Foam board Lancaster build

Welcome back after the festive season break – trust you're all looking forward to a good flying year in 2015 :)
Sorry this is taking as long as it is .... was supposed to be a 'quick & dirty' build - but things got in the way.
Anyway, back on track now I hope .......

Part 7
Finishing off the engine nacelles.

Cut some strips of foam board that are a 'snug' fit into the tops of the engine nacelles. See Pictures23 & 24 for the before-and-after look.
Length is not critical, but make sure its clear of the motor outer as it turns. Glue in place.
Then cut bigger pieces to cap it off. These should be at least bevel edged, and sanded curved if you really want to but once the thing is flying you won't notice the difference.
Glue on top of the nacelle as in Picture 25 , use a good amount of glue to make a strong structure.
Repeat for all four engines. This should give a reasonably strong finish to the engine pods and will handle the engine torque without breaking.

Apart from finishing the wiring that's the wing about done.
On the first one I built, I ran the power and servo wires inside the wing, but it was not that easy and I've elected to cheat a bit on this one.
There's a convenient step on the underside of the wing that is just big enough to hide the wiring.
So it's just possible to come out of the back of each nacelle and along the step to the next nacelle and eventually into the fuselage. I'll post a picture of the finished thing soon.

The PDF in Picture 25 shows a couple of possible ways to wire up 4 motors. There are others I'm sure but to keep things simple I would go for one of these two options.
I did consider using two batteries (one left, one right) but the thought of one running out before the other was too worrying to think about. I might, however, be tempted to run two in parallel just to give a better flight time – 4 motors on a 2200mAH battery does not last long.

If you do go for the two channel approach ( throttle for one side & rudder for the other side with mix) then be careful how you mix them, in my haste to try out the idea I did a 100% mix- big mistake, when coming in to land, on a left hand turn, I needed more power so opened the throttle with full left rudder on and ended up with no power to the left engines & full power to the right ones. It only takes a second for the thing to 'flat spin' into the ground – very,very quickly :-( …. not enough time to realize what was going on and hence good bye to the front end of my first Lanc.

I'm sure extensions leads and 'Y' leads are all available to get the right connections, but its easy for me to do in-line solder joints and heatshrink over them.
Remember that only one of the ESC's should power the receiver, doesn't matter which one, and leave all the other 'Red' wires 'not-connected' as shown in the diagram.

That's all for now, time to start on the fuselage :)

nacelle_top1[23].JPG
nacelle_top2[24].JPG
nacelle_top3[25].JPG
4_engine_wiring[26].jpg
 

ClearSkiesCalmWinds

Active member
Great to hear all is well after the holidays. House has finaly settled down after family tornado (mess). So I'm waiting on some carbon servos from Grayson's Hobby to continue build. Again I'd like to thank you for shareing your build. I would like to finish my Lanc to honor a RAF Group any suggestions.
 
Great to hear all is well after the holidays. House has finaly settled down after family tornado (mess). So I'm waiting on some carbon servos from Grayson's Hobby to continue build. Again I'd like to thank you for shareing your build. I would like to finish my Lanc to honor a RAF Group any suggestions.


I guess the obvious one to copy is the Battle of Britain memorial flight one .....
http://www.raf.mod.uk/bbmf/
 
How do you plan on doing the glass in the nose? it seems like a pretty good area to use a "smart water" bottle.

Hi,
on the first one I built I just made the nose up from foam board 'ribs' and covered with paper & glue. Then drew on the outline of the windows. Not that good close up but fine at a distance.
I'll do the same on this one too.

I used a cut up Cola bottle in the past for my FT Spitfire canopy, works well.
 
Part 8

Finishing off the wings.

Mount the motors to the firewalls and feed the three phase wires through the hole.
I've not bothered with down thrust, but it should be easy to slip some washers between the motor mount and the ply wood at the top if needed ….. I'll try without first, my original build seemed ok with none.

I used Velcro to mount the ESCs. I glued a small square of foam board to the ESC (but not on the flat heatsink side! ) then attached a square of Velcro. Then at convenient places in the engine bays I put the other half of the Velcro.

Cut some access holes in the nacelle formers and in the top surface (but not into the wing) then feed the wires through as in Picture27. They can exit the outer nacelles at the rear end where it tapers to a point then follow the step edge.
You need two power wires and two signal wires from the outer pods to the inner pods.
I happened to have some extra flexible 2mm (14AWG) cable so I used that for the battery power and small (7/0.2) equipment wire for the signals.
You don't really need the red wire from three of the four engines because the receiver will only be powered by one ESC … and it doesn't matter much which one.
Picture 28 shows all the wires laid in and held in place with dabs of hot glue. Use paper and 'white' glue to cover the wires – Picture 29 – and blend in with the wing step.
Also in Picture 29 you can see I've added a block of foam board to the bottom of the wing in the centre, this is cut to be an easy fit into the width of the fuselage and helps when lining the wings up.
I'm sure no one needs pictures of how to solder wires together right ? ….... well if you do then just shout.
So the last Picture 30 is the completed wing. For testing I've wired separate left & right power and signals, but I'll combine them together eventually.
Its probably worth adding some covering to the bottoms of the nacelles, just paper & glue will do but don't completely cover them because its nice to get some air flow over the ESCs.
Thats it finished, you need some props, I bought from Ebay some three bladed ones and they come as clockwise & anti-clockwise pairs. So when testing the motors make sure you end up with one side going one way and the other side the other.

wing_wire1[27].jpg
wing_wire2[28].jpg
wing_wire3[29].jpg
wing_finished[30].jpg
 

ClearSkiesCalmWinds

Active member
Nice clean work. With the B-25 I used strands of dental floss with access holes in the wing tape down to pass wires through after forming and closing the wing. Glad to see this going. I had to pause my build for the holidays and hope to get it going the coming weekend. Again, GREAT share. Would you consider posting a wiring diagram for us first time four engine noobes. Cheers!
 
Nice clean work. With the B-25 I used strands of dental floss with access holes in the wing tape down to pass wires through after forming and closing the wing. Glad to see this going. I had to pause my build for the holidays and hope to get it going the coming weekend. Again, GREAT share. Would you consider posting a wiring diagram for us first time four engine noobes. Cheers!

Wiring diagram is at the end of the last posting .... but shout if you need more info.
Kevin
 
Part 9
Starting the Fuselage


You will need to printout a side view of the fuselage from the balsa plans and mark it up like Picture 31.

The Red line is what you need to cut out and the Green hatched areas are the formers. There's a PDF below with the required formers but please cut them out of paper first and make sure they fit your fuselage sides before cutting & gluing foam board.

To keep the rear end simple I've made the moving elevator a single piece, that means we have to cheat a bit and make the center wider than the drawing to allow for adding a BBQ skewer to strengthen it. So, at the rear of Picture 31 I've circled where we will have to cut away some clearance for the elevator center section, but this is best done when the elevator is cut out and ready to fix.

Cut out two fuselage halves (they are not handed) by following the Red outline.
Note the slight slope under the wing to give it some angle of attack.

We need to cut a piece of foam for the bottom too. This is a simply a piece that starts at 65mm wide for 388mm long then tapers down to 40mm wide after another 410mm, as seen in Picture 32.

Some peoples PDF print outs might be slightly different in size to mine, so again, check the length of your fuselage and adjust the 388/410mm dimensions to suit.

Picture 32 shows the sides and the bottom laid out along with formers F1, F2, F3 & F6

Lay one side down flat and glue on formers F1, F2 & F3 as in Picture 33. The positions should be obvious from the side view. Use square blocks to make sure they are at right angles to the side. When they are set, glue the other side to them, make sure everything lines up and looks 'square' - Picture 34
Take the floor and crease it where the bottom starts to angle up towards the tail. Then glue this between the sides. I found it easier to do this in two stages, first the front half, where the sides are straight. Get that set and then it should be easy to lift the rear end and squeeze the sides together to make a nice tapered shape. Obviously, as I've said before do a 'dry run' without glue and make sure it all fits and looks square, then when your happy go for the glue. And add former F6 to the rear end.

fuselage_side[31].jpg
fuselage_parts[32].jpg
fuselage_build1[33].jpg
fuselage_partbuilt[34].jpg
 
Part 10

More on the fuselage.

When you've assembled all the parts in Picture 32 you should have something resembling a fuselage. So here's some details to add.
I fitted the elevator servo just behind the wing at the rear of 'F3', Picture 35 shows a square of foam cut for the elevator servo and glued into place.
For this build I'm experimenting with wheels! So added a second cutout for a servo to drive the steerable tail wheel – its up to you whether you do the same …... but its hard to add at a later date.
This picture (35) also shows side blocks to strengthen the areas where the wing BBQ skewers go through, just cut these blocks from scraps of foam.
I think its useful to add some bracing to the center too (this is where you will hold it for launching) , and stiffen up the BBQ skewers with some foam, picture 36, cut some strips the same width as the side blocks and fit them on top of the skewers between the side blocks, use plenty of glue.

And make sure you feed the servo(s) wires through a hole in 'F3' to reach the receiver on top of the wing center.

Print out from the plans a view of the rear stabilizer(elevator) and the fin/rudder. Lay these on some foam and mark out. You need one stabilizer and two fins/rudders.
Picture 37 is the elevator. In the real Lancaster there are two separate elevators on a single shaft, but to keep things simple we'll build a 'one piece' style. So we need to add some material to the center section and stiffen it up with another BBQ skewer. The blue lines on Picture 37 show the extra needed, the dimensions are not critical, and also extend the sides with tabs for the rudders to fix onto. Size of the tabs is not critical either but there are some lines on the original (balsa) plans you can use as a guide and make them long enough to go through the rudder thickness. When you cut out the rudders, make the slot in them the same size as these tabs, again there are lines on the plan to use as a guide.
The hinge is same as the Spitfire (and others). Score along the line half way through the foam, snap open – but be careful of the weak center section! - then trim or sand paper a bevel.
Cut a slot in the underneath to set in a piece of skewer, glue and cover with paper to make a smooth finish. See Picture 38 and Picture 38B for details.

We shan't be joining the elevator & rudders together yet, but we need the elevator to finish the rear of the fuselage.

You need to cut away the rear of the fuselage where the elevator fits to allow for movement, see Pictures 39 & 40. Also add a half height copy of 'F6' at the rear of the cutout to give more strength.

That's all for now ….. but plenty more to come.

fuselage_detail1[35].jpg
fuselage_detail2[36].jpg
elevator[37].jpg
elevator_2[38].jpg
rudder[38b].jpg
tail_detail1[39].jpg
tail_detail2[40].jpg
 
Sorry for the slow progress on this .... been busy with the original one I built, crashed it, rebuilt, crashed, rebuilt - again .... and minor crash - again! ... so some more repairs to do :-(

Hope to be back on this one with an update next week.
 

ClearSkiesCalmWinds

Active member
Great to hear your back on it. Mine was ruined by mistake (family) The parts are so big it's hard to put away at night. I will have to restart. Wish me luck.