abufletcher

What sort of flight time can I expect with a 6 oz. tank with a Magnum 52FS? I'd like to put in an 8 oz. tank but it just won't fit into the nose of my Eindecker! As an alternative I've also considered using 2 x 4 oz. tanks with one tank in the nose (on a rack above the servos) with a second tank behind the pilot's seat (as per the original).

Other questions:

1. How reliable is the two tank set up?

2. How much does the distance between the two tanks matter (it would be about 6 inches)?

3. Which tank would empty first -- the forward or rear tank (I'd imagine this would require in-flight trim).

4. How much does it matter if the tank is above the carb (since the engine is mounted inverted at a 45 degree angle)?

I'd really appreciate you expert opinions on these issues. When it comes to the "guts" of an RC plane I'm an absolute rank beginner!

--Don

abufletcher

BTW, here's the space I have to work with and I'm trying to have a semi-scale cockpit with scale pilot so the fuel tank have got to be "hidden either under the front deck or under the covered section behind the pilot (or both).

Any and all creative ideas welcome!

The PIPE

Dear Abufletcher:

The PIPE Here yet AGAIN...and I'm getting my pair of FMA Quantum-8 Ch.03 RC receivers NICELY ENCASED in some "hard shell" plastic enclosures from POLYCASE (the available PDF file on the EXACT case I'm using is at http://polycase.com/pdf/detailed/1521TX.pdf ) this weekend and into NEXT week...after that, recovering the right wing, making an all NEW spring steel tailwheel assembly with materials from Small Parts Inc., a complete REBUILD of the fuel tank (with STAINLESS STEEL lines through the stopper!), also courtesy of Small Parts, along WITH one of those NEW "hard-shelled" encased FMA Ham band receivers-will have MY dependable old Balsa USA Swizzle Stick...



...back FLYING again in a few weeks, after that solar glare caused CRASH last September...!

Your Magnum 52 SOUNDS like it SHOULD get pretty much the SAME economy as my Saito 56 was during the final stages of ITS break-in early last year...it was racking up a consumption rate of something like 5/8ths of an ounce a minute at FULL power...and a six ounce tank of fuel SHOULD last you about TEN MINUTES of full power flying, and perhaps more like FIFTEEN if you're likely to "manage the throttle" in a SCALElike manner like I've always done!

I've NEVER tried a DUAL fuel tank setup on any of my planes as yet...but IF you should choose to go with a single 6-oz. tank, you'll very likely get those figures I was getting...and since that engine IS going to be in your Eindecker, you MIGHT want to see how well it spins a 13 inch prop...those VERY oldest WW I birds DO like a big; SLOW turning prop, and 'on average', NOTHING turns a big prop like a FOUR STROKER can!

Hope this tip helped!

Yours Sincerely,

The PIPE!

abufletcher

I know this is a stupid question but what I would I be looking/listening for when I test with a 13" prop (probably 13/5) when testing the engine?

The PIPE

Dear Abufletcher:

The PIPE here yet again...and if you've got a TACHOMETER for your field gear, by ALL means use it with a four stroke engine!

My 1980s vintage Futaba "TachoTimer" unit is what I've been using since I've returned to the hobby in 2001...and I was getting figures of about 9300 rpm from its display with a 13 x 6 on MY Saito 56 on 10% Red Max four stroke fuel...the thread here at RCU that has my experiences about a year ago on my Saito's break-in progress at THAT time can be found at http://www.rcuniverse.com/forum/m_67.../tm.htm#670560 should you wish to read about it more!

By all means, make sure you START breaking an engine like yours in with NO larger than a 12 inch prop (a 12 x 6 would be PERFECT for the main series of initial ground runs)...and once the engine has been through the first few tankfuls, perhaps running it as Saito suggests [for THEIR 'mills'] at only a fast IDLE speed of around 4,000 prm for the first 15 minutes to half hour of run time. THEN slowly start placing bigger props on there...after about half a gallon of fuel has been run through the engine, THEN it should be time to try the 13 inch prop!

The 13 x 5 WOULD be a tiny bit LESS load than the 13 x 6 I used on my Saito in the test stand was using...but IF you get that "bit-over-9,000-rpm" on it as I got with my Saito 56, while running the engine just about a quarter turn RICHER in mixture than the peak RPM you'd be observing on a digital tachometer, you SHOULD be all right!

Hope these tips help also...!

Yours Sincerely,

The PIPE!

Trev

HI abufletcher

Unfortunately I have no experience with dual tank setups, to date I didn't know such a thing was possible, but I'm intrigued!
Otherwise I have exactly the same problem with my eindeckers fuel tank installation!
At 1/5 th scale the forward portion of the fuse would normally be large enough to accomodate at least an 8 oz. tank. Unfortunately the plyon former and brass tube (foward spar wing plug) severely limit the amount of available space. Most I can fit in the nose is a 6 oz. one and this even has to be installed at a 90 degree angle to the engine.
To concentrate as much weight as possible in the nose the servos will be on a tray just below.
Like you I have also considered installing the tank in the actual scale position behind the cockpit but the eindecker has such a long tail moment that I feared it might turn out tailheavy with this setup (a dual tank setup might allieviate this though).
I know 6 oz. doesn't sound like too much, but with the engine I'm using (OS 40FS) the running time should still be at 10 - 15 min. I doubt very much that my nerves could take much longer flight times anyway.
At just about 2 meters wingspan and approx 3 - 3,5 kg weight the model might be just slightly underpowered...I'm hopeful that this will result in slow scale like flight......on CALM days only
This is my first scratch built project/ my progress is slow but I'm sure learning a lot! I take every opportunity I can to gather valuabe info from the select few 'eindecker' threads here at rcuniverse. please keep them coming=)

Oh here are some pics. I've just started on the wing, the starboard panel is about 70% done.
the model will have wingwarping, full flying tail feathers and functional undercarridge. 'Plans' if they can be called that, are mostly compiled from tons and tons of images and 3-views from the web/

abufletcher

Mensch, das sieht doch fanTASTISCH aus! Looks like you are well on your way to a truly superior scale Eindecker. I started my project with far less of a scale focus but has evolved. Of course this means that work I did earlier on is not up to the same standard as later work. Also mine has the big fat BUSA Eindecker wing with alierons which I am coming to hate more and more every day but will in the end probably make this plane flyable for me. Your very authentic looking fuse and wings are a great start. Could you possibly post a close-up shot of the top pylon and pulley set-up. I'd also be interested to know how you plan to make the landing gear -- I'm struggling with this at the moment as well. I've just about given up on the idea of making the gear work like on the original but I'd like it to at least look right -- for example, by having the main gear enter through the side of the fuse instead of having it "straped" onto the bottom.

I've really learned to appreciate the subtle detail of the EIII. I originally picked this aircraft because I figured it would be an easy to build and fly WWI A/C. But after LOTS AND LOTS of research I can see how many fascinating details are required to do a top notch job.

I'd sure like to see more pictures if you have them.


--Don

abufletcher

Trev, BTW, I notice that you don't have a false firewall on your fuse (yet). Does your OS 40 fit into the short Eindecker cowl? It was moving back the firewall that really compacted the space availible for the RC gear!

I can already tell that someday I'll have to build another Eindecker -- and I suppose that means I can relax a bit on this one!

Trev

Don, do you have german relatives?

I do have more pics of various construction stages, I'm more than happy to post them. After all this project wouldn't have been possible without some folk's generosity in featuring drawings/images of the E.III on their webpage.
Here are some of the pylon, the wing, fuse rear section and close up of a fuselage intersection point.

Please bear in mind that I'm not a terribly experienced modeler, this is my first attempt at building a scale model and I'm making plenty of mistakes along the way (built 2 fuselages, discarded the first).

The pylon consists of 6mm aluminium tubes/ the various fastenings are made of 0,5 steel plating (took me 3 attempts!). A 3mm thread with nuts attaches both the pulleys and the small metal plate for the rigging wires to the pylon.
Note that I've used two pulleys for inner and outer wing warping wires respectively (instead of the single one a fastidious scale construction would warrant) I just thought that as both wires travel different distances there would be friction with a single pulley...also the pulleys are too small to lead two wires. I'm not entirely happy with the plyon yet, I think I'll still make some modifications to make it appear more scale like.
Art Shelton was so kind as to send me the scale airfoil he used on his big E.I. After cutting the ribs using a ply template I assembled the wing in a sort of 'comb' template to ensure proper spacing. As this is a strongly undercambered airfoil I didn';t see any possibility of aligning the ribs properly on a flat building surface.
ribs are 2 mm balsa, spars are 8x2 mm spruce, trailing edge is laminated 1 mm ply, leading edge is 6mm spruce, wintip is laminated 1 mm ply. Rib caps are still missing but will be 1mm ply strips. The wing is plugged into the fuse using 5 and 4 mm brass tubes (forward and rear spars respectively, accomodating 4mm and 3mm steel rods)
The fuselage glue points are all reinforced by interlocking gussets (0,6mm ply). They provide the glue surface for all formers, longerons and also the diagonal cross bracing (2mm hardwood dowels) intended to simulate the wires.
The canopy structure in the earlier pic was only trial fitted and removed...I wasn't too happy with that as it was a closed structure and it occured to me that I somehow have to have access to the servos and fuel tank when the plane is completed/ this would nessecitate a sort of removable hatch.

Regarding the landing gear...well I haven't much of a clue to be frank
I have some drawings, but I've just pushed that problem as far back as possible/ I did make the appropiate cut-outs in the forward fuse but that's it so far. REst assured that I will keep you briefed on any progress I make.
The OS 40 does fit inside the cowl...but only just, and only when the muffler is agled at 90 to the engine (need to order the proper exhaust manifold still).
And the cowl is another issue...I was so impatient to start this project that I didn't look around for one....looks like it will have to be a built-up one, at least until I find a good aluminium one.

I will post more images soon/

Trev

sorry, the pylon images were supposed to be larger
here goes again.

Trev

And here are just a few more

Ongoing construction of the rudder
Wing wire attachment point (standard quicklink attached)

and the comb templates or gantry assembly I mentioned. just slide the ribs into place and glue in the spars/ this can be used for both wing panels.
the small spacers are for aligning the short leading edge ribs.

abufletcher

I'm DEFINITELY impressed with your building skills. My skill set is much more restricted being limited primarily to a lot of static Guillow's kits as a kid. I'm impressed with how clean and precise all your construction looks. The interlocking gussets are just one example.

abufletcher

Here are a few more of construction pix of my eindecker. BTW, I have experimented with this same method of attaching the wires to the wings. My rigging however will be primarily for show. So, for example, I'll be building the top pylon directly onto the removable top deck and will need to figure out a way of "hitch up" the rigging easily at the field. I also tried the laminated route for the rudder but what I ended up with was very brittle and wouldn't hold it's shape -- again my newbie building skills. Anyway on to the pix (my apologies to those who have already seen them):

Oh, and on the cowl, I suggest you start looking for a nice aluminum cooking pot in the diameter of your cowl as soon as possible. that's how I ended up making mine.

abufletcher

More photos...

abufletcher

Sadly mine is just not up to the "interior" standards of a true scale plane and with these WWI types the INSIDE IS CLEARLY VISIBLE ON THE OUTSIDE!!! I'll just have to consider this my "close-enough-for-now" attempt at scale. NEEXT TIME, I'll start out right from the very beginning -- and not waste my time or money on a kit (mine started out life as a BUSA kit but about the only thing left is the wing -- which I cut up and installed completely differently. The kit's balsa was however excellent and I've carved it up and used it in many placed on the model.

abufletcher

Also I'd say that mine attempt is more about "illusion" while yours (and Art's) better reflect the belief that the best way to make a scale aircraft is to just build a miniature aircraft (to the greatest extent possible).

Oh, and I don't have any German relative -- but I did spend many years in German as a foreign language classrooms and a year at Georg-August Universitaet, Goettingen!

Trev

Don I think you're not giving yourself enough credit with the construction of your eindecker/ anyone who can take a BUSA eindecker which is semi scale at best and modify it so extensively has to have formidable building skills/
It also seems you've progressed quite a bit further with the construction than I have with good solutions for quite a few technical details I still haven't dealt with such as the removable canopy or the sprung skid assembly (quite like that one!)
The cowl and cheeks look amazing, I'll have to try and imitate your method for finishing them.

BTW it after seeing your disenchantment with the BUSA thick airfoil it occured to me that one also might be able to install equivalently sized ailerons in the original airfoil/ though I could honestly not say how effective they would be. To simplify things, the wires would in this case serve only the purpose of holding the wing firmly in position (it would be rather thin and prone to in-flight twisting)
This is just a thought/ but if you're interested I could post the airfoil I'm now using.
Though I must agree that using the standard BUSA wing does speak in favor of practicality and is also certain to perform reasonably well

I'm impressed that you know german Don, Goettingen is a beautiful city with lots of history, I almost went there myself.

Just a few more pics of mine:

brass tubes in the wing for plug in mount (shear webs still missing)

the state the other wing panel is currently in, namely not started

one of the elevator panels/ the structure is built around a 6mm aluminium tube/ 1mm aircraft ply leading + trailing edge (2 layers) and cap strips, balsa ribs

abufletcher

I started out planning to use (and at first actually using) an aluminum tube as a spar for the tail but even the thicker walled tubing seems to flex quite a lot and I was surprised at how easy I could bend the stuff. So after thinking about it a lot and lurking around the hobby shop A LOT. I bought a carbon rod in the same diameter and used this. It is considerably more rigid. After seeing people talk about using carbon rods to constuct a whole fuselage and seeing a DVII where just the cockpit area was done in dowls, I also played with the idea of doing this do that I'd have a scale looking interior but it was just too late for that. I also ended up using a heavier frame than scale on both tail surfaces.

Since my metalworking skills are just about nil, I had a hard time trying to figure out how to mount the rudder and tail. I ended up using a heavily carved out tailwheel bracket to support the rudder and then through trial and error (lots of error) I came up with an overlapping set of inverted V-shaped wire brackets that nicely held the bottom of the rudder. The tail is less elegant. I ran the carbon rod through a short length of styrene tubing then epoxied the control horns on either side. I'll actually mount this with a combination of plastic ties and epoxy. I'll then paint it to look like steel tubing.

At the 1/6 scale (roughly) I'm building at (actually I ended up blowing up the Joseph Nieto scale drawings to the size of the BUSA kit) the cowl should have been about 6 1/2" in diameter. The ABS cowl was just barely 5 1/2" and slightly conical. I had initially covered that in FliteMetal and it looked OK (see below) but not great and still the wrong size. The cheek cowls were made by shaping balsa blocks and then heating sheets of styrene over them with my heat gun. Then I covered them in FliteMetal (a serious challenge because of the compound curves) and then polited and finished with a borrowed electric eraser. I also tried burnishing aluminum roof flashing over the molds but with no luck. I've since ordered a cheap auto fender working set ($14 on Amazon.com) and will try Art's technique of hammering out some cheeks. I love the idea of having both the cowl and cheeks of the same material.

Anyway, I ended up using a 7" diameter pot and this fit perfectly over the modified 2" scale LeRhone kit from Williams Bros. I extended the cylinders and created new more scale rockers .with styrene (I had to thank Neo for introducing me to the wonders of styrene).

abufletcher

And here's the finished (more or less) dummy engine. Are you going to be using a dummy engine on yours? I gave up on the idea of trying to have it rotate (like a pinwheel in the wind).

abufletcher

Trev, I would also appreciate it if you could send along the airfoil profile you've used. One reason I decided to split the wing was to have the option down the road of using a scale(r) airfoil -- once I learn to fly a bit better! [8D]

Trev

Don I just tried posting a msg, but something didn't work and it was lost/
I'll just get the airfoil into a reasonable format/
pls give me a few min

Trev

Right here's the airfoil (I hope)

I've included the original scan I recieved from art, the 'clean' outline is a trace I did with CorelDraw and above is the fully modified airfoil I used for wing construction depicted in the angle relative to the fuse on my eindecker (not sure if that's entirely scale but I hope more or less)

I must say I'm very taken with the results you've achieved for the cowl, cheeks and dummy engine, they look superb!
Seeing your pics I've decided that a built up cowl will simply not do anymore, guess I'll have to keep my eyes peeled for some suitable camping gear
I can't imagine though how one could go about getting the dummy engine to rotate...either with the engine (attached to the crankshaft??) or passively...nonetheless that would be spectacular!
I would like to at some point install a dummy engine in my eindecker, seems a shame not to indulge that detail/
Does Williams Bros. manufacture a 1/5th scale dummy LeRhone or Oberursel?
I'd also be looking for a suitably sized Spandau gun/

Trev

Oh btw, on the topic of landing gear construction
I came across an interesting thread by Vue/ seems he's also scratch built a 1/6th scale E.III
it's got the whole works, sprung landing gear, wing warping ect.
There's also a diagram he made of his gear construction, seems like a good idea!

have a look at:

http://www.rcuniverse.com/forum/m_14...tm.htm#1435359

abufletcher

Trev, yeah it was Vue's EIII thread that inspired me to buy the BUSA as my second plane -- before the project took on a life of its own (and took over my own). But after looking at the pix again I'm convinced that the fixed music wire approach just won't cut it for me. Oh well, I guess I can start over on the landing gear I've been working on today...

BTW, what diameter cowl would you be looking for? For $16 at the local army surplus shop I got a camp set with a 5 1/2, 7, and 9 inch "cowl" plus an aluminum frying pan and some neat plastic cups and salt shakers!

Trev

The cowl diameter I'd need would be 20,4 cm or nearly exactly 8 inches/

Pity that it's just in between the pot sizes of your camping gear/ I suppose I'll have to get really lucky if I'm to find any suitable aluminium pot of that size./

Vues landing gear approach does seem very feasible (he's done a very decent job overall), I think I'll try and adapt a similar design to my eindecker, perhaps using the 6mm aluminium tubing (with a material thickness of 1mm it's very sturdy and nearly impossible to bend without breaking)
I only fear I might come to a standstill with some of the joints, esp. where the wheels attach to.

Btw, what is the approximate CG position of your eindecker? I presume that you've shortened the nose of the BUSA kit to achieve authentic proportions
None of the drawings I have indicate the CG and I can only guess as to its location. What I would need is a relative position on the airfoil (I would spontaneously guess just behind the front spar)