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Antonov AN124 Ruslan

Probably my last big Depron plane.

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Stephen Jones14/10/2019 19:11:06
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2729 forum posts
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Well Simon,

If it will not fly under power you could always find a hill to chuck it off smiley.

Steve

Erfolg14/10/2019 20:38:49
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I am not at all sure that the model is ideal for slope soaring. The wind speed, probably needs to be optimal. Perhaps more importantly, the model is probably not going to be robust for the rough and tumble that most sites impose.

Probably more thrust is what would be required. Even this is not necessarily the correct answer. More thrust often requires bigger or better motors and fans. Which implies for a similar duration a larger capacity lipo is needed, or a shorter flight is generally accepted. It could add up to a weight increase. Another issue could be, Simon is a Colin Chapman, the wiring to supply the current is often, to my mind marginal. It is all a fine balance in this area of construction.

Stephen Jones14/10/2019 23:31:53
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2729 forum posts
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I think it would still work in a gentle breeze.

Have you seen some of the light and delicate airframes that John Woodfield slopes.

Of coarse he would have to find a nice hill with a nice breeze in the right direction.

Steve.

Simon Chaddock17/10/2019 11:22:32
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With the other side of the formers added, its terribly wobbly to start with, the long slow job of planking continues.

centreside

Slow because each plank has to sanded and formed to fit the formers and its neighbour along it whole length. It the plank has to be forced into shape their is every chance the fuselage will develop a twist as the planking progresses.

The small un planked area is for the substantial leading edge fuselage to leading edge fairing. To ensure a smooth contour this will be completed when the wing is in place.

The inside is very empty.

centrefront

If it looks like it could stand the weight I might add a Depron floor.

The undercarriage housing 'bumps' are quite noticeable.

centrebumps

Eventually some reinforced finger holes will be added in this area in order to be able to hand launch it as the fuselage is much to wide to hold. wink 2

The exact position of the holes will have to be determined when the plane is more or less complete and the CofG set.

This of course is only a part of the fuselage. There are likely to be 4 more sections to complete it!smile o

It is going to take some time.

Erfolg17/10/2019 11:41:44
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11395 forum posts
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Will there be some longitudinal stringers, to aid bending resistance, and a little torsional resistance?

I cannot see you slope soaring it though. Even Winters Hill was a +10 mile journey when available, Mam Tor is what +30 and always seems to have good blow, as to Teds Nose, is this still available, again a good distance, I have not heard of anyone flying at Disley for years, although I guess the BATS club would know.,

Will you be sectioning the fuz, using transfer bulkheads/rings, to help in both transport and in my case it would be repairs?

Simon Chaddock17/10/2019 16:11:45
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5466 forum posts
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Erfolg

With a full continuous structural skin the fuselage is in effect a 'tube' which gives substantial bending and torsional rigidity so no further reinforcement is necessary. The only real concern is the thin section of the side wall part of the former to resist local compression resulting from handling but like most of my light weights it will require some care on the 'how and where' to just pick it up! smile o

My intention is for the fuselage and tail feathers to be all one piece as it will, I think, just fit in my car.

Repairs? I will cross that bridge when /if needed. sad

If the CofG position allows it I would like to place the battery(s) and rx in the wing so only the rudder and elevator servo connections have to be made when the wing is fixed on. It would leave the fuselage completely "scale" empty! wink 2

Erfolg17/10/2019 21:17:32
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11395 forum posts
1208 photos

As you know Simon the integrity of a tube and most monocoupes revolves around the uniformity of section. the stresses being pretty near uniform around the whole of the shape. Cut outs needing compensations, where as changes in section lead to stress concentrations. It is at these points where structural failure originate. The Ant is bound to have apertures and changes of section.

Full size practice has normally incorporated stringers, for structural purposes, even if perceived as there just for the joining of sheets.

But then again Colin Chapman was renowned for also being on the limit, even his street vehicles, the race cars just capable of getting to the finish line in many casessmiley

Mark Stevens 118/10/2019 02:58:10
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127 forum posts
48 photos

I would suspect yours will slope very well if you consider how it's bigger sibling (The AN-225) did here last weekend,

Have a look at the pics and see for yourself

Link

Mark

scott finnie18/10/2019 03:41:52
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756 forum posts
95 photos

And if you just don't want to try fly it you can sell her to me

Simon Chaddock18/10/2019 22:31:15
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5466 forum posts
2865 photos

Mark S

That 225, impressive as it is, took 3 people to launch.

Mine will have just one hand, mine, as my Tx will be in the other!

Mark Stevens 120/10/2019 04:09:51
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127 forum posts
48 photos

Simon, I don't think you'll any problem sloping yours.

Mark 😀

Simon Chaddock21/10/2019 13:36:05
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5466 forum posts
2865 photos

The next task is to build the section of the fuselage up to the nose door quite a complex shape as it includes that 'cantilevered' cockpit.

I do not intend to make the nose hinged but simply 'removable' so you can at least see inside. wink 2

Although it looks like it might be just a straight continuation in fact the top section of the fuselage changes quite a bit leading up to the actual cockpit so the formers are different however by using 3 part glued together formers at least the bottom portions are all the same.

front2

This allows relatively large planks to be used in the lower area.

front1

The reminder is still slow going as it requires relatively narrow individually fitted planks.

So far the fuselage has used 72 printed parts, most of which are different! smile o

Simon Chaddock24/10/2019 16:17:43
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5466 forum posts
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The initial attempt at the cantilevered cockpit on the front section.

cockpit1.jpg

It took a few 'iterations' before it was something like the right shape so the front and mid sections could be joined.

2fusejoined

"Designing as you go along" makes progress agonisingly slow.

Next is the removable nose section.

Not exactly looking forward to this as its a complex shape and has to fit the fuselage accurately! smile o

Colin Leighfield25/10/2019 16:39:18
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5961 forum posts
2492 photos

I’m trying to work out where this one fits into the scale of clever and complex projects that you have presented to us over the years. You certainly know how to keep the old grey matter occupied. It’s probably the most challenging so far?

Simon Chaddock25/10/2019 19:49:53
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5466 forum posts
2865 photos

Colin

I don't know about the most challenging but probably the most likely not to fly properly.

I had similar doubts about my Bombardier Q400 with its long fuselage & small wing, but compared to the 'whale' like fuselage of the AN 124 its fuselage now seems modest and ever so streamlined. With two big props the big unknown was not one of thrust but of control.

With its generous control surfaces the AN 124 is likely to be the other way round! wink 2

Colin Leighfield25/10/2019 20:36:11
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5961 forum posts
2492 photos

I think the An124 is likely to fly very well, although I take your point about power perhaps being marginal. If it is you will find the solution, I’m sure.

Simon Chaddock30/10/2019 10:19:46
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5466 forum posts
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The nose plan.

nosefull

Quite a complex shape as it has a 'cutout' at the top around the cockpit and a step at the bottom.

As before built as a half shell over the plan.

noseplank1

But the complex shape and the extreme change in section over a relatively short distance makes the planking very tedious.

After all it is just a big 'fairing' that serves no structural purpose so it has to be kept as light as possible. wink 2

Simon Chaddock01/11/2019 21:42:56
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Just a bit more progress.

With one side planked and the other side of the formers added,

noseplank2

The fully planked nose in place.

noseon

The nose is located on 4 pins, one long and 3 short, to make fitting easier.

nosepins

The nose cone will be 3D printed.

Simon Chaddock13/11/2019 00:33:35
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5466 forum posts
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The ext is the rear fuselage between the wing and the tail plane.

Built in the same way as before.

rearfuse3

rearfuse2

On the full size this would incorporate the rear door ramp but will not be included to ensure adequate rear fuselage rigidity.

Once complete it does allow the four section built so far to be stacked together.

fusestack

Its getting rather big and there is still a tail section to do that will hold the tail plane.smile o

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