bracesport DLG

[bracesport]

I tossed the ailerons away (easy to make new ones) and started stripping the foam wings - the Adams board is not so friendly for paper removal so I tried both the dampened cloth and then some denatured alcohol on the old ailerons, but it did not really do the trick - in the end, I managed to peel the paper off making sure to lift and peel evenly - in some places I needed to cut through the paper to make strips about 4cm wide which peeled easier - phew!

@flyboa 's fuse/tail is about 70g all-up-weight so the to go under 200g (maybe 180g) my wing needs to be around 100g - so far the weight drop is almost half and I plan to thin the foil section to 5-6% so the weight will drop a bit further before I re-skin the surface (adding weight)!

 

[bracesport]

the new fuse is taking shape too - AUW of fuse/tail assy is 45g.

 

[bracesport]

The radio gear I had in the previous model was 50g so that is going to have to be slimmed down!

I can strip the servo shells - shorten and hard wire the servo leads - the G-RX8 is excessive in function but it is small and light - I do have some RX6's on order, but who knows where they are with the Coronavirus, shipping, and lockdown - I see the G-RX8 can handle 10v so I wonder what will happen to the servos on 7.4v without a BEC - plenty to think about!

I think I need to target 30g for the gear!

 

[bracesport]

Ok, lets set some challenging targets - WIng 100g, Fuse45g, Gear30, CG (nose weight) 20g would give me 195g AUW - the Snipe II weighs 220g.

 

[Mr.Grinch]

The radio gear I had in the previous model was 50g so that is going to have to be slimmed down!

I can strip the servo shells - shorten and hard wire the servo leads - the G-RX8 is excessive in function but it is small and light - I do have some RX6's on order, but who knows where they are with the Coronavirus, shipping, and lockdown - I see the G-RX8 can handle 10v so I wonder what will happen to the servos on 7.4v without a BEC - plenty to think about!

I think I need to target 30g for the gear!

View attachment 165780

It seems a little funny to say it, but aren’t those servos a bit bigger than you need? Or do you need the torque? I just ordered some 3.7g servos...maybe they won’t work for this type of project?

 

[vastsky]

I tossed the ailerons away (easy to make new ones) and started stripping the foam wings - the Adams board is not so friendly for paper removal so I tried both the dampened cloth and then some denatured alcohol on the old ailerons, but it did not really do the trick - in the end, I managed to peel the paper off making sure to lift and peel evenly - in some places I needed to cut through the paper to make strips about 4cm wide which peeled easier - phew!

@flyboa 's fuse/tail is about 70g all-up-weight so the to go under 200g (maybe 180g) my wing needs to be around 100g - so far the weight drop is almost half and I plan to thin the foil section to 5-6% so the weight will drop a bit further before I re-skin the surface (adding weight)!

View attachment 165773 View attachment 165774 View attachment 165775

A dowel can help to peel paper off of DTFB.

Magnificent development work Mr. Bracesport!!!

 

[bracesport]

I am just using what I have!

It seems a little funny to say it, but aren’t those servos a bit bigger than you need? Or do you need the torque? I just ordered some 3.7g servos...maybe they won’t work for this type of project?

 

[bracesport]

Thankyou!

A dowel can help to peel paper off of DTFB.

Magnificent development work Mr. Bracesport!!!

 

[Wildthing]

I am just using what I have!

Do you not try to roll it off? Anything round can be used

 

[bracesport]

the Adams board varies in peel-ability - perseverance is the key!

 

[Wildthing]

the Adams board varies in peel-ability - perseverance is the key!

The stuff I picked up at Staples once is horrible to peel.

 

[bracesport]

it is a case of pick pick pick!

 

[bracesport]

Alls well that ends well

I managed to take the tape and paper off the second wing blank quite easily - thankfully - you can see a dirty LE which is a light coat of epoxy I put on previously to stiffen/strengthen the LE.

Next step will be to check the foil as this was one of my earlier wings it is a bit chubby through the middle - I will use DTFB for the ailerons and once de-papered is only 5mm at best, so there will most likely be some thinning toward the TE as well!

Once I have done that I will weigh the foam and include some 3x1 CF spars if the weight allows me - remember I am targeting sub 100g covered with paper (something light like a tissue rather than newsprint)?!

When I deconstructed the wing, I chopped out a bit of the wing root, so I will probably be in the 1.3m - 1.4m range.

 

[bracesport]

Starting to pick this one up again - this morning I re-blanked the ailerons and marked up the old wing to sand a bit thinner!

 

[Wildthing]

Starting to pick this one up again - this morning I re-blanked the ailerons and marked up the old wing to sand a bit thinner!

View attachment 172930 View attachment 172931

That reminds me, I should actually try mine

 

[bracesport]

@Wildthing - yes you should!

 

[rfd]

i'm having lots of fun testing out DTFB DLG components. this (the foam and the DLG) is all new to me - i'm an old school balsa scratch builder for the most part. currently sorting it all out to build a 1m DLG and eventually a 1.5m.

my DTFB wing build testing has shown that, like flyboa, outer paper skin covering affords good wing stiffness whilst keeping the build as simple as possible. packing tape does nothing for adding stiffness, but will water resist the paper. how best to build a strong but light wing will probably come down to personal taste in the build process. one does need to achieve a decent airfoil that's at least fairly consistently repeatable. at least for me, folding is out and two layer gluing ala flyboa is the way to go. this allows for interesting and perhaps more efficient wing design planforms.

a test wing ...

since my main interests in r/c aircraft is RES 2m to 2.5m sailors, i have no need for flaps/ailerons and only use RE tailfeathers. being new to DLG has me experimenting with control methods and a recent test with pull-spring has me going in that direction, with the spectra line running inside the CF boom. i drill 1/32" line guide holes in the boom, then expand them with 1/16" driil, angling the bit in the direction of the line exit. a drop of water thin CA seals the edges of the holes. the rudder line is easy to install because it'll exit the boom rear. the trick for the elevator hole is to use a piece of .018 to .025 or so music wire (guitar string) with a 1/2" angle at one end that goes into the servo side of the boom hole and pushed to where the angled end peeks at the elevator hole end of the boom. usually the wire pushes right out, but if not, a neodymium magnet coaxes the wire end out. the angle is snipped off and the spectra line is CA'd to the wire, pulled through. easy peasy.

notice the use of dubro mini ez servo arm connectors that will allow infinite pull-spring string adjustment ..

paper is easily peeled off DTFB by using naphtha (lighter fluid) liberally wetted over the paper, lightly rubbed in with a small piece of paper towel, tease off one end of the paper and you'll be amazed at how easily it just peels right off.

cheers and happy landings!

r.

 

[bracesport]

@rfd - I have built all kinds of wings and the tape was a waterproofing given out moist environment in NZ - I have only built a couple of DLGs and I love the thrill of the launch.

 

[rfd]

i have the same moist air issues here in the nor'east USA. still working out the kinks of a DTFB wing design for 1m and 1.5m, and how best to waterproof the paper.

 

[flyboa]

Flite test sells water resistant foam board. Might be a better option then trying to coat it yourself.