4 Engined LANCASTER Stunter!

Hi all, yes I realise when you read this, you are hoping to read
about how there is something to rival, Paul walkers, b17, alas,
I cannot say this is the case, as nothing will ever rival that superb machine.

The purpose of this post really is to try to guage some help, from those who are knowledgable in certain aspects of the b17 project, perhaps can shed some light on some issues.
I have plans ready for a 4 engined lancaster CL stunter, running approx 72" wingspan ( can be lengthed if need be ) I chose this for something different, a Challenge, to build, fly, setup ect, as I have been very impressed with some of windys and pw feats!

I have been unable to locate any real data on the tank setup as I also plan to run 4 x .15's ( 1st thought was to run more power, but weight issues come into play ect.. )
So ive settled on that plus the ground work has already been done, and I guess the reasons we " break and stretch the rules " is to allow others to follow patturn.
So Yes the task of a Lancaster will be undertaken, provided I can get a decent engine setup, ive thought about retracts, and its not feasable, everything else is ( within reason ) fairly straightfoward build wise.

---

What I know so far is The tank setup was a "central bladder tank" ive done some searches of past achives in stulka but was unable to find anythign substantial.

Any posts would be most appreciated, I will also accept emails to :
[email protected] (subject lancaster) otherwise it will get filtered as spam!
I believe Howard Rush you did some developmental work on it or Paul?? If you read this, If you can help id appreciate it, or anyone else.

I will also accept " your crazy " emails. I want something Different!
Anyone know where to get lancaster canopies......

P.J

Why don't we do 2 laps between starting and take off?

Starting is not a manuever.

If it was, there would be judging procedures for the perfect start.

Not to stray from the topic,
However you DO GET SCORED ON STARTING!!!

Technically, it IS a manouver, 10 points in FAI, jugding proceedure, is " starting within 1 minute, receives full points. "

Im not here to debate that however, its just and old expression.

Any REAL thoughts on my lancaster project??

PJ.....
I would contact Paul Walker directly...I'm sure that he will be happy to tell you all about his methodology....and remember, his works!

See Ya

I would say that the points for starting withing one minute is a bonus rather than a manuever. If were a manuever, you would lose pattern points for not starting within one minute.

I have been doing some expereients with a fuel tank for 4 engines because I am planning to build a B-17. The best thing I have come up with so far is a blatter fuel tank in the fuselage with a fuel line to each engine. I can start each engine one at a time on the test stand that I have rigged up and when it runs out of fuel all 4 engines stop at the same time. My blatter holds 100 CC's of fuel if you need more fuel use a larger blatter. Paint a toilet paper tube with clear coat and slide the blatter up inside the tube. The tube keeps the blatter in shape like a hotdog and holds it inplace.

That's great, Gary. What do you plan to use for engines?

That is very cool, PJ. You already have the flap balance tab technology you will need to relieve the ponderous hinge moment.

Dave Gardner was writing an article about the B-17 fuel system for Stunt News, but I delayed his progress by offering him some additional data which I probably never gave him. Now that someone is interested, we should finish the article.

I found a summary of the fuel system, which I may have posted here before, so if the following looks familiar, it may well be:

The B-17 fuel system resulted from the FAI rule that F2B airplanes can’t have automatic or pilot-activated engine shutoffs. This made it challenging to have all four engines reliably quit between the end of the pattern and the seven-minute F2B flight time limit. Paul’s first B-17 had four individual tanks. This system had too much variation in engine shutdown time. Would you have guessed that the four engines burn vastly different amounts of fuel as a function of position on the plane? He then went to a system having a central bladder and individual pressure regulators on each engine. Paul used this setup at the 1995 Nats. It was pretty consistent, but the time between when the left engine quit until the right engine quit was about 20 seconds. When the bladder ran out, the fuel in the manifold between the engines had sufficient head pressure to keep engines to the outside of the circle running. The engines would quit from left to right with about one lap between. Paul thought that for reliable F2B operation the engines would need to quit over a much shorter time. We decided to use pressure reducers on the engines on the right wing to attenuate the head pressure, so that all the engines would quit when the bladder pressure dropped at the end of the run. Ralph Cooney of Fourmost donated some check valves that I made into ball-and-spring 7-psi pressure reducers. These worked perfectly the first time we tried them—but seldom after that. A sideways tap on the pressure reducer knocked the ball out of its seat, after which the reducer did not reduce. I made some seemingly more reliable reducers out of Luer fittings, which Paul used at the 2001 Nats. I’d like to know of any other little pressure reducers one can buy; we haven’t been able to find any.

We tried various combinations of pressure reducers and got bizarre engine-shutdown results. I made an engine-shutdown simulation that actually explained the results and confirmed that we needed reducers on only numbers 3 and 4: one of the few cases of theory being of any help to the Bomber project.

Norm McFadden designed the regulators for combat. They proved very reliable over the years—-sufficiently so that several west coast combat flyers used them despite their small advantage for combat over a straight-through fuel feed from bladder to engine. Tony Huber makes the regulators, which are popular now with RC pylon racers. I’ll send you his phone number.

Get some of Ferocious's yellow bladder tubing and bladder end fittings.

The pressure reducers use parts available from Small Parts, http://www.smallparts.com/. Part numbers are:

W-1005009 Male Luer lock 3/32” with locking nut
Q-1005109 Female Luer 3/32” barb
W-BX-1-1/2 stainless steel ball, 3/32” diameter

I think I used the 3/32” ball, but I may have used 1/16” or 1/18”. Their part numbers are:

W-BX-1 stainless steel ball, 1/16” diameter
W-BX-2 stainless steel ball, 1/8” diameter

They are 9 cents apiece, so get some of each.

I made the springs from .005” stainless steel wire: the center strand of .015” stranded control lines.

The fuel system is still a little unreliable. I think it is unstable when the engines are running rich (the richer it gets, the richer it gets), so the engines have to run pretty close to peak RPM. Dr. Briggs and I have done some further experiments to try to fix this. I posted some of them here. I tried to make the bladder-fed engine operate at a steady four cycle. Nothing has worked so far.

What engines do you have in mind? One thing to look for is a positive gradient of crankcase pressure with RPM. The primary thing to look for is probably lightness. You really have to work to keep weight down. The bladder tube, for example, was made from two plies of .002" thick carbon prepreg.

Hey Howard, I've got an LA 25(stock) and an LA 40(stock) that like to run a steady 4 cycle on a bladder. It is kind of a pain for SL combat because the tendency is to set the plane off a bit rich so it can leanout and pick up speed on the first lap or so. These two motors, for some reason, will run the whole bladder at a nice steady 4 cycle unless they are launched running 2 cycle.

Gave me the idea for trying a bladder fuel system in a stunter. I found that when the prop load is increased(was running a 9/4 on the 40) even to just a 10/4 the motor was a lot more sensitive tofuel flow. If the bladder wasn't filled just right variations in fuel pressure would trigger the motor to go lean and stay there.

IF....and this is a big IF.....IF I were to build another 4 engined stunt plane (and I was thinking of a Lancaster as well) I would run 4 separate fuel tanks. Howard mentioned it in his thread, each nacelle location would use a different amount of fuel. I verified this by switching around engines, tanks, nufflers, etc., and the only constant was the nacelle location. It was surprising to me that engine 2 (the engine just inboard of the fuselage) would require the least, ~ 1 ounce. Engine 3 (just outboard of the fuse) would require 2 1/4 ounces. Engines 1 & 4 were both around 1 1/2 ounces. Remember that each engine was running at (as close as I could) the same rpm.

If another were built, I would first (in the test flight stage after construction) establish how much fuel each nacelle location needed for a pattern, and then procede to build custon tanks for each location. With good starting techniques, this might be good enough.

After the last B-17, I got the starting technique down. Quite a sequence to it, but it was very reproducable, and reliable, and a special thanks to Howard and his switched power supply. It did require a switch in the fuel line to the venturi, and that would have to be incorporated into a 4 tank version. I am sure I could get it down good enough to make this 4 tank configuration work and quit within a few laps of each other.

The bonus I would have is in not having to use the FAI rules again, and I could put a fuel cutoff in the system to kill them all at once (which is clearly another option, but at some weight penalty).

Yes PJ, I too like the Lancaster, and have thought about it. Be very careful with the weight, it can get out of control real quick, not that mine weren't.

At 100 ounces, the B-17 was still able to put up a 563 in qualifying at the NATS. That was it's slowest flight, and the most impressive at that speed. As the week went on, I had to speed it up to keep the engines lit....see Howard's thread. It got to the point of opening up too much, and I slowly started loosing points because of that. I still think that with a good running system, that plane (in the right conditions) could win the NATS! Maybe again some day, while I am still strong enough to fly it.

Oops...lost my thread...PJ...What version of the Lancaster are you building..The radial engine version, or the inline engine version?

Good luck.

Attaboy PJ! Don't let Paul Winter (GB) see this thread. He was showing off his part built Manchester recently, (the twin engine job the Lanc was developed from). He chose the Manchester because he was TOO CHICKEN to build the LANC! Heh heh heh.........

I'm pretty sure the Lancaster in the War Memorial Museum in Canberra, ACT, is the Merlin powered version, which just might 'fluence the choice. Steve

Gday all, thanks for the vote of optimism, I was honestly expecting lots of " your crazy " threds, but isnt it the old saying " all aeromodellers are crazy? "

Thanks PW and Howard, ill study those and PW i was thinking along similar lines about running 4 seperate tanks, your advice has pretty much convinced me that its the easiest way to go.

I was looking around at all the old style war ships for something different, my 1st idea was to do a p38 lightning, with 2 x .61's jsut for kicks, but after having a good look at plans, realised its really quite an ugly looking plane, and the changes needed to make it a good stunter would push it out of proportion and not look that scalish.

So the lancaster was the most obvious one i kept coming back to. I plan to build the "avro Lancaster Mk 1" Which for those who are unfarmiliar is as pw eluded to is the Inline merlin version, The original had, 4 x rolls royce merlins each pumping out around 1200hp ea! I think it looks cleaner than the radial version, plus you guys have done the radial thing to death! p47's b17's a26's just to name a few. My only regret is going to be, not being able to bring it to the USA and go head to head with the b17!
Ideally we need to get the top 10 us guys all to build semi-scalers, and have a world war nats !

Please tell me PW non of your b17 were takeapart...

My only real concern now is actually VERy small, but a crutial detail, Where on earth am i going to get custom made canopies from.. I need 3 bubble gun turrets, and 1 long top canopy.. windy? *blinking eyes*

I had planned to use 4 brand new os 15's. which version I havent decided yet, any advice would be well received.

Yes howard, I do fully plan to utilise by boost tabs, for 2 reasons, I wouldnt build a model without them im to used to it now.. and 2 : Im sure i will need it for a moster like this.

Paul W, can U give me a ball park on your wingspan? and root thickness??? I had contemplated 72" that seems large enough but not to large for stunt. So under 100 oz you say... well ,Lighter is better.

I didnt realise you built 2!!!!! I would find 1 a nightmare, which im to far into to back out now anyway!

How about using electric motors?

Multis are the PERFECT application for electrics.

As far as canopies go.... you are on your own here... however many Lancs had the Mid-upper turret removed, so one less.....
Another.. remember they had a Plexiglass front-piece for the bomb-aimer to look out of.... so add another one.
Of course the Lancastrian had no turrets, "only" the main canopy.
But of course you don't want to build a Lacey-Panty civil plane, do you ?

It came apart. The wings are separate, with an overdesigned spar joint. The fuselage splits into forward and aft parts, and the horizontal stabilizer is removable. At the 2000 World Champs, a typical day was to put the disassembled Bomber into the Hot Rod Skoda, drive to the practice field, assemble The Bomber and practice, disassemble The Bomber, put it back into the Hot Rod Skoda, drive to the official one-circle site, assemble The Bomber and fly the official flight, then disassemble The Bomber and return to quarters:

There's another Lancaster connection. I went to a shop that sold chunks of metal to get material for the B-17 cowl mandrel. The proprietor was an old Englishman. I noticed airplane pictures in his office, so I asked his story. He was a Lancaster crewman who had bailed out over Holland. He spent the last year of the war working in the Dutch underground and hiding from Germans. When I met him, he had just returned from visiting his Dutch colleagues, the family who hid him, and the guy who shot him down.

So that's what the bladder tank looked like inside. One of your hand-wound carbon tubes?

Those had to be the longest bladder tanks I've ever seen. Something like a foot long when limp.

You can actually buy Skodas here these days... saw one in the Megamall lobby on exhibit.

Yes i am well along the way to building the 4 engined lancaster, I honestly did not realise that PW was takeapart...... I bow down b4 the master, my god, seriously, this is like a dream, is there anything this guy HASNT done??????

Sorry to dissapoin u paul, but there is NO WAY i will ever be building a 4 engined takeapart ANYTHING!!!!

Obviously you have been told before, but i'll tell you anyway, YOU ARE THE KING!!!!! I hope my lanc is 1/2 competitive, but i have nothing on your b - 17, least im trying something new.

*mutter* takeapart b17, I had no idea......

No problem, you'll just need to find a used step van somewhere... Maybe U-Haul sells off its old models, like Hertz does..

Could you elaborate more on multi electric engine stunters? It seems to me that if the current technology is producing weak engines, the performance could be improved by using several engines. I don't know about batteries or extra weight though.

If you check out the thread on the timer for electric motors, you could connect one of those timers to multiple brushless speed controllers (I think one large speed controller can manage several brushed motors, but I don't think brushless motors would work that way - the controllers actually sense the position of the rotor through the unenergized coil, so you can't run multiple motors on one controller). You could also use one very large common battery pack, too.

I wouldn't say electric motors are "weak". Not any more. But you are right - done correctly, several weak motors could do the job of one powerful one.

>If you check out the thread on the timer for electric
>motors, you could connect one of those timers to multiple
>brushless speed controllers (I think one large speed
>controller can manage several brushed motors, but I don't
>think brushless motors would work that way - the controllers
>actually sense the position of the rotor through the
>unenergized coil, so you can't run multiple motors on one
>controller). You could also use one very large common
>battery pack, too.
>
>I wouldn't say electric motors are "weak". Not any more. But
>you are right - done correctly, several weak motors could do
>the job of one powerful one.

Ron B.
F4Fguy

Nice idea,but I believe both FAI and AMA Aerobatic rules prohibit the use of timers or external controls to limit or control engine runs.

True, but that'd be for F2B competition (I think things like Z-Tron are still allowed in AMA competition). If the thing is for AMA competition, no problem, and especially so if it's not for competition at all. It'd still be a neat airplane.

I suspect they'll probably have to make an exception for electrics eventually - I can't see electrics working at all if you aren't allowed to shut them down before you start losing power.

It's so cool, how he has his own crew with same jackets and uniforms.
Aircraft Commander, Navigator and Bomber Crew Chief.

Did you mean that the changes you would have to make to the P-38 plans made it ugly, or did you mean that the P-38 is ugly??? If the latter??? OFFENDED!

OK PJ!
Now that you know the "hows, whys, and wherefores" start posting pictures of the progress.
Can't wait to see it.
Bill <><

Gday guys, Its a 2005 project, dont worry its in the pipeline.

Like all things, I need to find where it sits in my "priority" listing.

See our 2005 Nats are in july, and I was thinking, I would like to have 2 new ships built, ( a new f2b ship, plus a Classic nobler )

ive got 1/2 the new stunter done, wings, tail ect.. But ive really been thinking about this lanc.. Some of me wants to push for a 20050july realease date, the other 1/2 of me says, take your time and do it properly.. So im not sure when construction will start....

Ive done plans, so really there's nothing stopping me starting tonight... well I can cut some ribs out anyway...

Ill keep everyone up to date..
Thanks guys.

If youre building a Nobler you'd better get rolling.

Thats about 200 pieces of Balsa isnt it?!

PJ,
Thinking about this, 4 engine bombers have been done before, a new approach is needed - a B36 With 6 X .15's neatly fits into the new FAI 15cc limit....
I hereby volunteer to make 6 X 8X3.5 CF pusher props, you figure out the rest.

>A new approach is needed - a B-36 With 6 X .15's neatly fits
>into the new FAI 15cc limit....

Yeah!

Swivel the power plants on a huge carbon fiber flipper for each wing in place of the normal flap.

You could have vectored thrust to add to the pitch change.

I can see the possibilities.

4 3 inch long scaled down Dynajets.

We need to get Gary Weaver in on this one.

Strategic Aerobatic Command!

--

There was a picture published, somewhere, of a HUGE, scale CL B-36 from, I think, the 1960s. This was bigger than the Chicagoland Circlemasters' scale DH Comet (the airliner) that was supposed to have flown with four Dynajets.

There was a B-36 model in an advertisement, Model Airplane News?...Sig? balsa?...early 60's.

The add has a small photo of an uncovered B-36...resting on saw-horses...the builder is standing on the wings, straddling the fuselage.

It is, a VERY large model...!

Can anyone dig up the issue of MAN with that add circa 1961-1965?

I have often wondered what became of that model!

Of course, the Ambroid/Aerogloss fumes did get pretty thick in the basement back then...

The picture I saw of the B-36 was reproduced in the Chicagoland Circlecutters newsletter. The plane was at the field, and someone was starting up the engines.

I don't think the Comet ever flew - and it's still a mystery as to who built the thing. Four dynajets.. whew.

You need to get on with it, because Paul Winter in the UK has already started a Manchester (early twin engined Lanc). Even more unusual.

Well, the show has started, engines have been ordered, 4 new os .15's

Those who are interested Down under, I plan to have it completed for the 2005 July Nats in Sydney, yes it will have to be takeapart..

Ohh that reminds me.

* Howard or Paul * can U please email me at [email protected] with some general guide as to how the wing plug was used for the bomber? ive got several idea's in my head but, guidelines for how 4 engines handeled would be nice. No need to over engineer it..

What else is news on the project.. All plans are finalised, Chords, templates, Should cutting out ribs this week, and starting the task of building her up!!

Guys guys guys!!!! enough with the 4 engined electric talk ! Its hard enough!!!!!
I had a good look at the manchester, just she isnt as imposing as the Lanc ! My only regret is going to not be able to make her with retracts, and its sort of ugly, with wheels down, as a friend said " "The wheels were functional !"

Well thats about it from me, there wont be any news for atleast a few weeks, till construction starts, thanks for the support. Ive got 5 - 6 months to get it done.

If we dont get it done, so be it, she will be done one day!

the two level laps are part of the takeoff maneuver. I think it used to be called takeoff and level flight at one time.

IIRC, starting and takeoff within one minute used to be a requirement in AMA CLPA. This changed a few years ago, and the 1 min starting was dropped with just the 8 min total requirement left.

FAI still has a requirement, no?

thanks,
Bill <><