know that many think electric power lacks "soul" as compared with IC, but it wins hands down on sheer practicality now. These days I don't see wind as an issue in choosing - you can have as much power (and weight) as you want with an electric set-up now - after all the top F3A aerobats are now often electric, and I see that even for control-line stunt is is now the top choice. For a model like the Debuntante a moderate power electric set up will make it just as flyable in windy conditions as a four stroke. It will also be a lot more pleasant to operate when a cold wind is nipping your fingers, especially as there is no congealed oily gloop to clean off at the end of the session! Anyway, however it is powered I am looking forward to seeing the model John.
Sundancer is offline Find More Posts by Sundancer
RCG Plus Member
Old Mar 18, 2013, 02:45 PM
Registered User
United Kingdom, England, Hampshire
Joined Jan 2010
44 Posts
John
What ever you decide for power I'm sure it will be brilliant.
But I hope its a four stroke.
MICK
micksem is offline Find More Posts by micksem
Reply With Quote
Old Mar 18, 2013, 04:51 PM
Registered User
Canada, ON, Hamilton
Joined Oct 2005
2,451 Posts
Nice looking model John. I really like your plan for the three piece wing. I too am/was undecided what to power my Lancer with. I was going to use an OS .26 FS, but have since changed my mind until I get a few flights in with electric. If it flies well, I’ll paint the trim and then maybe go wet. And I’ll be trying mylar or Doculam on a future model. Watching with interest; looking forward to your maiden flight.
John
JohnAV8R is offline Find More Posts by JohnAV8R
Reply With Quote
Old Mar 23, 2013, 04:58 AM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Slow progress on wing. Photos show the detail around the centre section with the ¼” and 1/8” carbon rods extending into the wing halves. Webbing completed on one wing but still to complete on other as I overdid the cyano hardening of the grooved blocking and the wing rods are VERY tight. Gradually easing them with 1/8th round diamond file and working the rod in the tube. Once that’s completed I will leave capping on top of ribs for a fill-in job while I move onto fuselage next. Wing sheeting on centre section needs to wait till the fuselage basic structure done so that I can rig the front dowels and the rear nylon bolts for the wing mounting. Once that is done I can then finish sheeting wing ( centre section and first 2 bays of wing halves ) and sand the lot – outside if nice to keep dust down

For those interested, the wing build sequence is as follows

1 – Notch Trailing Edge for ribs then pin down to plan with the front of the T/E packed up 1/32 ( for my size model) to line up with the undercamber of the wing section. When pinning down, the centre section was also located in place to ensure that all the spars, L/E and T/E all lined up.

2 - The front bottom mainspar was also packed up 1/32 as I had moved the spar back to be nearer CG and lifting forces

3 – All ribs then cyano’ed in with exception of root rib which is glued in at correct angle when the wing half and the centre section are lined up and the dihedral set. All the ribs are packed up 1/32 at rear to line up with T/E. Extra ribs added to bring the spacing down from 4" to 2.5”

4 – 2 top spars cyano’ed in - for the 80” span I added 2 top spars located above the bottom spars. These will be below wing covering as capping will go over them.

5 – Leading edge cyano’ed in

6 – wing lifted off and the rear spar dropped in and cyano’ed in place.

7 – with the centre section weighted down, the wing half was offered up to it with the wing tip raised to dihedral height. All the spars etc were then trimmed to the angle to get them all touching the centre section. The root rib was then glued in place on the wing half.

8 – The carbon rods were then pushed thru the centre section to press and mark the root rib where to cut the holes in the root ribs. Once cut, the rods are then pushed further into the wing to mark where to cut the holes in the 2nd rib. !/4 rod goes into 2 bays and 1/8 into 1 bay

9 – The ¼” sheeting is then cut to the shape needed to form the tubes for the rods. The rod seating on the edge of ¼ sheeting is grooved using a round file. It is essential to ensure a good fit here as the flying loads are carried from the spars thru the sheet onto the carbon rods. To toughen the surface of these grooves once a good fit is achieved ( not too tight and definitely not slack ) I put a little cyano along the grooves. The rods are then reworked in to ensure a good fit with the hardened surface ( I overdid the cyano – working in my shadow – must move my lights ). Once happy with “tubes” fit, then glue in the VERY NECESSARY vertical webs each side to complete the box structure. I used 1/8 hard balsa and thick cyano – with the rods removed off course. The sketch of the rod/tube cross section shown above illustrates the construction.

10 – sheeting capping and sanding follow as normal.
John38 is offline Find More Posts by John38
Reply With Quote
Old Mar 23, 2013, 08:05 AM
I like real wooden aeroplanes!
Sundancer's Avatar
South-west France
Joined Sep 2007
4,424 Posts
Nice carpentry John.
Sundancer is offline Find More Posts by Sundancer
RCG Plus Member
Old Mar 29, 2013, 04:44 AM
Registered User
Southampton, UK
Joined May 2007
759 Posts
Managed to get started on the fuselage this week and got the 2 sides built. Photo shows completion of the 2nd side on top of the first - seperated by clear plastic of course.

Balsa 3/8" sq longerons and spacers used. Original 40” sized Debutante wood was 3/16 sq and I used ¼ sq on the 60” version. 5/16 sq would have been a better size but that’s non standard and I had some 3/8 needing used. It’s a lot easier to work with as you can put much more pressure on the joints as the cyano ( medium ) cures but its essential to precurve the bottom longerons first otherwise the top straight longerons get pulled down.

To get a feel for the size of the model, the two 1/8 lite ply formers (F2 and F4 ) were dry fitted and then the wings were placed on the top – not a lot of room left on my bench.

Fuselage is 58” long, so longerons had to be lengthened using scarf jointing and short reinforcement over the joint – you can just make out the joints in the pic with the wings. The joints staggered between top and bottom longeron.
John38 is offline Find More Posts by John38
Reply With Quote
Old Mar 29, 2013, 06:09 AM
Registered User
Belgium, Walloon Region, Arrondissement of Mons
Joined Feb 2013
88 Posts
Very nice project.
Ptilou is offline Find More Posts by Ptilou
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Vic Smeed "Mams'elle" -- Britplan Build Off, January 2013 to June 2013 cpmcgraw Vintage & Old-Timer Designs 118 Jun 26, 2013 01:31 AM
Build Log Vic Smeeds Debutante scaled to 60 in span with mods John38 Vintage & Old-Timer Designs 58 May 14, 2013 11:03 AM
Build Log "Britplan" build-log Mams´elle Vic Smeed colibriguitars Vintage & Old-Timer Designs 88 Apr 14, 2013 05:19 PM