WhiteRook

My Feedback: (38)

has anyone out there built one? info apreciated, the brian taylor , den bryant plan
81 inches, or other

casor

White - I am working on a fifth scale design and I have the 120" fifth scale Bosman plans via AMA. I also have the Bryant and Frank Mizer plans which are both about the same size 80+" or 1bout 1/7. I bought all this stuff for reference but I am designing my own in CAD as the Bosman plans were not scale enough. Although they are all decent works, I would rate the Mizer plans as being the most accurate and the nicest from a presentational standpoint, although the other two are very good. Tony Nijhaus who works with RCME also has a design but I believe it is a smaller model. You can get a laser cut wood pak from UK for the Mizer plan and the model was recently presented in the Nov 2013 Flying Scale Models but note that it is an older design that was also presented some time ago I think in 06 by the same mag. Until I decided to do the larger, highly detailed model for competition, I was really going to do the Mizer model and so I recommend you look at that one.
Rob

stdcirrusdda

Whiterook, I have built the Denis Bryant Lysander and have had several flying sessions now gradually sorting out the trim etc. This link gives you some info and check the links within this for the build articles. Hope this helps.

http://www.rcmf.co.uk/4um/index.php/topic,100505.0.html

Max.

casor

Max, very nice model and I am happy to hear that it flies well. I too have read all the horror stories but I think if these are set up right (light, good power, washout) the Lysander should be a good flyer. I am doing a 1/5 scale model and I am pinging you for your movable slat design - actuation and how to make the slats. Any pics? Thank you
Rob C

stdcirrusdda

Hello Rob,

Thank you. Some detail of the slat construction is in part three of build articles in the rcmf link above. If this is not clear enough then let me know, if you zoom in on the photos it should be fairly self explanatory. A single servo in each wing drives the two slats via bellcranks and torque tubes. There are three pushrods/attachments for the inboard slat and four for the outboard. These are run through standard helicopter ball joints glued to the leading edge, these hold the push rod steady and allow for the angular change of the rod due to the rotating torque tube horn. Its all simple and light. I got the idea from here http://www.rcscalebuilder.com/forum/...036&PN=1&TPN=8 scroll down a bit. The slats themselves are made form balsa and lithoplate, I have found that RC Canopy glue is the best to stick balsa to lithoplate. Slats will warp easily so I covered them with glass cloth and resin as soon as I made them. I have tried the slats inflight and nothing noticeable happened which is fine, I imagined beforehand that something bad would happen.

Let me know if you need more. BTW are the build articles visible to you ie the links at the bottom of the rcmf thread ?

max.

casor

Max - thank you. I remember looking at Nigel's fabulous S79 build quite awhile ago but had forgotten about his slat mech. I was already thinking of a torque rod method but acting against curved sliders that att to the slat and that spring load shut. Kind of like a cam arrangement. Even in 1/5 scale, there is not much room out at the tip for "stuff".

I will check again but don't see the links you note.
Rob

stdcirrusdda

Hello Rob, try the links below if they dont work let me know as perhaps I have done it wrong on the rcmf forum. Could be they are in your 'downloads' and have not opened directly.

http://felbridge-flyers.org/Documents/felnew148.pdf

http://felbridge-flyers.org/Documents/felnew149.pdf

http://felbridge-flyers.org/Documents/felnew151.pdf

http://felbridge-flyers.org/Documents/felnew153.pdf

http://felbridge-flyers.org/Documents/felnew155.pdf

casor

Max - I did get the downloads with your latest, thank you for sending. Also a nice Storch in one of the newsletters! Definitely on the same page with the slat mech and it was good to see a photo on this. Don't really see any other reliable/easy way of doing that. I may however use glass/balsa to lay up the slats - right on the wing that has been covered with packaging tape. This model doesn't look it, but it is a ton of work....
Rob

stdcirrusdda

Hello Rob, Is there a build thread somewheres for your Lizzie ?

casor

Hey Max, no not yet if there will be one at all since it takes so much time to post. I have most of it designed outline-wise in 2D Cad although I had a friend do the wing for me in 3D since it is so odd. I also changed my mind on the engine, first planning for a BME103 and most recently wanting to go with a Rotomotor 85 four stroke flat twin. I have both and the Roto req'd me to blow up my outlines 3% or so for it to fit in the cowl. I had initially borrowed Dave Wigley's cowl molds with the idea that the Lizzie and the Beaufighter took essentially the same engine and he got the BME to fit in the Beau's 1/5 scale cowl. But all for naught now! The downside in all this is that I had already jig built the empennage and had started making a mold for the stab skin - but I may be able to still use all this with a bit of a fluff up. Attd are some pics of what I have

stdcirrusdda

Those look good, strong, light and it sounds as if your Lysander will be a more sophisticated build than mine but then the DB design is over 40 years old. Out interest what are the incidence angles for wing and tailplane on your plan please ?

casor

Plan? What Plan? !! I haven't determined the incidence I am going use yet, right now it is drawn at zero-zero. I am not doing the trimmable stab as per the prototype - just too complicated and not sure I really need it. To answer your question, I will probably put one degree pos incidence in the stab, keep the wing zero-zero and do a degree down on the engine and also right. All this is just a guess right now and I am open for suggestions! Help!

Re the empennage design, I saw no easy way to make it look right so I just did it as per the prototype. Alot easier in the larger scales. The ribs if you look closely are actually a sandwich of 1/8 balsa core with 1/64 ply on ea side. Overbuilt for the stab skin since I later decided to make this in glass but OK for open elev. I also did the fin/rudder in much the same way but w/ balsa ribs on the fin and skinnned with balsa. Made a steel/brass hinge for the upper hinge but not happy with it and will redo - only one hinge that I could see on the real one!

Plan for the wing root truss is brazed SS tube and the LG will be a welded horseshoe box of chrome moly sheet - kinda like the real thing. Attd are some drawings.[ATTACH]2011256[/IMG][ATTACH]2011257[/IMG][ATTACH]2011258[/IMG]
Rob

stdcirrusdda

Very impressive you are going way beyond me ! I am retired and still woud not have time for such detail and dedication I am just a club level scale fan.

Re rudder hinge I have various photos etc that I collected from the net so you probably have a similar collection anyway have you looked here http://www.cybermodeler.com/index.shtml at their Lysander sections ?

I asked about wing and TP incidence as mine was very nose heavy on maiden its better now and investigation shows the wing is +3 degrees and TP +2. On the Bryant plan it states +2 for the TP but does not give a value for the wing. Measuring the plan indicates the wing should be +5 deg which would be about right and cure my nose heavy trim whilst keeping the elevator more or less neutral. The important factor is the difference between the two incidences, +3 is enough +1 is not, this is with the 0/0 thrust line on the engine.

As you have more than one plan can you compare them re incidence angles and thrust angles ?

tks

Max.

casor

Max - I have both the Frank Mizer 1/7 plan and another from the AMA (Benson?) in 1/5 but I have not taken any incidence measurements from either. I will do so. Did you change the incidence of both wing and TP on your model? All this would seem hard to change after the model is built, so it would be nice to get right on the first try.
Rob

stdcirrusdda

Hello Rob,

No I have not changed the incidences on my Liz. The tailplane is as per plan at +2. The wing is only 1 degree more than this and I looked at increasing it with a 1mm packing piece under the front mount but this upsets the strut geometry. So I decided to live with it rather than mess with the struts as there was a risk of inducing a twist in the wing and as I have perfect aileron trim I did not want to fix one problem and create another. I have moved the CG back from the plan position by about 3-4 mm and this improves the elevator trim situation but does not affect the stall noticeably.

So I am very interested to see the values for all your plans either by what the plan states or by measuring with a protractor if you can spare the time. Maybe see if your Bryant plan measures +5 for the wing as well.

During construction I did not check the wing incidence. The parts were laser cut so click together and glue. I could see by eye that the wing seat had a positive angle and thought no more about it.

regards

Max.

casor

Max I will check over the next few days or so. Kinda surprised it needs +5 in the wing. Mizer's plan is very nice so his plan may be close to prototype, the other 1/5 scale plan was not scale enough. T Nijhaus also has a plan in 1/6 but I don't have it. I presume you originally used DB's CG location, is that right?
Rob

stdcirrusdda

Hello Rob,

Yes CG on my model is 3-4mm behind the DB plan position. As for the +5 this what I measure on the DB plan and is relative to the datum line, extended centre line of the crankshaft, as is the +2 for the TP, so a delta of +3 this is the important part . In flight the wing angle of attack would be about +3 and the TP AOA around zero again a +3 delta. My model has only +1 delta so it is nose heavy and needs a noticeable amount of up elevator to fly level on half power.

regards

Max.