6 Turning 4 Burning

[Jon H]

Posted by Denis Watkins on 22/01/2020 11:06:19:

I dismissed the SC30 4stroke motors, thinking them to be too powerful

Maybe I a wrong

As looking at my notebook, running 2 of these as singles

Give or take fuel at 0% to 5%, and props 9 x 5/ 10 x 5

These little motors can give out 300W based on 0.5hp achievable with prop/fuel

Therefore could 1800W = 18lb AUW ?

I had an ASM Hercules with 4 30's in it running 10x5's as you suggested. It was 100 inch but i never weighed it. The 4 engines flew it fine, but takeoff was long and only occurred due to curvature of the earth.

If the 36' is somewhere in the order of 100-120 inch and 20 or so lbs i think it will be well set. Some power could also be sacrificed in favour of 3 blade scale props, which may be required to prevent ground strikes.

[SR 71]

Yes they all used the same fuel, 36,000 gallons of it when she was full, it could fly for 40 hours without refuelling,a lot of the missions were 32 hours,

[Simon Chaddock]

Not often realised that the B36 jet pod and pylon was 'lifted' directly from the B47 inner pods. It even included the bulge between the jets that housed the retractable 'stabiliser' wheel used on the B47.

The only addition was the retractable aerodynamic 'shields' to stop the turbine blades rotating when not in use. With these in place it would still be scale to do without actually putting EDFs inside.

Edited By Simon Chaddock on 22/01/2020 14:20:36

[Erfolg]

I have seen a number of models of the B36 (in Mags).

One had a stringered fuz, it being essentially a tube, an easy solution. The other was a polystyrene foam version (shows how long ago it was). The first I think was in the 100" size the second, I do not remember seeing. Both were in the USA.

Both were electrics.

As for performance, I think the original was not fast. Loosing out to the B52, when the all jet versions came along. The B36 remained slow. Having previously beat the Northrop YB 49 in the piston engined era.

I have a book, Convair B36 Peacemaker, by Meyers K Jacobsen, Published Schiffer Military Press. In the book, it shows the B36 being loaded (Bell X1 style) with a RepublicThunstreak, as part of the FICON programme. Apparently seeking more speed ever more powerful engines were fitted, still a max airspeed of 441 mph and a ceiling of 44,000 feet. The aircrafts forte was bomb load and distance.

There is a (few) photos of the XC 99 passenger (two tier) aircraft.

IMO power, is not a must have for this model, its proportions are eminently glider like. You just need moderate power, a standard type build, no need for looking for significant weight saving. I guess you would have a viable model with two powerful (relatively), inboard motors and  mostly show 4 low powered outboard. I am also guessing that 2*4s parallel batteries of moderate capacity (relative to watts in) would do the job. No need to build a lightweight model, that can only be flown on a calm day, liable to casual damage.

As a model it seems a goer at almost any size, with a bit of thought. I must confess, when I switched from gliders, this was on my to build list, as a powered glider I have also thought along the same lines with the U2, for DF. As with many modelers, my list of, I must build models just lengthens.

 

 

 

Edited By Erfolg on 22/01/2020 14:35:29

Edited By Erfolg on 22/01/2020 14:39:59

[Don Fry]

I know it's a very long shot, but John Wagg has a post going yesterday, titled "New old stock - SC30FS - just purchased", yesterday. May there be more old stock?

[Erfolg]

In the case of the B36, I personally never ever considered the complication of EDFs. Having only built one twin, a Bf110, I was unpleasantly surprised how much weight the cabling added to an otherwise light model. I have resolved that in future I will compromise on cabling size, to save weight, living with a higher resistance. The thought of six sets of cables is daunting. I personally would down rate both the motors and cables on the outer 4 motors. I probably toy with having the outer 4 capable of capable of being switched out, with braked propellors.

There would be no thought of a scale aerofoil section, instead E205, or similar Possibly a foam veneer wing if obtainable at acceptable price. If not a convention spared wing, built lightly, not as if it were to be tow line or winch launched.

The whole emphasis on being a model that can be safely flown in 15 mph winds, and strong enough to fly every day, when thrown in the car, landing on winter pasture (or what passes for a mown field where I now fly.

At one time I considered PVC drain piping for the fuz. dismissing the product as being to heavy, at the diameter i wanted. I could not identify a tube long, or light enough, of sufficient strength and at a cost I would pay.

I guess that in the era of 3d printing 6 engine pods can be produced, that reduces the work involved considerably. I do not a printer, though as many others I keep toying with the idea.

I many ways it could be a simple model to build at normal type scales, if the tube and nacelles issues can be solved.

Edited By Erfolg on 22/01/2020 16:34:32

[Andy Stephenson]

SR71,

How about this, a model with twice as many engines as you are considering...

12 engine Dornier

A.

[SR 71]

Oki have made a start, found a piece of 160 mm drain pipe the right size for the centre section of the fuselage

[Erfolg]

Hmm, I also have a long length in my garage.

From memory what finally doused my enthusiasm for a B36 was an anticipated CG issue. My thoughts went along the lines that the TE was straight and 90 degrees to the Fuz. All of these motors (mass) would be on the wrong side of the CG. I anticipated that even with the Lipos right up against the cabin, there would be to much mass aft of the CG. There is the obvious tail plane and a massive rudder/fin arrangement. All on a roughly equal moment arm to the Lipo, potentially of similar masses. The motors would alter the balance for the worse.

I had a solution, that was extension shafts to the motors. This could move the motors onto the CG. My problem was I did not and do not have a lathe.

I envisaged a plug in nose which carried the Lipos

Yet, I know others have achieved a viable model, that can be flown in most weathers.

Edited By Erfolg on 22/01/2020 19:00:08

Edited By Erfolg on 22/01/2020 19:02:02

[Don Fry]

SR 71, having seen your previous efforts, respect.

But as the old joke goes, how do I get to Birmingam. Arrr says Worcestershire yokel, I wouldn't start from here,

Weight behind the CG is rarely good. Or is it a mould.

[eflightray]

Have you got 6 G-26 engines ?

.

[john davidson 1]

In the video 6 burning 4 turning, the rudder acts in opposition to the nose wheel, I can't see a reason for this, any theories?

[Simon Chaddock]

john d

I think you will find the nose wheel steering is independent of the rudder and has its own control. Once lined up on the runway the nose wheel will be locked to straight ahead.

I think the 'steering wheel' is on the commanders side.

https://davetzold.files.wordpress.com/2011/08/b-36-cockpit-wright-patterson-afb-museum.jpg

Edited By Simon Chaddock on 22/01/2020 21:56:26

[Former Member]

[This posting has been removed]

[Brian Neasham]

A lot of larger aircraft have a nose wheel steering control which is not connected to the rudder pedals

[PatMc]

You can see that the rudder is being held over to the left the whole time that the aircraft is taxying. IMO it probably to counter the fact that all props are turning anti clockwise when viewed from the rear which will be causing the aircraft to swing to the right.

Edited By PatMc on 22/01/2020 22:09:02

[Denis Watkins]

You can also see that the pilot is a cool customer, and a very adept flyer.

The model is constantly trying to lift it's nose, and appears to prefer a certain track

The pilot overcomes this in a controlled scew appearance.

Has already been said, that with power and squish all along the wing must be unique properties to fly

[Erfolg]

I was not sure if it was just me, that I thought there were some issues whilst flying. It certainly did not have a rock steady flight path, I have seen with many large models.

I was impressed that he managed to thread the model through the fence opening, when I thought, will it actually fit.

It would not surprise me if there were a couple of church roofs of lead up front, although the flying did not suggest a forward CG.

As for its general performance, I suspect under my control, all would not have gone well. It would have stressed me that it did not appear to be a pussy cat. To the extent I would have been fumbling for the trims, unable to find them, I would have become more stressed and so on. Yep, the pilot did very well.

[Trevor Crook]

There's a bit of info and footage of B36's in this tale of a mind boggling incident:

https://youtu.be/p0gRHgwSGhE

[Erfolg]

Not surprised that a bomb was accidently dropped. I seem to remember that some weapons were lost in to the sea of Spain in the past. With every single thing you can think of from weapons to the domestic clothes iron, (almost) every household has, there will be accidents, some you can scarcely believe.

In the Spanish incident, i think the main priority was to recover the devices before the Russians saved them, on behalf of humanity.

In this case we were told that th Pu hemisphere were not in the weapon, as apparently was normal procedure. There could well have been other safety devices that we were not made aware of.

I did like the pictures of inside the aircraft, showing quite a lot of detail.

 

Edited By Erfolg on 23/01/2020 15:34:00

[SR 71]

1. Found somie left over MDF from building my hanger, so i have used it to make the front and rear sections, glued it into the drain pipe

[J D 8]

Drainpipe, MDF !!! Having a Giraffe.

[Denis Watkins]

Posted by SR 71 on 23/01/2020 17:00:05:

1. Found somie left over MDF from building my hanger, so i have used it to make the front and rear sections, glued it into the drain pipe

You are making a FORMER to MOULD the fuselage

SR71

[Don Fry]

We hear about death by planking. Glue the wood together, stick it in a wood lathe, tailstock out, and if you get it straight, a light skin, if you feed it straight. Not the cheapest, but quick. Lot of aircraft, can't mess about.

[Erfolg]

Denis

I suspect you have got it in one.

This is going to be an interesting project.

I suspect that it meets one of my criterion for a good model, it can be flown in most weather. I am also guessing criteria number two will be achieved, that it will be robust.

I am really interested how the CG issue will be solved without a load of lead.

I have always have had reservations about the model that requires, almost a dead calm, that need careful handling because there is not the power etc. Almost any one can build the fragile floater. I suspect this is another animal.