Electrification of Cassuts

[Erfolg]

Look forward to seeing the Cassutts with the spats.

 

I have made a little progress on my own model, completing the rear turtle deck.

 

During the work, I thought the model seemed a little heavy, so I have weighed it on the digital scales. To date it is 560g. I am not sure where this takes me other than knowing the completed model will weigh more.

 

I have been thinking that the motor in Weisskanninchen, below, develops 220w 

 

And is 40g lighter. So I may buy another of those motors, if necessary to save weight.

 

This week has been taken with running repairs. One failed Lipo, one shed blade of a folder, luckly the motor disconnected some how, before the motor was torn of.

 

Many, many years ago, when I started studying, I went to college with a guy, who subsequently married a Swedish girl, and went to live in Sweden (some where in mid Sweden, he goes hunting now, his parents are close neighbours). He told me (last year)that in the museum in Stockholm, the worlds first jet engine is exhibited, circa  early 1900s, built by a Swedish scientist. Have you seen it Tommy?

 

Erfolg

[Tommy Soderstrom]

There are quite a few museums in Stockholm and I haven't been to all of them but can't remember seeing something like that.

 

No flying this week either, too windy...

 

Station: Möcklesund
Mätningstid  Maxvind   Riktning  
03/10 20:03  17,3 m/s  syd
03/10 19:31  17,9 m/s  syd
03/10 19:00  18,0 m/s  syd
03/10 18:32  17,7 m/s  syd
03/10 18:00  17,5 m/s  syd
03/10 17:30  16,4 m/s  syd
03/10 17:01  16,4 m/s  syd
03/10 16:32  18,9 m/s  sydväst
03/10 16:00  13,0 m/s  sydväst
03/10 15:31  15,8 m/s  sydväst
03/10 15:00  17,2 m/s  syd
03/10 14:30  17,0 m/s  syd

[Tommy Soderstrom]

So, finally, after one month of wind and rain, today was flight no2 for little Miss Demeanor...

 

The first battery was not feeling well I guess but the second one was better with more punch. Too bad the ball bearings in the motor gave up after only a few flights. Going to change them or maybe install a slightly bigger motor.

 

This time I even had my camera woman with me... 

Miss Demeanor, the second flight. 

 

/Tommy

[Peter Miller]

Well, that really performed as well as my original ic powered model.

 

Were the trees and greehouse as close as they looked?

[Tommy Soderstrom]

Depends on how close you think they seemed to be...

No, not that close. The camera makes them look closer than they are.

 

Nice to hear that my little 50g motor gives about the same performance as your original Peter.

 

/Tommy

[Erfolg]

Tommy

 

The museum with the Jet engine is the Norsk museum, in Stockholm. It was designed and built? by Aegidus Elling in 1903.

 

Although great claims are made for Frank Whittle, the first pattent was issued to John Barber (a clergy man) in 1791.

 

This was followed by a Frenchman, Maxine Guillame in 1921, for a pattent for use in aircraft ( alla Dyson and the cyclone, for home cleaning purposes, initially).

 

Then in 1926 Whittles senior, Griffith (of crack propagation theory, the maths bit)published a paper on jet propulsion and design. He concluded that the concept was not viable at that time due to material of construction issues.

 

Any way I would like to see it, the Elling unit.

 

I have now completed the most of the nose area. This brought up another issue. I had noted that you continued the cheeks into the wing, whereas the Peter Miller drawing indicated that they stopped just short of the wing. It was at this point that my modem failed. I reasoned that as its purpose is to cover the cylinder heads and provide a route for the exhaust and gasses, so would stop short.

 

When I got back on line, about 3 days back, I found that they actually do blend into the wing. Although It does appear that the most cheeks are very well rounded and mostly apparently tapered.

 

So at present I have not made any decision on what to do, other than probably scrapping the cheeks (blue foam) that I have started on. Iam very impressed at the fit of your cheeks (on the model).

 

My other decision is to where to place the servos. I have looked at your pictures, but I am still not clear where yours are located.

 

Erfolg

 

I will take a photo in the near future 

[Peter Miller]

You forgot the Coanda system as well.

 

The Cheek cowls as shown on the plan are simplified and stylised . What you do with them is up to you.

 

The originals are much bigger to cover the full size engine. You can see lots of pictures if you google Cassutts.

[Tommy Soderstrom]

I have searched for Elling and the early jet engine but found nothing about it in the museums in Stockholm on the web. Seems like Elling was from Norway and I don't know if there is a Norwegian (Norskt) museum in Stockholm. The closest I found is the Nordic (Nordiska) museum.

 

Like Peter says, on the real Cassutts the cheeks are much bigger and more moulded/integrated in the fuselage, especially on the Miss Demeanor plane.

I planned to make exhausts underneath the cheeks on my plane but somehow that idea was lost along the way. I wanted them to look something like this.

The apple cheeks on my plane is built like tapered boxes so they can act as air intakes. It took some time to make them fit the nose and wing and then when they were covered I ruined the perfect fit with the covering iron. The edges on the cheeks were quite thin. Then again, you hardly notice the small gaps anyway... The apple cheeks were actually glued directly on the covering with UHU-Por and that seems to work just fine.

 

My servos for rudder/elevator sits just behind F3. I can take a better photo if you like.

 

/Tommy

[Erfolg]

Tommy

 

I lifted this from Wikipedia

Jens William Ægidius Elling (also Aegidus or Aegidius) (July 26, 1861 – 1949) was a Norwegian inventor who is considered to be the father of the gas turbine. His first gas turbine patent was granted in 1884. In 1903 he completed the first turbine that produced excess power; his original machine used both rotary compressors and turbines to produce He further developed the concept, and by 1912 he had developed a gas turbine system with separate turbine unit and compressor in series, a combination that is now common.

One major challenge was to find materials that could withstand the high temperatures developed in the turbine to achieve high output powers. His 1903 turbine could withstand inlet temperatures up to 400° Celsius. Elling understood that if better materials could be found, the gas turbine would be an ideal power source for airplanes. Many years later, Sir Frank Whittle, building on the early work of Elling, managed to build a practical gas turbine engine for an airplane, the jet engine.

Ellings gas turbine prototypes from 1903 and 1912 are exhibited at the Norsk Teknisk Museum in Oslo.

Elling also did significant development work in other areas, such as steam engine controls, pumps, compressors, vacuum drying et cetera.

In 1914 Elling produced a book called Billig opvarmning: veiledning i at behandle magasinovner økonomisk og letvint. (English: Cheap Heating: Guidance for the simple and economical treatment of base burners), which was published by Aschehoug. Books written by Elling are now rare, and are mostly found in museums and libraries.

 

When I learn to read, I will be able to tell the difference from Oslo and Stockholm. How my ex-fellow student came to be in Oslo, I do not know, I only know he lives in the mid region of Sweden, in a forested area. I just know that it was s quite a surprise to meet him a few years back, as he was middle aged or even old, no longer 19. Where as I...... well, hmmmmm.

 

What i find just extraordinary is that two other companies built what we would call jet engines before 1939 ish. Brown Boveri of Switzerland built what we would call a bypass jet, for a German steel manufacturer. Apparently there was a compressor section, the burners then the drove a rotor which was connected to both the compressor and the fan at the front. It ran on gas and was used to supply compressed air to the furnaces. Apparently it was much less efficient than the conventional compressor systems. It was removed when it became apparent how costly it was to run.

 

 I guess from a patent point of view, the application was not for aircraft. I personally find this type of distinction bizarre, could I get a patent for using a pencil to scratch my nose etc.?

 

I am very tempted to make them {the cheeks) a little larger. How ever I do not want to introduce to much drag. From your flying experience, do yo think it will matter to much? I wonder what Peters opinion is?

 

Your posting shows nicely both the exhaust, which I wondered where and how they are routed and the size/shape..

 

You have made no comment on positioning your  elevator and rudder servos. I would like to get them rearwards, so as to maximise the area for the lipo location. I guess i am at the point where I can judge how necessary it might be by placing the lipo and servos in the model, as a guide to possibilities 

 

Erfolg

Edited By Erfolg on 28/10/2009 10:42:25

[Erfolg]

Peter

 

I am not certain what you are referring to, when referring to Coanda. I associate Coanda effect with a fluid attaching itself to a surface. Is it that you are suggesting, that the effect may be beneficial in the attachment and control of air around the nose area. An advantage?

 

Or am I totally misunderstanding your comments?

 

As an aside, I came across a picture (in an old mag) of a model design attributed to yourself. Miss 57. I at first thought it was a scale model of the Harold Neuman "Ike", but the caption said it was a sports model. Is it?

 

Erfolg

[Peter Miller]

Coanda developed a jet engine and fitted to and aircraft and tested it in 1910. IT was a fan driven by an engine, Fuel was injected into the airflow and ignited.

 

Google Henri Coanda First jet engine. You will find an interesting film on You Tube..

 

Yes, I know I should find out how to post links to You Tube.

[Erfolg]

Peter

 

Ahhh. I do remember having seen old news reports, within programs that talked about the development of the jet engine. I have also seen the odd picture.

 

What particularly interests me are those early devices, which can be easily be analysed by the Brayton cycle (assuming that it is a closed system, that is the air/gas is expanded to atmospheric conditions and feedback into the intake). In essence the gas turbine as we now know it, even if only in principal

 

I really feel that John Barber is a forgotten British hero, I guess that political forces required that all other claims on the development were swept aside, in favour of the Frank Whittle engine concept. I would suspect to re-enforce British technological lead over the  Germans, at the end of the Second World War.

 

It seems that Griffiths also received rather short shrift, in the story.

 

Erfolg

 

[Erfolg]

Peter

 

I have just looked at the video. It is quite different to the one I supposed, which was an Italian aircraft, of similar concept.

 

Quite remarkable really.

 

It seems that a lot of ideas, have their origins in the past. It also seems that the real problem is often being able to get some predictive relationships and mathematics in place, both to explore the opportunities and limitations, before physical developments are attempted. It costs so much to do the full size stuff.

 

Yes, very interesting

 

Erfolg

[Peter Miller]

I think the Italian aircraft you are talking about is the Sipa Caproni. The big duct with a Gypsy engine in the middle.

 

No, there was another one now I think about it, again, a Caproni. But looked more like a real Jet. But they were in the 30s.

 

 

[Erfolg]

I have been considering the cheek blisters. My efforts have been not a complete success.

 

I think I now know why. My nose is not as tapered in plan view as the full size. The second issues is the underside of the nose, this appears to taper more than my own, with the carburetor intake sticking forward ( a bit of an issue for me flying of rough surfaces).

 

So I guess my cheeks will be a compromise, that will possibly not look quite right, particularly if a full size reference is handy.

 

My major issue is I cannot get the fit of either Tommy or Peter. How have you achieved your results?

 

Erfolg

 

 

[Tommy Soderstrom]

Patience, a lot of patience...

[Doug Ireland]

I did make some for mine but they just looked tacky so in the end I didn't fit them.

[Peter Miller]

My fit isn't that wonderful. Takes a bit of practice and quite a bit of filler.

[Erfolg]

I have finally finished the nose area, still not happy with it, does not have the feel of the full size aircraft.

 

I have now started on the servo and cables for the rudder and elevator. I did consider omitting the rudder servo, on balance decided that the weight saved is insignificant,

 

I will be able to close of the underside, once the cables are in. Looking at the posted photos and the magazine pictures it would appear that the cables emerge  at the front edge of the tailplane. Was this found to be adequate, I normally use a screwed end with clevis. I think Tommy uses a "Z" bend, does indicate that you use  a piano wire wire in a tube?

 

Erfolg

[Peter Miller]

Feel free to change the cheeks to a more scale shape. I call it character scale.

 

I use snakes with threaded adaptos that screw i to the snake and then a metal clevis.

 

Part of the snake outer extends outside the fuselage to support the inner as far as the threaded adaptor

[Erfolg]

Ohhhhhh Peter

 

I have tried to capture the contours/shape as seen in the various pictures.

 

Alas I have failed. I made them slightly larger, raked back the leading edge more. Crated a "V" shape in contour, as I think they generally are. Contoured the cheeks into the wing Ala Tommy.

 

The end result? Much the same as if I had carved them as a rectangular block!

 

Any way, on wards and forward I hope.

 

Erfolg

[Tommy Soderstrom]

Erfolg, I think one can carve on the cheeks forever if one wants to, but then again, it has to stop somewhere. I made a first revision of the cheeks on my plane, then made them a little bit thinner, then some more sanding on the corners, then, then...

No one will notice in the air anyway and that is what we build our planes for, isn't it? To fly them.

Doug's plane looked very good without the cheeks if you ask me.

 

Yes, for the elevator/rudder I use a piano wire in a plastic tube. The piano wire actually has an "L-bend" and a small plastic thing to lock them in place at each end, and it works really good.

I got a new toy a while ago, an Eagletree eLogger. This is the readout from a static test in Miss demeanor.

238W and almost 22A is pretty good for a 50 gram motor! Especially considering it's rated for max 16A...

 

/Tommy

[Erfolg]

The Eagle Tree logger sure produces useful data, particularly when having completed the model and early flights. Wish I could afford the system, at present in the UK they are a luxury, a shear luxury.

 

Just finished a balance test of the Cassutts, my main worry, that the motor would make the model nose heavy, seems ill-founded at this stage. So I have fixed the servo tray for the rudder and elevator in place, waiting for the PVA to dry. Then I will install snakes and close of the complete bottom.

 

I will then need to start thinking about the UC. At present I am drawn to either Aluminium or Glass Fibre. My concern with both set ups, is where or how do I make the stub axles. So how do others do it?

 

My only reason for rejecting the PM torsion bar solution, is that I fly of a rough field. The torsion bars would transfer the shock loads to the body. Whereas with a bolt on system, I just replace the Nylon screws as is necessary.

 

Not far from finished, yet I am probably some time away>

 

Erfolg

[Peter Miller]

Unlike ARTFs, my undercarriages don't rip out 

 

However if you prefer to bolt it on go ahead.

 

Axles are best made from caphead bolts. They don't bend. Use stiff nuts on the outside of the aluminium leg and do them up really tight.

 

A dodge for mounting Spats to axles or wire U/Cs. Solder a plate made from printed circuit board to a collect and screw the spat to that.

[Erfolg]

Peter

 

Do not get me wrong, I really do like torsion bar suspension. They are possibly the best and simplest suspension system. The problem is, our field is so rough, there is no chance of any taxing even 50mm. So landings are pretty much nose overs, take offs are hand launches.

 

A great pity.

 

My Tomboy, when ever I fly it, which is not often, requires the UC to be bent straight nearly every flight, due to the terrible surface to our field..

 

The cap head bolt idea is very good, must check that screw fix do the a size which is acceptable. Thanks Peter.

 

Erfolg