Topic: 1/4 scale SE5a

Just looking at these photos again Shaun.   

I think I'd be tempted to make the shear webbing  extended along the full span of the wings betwen the top and bottom spares (or maybe go for diagonal braces in Warren girder style).   Not much weight but a huge increase in rigidity and strength.

Just an idea ......

Alan

Alan I was thinking the same but when the wings were on and rigging temp fitted it was very solid and if you look back at the pup which is a similar size that has no extra webbing etc so will go as is I think.

I made up from a bit of 2" X 2" the cabane fairings yesterday, slotted them to go over the wire on the circular saw and rebated for the wire bindings.  This job has been plaguing me for ages and had a right bee in my bonnet about doing it but when I actually got down to it I enjoyed it.  The epoxy has now dried and 2 more rigging points have been made up and fitted on the hoop/bulkhead? at the front cabane position (no picture of them).



I got an email from the chap that I bought the clevises from, I explained I had to tap out all but 1 and he gave me a 100% refund!  I didn't ask for or expect one, what a fine Ebayer and chap he was  

Can you not get a prop and RPM reading from the Honda? When compared to a 38 for example, you can see where she comes 

Mat 

There are some figures on page 6) of the HONDA thread I did.  I have to at least try it, if it will lift off I'm sure I can either drop it straight back to the ground in a straight line or do a circuit 1st, I flew my older one (lighter) with a 22cc Zenoah with booga all revs throwing a 20" X 10" Master nylon, it was hanging on it's tail but still managed to do a circuit and land safe on a small marshland strip.

To change it out for a G38 would mean little work maybe just a 2" box bolting to F1 to bring the engine forward and a DFA on the throttle link.

Right, just been looking at the hinge and chamfer on the ailerons.  As this is not really plan or kit built and going from the pictures I have seen I think hinge line 1/3rd down from top would be about right.  Normally they are hinged from the centre but as the section is not scale and thicker and having differential I think 1/3rd down would look better as it would have less of a V gap showing from above where it will be seen closer, cant see that much in the air can ya (luckily).

What's the general consensus?

I have glued on the chair leg beech servo fixing bits and screwed in the aileron servos + done the horn clearance slots.  As the aileron horn is in a different place they now exit the servo mount ply right on the edge.  I glued in the aileron horns............ oops, still gotta do that chamfer so made my life harder as they will be in the way a bit 

1/3 the way down seems like the best option. The full size had quite close fitting thin shrouds over the aileron gap so I reckon the way you planned will look great.

Tidy modelling mate

Ian.

That's settled then, this is after all a stand right off scale toy so 1/3rd down it is.  I had thought about that shroud and maybe doing it from litho but with my sausage fingers and poor storage they would get bent up quick smart 
Ref rib stitching you mentioned in tother thread Ian "hot iron in three passes. First down the side of the rib to stick the first 1/3 down, then down the rib itself, following immediately with a cloth to push the tex down and take the heat away, then a final pass down the last edge of the tape. "

I tried it like that on my pup but failed    The SE5a wont even have rib cappings just sticking with the 2mm lite ply ribs and i think just a rib tape 1/4" wide............ better than nothing 
If I put capps on now the leading edge will need removing and replacing as it's already roughed out to profile.  I have several bits that needed more thought before putting knife to tree but then I would never build anything so this will never be a great design or build but hopefully will be light and fly well............... I'm looking for grin factor and my ole pup "Betty" does that for me and she is as rough as guts 

NFG

  on the subject of rib stitching, i to tried Ian's method, and have the same problem as your good self sausages for fingers and i cant make it work, so i do mine a differant way, if you don't mind a long explanation, first decide on your stitch spacing, (i have a web site saved on my school computer that gives all stitch spacing from pre WW1 to present day) any hoo, when you have decided cut a nice piece of 15 mm thick MDF a couple of inches wider than your wing chord, draw on lines at stitch space and knock panel pins into each end of the line then cut yourself a piece of solar Tex to cover all the area twixt pins and length, sticky side up, enough to cut as many strips about 5mm wide for 1/3, 3mm for 1/4. then wind some suitable thread around the pins to make parallel lines of thread, make sure it is pressed against TeX, a quick coat of balsa lock/cover grip over thread to stick it to Tex, when dry you can cut nice neat lengths of Tex with stitching attached either with a scalpel and steel rule or a nice cheap roller guillotine from staples (for cutting paper) to put it on, gently attach on end to front of rib then at the back (if you mark a fine pencil line along your wing where you want the first stitch to be you can get them all in line) then do the iron and cloth bit along the tape, hey presto rib stitches follow it with the correct width of rib tape again with the iron and cloth bit, its much easier / quicker to do than explain, i will take pics of mine tommorrow, i have them ready made in 1/5 1/4 and of course 1/3 scale. sorry for the epic.

  Chris

I think I will be doing a few test pieces to see how I get on with this stitching and try both glue lines and thread methods.

Quick question, the wing centre section is held to the cabanes via 8 X 2mm bolts (2 on each strut) and considering they are in sheering plane I think they will be strong enough but need to know soonish as I will be putting a piece of cereal box over the top shortly which will make it impossible to drill out for larger bolts later.

I have also put some triangular pieces of 3mm ply against the spars as a justin.  Justin case the rigging doesn't stop the wings sliding outward on their carbon rods.  I have cut some pieces of good ole 1mm galv steel 1/4" X 15/16" that will have a screw in each end to straddle wing sections and stop sliding.

just for your interest

  rib stiching Product and Services

  chris

Thanks for that CJ 

I been weighing up the 8 X 2mm bolts and I think they are stronger than the 6 plastic saddle clamps that hold the bottom of the wires to the fuselage so will stick with 2mm.
I can just about get a screwdriver through the lightning holes in the end ribs to tighten up the bolts so will solder the 4 of the nuts to the steelwork and epoxy on the other 4 to the woodwork where I wont be able to get to when all covering is on.

I been looking at the full size pictures again and see that the top centre section of the SE5a appears to be ply covered with ali on the front edge so I have glued on a Cheerios packet to the top, not done the leading edge yet as the packet was not big enough but will this afternoon then cover the front bit up to the main spar with litho.

Also added some 1/32" ply 3/4" wide to the root rib as per full size (well looks like it to me anyway  )

Looking great Shaun, but ........

Those thin spares still don't pass the George Stephenson test for me.   
I know the wing bracing is functional etc etc and hope it will be OK  but for me, ships and ha'peths of tar spring to mind  
Sorry to nag, but the question I would ask is why wouldn't you put shear webs in?

Worried of Bedfordshire

Looking great Shaun, but ........

Those thin spares still don't pass the George Stephenson test for me.   

Thems cut from a nice piece of 2" X 2" tree wood and are stiffer than the 1/4" X 1/4" balsa main spars.  It's one of the things I did coy from the DB plan so theoretically should be fit for purpose.

I pooped right up yesterday, epoxied nuts to the top centre wing section and soldered others to the rear cabanes............. should have been tother way round  Unsoldered and yanked off glued nuts so back to square one again    Just ordered some alan key cap head bolts of 3mm and a ball end driver as unscrewing the slot head 2mm was almost impossible!

It's a perfect day for flying or building but I got the blues so flying wont happen.......... I hope to get a little building done though.

We're following your excellent build with great interest - WWL jr has just started his 3yr old DB SE5 kit, modifying it to get the Zenoah 38 in.
Picking up some useful hints from your thread along the way
By the way, you can get M2 socket head bolts from Giantcod.

Shaun, a flying buddy of mine is currently building one of these from a set of the original plans, but it has no reference as to where the cg is. Could you have a look on your's and let me know where it is please.

Shaun, a flying buddy of mine is currently building one of these from a set of the original plans, but it has no reference as to where the cg is. Could you have a look on your's and let me know where it is please.

Mine is also based on those same plans so no C of G marked on then either however the DB WEBSITE says C/G 5.5" from top centre section L/E 

I have decided tonight that I will initially maiden using a G38 (Pupcams old bent and straightened one) leaving F1 in it's original position and make a 2" box which will bolt to it bringing it forward enough then the Honda can go back in as and when it flies ok if the G38 appears to have loads of power for the airframe  .

Reason is it's packing on the weight with things like centre section covering, 1/32" ply strips etc on the wings.

Still need to either make of find some small wheels suitable for the fake aileron and elevator closed loop, anyone seen any anywhere like Ebay or anywhere else I cam mail order?

What do they look like Shaun. I used Model railway wheels in the pup wings

Simon

What do they look like Shaun. I used Model railway wheels in the pup wings

Simon

Looking at them I may be as well to make up some ply discs and paint them silver.

Servo discs .
Is what i have used. ( i knew they had a use!)

Bonzey

Servo discs .
Is what i have used. ( i knew they had a use!)

Bonzey

Or bend up a bit of ali?

Perfick!
Make me some 1/3 scale
Bonzey

hi ken

  what dia and do you want them in brass or ally, i,m doing some for my pup now 

  chris

 (MD  CeeJays  scale bits and bobs Inc  offices in staffs,  arizona and peckham )

Do you know what........... now I have been messing about most of the day bending aluminium I don't know if I can be bothered to actually make the other 5 T shaped pivot bits and fit any of them.  Not sure what to fit them to and cant see a nice way to get a dummy wire to go round them from the control surface without a lot of messing about.

Mess about mate, you can't go that far and te=hen only do 1/2 a job, you'll be glad you did when it's finished,

i wish I could make stuff like that 

Shaun, dependant on where they are placed on the wing, would it be possible to retro fit a block of wood, be it balsa or ?? and then screw t piece to it, also thinking about it, what about a very thin piece of piano wire bent to shape, and fitted in to a bit of scrap balsa, attached to ribs or whatever ?

Shaun, dependant on where they are placed on the wing, would it be possible to retro fit a block of wood, be it balsa or ?? and then screw t piece to it, also thinking about it, what about a very thin piece of piano wire bent to shape, and fitted in to a bit of scrap balsa, attached to ribs or whatever ?

Not as bad as I 1st thought, the pulley on the top wing has it's window on the under side so in my opinion no need to fit anything but a little triangular window and on the top a piece of 20swg piano wire vanishing into a 1/16" ply fair-lead.  Bottom wing window is visible from the top but the closed loop would exit on the underside so I can just put a fake piece of rigging wire running span wise round the pulley then rearward.  Elevator ones are not so easy, visible from the top with c/l wire going round the pulley exiting the window and to the elevator horn, may need a little light spring there to keep tension on the wire.

I'm bored stiff with pulleys and would rather be doing something that would move it toward FLYING 

Oh, Mudflap........... ref being able to make things, I would like to bring your attention to a DVI 

So common then, how do you make them 

I see the finished item, but haven't a clue how you'd go about crafting them, unless it was on a lathe   

I should take some pictures as it would be easier.  Anyway, I cut a bit of ali oversize and held it against a bearing with a socket which goes through the hole in the bearing with some clearance, put it in a vice and nip it up which gives it a dent a bit like a waste in a s/s sink.  then I put it flat dent upwards on a bit of steel (the rear of the vice) put the bearing back over it and twot it to make sure it's flat as it can deform a bit.  Then I cut it to a round with my trusty Guilbows snips and file it round after which back on the flat steel and using a piece of tube as a punch twot the middle to get the reverse dent.  Mate 2 back to back with a bit of cyno and job done.

So your basically pressing the ali to shape?



With the odd 'twot' for good measure 

I should take some pictures as it would be easier.  Anyway, I cut a bit of ali oversize and held it against a bearing with a socket which goes through the hole in the bearing with some clearance, put it in a vice and nip it up which gives it a dent a bit like a waste in a s/s sink.  then I put it flat dent upwards on a bit of steel (the rear of the vice) put the bearing back over it and twot it to make sure it's flat as it can deform a bit.  Then I cut it to a round with my trusty Guilbows snips and file it round after which back on the flat steel and using a piece of tube as a punch twot the middle to get the reverse dent.  Mate 2 back to back with a bit of cyno and job done.

Ingenuity that's what I like    Just goes to show there's more than one way to skin a small furry animal.   

Top marks Shaun for a very informative post - a completely different way of making something that you might imagine turning as the only way of doing it.  Just what the foum is all about IMHO.

Alan

hi ken

  what dia and do you want them in brass or ally, i,m doing some for my pup now 

  chris

 (MD  CeeJays  scale bits and bobs Inc  offices in staffs,  arizona and peckham )

Chris, i shall have a measure up matey and let you know.
PS,  I have 4 built wing panels

Bonzey

With the odd 'twot' for good measure 

to go with the odd fool... 

to go with the odd camping stove...  

Lost me on that one  

I did make up pulleys for the top wing as well as bottom and just epoxied them in.



Koverall going on with cellulose gloss clear (dope as far as I can tell  )



Edges stuck down but still unshrunk.



Shrunk and 2 coats of cellulose stuff thinned out 50/50



Still have a window to make up and I forgot the put in a lead for the fake control wire on the top side but will fathom something out later.  This is one occasion where the camera actually make s the work look worse than it is, normally it's flattering!.



Just 3 more to go now 

to go with the odd camping stove... 

ah, the swear filter got to me..

when mudders said.

"With the odd 'twot' for good measure"

should have the reply.....

" to go  with the odd  t w a t ....




"to go

hi ken

  what dia and do you want them in brass or ally, i,m doing some for my pup now 

  chris

 (MD  CeeJays  scale bits and bobs Inc  offices in staffs,  arizona and peckham )

Hi Chris.

6@ 18mm in ally Plz mate.

Bonzey

To prime or not to prime........... that is the question 

I believe when you Dawn Patrol guys have painted WBC on Solatex you put it straight on    so with this in mind should I do the same over the doped Koverall after a very light sand?

I painted straight onto my doped Koverall, with a variety of paints with no issues

The WBC went on fine with no reactions and good coverage

Steve

I have used doped Koverall and found that dark colours cover well, but lighter paints needed a lot more coats,so I put primer on first for the light surfaces. I also used Phil's WBC paints (not forgetting the few drops of "magic").

Hmmmm slight difference of opinion, perhaps try the linen colour on the bottom of the ailerons 1st and see what the cover is like then.

2nd top wing covered now and windows fitted.  They were made from some clear packing, you know the stuff you HAVE to open with scissors heat sealed stuff stuck on with dope then with a bit of solatex round the edge after it had dried.

The light colour I used from WBC was a light blue on the underside of my Albatros, maybe a linen colour would need primer first. I did give it 2 light coats and no problems.

Steve

I had thought about doing the rib stitching as this has evolved from chucking something together for the Honda to using a G38 and adding a few more details than I had intended but the stitching will have to be waved, I just don't have the drive for it so tapes only 

If I had intended making this more detailed then it would be more scale in its outline and would have had cap strips on the ribs as well as tapes and stitches.  More planning needed in future.