Bundy

Hello All

This is thread to follow the building of one of Tony Nijhuis's 132" Lancasters. It will be a joint build between myself Richard who lives in Bundaberg and my mate Sid who lives in Brisbane about 5 hours away. I have cut all the plywood parts on my CNC router and made up a kit of most of the rest of the bits needed and Sid will be doing the actual building as I'm fully committed with composite CAC 13 Boomerang project.

This will be Sid's first build of a flying plane but he is of the old fashion craftsman school who take great pride in doing something well so there is no doubt he will a top job given a little bit of help with the technical bits. We might even be able to find someone through this thread who lives in the Brisbane area, who has some experience with this sort of model who could give some 'on-site' help if needed ??

The idea for this project came after seeing a number of very impressive, large scale bombers at our local Bundaberg Warbird weekend back in September the biggest being Steve Thomas's B-17 - http://www.rcwarbirds.com/Projects/T...-17/Thomas.htm - very inspiring stuff! These big multi engined planes tho cry out for electrification to simplify getting all those motors working together and throw in a sound card and you'd have a very nice package.

We'll be doing things a little differently to the standard plan. We want to do the full detailed finish with 3/4oz cloth and rivets, sprung undercarriage and brushless/lipo power. I have an own design 84" B-25 ( http://au.youtube.com/watch?v=r6eULvCF58g ) which at 18lbs is powered by a single EvoLite 5S 5300mah lipo driving 2 Turnigy C5055 each turning a 15 x 10 APC prop. This combination works extremely well giving a very safe 6 min flight with a good 3 min of safety margin and plenty of power with scale flight at just a tick over half throttle. My plan is just to double this for the Lanc. Tony's target weight was 20lb. With the extra detail we are looking for we are aiming for somewhere around 30lb and with nearly 14sq' wing area this is still only a 35oz wing loading which should be fine. I don't think we'll need flaps as I have a smaller Partenavia Victor P68 with a 40oz loading which flies beautifully and doesn't need flaps altho they are there.

No real time targets with the build but it would be good to have it flying by the next warbird weekend here in Bundy next September. Should be fun.

Richard

ticketec

My Feedback: (2)

Hey Richard,

Steve's B-17 is pretty impressive, i was there with my 1/6 Fw-190 and was keen as mustard to get up there with steve's B-17 and do some straffing passes, but it was a certification flight and a new beast for him so i'll give him pletnty of time to get comfortable with it before i broach the subject with him. had a p-38 chewing my butt instead!

It's almost fate that i stumbled on this thread. I have the same plan and vac formings i picked up in england and have here at home. I have been busting to build it for the last 1 1/2 years, but the major problem is that i can't transport it in the car i have at the moment. I have been toying with the idea of starting anyway and have started looking into CNC cutters who could cut up the bits and pieces for this kit.

I'm in Brisbane ( Redcliffe to be precise) so i could lend your mate a hand with the build, and it would be even easier if there were two being built side-by-side. I've just got to finish fixing the aileron on the Fw, and maiden the F-16, then the bench should be cleared enough to think about starting....

I'm going the same way as you are with glassing (although i will use 1/2oz cloth and save a little weight, rivets, etc and brushless power of course, and was thinking of two sound modules one in each wing.

Thanks

dave

Bundy

Great to hear from you Dave

I'm sure Sid would love someone else building one of these Lancs to build along with and compare notes. He is very new to all this and I'm still in the process of getting him signed up to RCUniverse but once he is I'm sure you guys can make contact. He lives at Greenbank BTW.

Sid is also a cabinet maker and is planning to make a fully enclosed box to carry this thing on the roof of the car - might be an option for you??

I bought my Lanc plan from Tony Nijhuis in electronic format coming both as a dxf file as well as pdf. The molded parts came separately. This made it much easier to convert it into cut files for the CNC router but Tony was understandably reluctant at first to do this fearing mass reproduction of his design. I made strict promises not to cut extra kits but since you already have bought his plan and parts and if it is alright with Tony I'd be happy to cut you a kit to get you underway. Let me know if you are interested and I'll check with Tony.

I cut the ply parts from good old Bunnings ply which is not the fanciest but you can't beat it for the price. Balsa supplies came from BalsaCentral.com in Adelaide and I've been really impressed with their quality and great pricing.

I've also made a number of changes from the original plan with the main ones being different nacelle frames to allow for brushless motors and keying the ribs together to make for easier and more accurate alignment.

Like your thinking with 1/2oz cloth - will have to check with you down the track as to where to get it. Also 2 sound cards. I was tossing around whether this would be worth it over 1 with a 4 engine sound. Not an immediate concern but a fun thing to think about as work progresses.

Hey were you the 190 chasing my Corsair around at the Bundy warbird weekend?? I'm building a second one of those Brian Taylor Corsairs because they just fly so well but this time with folding wings and sound card - big project!!

Richard

ticketec

My Feedback: (2)

Thanks for the offer, That would be great to get some CNC bits off you. i'll see if there is an invoice or something similar attached to the plans box,

Doh, nothing on there

All that the boxes and plans have are the "postage paid" stickers on them with some type of number. failing that, i could just take a picture of my self with the plans and vac-formings??

I am going to have change cars soon anyway, so i should have something a little bigger by the time i finish the lanc anyways.

I checked were sid lives and he's almost at the gold coast! a fair way away from here but that's not to say that i couldn't pop round once in a while to help out. failing that he is welcome to come round to my place also.

Here are some pic's of my Fw-190 and your "inspiration". you can see why i only had 2 flights with her that day.[X(]

thanks

dave

Bundy

Hi

Sid is making great progress as you can see in the pics. Bit scary actually. I'll have to get on and make the retracts and legs very soon.

We're unsure how the balance is going to work out with bigger brushless, lipos and glass finish so we going to look at making a hatch under the cockpit to maybe use this as possible battery hatch. Would be a good general hatch for radio switches ,air valves etc as well.

Richard

ticketec

My Feedback: (2)

Wow,

By the time i get down there he'll be finished and ready for the maiden!! I prefer the finishing and painting anyways

I love your CNC work, it looks excellent! I've been studying the plans and reading the building article to get up to speed on the build and she seems a pretty straight forward construction. I layed the plans out on my building bench and she's about 6" too short[&o] i have a solution which isn't the prettiest but should do. I also priced up the amazon quantites of balsa required[X(]

As for battery hatch, i'm thinking of making the forward turret removable or something along those lines. nice and easy to get into, and you don't have any hatch lines to try hide. Do you have a heavy model inspector lined up already? At the rate sid is working he'll need to have it inspected pretty soon.

Thanks

Dave

dmyers0403

My Feedback: (48)

I would like info on how you plan on setting up your electrical system:
I have an old Conachen 11ft Lancaster. I had it ready with electrics for maiden last season, but scraped my original setup and in process of reconverting layout. I had the ESC's mounted in nacell's near each motor and had planned on putting all the batteries in the main fusilage. This resulted in very long leads to controller from battery. I then read where this was a NO-NO. All my search on various forums also indicated this as a NO-NO due to excessive voltage variations etc. I am now modifying construction to allow each nacell to carry the controller and battery for it's respective motor.
What is the balance CG and throw on your kit. Conachen provided no info. Mabey they would provide a good starting point for me. I have no idea who Conachen copied his kit (fiberglass) from. He is now out of business and back then he would never answer my questions.
I am using the Turnigy HV-100amp controllers (4) and Atlas 5020/30 motors with 10S-5000mah batteries at each motor.

Bundy

Hi There dmyers0403

Interesting question you raise there regarding battery lead length and wiring up 4 motors. I have no real qualifications here other than having used big electrics now for nearly 5 years, made some mistakes and learnt some hard lessons but now have a number large electric planes both single and multi engines that fly very well and trouble free for a number of years. These are my thoughts just from my experiences.

There seem to be 2 concerns with battery lead length and electric motors and ESCs. One is the blowing up of the ESC if too longer leads (200mm was suggested) because of voltage spikes being induced in the longer leads and the other concern is radio interference from excessive/messing wiring.

I seem to have avoided the first problem by putting an extra large filter capacitor close to the ESC in addition the bank of capacitor built into the ESC itself. In my current twin - a B-25 Mitchell I have a 1000uF 63VW capacitor in each nacelle as you might be able to see in the pic wired across the battery leads. In this plane I have a one 5S 5300mah battery in the fuselage driving both motors. With the loop back to the arming plug in the top turret there is nearly 600mm of wiring between the battery and each ESC. This has worked flawlessly for over 6 months of flying. I know the conventional wisdom says not to do this but it works for me.

The Mitchell's power train is what I will be duplicating in the Lancaster. The B-25 weighs 18lb, has one 5S 5300mah lipo powering both Turnigy C5055 motors and 15 x 10 props, has power to burn ( I hate to bombers that fly like pattern planes) and flies a very comfortable 6 min with 3 min on hand. My plan is just to double this in the Lanc. Depending on balance - I'm guessing it will need nose weight - I'll either put 2 or 3 5S lipos in the nose or 1 in each inner nacelle and 1 in the nose to give a 5S 15000mah battery driving all 4 motors.

Your plan to put a 10s 5000mah battery in each nacelle sounds way too much power. 10s is around 38 volts and even propped conservatively around 40amp draw that is 1520 watts X 4 which is around 6000 watts total. Aerobatic warbirds fly great on 100watts per pound and bombers even on 75 watts per pound or less. How much does your Lanc weigh??

The other problem is that of radio interference and I had personal experience of this. I lost 3 planes in the early days of electric with interference causing a PCM lockout of my radio. A little bit of noise from messing wiring or just longer than needed wiring caused just a minor hickup which sent the PCM radio into lockout mode. Stringing a few of these lockouts together and waiting for the recovery time saw some big crashes. I solved this in the first place by going back to PPM radio but more recently going to Spektrum 2.4g. I have been using Spektrum for about a year now with not the slightest problem. I run their data logger in new planes for the first dozen flights or so but have never recorded anything more than the a few fades on any of the receivers let alone a lockout. For me Spektrum is the greatest thing to happen to electric flight.

I'll go and check CofG and throws on Tony's plan/instructions and get back to you. Got any pics of your Lanc you could share with us? Any details like weights, where it wants to balance etc??

Richard

dmyers0403

My Feedback: (48)

Thanks for info I am projecting about 45LB completed-assembled-balanced and ready to fly. What is the rule of thimb to size capacitor I assume your sizing will work for mine -The fiberglass from Conachen is very heavy. Any info you have is appreciated. I can still put batteries back into fusilage but will need to complete redo of engine boxes and nacells since the original completed mounts were cut during an evening of uneducated disgust.
I am using Century Jet retracts what are you doing for retracts??

PS: I am going with the Grand Slam Theme, so front bomber glass has been converted to solid nose and top turrent has been removed.
I am also looking for better detailing information - picture etc. to simulate some degree of detailing for guns and interior at rear turrent, especial the insidemount/fitting of guns.

Bundy

Hi dmyers0403

Balance point on Tony's plan is 27%, 40mm elevator, 20mm ailerons and 25mm rudder. All pretty normal stuff as you would expect. It should give a starting point in setting yours up.

45lb is getting up there with what I imagine is a very similar wing area of around 14sq'. Even at 45lb tho you are only looking to each motor to give you around 1100watts max and with the efficiencies of having 4 props as opposed to one massive one and given this is bomber and not a fighter, to my mind you would only need to be running 5s or maybe 6s lipos. One of my 5s 5300mah packs weighs about 600g so if you could run 5s packs instead of 10s ones you would be looking at a weight saving of 2.4kg or 5lb right off the top. The trade off would be maybe 9min flights instead of 18min but to get the weight in under 40lb and a wing loading back under 50oz, I'd live with this.

I can't remember the rules governing the capacitor size but I'll go digging. I think was an old Gorden Whitehead article from Scale International mag. More importantly than the uf rating was the WV ( working voltage) rating. Again from memory I think this ideally had to be at least twice your normal working voltage.

Undercarriage will be a home made job making oleos from aluminium and a pretty straight forward mechanism using a Robart 5/8" cylinders. Plan is to build these soon so Sid can build them in as he goes so I'll be posting pics here.

We are building the dam buster version and we are continually collecting detailing information. Dave who has posted here might have some interesting stuff to help out here.

Richard

ticketec

My Feedback: (2)

Hey Richard,

If tony takes too long in geting back to you then i will just start cutting them out by hand...

As for the info, apart from the book we already spoke about, i also have in effect a photo essay of the Lancaster at the imperial war museum Duxford, the Lancaster at Hendon, the cockpit section in the Imperial War Museum London, and a few pictures of G for George in the Australian War memorial, incuding the landing gear. Seeing as had just picked up the plans when i arrived in london, i made sure i had some pictures for more info. The are not always the clearest of pic because the black undersides of the Lancaster make it hard to photograph clearly without extra lighting(which i did not have available).

The pictures of G for George was part of another trip i took to Canberra as i had organised special access to the Me-163 for my 1/4 scale project. I'll burn what i have onto a disk and send it your way.

Thanks

Dave

Canuck1

Great thread. Would love to build a Lanc this size. I have a 91in one, just to small. Keep the build pics coming

Craig.

Bundy

Hello

Here are some pics of one of the retracts I've made. It is nothing fancy just pretty much as per the plan but with oleos in each leg, 6" DuBro wheel, an old Century Jet unit and some basic bracing. Weight is about 1.5 lb for the wheel, legs and retract unit.

I was working on specs for the DuBro 6" wheel that said its width was 38mm but when I actually bought them I found they are closer 49mm. With a 12mm leg each side this makes for a very tight fit between the two w3 ribs and an impossible fit between the 2 nacelle sides NS1. It looks like the 2 nacelle formers may need some reshaping to allow this width to retract which is why I've made this basic unit to test the fit. Depending on overall weight, fit and balance I would ideally want to be able to add a deal more detail to the undercarriage and even scale geometry but there sure isn't a lot of room in there.

I have a pair of 176mm dia wheels which would be closer to scale in looks and size. Width and weight I think will see the DuBros getting the ride however.

Richard

Gtarling

Great thread folks - keep it up! I'd LOVE to build one of Tony's large models, but just don't have the space at the moment. As far as long battery leads on ESC's are concerned, there's some good info on the Schulze website - http://www.schulze-elektronik-gmbh.de/tips_e.htm However, on a model of the size you're building, I wouldn't recommend putting the batteries in the fuselage, as this will result in too many connections and leads that are way too long. Either use one pack per motor, in each nacelle, or think about one pack per wing, in a hatch between the nacelles. Personally, I'd go with one pack per motor, as it has much greater redundancy.

Bundy

Hi Gtarling

I love the way these threads bring up interesting ideas and points of discussion. It makes you rethink things and examine why we do things the way we do - just habit maybe.

Nothing is set in concrete at this stage as to how we will wire up these 4 motors and there are lots of things to consider.

I built my first electric twin back in 2002 - a RCM&E Partenavia Victor which is one very sweet plane and still going - and 3 others since then all B-25s of various sizes. Over that time I've had two instances where something has gone wrong and a motor has shut down. One was where I had a battery per motor and one was with a common battery in the fuselage. Maybe just personal preference but having experienced both I would much prefer to be total dead stick than have asymmetrical thrust.

The most recent instance was with my 84" 18lb Mitchell. It had just taken off, close to full power, wheels had just come up and doors were closing when there was a total loss of power just a few metres off the ground. Running off one battery they both shut down and she came in for perfect belly landing just shy of the edge of the field - real scars on the nacelles! One of the wires to the dean plug on the battery had simply broken off. This pack was about 3 years old, well used and under its heat shrink tubing I hadn't seen it working loose. The extra current and heat of a take-off must have finished it off. If this had been a battery per motor installation that would have been a bag job. Again this is just personal preference - there is no good time to lose a motor on a multi and there would no doubt be stories of getting home on one engine.

Another problem I have with the battery per motor option especially here with 4 is the start up sequence. My normal start up is to go to full throttle, insert the Dean plug arming key which applies power to the ESC (s), get well clear of the props, go to low throttle before the ESCc enter setup modes, give a blip on the throttle to get them started and away we go. This is where habit maybe a problem. Somewhere in all those pages that come with the average ESC there maybe a way to safely arm a ESC without entering its setup mode and without the chance of one of the other motors starting even if the throttle is accidentally knocked. There are a number of horrific stories of severed digits from working on these 4 engined monsters across the various forums and most recently at out Warbird weekend when Dennis left a trail of blood across the wing of his new 14' Sterling. One (big) battery powering 4 motors through one (initially anyway) Dean plug key to start all 4 at once appeals to me. Since Dean plugs are only officially rated at 60 amps you would have to parallel a number of keys before going to full tilt.

I don't think this set up would mean too many plugs. There would only be one power plug into each wing and the normal one to each battery whether that be 2 or 3.

This brings up the battery lead length issue and I know what the official line is here and I know I spent many long hours in the shed in the early days rearranging things to suit the 200mm ideal. Once I read Gordon Whitehead's explaination of why this 200mm limit was there and what could possibly be done to extend it I haven't had a problem. This may be just dumb luck and I know I have pushed my luck here. The Partenavia has 1100mm leads on a pair of AXI 2826 and 5S battery and my Brian Taylor Corsair which has a big AXI 5345, 10S battery and from memory draws around the 60-70amps has 600mm leads. As long as the working voltage of the capacitor is way above whatever voltage spike it is likely to encounter it seems to work. I certainly couldn't suggest anyone else do this but I get great fun from playing around and finding out what actually works and what you can get away with. And I promise no tears when it all goes wrong!

Sorry if this is a bit long winded but I love talking about this stuff. As a I said nothing is set in concrete yet and we would love to hear anyone's thoughts.

Richard

ticketec

My Feedback: (2)

Hey Richard,

Nice legs!!

Hey richard, If i scan my plans and make some changes could you cut it out for me still? There are some things that would make the building of the kit easier, like the fuse formers, if you cut "tabs" to the bottom of them in a similar fashion as the ribs, so that they can sit directly on the plan, and so then your not banking on the fuse stringer being straight to ensure that she is built square would be great. I also will build the standard bomber and not the damb buster version. Some swiss cheesing of some of the frames could save some weight, which would be a pain to do by hand but the CNC wouldn't even blink at it.

I'll have a chat with the aero engineers at work tomorrow in regards to removing some more weight and if they suspect that it might have a detrimental effect on the strength.

Also i just called Sid and if he's available i'll be poping round tomorrow after work to look over his progress so far. i'll bring my camera along for some more pic's.

Thanks

Dave

Bundy

Hi Ya Dave

Shouldn't be any problem cutting from your plan. I have promised Tony that will not cut extra kits from the electronic version of the plan I bought from him but if you can get your plan scanned that shouldn't be a problem. Any copy shop such as Mango 4 should be able to do that for you. Make sure you get them to do it in jpg format and not tiff as the tiff files are ENORMOUS! I can convert jpg to AutoCad files and you can make all the changes you like.

After seeing where Sid has had troubles so far there are a number of areas that could be simplified especially if you are cutting the parts on a CNC router. Like you say the fuselage formers is one such area. Can you make out in the pics how I have built this fuselage around a thick walled aluminium section? Makes for a very straight and quick fuselage build. Sorry Sid I didn't think of this earlier. Could also do like you say and build tabs onto the bottoms of the formers. Keying the ribs together thru the ply bracing also has worked well.

Lightening holes are really easy on the CNC so go for it. Do you have access to a CAD program such as AutoCad or Rhino??

How cool would it be have two of these things flying around together!

Richard

Oakey

Looking fabulous there Richard

I agree with gordon, i would go with a pack in each nacelle. i had to put the batteries in my mosquito in the fuz and the leads have a number of caps in them as per the article that Gordon pointed out

cheers

C

ticketec

My Feedback: (2)

Hey Richard,

I find this a funny stand point from Tony if he had an issue with it because I have bought the plans and vac formings from him, and there is nothing stopping me from going to PCK or Laser Lizard in the US and asking them to make a set of CNC bits for me..

either way, with the changes i(well we) want to make she'll end up being a fair bit different. I have AutoCad and will have the plans scanned in soon. failing that i have a flat bed scanner at home i can just scan in each former at a time.

Thanks

Dave

Bundy

Hello All

There has been a slight change in the direction of this build. Sid will be out of action for a little while to have his insides tinkered with by the good doctors. He will be back very soon, rebuilt and better than ever tho.

To keep things moving along I've decided to start a second Lanc. My main building project at the moment is a 5th scale composite CAC 13 Boomerang but I need I second project underway to keep from getting too bogged down and stale with one. I have been building a second Brian Taylor Corsair but the more I get into the design and construction of composites, the more the Corsair cries out to be built like this. So a second Lanc would fit the bill.

Sid's will still be the main one built pretty much as per Tony's plan. My one will try out a number of different ideas that have arisen from cutting and watching Sid's progress and talking to others. Not that there is anything wrong with the original design but just to indulge personal preferences, try different things and basically have fun with it. By building along with Sid's I would hope to be better able to help him through the more trickier spots as well.

To start with I've redrawn the fuselage formers to incorperate a central aluminium tube to build around ( will be removed later!) , build in a central battery box that includes mounts for a conventional aluminium wing joiner tube ( battery box may or may not be used depending on balance), make the main canopy section a removable hatch so you don't have to climb underneath to get at bits or attach wings, build in flaps just because I like them not that they are needed and at least the inner nacelles to be fully moulded. No doubt it will be heavier than Tony's original but I'm not too concerned at this stage. I'll have the power there, the wing area is there and I may be mad but I like the way slightly heavier planes fly.

As you might be able to see in some of the pics there are a few wanderings in some of the fuselage stringers as taken off the plan. I've thought about re-lofting them to get a better fit but so far ( back to f6) I don't think they are bad enough to justify the effort in redrawing them. Any one else built from the plan and found the same sort of thing?

I've also attached a drawing of what I'm currently thinking for wiring up the four motors. Bit of a hybrid between batteries in the fuse and nacelles. Basic idea is to have a power bus or grid that runs right across the wing and to which batteries can be added at any point or motors can take power from the grid. High voltage caps would go at each ESC and as Craig has suggested even at every 200mm or so along the bus. This approach would allow great flexibility in positioning batteries to get the balance right and would allow you to connect up all the batteries, close hatches etc before any chance of a motor starting. You could then stand behind the motors, insert the first Dean plug key to power up all the ESCs, get them started then add the other keys to connect the other batteries to cope with the power load of flight.

You wouldn't want to gun the motors until all batteries were keyed in and you would have to carefully watch that all the batteries were balanced. The main reasons behind this approach are staying attached to all 10 digits and flexibility in battery placement. Any thoughts?

Richard

Oakey

hi Richard

somehow i knew that you would end up building one . i must now formally appologise to patsy for sending you the pics of the lanc at the AWM. sorry patsy but i am looking forward to seeing this new beastie when i come up at Xmas.
i think that you have come up with a very good solution indeed. a Bus idea is a pretty sound approach, particularly as it will keep all of the motors connected to any of the batteries, and they should all discharge together. I might have a chat with my electrical / transient fault expert at work and see what he thinks.

more pics mate

cheers

C

ticketec

My Feedback: (2)

Hey Mate,

Sound great, another person to build along with!

We arn't the first in Oz to build this model either...... check out the pic's from the temora invitational. i think they are trying to build this as Australia's top gun.

http://boatin.smugmug.com/gallery/65...15366920_JTvUb

Beautifully executed Lanc in my book. very well done.

Thanks

Bundy

Hi Dave

That sure is one very nice looking Lanc and great inspiration to us just starting the build. Any details such as motors, weight etc?? Isn't it good to see all the detail and like you say it really adds another whole level of appeal. Thanks for the link

How did Steve's B-17 go?

Richard

Gtarling

Richard - there are so many ways to configure a multi, that it's really difficult to make the 'right' choice. After all, what IS the 'right' choice? Your scheme of a busbar running across the aircraft seems like a sound one, on the face of it, but you do need to ensure that you have very sound connections across the wing/fuselage joint(s). Also, you will need to add those extra capacitors at regular intervals across the busbar - please make sure you use 'low ESR' types. I think I'd be tempted to go for the safety of one arming link/plug per nacelle, regardless of how the batteries were configured.

Gordon

Bundy

Hey Dave

How would 4mm AA marine ply made from hoop pine go?? About $70 for a 2400 x 1200 sheet. True aircraft grade ply is near on impossible to get locally but still looking.

Richard