build DB Mighty Barnstormer

[EarlyBird]

Cap strips on, top and bottom.

 

Next will be the wing tips. 

This could be more fun because I am not a fan of block balsa wood, the idea is to sheet the tips. We will see 🙄

[Ron Gray]

15 minutes ago, EarlyBird said:

I am not a fan of block balsa wood

Interesting 

[EarlyBird]

After a long day here we have it. 

The easy bit first the trailing edge 

Followed by the hard part the leading edge 

And all-in-one our top view of the tip.

Unfortunately the bottom is not complete. 

Oh dear the sheet looks to be a bit short. No problem I will sort that out tomorrow it's been a long day so it's bedtime for me. And so to bed said Zebedee. A bit of The magic roundabout just for the younger ones who do not understand.

 

Steve

 

[EarlyBird]

Not brilliant but it will do as it is only the bottom.

The top. 

I was going to sheet the whole of the tip I am now having second thoughts as I could just apply cap strips. I do like a challenge though I will see tomorrow.

[John Rickett 102]

Steve, Did you wet the sheeting at the tip before applying, it will bend easier when wet though will take longer before the pins or clamps can be removed. The same goes for the whole of the leading edge sheeting, wet one side and you'll quickly see the curve that the wood adopts, this then helps relieve any stresses that would arise when pinning into position.   

There is little point in sheeting the whole tip, it may offer a bit more ding protection but that's about all. You could perhaps add an intermediate fillet to prevent the covering sagging between the bays. As it is, it will be adequate for the job its got to do.

When covering, cover the bottom of the wing first and finish the covering onto the top side of the tip (1/2" will be more than enough) the top covering can then be carried round the curve and attached to the bottom covering....you had pre-planned this already I imagine.     

[EarlyBird]

Thanks John, but I had already started so I had to finish. 

 

I am now looking at the top and wondering again whether to cover it or not as I am not too pleased with the outcome of the tip. I think there is two much of a curve on the edge which is caused a slight depression towards the front. 

 

 

I'm now considering all of the options to make this look right 

 

Steve

[EarlyBird]

On 09/11/2024 at 06:59, John Rickett 102 said:

Steve, Did you wet the sheeting at the tip before applying, it will bend easier when wet though will take longer before the pins or clamps can be removed. The same goes for the whole of the leading edge sheeting, wet one side and you'll quickly see the curve that the wood adopts, this then helps relieve any stresses that would arise when pinning into position.   

There is little point in sheeting the whole tip, it may offer a bit more ding protection but that's about all. You could perhaps add an intermediate fillet to prevent the covering sagging between the bays. As it is, it will be adequate for the job its got to do.

When covering, cover the bottom of the wing first and finish the covering onto the top side of the tip (1/2" will be more than enough) the top covering can then be carried round the curve and attached to the bottom covering....you had pre-planned this already I imagine.     

That's a very good description of how to form and cover a wing the only thing I would add is for the tip which is glued and clamped at the leading edge first then along the edge towards the spar. Last is the spar which is covered by the sheeting and gradually forms a curve which when dried can be cut to a straight line with the spar. While sitting here looking at the wingtip I notice the line I should have used was already drawn, now that is annoying.

My thinking is that I should remove the sheeting and cut to that line. 

 

Steve

[EarlyBird]

Offending wood removed. 

And glued pinned and weighted down. 

It's a case of wait and see.

 

Steve

[EarlyBird]

Much later 

That looks better, trust me. 

 

Steve

[EarlyBird]

With the extra supports in place I am now ready to fit the wing tip sheeting.

 

Steve

[EarlyBird]

Waiting to dry. 

 

Steve

[Ron Gray]

That’s better Steve

[EarlyBird]

And with the clamps off and with a bit of sanding even better but not perfect 

A bit more tidy up to do but for the time being I will put this to one side and start the second Wing or is that the second half of the wing?

 

Steve

[EarlyBird]

Start by shaping the bottom spar.

To fit 

Dry fit everything to check all is okay.

Clearly not as the ribs do not sit on the spars and trailing edge sheet, I will investigate, back later. 

 

Steve

[EarlyBird]

I've added 1/16 packer in front of the 1/32nd.

 

With another dry fit I feel confident this will work so the first rib is glued in place with a help of the bit of weight 

 

Just waiting for the glue to dry again 

 

Steve

[EarlyBird]

First rib glued and shear web used to brace ready for more ribs to be added. 

I use pegs and spar pieces to hold the shear web in place 

 

Steve

[EarlyBird]

The tip shear web is glued in place to brace for the additional ribs. Then the new rib is dry fitted and marked up.

Glue is applied to the rib and set to one side 

Then glue the web and push into place and do the same for the rib. Check the straightness and for vertical at each stage finally add the weight to keep it in place. 

Now pull up the leading edge sheet and use the profile I made earlier. 

This is the method I used on the first Wing, this is my first time at doing it this way. 

 

Steve

[EarlyBird]

All of the 1/8 ribs are now glued in place this just leaves the three 16th ribs which need some special attention I'm going to start with the tip rib which will be different to the first Wing as I will be adding the sheet framework before glued in place. All will become obvious tomorrow I hope. 

 

 

Steve

[EarlyBird]

Wingtip fabricated and glued in place.

 

The last two ribs glued in place after cutting the slots for the braces. 

 

I have been trial fitting the wings together and I was wondering when is the best time to join both wings as I could do it now any ideas?

 

Steve

[john stones 1 - Moderator]

When you  need them to progress Steve, gluing the tail end on and aligning, or work on struts, till then no rush.

[EarlyBird]

I have dry fitted the two wings together to measure the spars. This highlights the issue I have with joining the two wings together.

 

 

My room is not big enough 🤣😭 so it looks like I will have to work by dry fitting I'm taking it apart before bedtime or I will be walking into it in the night. 

 

Steve

[kc]

It might have been easier to have left the wing tips till later as it would be a bit shorter! Too late now.

 

I suppose join it in the garage if you have one but note that it will be too cold there for PVA for the next few months in UK. 

 

Before you join the wings measure your car to ensure it will go in!   It's not too late to turn it in to a two piece wing............

[EarlyBird]

Thanks guys, 

I have decided to keep the two wings separate for as long as possible because this wing is big and will cause handling problems once joined so I have continued on the wing by installing the spars and the root rib after dry fitting this first Wing. The top spars are not glued to the root rib this will allow some flexibility when gluing together the wings. 

 

 

The next job is to dry fit again so that I can line up the top sheets and mark their positions with straight edges.

 

Steve

 

[Ron Gray]

Even if you have not glued the spars, won’t the D box sheeting lock the root rib in place?

Edited November 21 by Ron Gray

[EarlyBird]

On 18/11/2024 at 16:35, kc said:

It's not too late to turn it in to a two piece wing............

This has made me think I think a change of plan is called for. I had planned on a single piece wing as transport is not a problem I was just concentrating on reducing the amount of work needed at the flying field. It has now become obvious that a single piece Wing is huge and there will be a lot of damage caused in the workshop and hangar. I am now exploring the way to make this a two-piece wing.

 

Steve