84" EPS Lancaster Build

[baz49exe]

Wow Bill and Michael, you have both thrown up some thought provoking issues and now I'm worried.
I know there can be real issues with a lack of rudder on model aircraft but I don't notice it at all on the fun fighter sized models and I've had no problems at all on the twins up to 64" span.
The 84" span Lanc is very different so I may be in for a shock and only time will tell at the first hand launch. I'll find out very quickly then whether things work or not.
It wont be a huge issue to add a rudder function but I don't want to unless I need to I guess.
The ailerons are a fair size and I've extended them inboard to take advantage of the prop wash from the out board motors so that might help.
I'm more concerned about the stability of the large tail plane at present as it could very easily develop flutter in flight.
The plane won't be going fast but I'm going to add another coat of silk and varnish to it as a way of stiffening it up without adding much weight.
I was concerned about adding weight with thick wire on my smaller models especially when I ordered a thicker gauge servo wire than normal in error.
The difference in weight was surprising as Bill says. Hopefully the speaker wire being two strand is not any heavier than the equivalent three strand servo wire and although it's not crucial on a model this size I do want to make it as light as I possible can so that it will fly in as scale a manner as possible.
Any way it's all good fun and if it does fly I'll be very happy. If it doesn't I was going to say I'd hang it on the wall but it won't fit will it!!!

[Bill G]

I wouldn't worry much about aileron issues, as mine were undersized in length, but it did show an interesting phenomenon that once the aileron becomes slightly undersized, it becomes almost completely ineffective. The scale length of the Lancaster's ailerons are longer than the one's I had issues with. The reason it caught my attention is due to their similar short chord length. The plane I had an issue with is actually now a good flyer in that it's very sedate, although the turns are still a bit large. Before lengthening the ailerons 1", it was very difficult to turn. The Lancaster's aileron length proportionally appears to be a bit longer than mine are now, after I lengthened then.

[baz49exe]

Bill, that's reassuring ! I don't think there'll really be a problem either but aileron response is a weird science to me.
I saw a friend maiden a beautiful scale Westland Lysander a year ago. Plenty of aileron size and movement but it wouldn't turn.
It turned out to be adverse yaw problems as the down movement on the ailerons was as great as the up.
I think I've solved the issue on on my twins purely by accident combined with ignorance.
Being weak foam the wings have been made thickly so cutting the aileron bays out produced a deep section to the bay. I decided to use thin sheet balsa for the ailerons themselves to provide the stiffness needed in torsion and to still keep it light.
They were top mounted flush with the upper wing surface producing a deep step beneath the aileron. These have proved to be very responsive on the large wing as I believe the step blanks the downward effect of the aileron to some degree. Pure accident on my part but it seems to work well.

[Bill G]

One of the simplest ways to set differential that also responds in a desired non linear fashion, is to do what Alfa models does, such as on the FW190 I have. The aileron horns will provide aileron differential response if mounted such that the clevis (pushrod attachment) point is behind the hinge line, rather than aligned vertically with the hinge line. I believe the Alfa has the linkage offset somewhere between 5 to 10mm from the hinge line. For whatever reason this rarely seems to be mentioned on the forums, and most people just align the linkage point vertically with the hinge line. Using a compass to draw a circle from the hinge point through the linkage point will show that the ailerons will move in the upward direction more than in the downward direction, per incremental movement of the pushrod. I started using the method years ago, as single servo ailerons with a light cable are lighter than dual servo setups. I've gotten lazy over time and use less single servo setups however. When 5-9gm servos were $12 and up, it was also a good reason to use only one servo.

[Voyager2lcats]

Barry, this must be the largest wing span aircraft you have built- is that true? I am going to be very curious to see if it banks and turns as well as the Wellington. I am an optimist as the majority of your foam aircraft (Maachi Saetta being the lone exception) have been excellent scale performers. So if the Lanc is anything to go by you should have the penultimate 4-engine scale performer! Okay, the B-17 was supposed to be able to out-turn an ME-109G at 30,000 feet altitude(!!!), so the argument could exist for that. Your pal,

Bob

[baz49exe]

Hi Bob, it's by far the largest model I've built in fact it feels more like interior renovation than modelling.
I'm hoping it turns out as well as the Wimpy myself Bob. The story about the B-17 which was once built by a club member and which wouldn't turn doesn't help though.
I'm working on the nacelles now and the maiden shouldn't be too far off so I'll find out soon enough.

[baz49exe]

Originally Posted by Bill G

One of the simplest ways to set differential that also responds in a desired non linear fashion, is to do what Alfa models does, such as on the FW190 I have. The aileron horns will provide aileron differential response if mounted such that the clevis (pushrod attachment) point is behind the hinge line, rather than aligned vertically with the hinge line. I believe the Alfa has the linkage offset somewhere between 5 to 10mm from the hinge line.

That's really useful info Bill.
I've been using HK horns for a while now and still have a packet full. They have the attachment holes off set forwards so the attachment point is actually directly on the hinge line to provide a neutral position.
This is a mod that is well worth looking into. Thanks a lot.

[baz49exe]

At last I've sorted out one of the outer nacelles so that it will contain the motor, ESC and lipo with easy access to load the latter.
Boy this was tight but the lipo has room to sit on the motor mounting stick.
The top cover had to be very thin to slide over the battery and lock under the rear of the plastic cowl so it had to be planked out of 1/16 th balsa over a balsa frame.
Now it works ( at last) I can surface finish the whole nacelle with silk and spackle.
Just three more to make now.
The ESC signal wire protruding from the top of the nacelle body will be soldered to the wing loom just before the nacelle body is glued into place under the wing.

[Voyager2lcats]

Barry, looks great. Yes, now you just need to make three more(!). I love the speaker wire as your ESC extension cords- what a simple yet elegant solution to buying some overpriced hobby extension wire. Of course soldering would be my hang-up as I am never sure my soldering iron is up to the job (need to replace the tip as the outer layer of metal is worn off). Your fuselage and wing are looking wonderful. You make scratch building from a 3-view look easy!! Keep up the great work as I think you are an inspiration to old and young scratch builders alike.

Bob

[baz49exe]

Thanks very much Bob. It's very rough at present but should tidy up OK when its been blended into the wing.
Now I know why four engines is a bad idea. Three more to do yet

[BradT]

Barry, any thoughts of 4 motors being a bad idea will evaporate the moment you see and hear that Lanc in flight, it'll be magic!
Brad.

[pattern14]

Originally Posted by BradT

Barry, any thoughts of 4 motors being a bad idea will evaporate the moment you see and hear that Lanc in flight, it'll be magic!
Brad.

Never a more true statement there My 4 engined He 277 sounded totally unique, and your Lanc will no doubt be even more sweet ( and fly better)

[Bill G]

Originally Posted by baz49exe

Thanks very much Bob. It's very rough at present but should tidy up OK when its been blended into the wing.
Now I know why four engines is a bad idea. Three more to do yet

I hear you on that one, as I finally got around to finishing the blend work and covering a mere two nacelles, versus four. Of course all the covers have to be made and finished as separate removable parts for serviceability, adding yet more work to the project.
The next build will be a Piper Cub.

Originally Posted by BradT

Barry, any thoughts of 4 motors being a bad idea will evaporate the moment you see and hear that Lanc in flight, it'll be magic!
Brad.

With the right props they sound really good, such as GWS HD which are a bit noisy. I'll sacrifice some efficiency for good sound. Geared setups were even better for sound, but most of us have gotten away from them, as the outrunners are cheaper and easier to install.

[baz49exe]

Originally Posted by BradT

Barry, any thoughts of 4 motors being a bad idea will evaporate the moment you see and hear that Lanc in flight, it'll be magic!
Brad.

Thanks Brad, that'll be my mindset now for the next three. Hope you are all well.
Barry

Never a more true statement there My 4 engined He 277 sounded totally unique, and your Lanc will no doubt be even more sweet ( and fly better)

Michael, if it does fly better than the He 277 I'll be doing very well indeed. I'll be happy if it'll just fly after all non of these heavy lifters were aerobatic machines in real life were they?? If I keep my expectations low I may be pleasantly surprised. LOL

I hear you on that one, as I finally got around to finishing the blend work and covering a mere two nacelles, versus four. Of course all the covers have to be made and finished as separate removable parts for serviceability, adding yet more work to the project.
The next build will be a Piper Cub.

I'm glad it's not just me Bill as I'm almost feeling guilty about the level of resentment I'm feeling towards these nacelles.

With the right props they sound really good, such as GWS HD which are a bit noisy. I'll sacrifice some efficiency for good sound. Geared setups were even better for sound, but most of us have gotten away from them, as the outrunners are cheaper and easier to install.

I've been thinking prop choices at the moment Bill. I have two versions of the same motor. One has the threaded shaft cut off and uses a 3mm collet adaptor to spin a 7 by 6 APC style prop to give 200watts.
The other retains the threaded shaft and takes a GWS HD 7 by 3.5 prop to give around 130 watts.
I would like to use four of the latter setup to fly the model however for the initial flights I'll probably use two of the 200 watt setups inboard and the 130 watt setups out board just to give a " first hand launch " safety factor.
Either way I can't wait to hear the sound of "four turning"

[pmullen503]

Just a thought here. It might make sense to add in a hard point for mounting either a catapult hook or maybe some structure to mount fixed landing gear latter. That's an awfully big model to hand launch and you'll have 4 spinning props to stay clear of.

Fantastic work. Do you have an estimate of the final weight and wing loading?

[baz49exe]

Originally Posted by pmullen503

Do you have an estimate of the final weight and wing loading?

Not really. It's going to be as light as I can make it though.
According to the online calculator, the Wellington has a wing area of 504 sq ins and a loading of 14.8 oz per sq ft.
The Wellesley has a wing area of 434 sq ins and a loading of 7 oz per sq ft.
I'm hoping that the Lanc will be nearer to the Wellington as I can't expect it to be anywhere close to the Wellesley.
The Lanc has a wing area of 756 sq ins so a model weight of 78 ozs will give me the same wing loading as the Wellington at 14.8 ozs per sq ft.
So if I can keep it within 4lb 14 ozs it'll have the same loading as the Wellington does at 3lb 3ozs AUW.
Wow that hurts

[baz49exe]

I pocketed the aileron servos into the outer wing panels today leaving room in the side of the box for the soldered wire connections so that in the event of a servo change the connections are easily accessed.
The wires were recessed into the underside of the wing in the same way as the ESC signal wires.
The outer nacelles could now be carved to fit the slope of the outer wing panel and the signal connection wires were soldered to the motor wiring loom.
Both nacelles were than gorilla glued into place over the wire runs set into the wing surface beneath them.
When the inner nacelles have dried they will be fitted in exactly the same way.
I think I'm starting to see a glimmer of light at the end of the tunnel.

[pattern14]

Originally Posted by pmullen503

Just a thought here. It might make sense to add in a hard point for mounting either a catapult hook or maybe some structure to mount fixed landing gear latter. That's an awfully big model to hand launch and you'll have 4 spinning props to stay clear of.

Fantastic work. Do you have an estimate of the final weight and wing loading?

Managed to handlaunch my four engined scratchbuild without any problems at all, as the props are spinning well forward of your hand. Still have scars from handlaunching a pusher prop twin though With its comparative light weight and generous wing span, I can see this one leaving Barry's hand like the proverbial bird

[baz49exe]

Originally Posted by pattern14

Managed to handlaunch my four engined scratchbuild without any problems at all, as the props are spinning well forward of your hand. Still have scars from handlaunching a pusher prop twin though With its comparative light weight and generous wing span, I can see this one leaving Barry's hand like the proverbial bird

Glad to hear it Michael ( the bit about the easy hand launch not the prop bite scars).
I still worry about pusher prop set ups myself which was one reason I built the Me 163 as a tractor prop design. The BV 215 looks threatening just sitting on the ground never mind the dicer spinning on the back of it.
In many ways, I can't see this model being significantly more difficult to hand launch than the Wellington and I think you are dead right when you point to the wing loading being the pivotal part of the whole plan.
I'm convinced that it'll fail, as I always am, as that way I get a nice surprise if it does go well.
So far, since I went all electric, only one of fifteen builds has given me real flight problems so I guess the law of averages is against me on this one.
Time will tell.

[CHELLIE]

How did I miss this Build Nice Build Barry will you be using those 1800KV Micro Motors with a 7x6 prop I you do, its going to sound really Sweet Dont forget That I get to do the Maiden Flight LOL, Just kidding, Take care and have fun, Chellie

[baz49exe]

Originally Posted by CHELLIE

How did I miss this Build Nice Build Barry will you be using those 1800KV Micro Motors with a 7x6 prop I you do, its going to sound really Sweet Dont forget That I get to do the Maiden Flight LOL, Just kidding, Take care and have fun, Chellie

Hey Chellie, good to hear from you!
Yes it's getting those 1800 KV motors as I've standardized on them now for all my builds so it makes things easy for me.
The two inboard will start with 7 by 6 props and two 7 by 3.5 on the outboard motors. If the power is more than sufficient I'll change to a 7 by 3.5 setup all round.
Take care, Barry

[baz49exe]

All four nacelle bodies are now wired in and mounted beneath the wing.
I've decided to mount the receiver and V Tail mixer in the lower fuselage fairing so that the tails from the aileron and ESC wiring can be plugged directly into them. That means that only the elevator and power leads will need to to fed from the body to the receiver and that will greatly reduce the plugging and unplugging needed for wing attachment and removal.
Just the battery covers to make and the cowls to install and the nacelles are finished. At last!!!!

[Voyager2lcats]

Barry, I am online and viewing your thread. The Lancaster nacelles look superb. I look forward to the day you launch this plane at the field and report back on the flight. I was staring at the Ki-43 wing sitting in my bedroom walk-in closet this morning and it was talking to me: "Give me some spackle and silk!". LOL. I am looking at my SE5a right now and am going to balance it. Look forward to hearing from you.

Bob

[baz49exe]

Thanks Bob,
I hope you get your SE5a into the air soon, looking forward to the maiden report.

Barry

[riverrat]

[QUOTE=baz49exe;900855]All four nacelle bodies are now wired in and mounted beneath the wing.

Looking GREAT.

A Master Foam Craftsman @ work!!

Regards
Jimmy