DB Spitfire Build

I just started sheeting the bottom wing today . I have added an access bay where the aileron servo lead joins the extension as the routing is a bit convoluted and I didn’t want to install a paper tube lead tube . The retract bay cutting will be started once the glue has set and before the next sheets are added.

I will later on glass the inside surface of the upper sheeting in the split flap bay with thin matting to add rigidity as suggested in the instructions. I also plan to glass the wings on this model .

The top and bottom of the wing are now both sheeted . Next task is fitting the flaps . Then it’s on to repeating if all again for the second wing as I don’t have space to build two wings at a time.

One slightly frustrating thing is that I can’t really test the retracts yet. I would like to do it to test the angles and wheel well depth etc. The barbed air fittings the flaps came with are designed for a single fitting and did not include quick release “bayonet connections”. If I am to fit and test them I will probably need extra tubing plus quick release fittings etc . As I’m new to air retracts I didn’t have any spares. These fittings will be necessary on the finished model too unless I want to keep the wings on permanently ! The standard barbed connectors I don’t think would appreciate being connected and disconnected repeatedly.

Flap installation is slightly complicated but I have spent a few hours thinking about the installation. The flexible flap tube is held to the wing by “plastic coated electrical wire” and diagonal holes are drilled in the rib to accommodate this. I don’t like the sound of that and will probably make a small and narrow aluminium saddle clamp instead. I’m also using some plastic tubing to act as a bearing where the torque rod runs through the rib into the small flap dowel. As the instructions say the flap area will certainly need some reinforcement.

Edited By Tim Flyer on 13/01/2021 18:35:09

typo in my previous post should read.....The barbed air fittings the “RETRACTS “came with ar

On the bench i use a syringe with some pipe on it to kick the locks out on air retracts. I can then move them by hand and use the syringe to kick the locks back in when i get sick of them flapping about. Poking them with a screwdriver can work, but you can end up scratching things up so using the syringe to give enough pressure to move the locks is a better bet.

Beyond that, i always try and mount my air tank and all the other retracts gubbins in/on the wing as it means i can work on the retracts without the fuselage falling all over the work bench. With the whole lot contained within the wing its so much easier to deal with and saves a pointless connection (aka, point of failure) to the fuselage.

Thanks very much Jon for you’d good advice . As I mentioned these are my first air retracts so it’s a learning experience. Sounds a very good idea keeping them connected. My split wing might complicate it a bit...

Nah, just keep the air tank, filling valve and selector valve in one wing and have two disconnects for the lonely retract in the other wing. Alternatively, have them plumbed together but with sufficient length of spare tube to one side to allow the wing to come apart. You can then fold the wings like a book and store them as one lump but with everything still connected.

Thanks Jon👍

Good work Tim

Were there any problems with the washout by following the instructions as Jon said there could be? I forgot to ask you last time i was on here, what was the waiting time from ordering to getting the Unitracts ?

Dave

Thanks Dave . The honest answer regarding washout is that I don’t know if there will be a difference as I haven’t started the second wing yet. My first wing seems ok and I did my best to follow instructions.
I guess the big problem comes if the two wings don’t match properly . The leading edge and tip sanding etc is done later on and then I will be able to properly compare the two wings .

i glued in the little flap torque rod today . I decided to “bush” the hole where the wire goes through the spar with a short piece of plastic tube and hardened the area with thin cyano. As I have used standard ailerons I have a bit of plastic tube spare .

Edited By Tim Flyer on 14/01/2021 10:32:03

Hi, Tim, I have just started mine its an earlier foam wing version I have the tail done and just started joining the fuz parts

Hi Rusty good to hear from you and I look forward to comparing notes. I think there are a few pictures on the web of the foam wing version build.

Today I continued with the split flaps. I glued the ribs onto the dowel with cyano. I used aliphatic Tite bond to glue the flap sheeting down as I was a bit concerned about accidentally spilling cyano on the wrong part and ending up with “stuck” rather than split flaps 😊. Just waiting for glue to set then I can carry on . I’m still thinking about solution to tie down the flexible flap joiner . As mentioned earlier DB suggest plastic coated electrical wire. I had thought of making a miniature saddle clamp from tin plate using very small screws to secure it ...but I haven’t decided yet .

Tim, that little inboard flap section needs a bend on it. The underside of the spit wing has quite a gull wing sweep to it and you will need to replicate that for the flap to line up. See photo

Its not explained very well in the plan and i think you should add a little spar ahead of the flap leading edge to support this gull wing shape

Edited By Jon - Laser Engines on 15/01/2021 12:35:28

Thanks Jon . That first photo was with just one of the small flap ribs in . I have now added the others and clamped it to form a bend . As you said I think it might need an additional spa in front of the small flap in order to match the lower sheeting .

The plan doesn’t mention the bend at all in the small flap so lucky you mentioned it 👍

My photo has gone for some reason. Anyone know why?

Anyway, the inboard end of the inner flap needs to bend upwards. Dry fit some of the inboard sheeting and you will see what i mean.

This is another photo