New Vintage design project?

[john stones 1 - Moderator]

Is it a big deal if you build flat bottom, rather than undercambered wing ?

[David Ramsden]

Posted by john stones 1 Moderator on 02/02/2021 16:43:39:

Well I'm on tenterhooks here, wondering if Thermal Magnet has a chance.

Well John. The plan for the Thermal Magnet is pretty sparse whereas the plan for the Stentorian has a lot more detail. Given that the models are so similar I'd say the Stentorian 'has it' by a nose.
Mind you, we're not quite on the home straight yet because I'm still not convinced that an under-cambered section is best for the performance/handling I'd like.

 

 

Edited By john stones 1 Moderator on 02/02/2021 19:03:36

[David Ramsden]

Posted by kc on 02/02/2021 18:28:19:

There is a Mick Smith Mercury which is a very rounded shape and about 78 inch span. A famously good looking design

Thanks KC. The Mercury 1V looks great. Very similar to the Thermal Magnet and Stentorian in it's nice rounded wing and tail feather shapes. Interesting to see that someone added ailerons and flaps. Huge but I could scale it down. The Mercury fuselage is much more rounded in section too which is nice.

Mind you, I'm still attracted to the 'perky' look of the Deacon which although boxey in cross-section has a lovely top-line curve that most seem to lack. **LINK**. I wonder if it's practical to have a rounded-top fuse that curves upwards. No doubt it's been done before. It would be fun bending the stringers!

Maybe I should KIS (keep it simple) and build two different models!

Great to hear about the existence of the RC Peacemaker plan. Thank you. That's definitely on my 'future projects' list.

[Robin Colbourne]

Hi David,

How about Henry Stuck's 'New Ruler'?

72" or 74" span (depending on which of the Outerzone plans you build from). A 1940 design so definitely vintage, and if you built it with dihedral instead of polyhedral, it should take ailerons nicely. The single pylon would work well with bands fore and aft if you make the wing seat wide enough and you could extend the nose if your engine is light or the tail comes out heavy.

[Robin Colbourne]

Posted by Capt Kremen on 01/02/2021 19:55:09:

Would this low-wing design 'Dragon Fly' by C K Williams from 1938 'Flying Aces' fit the bill?

(I recall an Aeromodeller plan design not dissimilar which was enlarged by the late great modeller Arthur Fox to 84" span for R/C called 'Something??' Müeller'(?) it was published in 'RCME' and featured on the cover if distant memory serves correct.

Capt Kremen, It sounds as though you mean the Schiffermuller.

The original plan' had almost no information on the fuselage construction except that it was monocoque.
If you click on 'supplement' a the bottom of the page, the plan shows the construction in the picture above.

[Robin Colbourne]

If you like the style but not the complication of a parasol wing, you can always put the wing on the fuselage and have the cockpit behind it, as on the KeilKraft Sportster and the Comper Swift.

[David Ramsden]

Hi Robin,
You've certainly pulled some very different ideas into this thread! Sadly no, I'm not keen on parasols or pylons or low wings, at least not this time around.

What attracted me to the PD Parasol was not the parasol or the fuse shape, it was the wing and tail feather shapes, the ailerons and semi-symmetrical section, the light build and relatively low power needed, slow flying ability and maneuverability. For fuselage shape I like curved top and bottom lines, if possible, a top with a rounded cross-section. Definitely a high-wing, cabin, taildragger, configuration. Around 70" span.

This has been a very interesting thread. I'm coming to the conclusion that precisely what I'm looking for probably doesn't exist which is not surprising given that I have such strong pre-conceived ideas (as stated in my opening post).

Except for it's fuselage top line and under-cambered wing, Jonathan's recommendation 'The Stentorian' (with the addition of 3-axis control surfaces) is almost exactly what I had in mind.

Thanks though. I've really enjoyed everyone's contributions.

[Robin Colbourne]

Hi David,

Thanks for the reply and the summary of what you are after.

Are you aware of the Powerplanes International Detroit Custom Cruiser? A bit smaller than you had in mind (63" span), but if you were building from a plan scaling up would be possible. Its got ailerons too. The kits come up on ebay occasionally.





There's a thread about it here: Powerplanes International Detroit Custom Cruiser

[Robin Colbourne]

With regard to fuselage shape, the Eros appears to tick your boxes.

[David Ramsden]

Thanks Robin. I prefer the Eros to the Cruiser. The only plan I've found so far is for the free flight original (**LINK**). Not seen one with control surfaces but never mind. It certainly does tick some boxes. Very interesting turtle deck and unusually high tail. Nice rounded wing tips too. Looks surprisingly modern given that it dates back to 1948.

[Roger Jones 3]

David,

A while ago I looked through the entire Outerzone 'Free Flight Sport' and 'RC Sport' sections for inspiration.

It takes less time than you might think and with the opportunities for sex, drugs, and rock 'n roll currently restricted, why not?

[Peter Miller]

I just bought a DVD with well over 2000 plans on it for just over £4. Most are PDF files and they cover everything and allsizes. Well worth the cash. If you can't find something there....give up

**LINK**

[David Ramsden]

Hi Roger and Peter. Yes I did go through all the 'RC Sport' pages on OZ. Took me three sessions. That's how I found the designs that inspired me. I also looked on various kit websites and did a Google Images search. I didn't find exactly what I wanted hence my original forum post.

So. What I'm going to do (I think) is design a 70" Deacon/PD Parasol hybrid. This won't please the vintage purists but never mind. I love designing.

[Peter Miller]

That is why I design.

I design what I like. It has to grab me. For example when I aw the Team Minimax in the colour scheme that I use I just HAD to build one. I had looked them many years ago but never did anything about it.It was the collour scheme

As an added bonus, it flies like a dream.

Then there was another model that I justhad to design and build.Destiny

Edited By Peter Miller on 03/02/2021 11:14:08

Edited By Peter Miller on 03/02/2021 11:14:47

[Peter Miller]

Then this is one that you might have liked. My Rhapsody. Very aerobatic indeed almost 60" span on an SC 32.

Plans a pre cut parts available from here

http://flyingscalemodels.com/store/products/rhapsody-58-5/

Edited By Peter Miller on 03/02/2021 11:31:16

[Piers Bowlan]

Posted by David Ramsden on 01/02/2021 18:57:36:

I thought I’d take a break from designing and build a classic along the lines of the Junior 60. I wanted something light and slow but 4-channel rather than 3.

I found quite a few 3 channel designs that I really liked the look of but I had my heart set on having aileron control for some slow, low-energy, aerobatics with half-decent rolls. An aerobatic vintage design called the Over & Under caught my attention but I couldn’t see any way that its fully symmetrical section would give a low sink rate when compared to the flat bottomed Super 60 or the semi-symmetrical PD Parasol.

David

You have said that you want a vintage style design (cabin monoplane) with plenty of dihedral, like a three channel model (R,E Th) but fit ailerons as you want to do aerobatics.

You can perform simple aerobatics in any aircraft, - loops, barrel-rolls chandelles etc. provided it is strong enough and most are. However, the unavoidable truth is that a high wing cabin monoplane with 'vintage style' dihedral will not fly nice slow axial rolls or be able to maintain inverted flight without effort, they have too much aerodynamic/pendular stability (regardless of what type of ailerons you fit).

You also mention that you want to be able to fly slowly but you see your proposed semi- symmetrical (or symmetrical) sections as a disadvantage. An aeroplane's slow flying ability is not simply a function of the aerofoil used but also of the aircraft's wing-loading and the thickness of the aerofoil (fineness ratio). Think, Wot 4 or any fun-fly;- lots of wing area in relation to their weight and a thick semi/symmetrical section. They fly slowly and have a slow sink rate too, if not necessarily a great glide ratio. It all depends on what you mean by 'glide well'. Most agree that they fly well but they don't look like your vintage style aeroplane.

Aircraft display a yaw/roll couple, some more than others (further effect of yaw is roll and visa versa). Rudder/elevator models with lots of dihedral have a very strong Y/R couple, necessary as they don't have ailerons. Ailerons cause adverse yaw but how much depends on several factors. So, for example, left aileron applied to your vintage style aeroplane will cause a bit of right adverse yaw, because of the drag from the down going right aileron. The right hand yaw will cause a roll to the right because of the strong yaw/roll couple with the large dihedral. Consequently the ailerons are rather ineffective and only increasing the aileron throw will exacerbate the problem. As Rich2 says, differential aileron mitigates this to some degree and in fact there is nothing to stop you programming in 100% differential aileron to your transmitter or indeed coupled aileron and rudder to counteract the adverse yaw. However, is it not easier to build the wing with less dihedral in the first place?

I think having a fixed idea of what the model looks like is fine (aesthetics) but 'form governs function' so that form will influence how it flies. I think you are right David when you said in a later post, you need to build more than one model aeroplane.

[kc]

There was a Mini Eros in one of Boddo's RCME Special issue in the 80's. I think it was a half size version - could be scaled up.

[Robin Colbourne]

Posted by David Ramsden on 03/02/2021 10:37:18:

So. What I'm going to do (I think) is design a 70" Deacon/PD Parasol hybrid. This won't please the vintage purists but never mind. I love designing.

Go for it David! This is your hobby to enjoy the way you want. We wouldn't have much choice if we only built what was already out there.

My Dad really enjoyed the vintage style models, but always used to say, "I didn't build other people's designs in the 1940s & 50s, so why should I do so now?"

You never know; if your design looks good and performs well, we might be seeing the plan in RCM&E one day.

With regard to Piers comments and your desire for appearance and aerobatic performance, why not build two wings, one with, say Clark Y section and vintage-style dihedral, the other with a semi-symmetrical section and minimal dihedral.  If you look at a Cessna 190, lack of dihedral is not necessarily unattractive with a high wing.

Edited By Robin Colbourne on 03/02/2021 13:19:53

[David Ramsden]

Thanks Peter, Piers, KC, and Robin for your posts.
Peter those are great colour schemes - I know what you mean. I call it 'inspiration'.
Piers, I wasn't looking for plenty of dihedral. Sorry if I said something misleading.

The PDP has 1" under each side of a 60" span. The Deacon has 3 1/2" under 52". I was thinking of about 2" under 70"

[Piers Bowlan]

How about a 120% scale up of Peter Miller's 58in span Peggy Sue 2, David - with a Leccy conversion (about 70in) You could add whatever dihedral you like, it is a free country, unless you want to go out and fly your model aeroplane that is!

Could be a bit more exciting than a Super 60 to fly, not that I am knocking a Super 60. 

 

 

Edited By Piers Bowlan on 03/02/2021 14:18:19

[Peter Miller]

Now Peggy Sue is VERY aerobatic. So is Rhapsody.

Peggy Sue is one of those models which I say only that I fly straight and level while it is inverted. That is true!!

[David Ramsden]

Posted by Piers Bowlan on 03/02/2021 14:01:53:

How about a 120% scale up of Peter Miller's 58in span Peggy Sue 2, David - with a Leccy conversion (about 70in)

Peggy certainly is curvaceous(!!) and I already have a 3s 2200 mah. I'll certainly check out her wing construction. Could be onto something here.

[Peter Miller]

David

I have sent you a PM

[Roger Jones 3]

Posted by Piers Bowlan on 03/02/2021 12:31:28:

 

Aircraft display a yaw/roll couple, some more than others (further effect of yaw is roll and visa versa). Rudder/elevator models with lots of dihedral have a very strong Y/R couple, necessary as they don't have ailerons. Ailerons cause adverse yaw but how much depends on several factors. So, for example, left aileron applied to your vintage style aeroplane will cause a bit of right adverse yaw, because of the drag from the down going right aileron. The right hand yaw will cause a roll to the right because of the strong yaw/roll couple with the large dihedral. Consequently the ailerons are rather ineffective and only increasing the aileron throw will exacerbate the problem. As Rich2 says, differential aileron mitigates this to some degree and in fact there is nothing to stop you programming in 100% differential aileron to your transmitter or indeed coupled aileron and rudder to counteract the adverse yaw. However, is it not easier to build the wing with less dihedral in the first place?

 

On my Junior 60, with the standard 'very steep' dihedral and 'inset' ailerons near the tips with arbitrarily chosen 50% differential the ailerons worked fine from day one. So much so that I had to 'INCREASE the rudder travel as I like balanced controls (eg half stick with EITHER ailerons or rudder gives an equal turn and the amounts of turn are still equal with full stick).

Ailerons not working well on such models is not any kind of theory, it's just guff put about by those who have not tried it. They work fine but it is nice to remove the associated drag-caused adverse yaw (for those who don't know how to do coordinated turns or cant be bothered).

On a 'full size' old light aircraft I often fly it's fun to keep a landing approach on the runway centreline using ONLY the aileron adverse yaw and not using the rudder at all. Though I would not recommend it to the inexperienced or those of a nervous disposition.

As for reducing the dihedral, it is not only completely unnecessary but one of the main POINTS of keeping the steep dihedral is to keep the vintage appearance and 'atmosphere' of this originally 'free flight' model. It is one of the Junior 60's distinctions and without it you had just as well build something else.

As for "easy" it's no harder than a lesser dihedral. Anyway 'easy' is not necessarily an objective in a model.

Edited By Roger Jones 3 on 03/02/2021 15:54:34

[Roger Jones 3]

Posted by Robin Colbourne on 03/02/2021 13:11:56:

Posted by David Ramsden on 03/02/2021 10:37:18:

So. What I'm going to do (I think) is design a 70" Deacon/PD Parasol hybrid. This won't please the vintage purists but never mind. I love designing.

Go for it David! This is your hobby to enjoy the way you want. We wouldn't have much choice if we only built what was already out there.

My Dad really enjoyed the vintage style models, but always used to say, "I didn't build other people's designs in the 1940s & 50s, so why should I do so now?"

You never know; if your design looks good and performs well, we might be seeing the plan in RCM&E one day.

With regard to Piers comments and your desire for appearance and aerobatic performance, why not build two wings, one with, say Clark Y section and vintage-style dihedral, the other with a semi-symmetrical section and minimal dihedral. If you look at a Cessna 190, lack of dihedral is not necessarily unattractive with a high wing.

That's rather nice. The Cessna C34 (I S Cameron Aeromodeller March 1960/Outerzone) is similar.