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-   -   To design up and build an Avro Lancaster (http://www.Wattflyer.com/forums/showthread.php?t=68344)

solentlife 10-18-2012 11:06 AM

To design up and build an Avro Lancaster
 
First an intro as to why I need to do this ....

Hobby King Lancaster is refused on basis of size / weight via Latvian Post etc. - so my intended purchase is now cancelled.
I've built various over the years from plans etc. and I have a couple of traditional plans + a general of a foam block version.

I need help, ideas, thoughts as to putting this together in easiest way. I want to avoid hot-wire cutting if possible, at least avoid large sections as what generally happens there is ruts and divots ..

Size ? Somewhere between 1000 - 1500mm ... small ennough to be easily transported, but large enough to look part in the air. I also want to be able to hand-launch it at rough sites as well as have retracts for good paved areas ... Seriously !

My first ideas are that the Lanc has a relatively flat slab sided fuselage, the wings even though break-jointed at a nacelle are basically near flat bottomed.
This leads me to consider ;

Fuselage can be set up as slab side sheet with formers and folded sheet for top / bottom curved sections. Each side being laminated from two 6mm foam sheets to stiffen up such a long structure but keeping light. Top decking from 3mm, bottom from 6mm. All formers are laminated from 2 x 6mm or 3mm as appropriate.
Canopies and turrets can be foam block as I don't really need clear etc.
No need for bomb doors .. a slot in bottom would be good enough with removeable hatch for any 'sweet drop' at displays / meets etc.

Wing - this is the part that needs care as the wing has that break-joint plus has to carry 4 nacelles / motors ... plus retracts if I can squeeze them in. I want to avoid too much CF and weight to stiffen wings ... so reckon I might adapt the method I used on the SE5 I built ...
The Lanc wing is near clark Y, actually I believe the real wing is Clark YH ... so a flat 6mm sheet forms the basic shape. I can then cut 6mm strips to laminate into 12mm spars with width about 9mm ... these then resined onto the bottom sheet. A top 6mm sheet is then bent and resined to the spar and LE / TE to form an aerofoil shape. The wing would then be cut at the break dihedral point and extra infill made to strengthen for the nacelle and angled joint.

That's the barebones at moment in my mind ... so thoughts ladies and gents ...

If anyone wants to suggest inventory .. then please note that due to lack of LHS etc. - I'm pretty well forced to use Hobby King or ebay for most things. One area I'm undecided about is motors and props. I don't really want screaming high KV motors, but I cannopt fit low KV and big props .. not enough clearance between nacelles. So what to use ?
Battery ? Is it better to have a single large in bomb bay ? or split it to two batterys .. ie one battery powering inboard motors, other the outboard ? and carry them in wing ?

Controls ... unlike many who consider it too hard to connect up rudder ... I propose flexi snakes or stiff transverse rod to provide rudder control ... more on this later once I sketch up the idea.

Looking fwd to input ... I know it's only a planning stage on this thread at moment and I have about 2 weeks before I return home, but I hope this can become a group effort and others may jump on and build as well. Before anyone asks - I''m no good with CAD software - so plans will be based on sketches ... and eyeball work ... but I will try best to post up sketches ... anything I can for others to use / amend / modify etc.

Fingers crossed and wish me luck !

Nigel

solentlife 10-18-2012 01:12 PM

Motor / Prop selection ...

My idea is lets say a 1.2m span ... maybe 4 x 1200 - 1500kv motors with 7x5 props with 3S Lipo. (Correct me if thoughts are I should change that ...)

Question : With 4 props spinning away .. contra rotation. My thoughts are to not only have contra rotation based on each wing side .. but also the pair each wing ... that is ....

not only one pair contra to the other pair per side .. but also the two making up the pair are contra.

ie left outer anticlockwise rotation, inner left clockwise. Inner right counterclockwise, outer right clockwise.

The motors paired as inners and outers ... so in event of one system failing - we still have a prop either side turning.

??

Nigel

solentlife 10-18-2012 01:18 PM

1 Attachment(s)
Here's a PDF file of a plan available online ... at 74" and traditional build it's more for outline and style than actual build ... but gives a good idea of form.

Nigel

Bill G 10-18-2012 10:47 PM

I imagine you've seen the other Lancaster plan at outerzone.uk also. I'd probably take either one of the plans and use them for the former outlines, drawing keels from the plan and building it somewhat like a Guillows buildm with simple keel and former construction. Really simplifies the build, versus trying to figure out exactly what the designer had in mind, especially when there are no build photos for many of these vintage plans. No chance of talking you out of foam and using balsa? With 1/32" sheet there are a few dips and waves, but they can really be lightened up from using 1/16" or heavier sheet. I've been using it for fuses all the way up to the size of the Comet build, keeping the weight down with good results.

If you want a really good Merlin engine sound, you can't beat gearboxes, although they're obviously more effort to mount and fit than outrunners. I like the mini-Merlin sound I got out of my P51, with a geared 370 inrunner setup:
http://www.youtube.com/watch?v=JNzCN...3&feature=plcp

pmullen503 10-18-2012 11:33 PM

Here's a Lanc in about the size you want and done in foam. http://www.rcgroups.com/forums/showthread.php?t=1550827

I can recommend this motor for a 7" prop http://www.rctimer.com/index.php?gOo...0&productname=

Inexpensive, runs quietly, and is robustly made for it's size. 12-18A, 18 to 25 oz. of thrust on 3S. Very efficient with a 7x3 on a Bixler and fast on my Polaris with a 7x6. The motor doesn't even get warm with either setup. You could probably use GWS 7x4x3 which are available in CR styles. Probably overpowered for only 1.2M but you would definitely be able to hand launch it!

Of course, that means 4 ESCs, but you might want differential throttle anyway.

I agree with Bill, four brushed motors with gear boxes would sound pretty cool.

I think you could get away with 3mm wing skins. The scale airfoil is thick enough for a decent spar.

solentlife 10-19-2012 02:32 AM

Foam vs balsa .... the problem here is supply. In Latvia we have only 2 shops and they are 3hrs drive away and prices are unreal. The size balsa they have is limited also. Foam is available 5 mins walk from my house !

I'm a traditional old fart builder balsa etc. but have graduated to replace in various areas with foam ... good example is where I crashed my Ultimate Bipe (World Models wood job) and rebuilt front with foam blocks and wood spars. Same weight, but quieter and motor mount is far better now.

I like the gearbox idea ... but prefer efficiency of brushless motors ... and the reduced weight of them.

All good stuff ...

Yes I have the Outerzone as a favourite and have downloaded the plans etc.

The best plan of course is the Tony Nieuhaus one as the Plans service also offers vac-formed turrets / canopy etc. to fit ... but it's not cheap ! I remember back in the 80's when it was featured in UK Magazine .. with 4 x 20 IC glow motors. I had the plan but lent to another ... we were going to build it for a Club Display model ... unfortunately he passed away and plan got lost with his things when cleared out.

I'm thinking that the formers etc. shown on plans can still be made up with foam .. I found it surprising how stiff a structure can be once formed even with thin foam. That SE5 wing was an eye-opener.

To keep weight down - it's possible to laminate foam either side off thin balsa ... gives good stiffness but light weight ...

I'm really open for all ideas ... and I do apologise if I don't use odd ideas - no offence meant ... at end of day - I will have to work as materials available dictate and also my ability.

The end result is to do honour to my Mum who worked on Lancs during WW2 ...

Nigel

solentlife 10-19-2012 03:09 AM

RCtimer .... I use them for replacement motor shafts and C clips as well as liking their motors. I cannot be certain but their motors and Turnigy look remarkably similar ... both have always had good use out of.

I will certainly have a serious look and likely use those linked to... a 7"prop is about the size I'm considering ... with the contra set-up already mentioned ...

51" ... yep that's about right.

The RCGroups thread .. the build system was what I was thinking about ... Keels, Spines and formers. I've printed of the thread ... as a read to fall back on.

Greeat stuff ..............

Nigel

solentlife 10-19-2012 03:55 AM

Now as everyone knows - I'm a bit of a budget conscious person ... a cheapskate !

Found this :

http://www.hobbyking.com/hobbyking/s...ess_Motor.html

Reckon 4 of those would do the job ... with 7x4 props and 3S ... 20A ESC's ...

Still looking at RCTimer though ...

Nigel

solentlife 10-19-2012 04:41 AM

OK .... possible motor / Props / ESC combo (4 of )

Motor : 2204 1550KV
http://www.hobbyking.com/hobbyking/s...ess_Motor.html

(the RCTimer motor is over 200W and 30A ESC ... maybe that's a little too much with 4 motors ? ... needs a lot of battery ... 200W on a 3S = 18A ... so 36A per battery .. for 5 mins flight = 3000mAh pack at least per pair... )

2 Right hand APC 7x5 + 2 Left hand APC 7x5

Each motor with 20A ESC ...

http://www.hobbyking.com/hobbyking/s...C_3A_UBEC.html

If the motors draw around 10A ... then 2 x 1800mAh 3S should give me a reasonable 5 mins flight time.... using Zippy Compacts I can keep size and weight down. Plus of course I do not need heavy high C ratings.

mmmmmmmmmmmmm itching to get home and started !!

Nigel

pmullen503 10-19-2012 02:47 PM

The RCtimer motor I recommended is over kill for that size Lancaster. It's one of my candidate motors for a 2m Dehavilland DH-91 that I plan to build this winter.

I have another recommendation: http://www.hobbyking.com/hobbyking/s...idProduct=5684

I have 8 of this series (in the 2209 and 2217 sizes) in various planes and they are nice motors. I think it would easily turn 7x5 props.

Here's another possibility: http://www.hobbyking.com/hobbyking/s...er_1534kv.html I haven't gotten my hands on it yet (backordered of course.)

Bill G 10-19-2012 07:36 PM

Quote:

Originally Posted by solentlife (Post 886196)
Foam vs balsa .... the problem here is supply. In Latvia we have only 2 shops and they are 3hrs drive away and prices are unreal. The size balsa they have is limited also. Foam is available 5 mins walk from my house !

I'm a traditional old fart builder balsa etc. but have graduated to replace in various areas with foam ... good example is where I crashed my Ultimate Bipe (World Models wood job) and rebuilt front with foam blocks and wood spars. Same weight, but quieter and motor mount is far better now.

I like the gearbox idea ... but prefer efficiency of brushless motors ... and the reduced weight of them.

All good stuff ...

Yes I have the Outerzone as a favourite and have downloaded the plans etc.

The best plan of course is the Tony Nieuhaus one as the Plans service also offers vac-formed turrets / canopy etc. to fit ... but it's not cheap ! I remember back in the 80's when it was featured in UK Magazine .. with 4 x 20 IC glow motors. I had the plan but lent to another ... we were going to build it for a Club Display model ... unfortunately he passed away and plan got lost with his things when cleared out.

I'm thinking that the formers etc. shown on plans can still be made up with foam .. I found it surprising how stiff a structure can be once formed even with thin foam. That SE5 wing was an eye-opener.

To keep weight down - it's possible to laminate foam either side off thin balsa ... gives good stiffness but light weight ...

I'm really open for all ideas ... and I do apologise if I don't use odd ideas - no offence meant ... at end of day - I will have to work as materials available dictate and also my ability.

The end result is to do honour to my Mum who worked on Lancs during WW2 ...

Nigel

I can understand the balsa dilemma. I glue scraps together to create sheet for cutting formers. I only throw away balsa scraps under 1/2" in size, and have all my scrap balsa from when I started building in a small box. Even with the recycling program, it's still expensive, and has something to do with why I build mostly smaller scale planes. At 70", it starts to get expensive.

The geared 370 setup is a brushless setup. They are actually a bit more efficient than an outrunner, when ideally setup. Using props like the GWS HD is less efficient than the SF prop on the setup I showed, but they really sound like a fuel engine. I have one that people have thought was a really smooth running glow motor. The exact motor of the one I showed was a Himax 2015-4100, which is generally considered 370 class, such as the Park 370 inrunner. Four of them should provide ample power for a Lancaster of around 50" to 70", or even larger. The gearboxes are getting a bit harder to come by however, with GWS not producing much. The GWS cloned gearboxes such as Eflite are too expensive at $10 US or more, for what I care to pay.

mclarkson 10-19-2012 11:12 PM

Wow. Getcha a little foam and you go crazy! :D

Good luck with the build, sir!

pattern14 10-20-2012 01:39 AM

esc options
 
It's just a thought, but when I built a four engined bomber prototype last year, I ran four seperate esc's inside the nose, which took up a fair bit of space. My good mate Barry (bazex49) devised a system of putting the motor/battery/esc inside each seperate nacelle, with only the wires to the rx going into the fuse. Also, the quad copters advertised on HK use a 4 way esc set up which may be able to be adapted to your Lanc. I also ran two pusher and two tractor props to cancel out torque, and it flew rather well:) It is a very unique sound in the sky, and well worth the effort. Best of luck with this one[popcorn]:ws:

solentlife 10-20-2012 04:09 AM

I have a pal who flies quads .. and another who has developed multi for commercial camera work. Both these guys will be invaluable for help on the ESC / multi side.

To pmullen ... both motors interesting, along with the 'Donkey' I found on HK.

The 7x5 prop is actually more than I really need I reckon .. but the problem is to get left and right hand via same supplier in same check-out. 6" is too small in my mind .... 7x4 is ideal, but as far as i see not available in L + R. I'd like 3 blade - but as I will be hand-launching and belly landing quite often - not a wise choice !

I noted another scratch builder had his props overlap ... not something I want to do. Means offsetting the nacelles.

As long as I can keep the ESC's and gear reasonably small - I can instal in the fuselage and only have to run the motor leads out to the nacelles, leaving room for the servo-less retracts.

Baz49 is already an email pal ... and we have interesting chats at times ... Brits together and all that !
He built a Wellington ... a model I plan to go for later as my father flew Wimpy's during the war.

To another who saves balsa scraps ... absolutely !! I also save foam scraps ... waste not - want not ! In fact it just about covers most things .. even bits of wire etc. that get snipped of ... they all find uses.

OK onto another area ........... with the availability of miniature servos .. I'm wondering about having servos instead of link rods for such as the rudders .. I have a box of 4.5gr servos that are remarkable and I already proved their ability by use of 2 on a 64mm EDF elevator system. They would be more than capable of 1 for each rudder.
There's an idea I toyed with many years ago but never actually tried. Here it might just be the ticket.

We all mount servos and then have a link rod or snake to the surface. What if the servo was inserted into the hinge line and the arm centre aligned with hinges .. such that the arm actually was embedded into the surface and direct operation ? Admittedly there would be a slot to allow servo body to clear ... but no slop, absolute control.

So lets look at :

Rudder control.

1. Above embedded servo ? But leaves tail wheel to connect up.
2. Single central fuselage servo with transverse rod
3. Flexi snakes from single servo
4. No rudder control and only tail-wheel ... not really what I want !

Elevator.

This I consider warrants split servos to ensure accuracy.

Ailerons.

Also split servos and to be outer wing panels only.

Flaps.

Inner wing section only and split servos.

Total : 8 - 9 servos .... which means separate BEC especialy that I shall be fitting a pair of servo-less retracts as well. This brings me to powering the retracts separate to all other .. ie a second BEC specifically for the retracts.
Anybody care to suggest the wiring for that ? as I think ... the retracts signal wire along with ground plugs to Rx .. the +ve and ground connect to separate BEC. The first BEC for Rx / servos as usual with ESC BEC's isolated ...

BUT .. considering I have 4 ESC's ... is there no way I can use these BEC's to advantage and save installing separate ? Can I not use 1 to Rx and servos / retracts receive power from other BEC's of the ESC's ? Is it not a case of connecting the + / ground of each servo to a respective BEC ? with signal wire / ground to Rx ?

Nigel

Bill G 10-20-2012 10:33 AM

If you want counter rotating 3-bladers, GWS has them in 7" and 6", if you can get them. I've been using Dynam ESCs, which I believe have a 3A switching BEC, all the way down to the 12A size. I never thought about it, but I wonder if the switching BECs can be combined? I know that shouldn't be done with linear BECs, but maybe it can be with switching. Irregardless, you could quite possibly run 9, 4.5gm servos from a 3A switching BEC, granted the 3A rating is actually correct. I know firsthand that the Eflite 30A Pro ESC will run at least 5 of them, and I believe it has a switching BEC of only .7A.

solentlife 10-20-2012 11:05 AM

Quote:

Originally Posted by Bill G (Post 886385)
If you want counter rotating 3-bladers, GWS has them in 7" and 6", if you can get them. I've been using Dynam ESCs, which I believe have a 3A switching BEC, all the way down to the 12A size. I never thought about it, but I wonder if the switching BECs can be combined? I know that shouldn't be done with linear BECs, but maybe it can be with switching. Irregardless, you could quite possibly run 9, 4.5gm servos from a 3A switching BEC, granted the 3A rating is actually correct. I know firsthand that the Eflite 30A Pro ESC will run at least 5 of them, and I believe it has a switching BEC of only .7A.

3 bladers I think will be saved for decent surfaces ... which rarely have now. Belly landing will destroy 3 bladers I reckon ... I can take-off as I laid 25m of hard rubber runway, but it's only 1.4m wide !!

The ESC / BEC question ... I have no worries unlikje some about linear BEC's .. never had a problem so far. I've run and do run 5 servo machines of 3A .. 5A BEC's ...
But here I will be running possibly 9 servos + 2 servoless electric retracts. That's a lot for a single BEC, separate or not. So I want to see about using more than 1 BEC from the ESC's ..

1 dedicated for the retracts just in case of stalled leg !

the remaining servos divided up among the remaining 3 BEC's ... ie 3 servos each.

How to wire them up ? Is it connect red leads direct to BEC's and only one red to rx ... with signal and grounds common ?
Is it better to have separate Rx power pack with servos powered independently ?

Anyone done this ? I bet others are interested if they do multi motor jobs ..

Nigel

pmullen503 10-20-2012 03:05 PM

Quote:

Originally Posted by solentlife (Post 886388)

The ESC / BEC question ... I have no worries unlikje some about linear BEC's .. never had a problem so far. I've run and do run 5 servo machines of 3A .. 5A BEC's ...
But here I will be running possibly 9 servos + 2 servoless electric retracts. That's a lot for a single BEC, separate or not. So I want to see about using more than 1 BEC from the ESC's ..

1 dedicated for the retracts just in case of stalled leg !

the remaining servos divided up among the remaining 3 BEC's ... ie 3 servos each.

How to wire them up ? Is it connect red leads direct to BEC's and only one red to rx ... with signal and grounds common ?
Is it better to have separate Rx power pack with servos powered independently ?

Anyone done this ? I bet others are interested if they do multi motor jobs ..

Nigel

I'm not aware of any simple, cheap system for pooling the output of several linear BECs. Just connecting all the red leads and grounds guarantees that only one will take most of the load. It's cheaper and simpler to just use a high capacity switching BEC or a receiver battery.

You can use an second receiver to simply split up the loads. Say, retracts, flaps, and two motors hooked to one receiver taking power from one of the ESCs. Ailerons, rudder, elevator and two motors on the other receiver powered by a proper UBEC. That way a gear jam that takes out the entire second system only takes out flaps and two motors. The onboard BEC can easily handle the retracts.

I've used multiple receivers to ease assembly by putting one receiver in the wing and one in the fuse. That way, all you need to do is make a single power connection when assembling at the field. With compatible receivers for many systems so inexpensive, it sometimes costs less to add a second receiver than to buy the servo extensions!

I went the thin flexible push rod route to do the twin rudders on my Beech D-18. The idea of burying the servo arms in the rudders is interesting but I'd be concerned about maintenance and adjustment.

solentlife 10-20-2012 06:22 PM

1 Attachment(s)
mmmmmmmmmmmm I forgot about splitting Rx's .... interesting solution.

I'm definitely not going to run all of one source. I think that's risking fault.

Attached is a simple diagram of what I think about ...

Nigel

mclarkson 10-20-2012 09:50 PM

While there's something to be said for redundancy, there's also something to be said for reducing the number of parts that can go bad. Modern jetliners have two engines rather than four in part because there's less to go wrong.

pmullen503 10-20-2012 11:04 PM

Quote:

Originally Posted by solentlife (Post 886412)
mmmmmmmmmmmm I forgot about splitting Rx's .... interesting solution.

I'm definitely not going to run all of one source. I think that's risking fault.

Attached is a simple diagram of what I think about ...

Nigel

I can't say if it would work or not. I think it would be a nightmare to wire: 3 separate connections for each servo!

What about a fast acting 1A fuse in the line to the electric retracts?

Bill G 10-20-2012 11:37 PM

Some of the electric retracts have current limiting, in the event of a bind. The retract draw is only momentary and not continuous like the servos. I'm more along the school of thought that an ESC with a 3A switching BEC would probably handle the load, and that heat buildup is as much of an issue as momentary peak draw. The only BEC failure I ever had was almost certainly due to almost no air circulation at the ESC, and the weak 1.5A linear BEC finally shut down at the end of a long flight, driving 5 servos on 3s lipo. I believe the line voltage increase due to dropping throttle on landing approach is what finally shut it down. To each their own, but I wouldn't cringe at running a number of efficient 4.5gm servos and electric retracts on a 3A switching BEC.

I've heard of paralleling BECs with Schottky diodes, but I'm not sure how this really works in practice.

On Mark's thoughts, some folks have ran 4 engine planes with 2 engines and 2 props freewheeling. In the air nobody can tell the difference.

solentlife 10-21-2012 02:47 AM

I considered freewheeling 2 props ... but decided that if I'm gonna do it - I should do it properly and have the 4 working !

The wiring of the servos would be simplified by using a junction block. The servo leads themselves would stay as is ... then extension leads of split to the various contacts in the block. Sounds a mess but in fact would be simpler than you think.

The extra Rx is still a serious contender ... it would make the whole a lot easier ...

Given that we have potentially 4 BEC's ... why not capitalise on this ... have 3 Rx's ... given that use FrSky, cost is not that great and they are small ... particularly the 7 ch. I'm not so sure about the 4ch - as I've never used that. Is the 4ch a full range or a park Rx ?

More I think about it - the more I am inclined towards the multi Rx solution.

It also eases the question of dismantling the model for transport if only the LiPo connections need making / breaking ...


Nigel

pmullen503 10-21-2012 03:45 AM

Quote:

Originally Posted by solentlife (Post 886487)
I considered freewheeling 2 props ... but decided that if I'm gonna do it - I should do it properly and have the 4 working !

The wiring of the servos would be simplified by using a junction block. The servo leads themselves would stay as is ... then extension leads of split to the various contacts in the block. Sounds a mess but in fact would be simpler than you think.

The extra Rx is still a serious contender ... it would make the whole a lot easier ...

Given that we have potentially 4 BEC's ... why not capitalise on this ... have 3 Rx's ... given that use FrSky, cost is not that great and they are small ... particularly the 7 ch. I'm not so sure about the 4ch - as I've never used that. Is the 4ch a full range or a park Rx ?

More I think about it - the more I am inclined towards the multi Rx solution.

It also eases the question of dismantling the model for transport if only the LiPo connections need making / breaking ...


Nigel

On the multiple rx solution, I've only done this with non-telemetry radios. With Spektum, if you bind both rx at the same time you can bind them to the same model number.

As a new convert to Frsky I have not had the chance to actually try two "D" series receivers simultaneously. I suspect the telemetry would be messed up at the very least. Probably not a problem with "V" receivers. On my 9x, I'm thinking about adding a DHT to go with the DJT module, and using PPM16 protocol for 16 channels.

Once you get telemetry, it's hard to live without.

solentlife 10-21-2012 05:06 AM

The 9x is a doddle for multi Rx use .. as it has no Model match.

My present 9x is non-telemetry module - so that's simple bind and go. The 2nd 9x on it's way to me as we speak is with telemetry even though I have no plans to use T. It's just that FrSky now basically provide the T enabled module cheaper ...

Most of my Rx's are the 7ch version and I love them ... simple, light and easy to bind. The re-lock time on them if you test by switching of Tx and then back on is fast ! Makes me wonder why anyone would want to use any other system !

Checked the 4ch ... it says 1.5km range - but its single antena, which says to me more for parkfly than serious range. So it's 7 ch Rx's for me. Given they are only $3 more .. why risk it !

So at present .. idea is to have 3 Rx's ... each powered by a BEC from ESC. The 4th ESC to have it's BEC red lead disconnected.

Now here's next question.

We have 4 motors. Do we connect all 4 to one channel ? so moving throttle stick controls all 4 together ? Or do we split inboard / outboard to separate controls ?
Years ago when I saw another with a 4 engine job - he set inboards via a slider and the outboards via the throttle stick. It meant the motors could be adjusted to balance in pairs. For landing he just reduced stick and the inboards were enough to maintain control but not to keep steady height. He could of course slip hand down to slider to increase or decrease as needed.
With the 9x - I reckon I could do similar but maybe also mix the two so when I push to max on stick - both pairs increase ? still with pot controlled pair able to adjust ?

??

Nigel

solentlife 10-21-2012 07:18 AM

Summary so far :

Size : about 51"

Motors : 4 x 2208 or similar at 1400 - 1550KV

Props : 7x4 ... 7x5 contra rotating pairs

LiPo : 2 x medium 3S ... ie 1800 - 2200mAh

Servos : 2 x aileron, 2 x elevator, 2 x rudder + 2 retract

Rx : 2 or 3 depending on set-up of ESC / BEC

Construction : Foam sheeted framework with balsa stiffening where required. Wing to be foam sheet over laminated foam / balsa spars. Tail feathers to be foam sheet. Bomb-bay hatch to be magnet style hatch access for batterys etc., removeable to allow sweet-drop if reqd.

OK .. moving on ..

Painting : One guy I fly with uses fax roll paper to cover foam ... with watered down PVA glue as fixer. Will trial this on scrap before committing. My initial idea was to get model tissue and use that with PVA to form a skin. The paint will be household emulsion semi-matt. This gives excellent coverage and really good WW2 style look ... unlike most ARF / RTF models gloss ! It is also available in any shade you want mixed.

Wheels : What size wheels for such a model ? When you look at real life photos of Lancs - you note that main wheels are actually quite large diameter. For simplicity I will have wheels into slots in nacelles and no doors. Once in the air - I don't think it will be that noticeable.

Anyone else have anything to add to the summary ? It really is my wish that a list can be drawn up that embodies many peoples ideas and provides a base for others to build as well.

Once I get home and started on this - I will detail all the materials and ways I get around obstacles ...


Nigel


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