abufletcher

Ten years ago I was entirely ignorant about such things. But from what I recall about how the BUSA firewall was constructed there wasn't any built-in thrust angle. At any rate, with the recessed firewall I used there definitely isn't any.

The BUSA wing wasn't even close to a scale location (too far rearward) so I moved it forward, but I think I may have kept it at the same AofA. Looking at this old construction photo, it looks like the bottom of the wing might be parallel to the thrust line...so that would make the actual wing incidence (from TE through to LE) a couple of degrees positive. I guess I can measure this. I think, when I flew it before, we just set the elevator "in the middle" of the fuselage tail, such that full-up brought the LE up to the top longeron and full-down brought it down to the bottom longeron.

abufletcher

Here are a few more photos. The first shows elevator and rudder...there are so many "ugly" aspects to this isn't not really worth trying to correct them. The second is also an extremely ugly photo of some less than photogenic parts of the skid. But gives an idea of how the rudder is actually held in place. There's a music wires attached to the skid that comes up through the tip of the skid support, through a tube built into the rudder, through a pivot point made from a cut-down tail-wheel support and continuing up through the rudder. The skid bungees as well as the rudder pull-pull cables hold it all in place. The third photo shows the rather crowded servo installation. I was quite proud of the 3-D thinking that as involved in getting all the servos packed into the first couple of inches of the fuselage. The wires need to be tidied up a bit. The fourth photo is the custom brass tank I made. With the servos installed the way they are there was no room for a stock tank. The tank seams are all soldered and then I added an extra layer of leak protection with aluminum tape. It seems to work. The final photo shows the rough tank location. As you can see it's all very tight up front.

abufletcher

Towards the end of my original built, I was just sort of slapping things together to get it done in time to fly before leaving for Japan.

Flying Fox

So maybe the original incidence set up is thrust line =0 degrees, tail =0, and wing a couple of degrees positive, maybe +2 degrees.
Just measure it.

It's a good thing and nice that BUSA takes care of all that aerodynamic stuff for all the semi-scale & stand off scale fliers and non-aeronautical engineers amoungst us. They give you a fairly straightforward build that looks pretty good and flies very well from what I've read. If you are so inclined you can add detail to your hearts content or bash it to various degree to be more accurate scalewise.

I think I know just enough aerodynamics to get myself into a whole lot of trouble!
I guessing that - even though you lengthened the distance between wing and tail it sounds like you kept the 3 respective incidences the same so I suppose the aerodynamic relationship would remain the same and thus it would retain its nice flying quality. You lengthened the tail moment and so probably added even more more longitudinal stability. I bet that as long as you keep these incidences the same then even if you change to an undercambered airfoil it will fly just fine.

I have this same issue with the set up of my MS-N. Basically not much to go on. I can measure off the 3D sideview as it is very accurate/detailes but must remember this is for a relatively slow, full size plane of 1915. I'm assuming a flying model with its inherrent faster speed would need the wing incidence tamed somewhat. I'll have to think a lot more on this and will be asking for advice when time comes. Maybe engine thrust -1, wing +2, and tail 0.

Bri

Flying Fox

Don't be so hard/critical of yourself Don - that was a damn good effort, especially for your first build. It's not museum scale as is your Snipe, but hey, stand back just a foot or two and it STILL looks like one very fine aeroplane!

I really like the brass tank you built, might consider trying one for my MS-N. I notice the irregular swirl patten on the cowl, cheeks and tank - is this not absolutelty scale accurate for the eindecker? Most guys make the mistake of swirling in nice geometrically even circles when in actuality the swirls were irrigular and 'snakey' or wiggly shaped right?

Look'in good
Bri

abufletcher

Here is a set of pdf's on the topic of making a custom fuel tank. It was actually quite easy.

Yes, one of my MANY pet peeves when it comes to 99.9% of the eindecker models you'll ever see is the use of those neat rows of English style "engine turning" instead of the correct "random squiggles" seen on the Fokker. I did the squiggles with an electric eraser. I bought a couple of cheap aluminum pots from the $1 store to practice on first. At first, I was being too controlled and ended up with something that looked like Arabic! BTW, the squiggles on the San Diego replica are much too large. What I found worked best was to just jump around randomly filling in the space with 1-2 second bursts with the eraser. I would love to know what sort of tool was used to do this back in WWI.

abufletcher

I'm glad I was forward enough thinking 10 years ago to imagine my future self having to remove all the radio gear to replace the UC bungees! Getting down to the bungees was like an archeological dig and some of these things haven't seen the light of day in a decade. But it was all painless and now that everything's out, putting on new (tighter) bungees won't be a problem. The trick with the bungees is to have the cords support the weight of the model in a "down" position while sitting on the ground (and taxiing), yet still be able to flex on a rough landing.

And since I'm down to the level of the throttle servo, I'd like to improve the linkage. Before I was using an unsupported golden rod which snaked up to the engine throttle arm.

ARUP

FWIW, I used springs mounted vertically in lieu of bungee wrap. They were set up like adjustable shock absorbers (spring in tubes) in that there is an allen head screw on top mount to change the pre-load of spring. Works a treat!
How'd you get that nice 'galvanized finish' look to your metal parts? Very convincing. Thanks for your reply.

abufletcher

Got the bungees done...and in the process discovered that for some reason I can't figure out, the fuselage doesn't sit level on the UC. Can't understand why. Anyway, rather than waste time pondering the geometry, I just fudged it by adding a small wooden block to limit the travel on one side.

I also replaced the golden rod throttle linkage with a standard 2-56 rod with a Z-bend that lowers the rod to the level of the carb arm. This also involved putting a ball-head on the inside rather than outside of the carb arm. But everything moves without interference now. Next I'll apply two-part urethane to the engine area and then I can start to reassemble all the radio gear.

ARUP, I answered your question about the metal work in my post above.

Idigbo

Great to see this model being restored, how many flights (ish) did it have and why was it retired, or was it that you left it behind in the US? I have always liked the EIII and earlier, but hate the looks of the EIV, its way too ugly!!!

Ian.

abufletcher

I think it was only flown four times (twice on two consecutive Sundays) before I hung it up figuring there was no point bringing it back to Japan with me. At the time, I wasn't aware of any RC flying club in my corner of Japan and I wasn't set up to do any building at all in my house. Bear in mind that it wasn't just transporting the model but also all of the field equipment. I was also in my final year of a Ph.D. It was probably a year or more after my return that I discovered a flying club not more than 15 minutes away. And bit by bit, tool by tool, I started collecting stuff for a workshop. At first, I was just working on a coffee table with hand tools from the yen-version of the $1 store.

Then as the years went by, it always seemed so inconvenient to transport the EIII here. There was always something else that had higher priority in my luggage allowance. And to some extent, I had simply moved on. And frankly, I hated the fat BUSA airfoil wing...not to mention that there was only one. But, finally on this trip the time seemed right. We're about to move into a new house so it was going to have to be boxed and transported anyway and I didn't happen to have anything I was bringing back to Japan with me.

So here it is, and I might have it ready to fly next weekend.

abufletcher

Time to think about balance. At the moment, with it all put together (engine/prop/muffler/cowl/radio gear/tank/wing in place but minus the rigging and the Rx battery) it balances at about 4" behind the LE of the wing. I seem to recall that before it was balanced at 3" back with the battery/pilot figures in place (behind the CG). I'm not going to use the dummy engine for now.

After years of seeing the BUSA construction manual laying around the house, now when I look for it, I can't find it anywhere. Can anyone tell me what the recommended CG for that is? My EIII has both a shorter nose and a longer tail but it's still the same old BUSA airfoil, so would the CG still be the same? The cord is about 11" and the main spar is located about 3" back from the LE. If we go with the 30% MAC rule then that's about 3.3" back. If we use the more conservative 25% MAC (which I tend to favor for a "maiden" having had far too many wild rides at the recommended CG) that would be 2.75" back.

Here's the results on a fairly sophisticated looking CG calculator. With a conservative "static margin" (10% in a 5% to 15% range) the CG would be at 2.75" back from the LE.

http://adamone.rchomepage.com/cg_calc.htm

abufletcher

Given that I need more weight up front, I've rethought the dummy and will include it. Previously it was only for static display. To get it to fit properly (and with proper space) over the engine, it needed to be trimmed rather severely...which was a shame. I removed one cylinder entirely. On the plus side, the silver Saito 56 fills the gaping hole reasonably way. Given the shape and size of the engine mount, however, the dummy has to sit quite far forward...far enough in fact, that I decided just to epoxy it to the inside of the cowl. I also need to do some interior reinforcing of two of the lower cylinders that had to be trimmed quite a lot at the base. It's not pretty, but it's better than not having any dummy. And as I said, it adds maybe 60g just about as far forward as possible. I also switched to an APC plastic prop instead of a wooden one for some extra weight.

All of this moved the CG forward about 1/2 inch to 3.5" behind the LE. Next I plan to build a battery box on the firewall and that should just about do it. Tomorrow, if it stops raining I might try testing the tank/engine setup.

abufletcher

Major stuff done so far: Replaced the Magnum 52 with a Saito 56, re-routed the fuel line, improved the throttle linkage, reattached and remounted the full-flying elevator, Replaced the UC bungees in the fuselage, and re-did all the servo setups. The one major task remaining is to redo all the rigging of both the UC and the wings. Technically, the flying/landing wires are just for show on the cantilever BUSA wing, but what's an eindecker without rigging! On the other hand, the cross-bracing on the UC is very much functional.

abufletcher

A little historical reminder for all those BUSA eindecker builders who just use the color scheme on the box (the one with the black, white, and "red" diagonal strips on the fuselage): That red strip was according to the late and greatly respected aviation historian, Dan San Abbot, probably NOT red at all. This color scheme is supposed to represent Ernst Udet's EIII but careful analysis of original BW photos combined with the fact that Udet was a proud son of Bavaria strongly suggest that this strip was instead Bavaria Blue (think BMW logo).

I suspect that one reason the black, white, and red scheme is so popular is that it mimics the colors of the well-known WWII Iron Cross ribbon.

abufletcher

Incidentally, after clearing a little gunk out of the Magnum's fuel nipple, the engine roared immediately to life. It was oddly comforting to hear a sound I had last heard 10 years ago. Actually, I've got two of these Magnum 52s sitting around now. Guess I should look into building a twin! Maybe an AEG GIV...

Flying Fox

Glad to know I'm not the only ne who does this[:@] but sorry for your misplacement, maybe someone can look it upl for you.

Don, I've used that partuicular CG Calculator before to set up two planes where I did not know the balance point. Both times the program proved itself and after flying a while I was able to work the balance point aft somewhat. With a fairly stable BUSA bashed kit you should be fine with anywhere between 25-30% MAC. Play around with the numbers a little ans see what kind of ranges it comes up with.

Don't you just love that fat BUSA wing! You're doing a great job, it really looks good - amazing how much you can accomplish on a rainy day isn't it!

The black-white-red scheme has good colour appeal too. So go with it if you like the looks otherwise bring on the Bavaria Blue. BTW I often see a black-red streamer often trailing off the wing out near the tips. Was this some sort of flight leader designation or equivalent?

Bri

abufletcher

The only thing that keeps me from ripping it off the model and starting a bonfire with it, is the fact that when seen from certain angles it just looks like the thin undercambered wing with its high AoA.

Well, it's only been raining tonight. This morning I took the Puppeteer out to fly. I'm getting bolder and bolder with it...a typical flight nowadays includes a bunch of stall turns, a loop, some "retournement" wing-over turns, a couple of big sloppy barrel rolls (the only type of roll my Puppeteer will do) some 'strafing runs" and a recently added cross-controlled semi-sorta-half-baked knife edge. I like to pretend I'm trying to shake off an attacker...and get around on him. So I do lots of weaving up and down, in and out and just generally wiggling the tail to throw the attacker off. I'm not sure the Puppeteer will do a proper Immelmann, though I do remember doing a very scary split-S a while ago. It just barely pulled out in time. Today, on the second flight the tail post tore out as I was taxiing for take-off and that took out the rudder. Anyway, between today and yesterday I got in 6 flights so I'm satisfied. Tomorrow's a holiday ("Coming of Age Day") but it will likely be raining.

I'm not familiar with this myself. Got a photo?

ARUP

Thanks for the info on the galvanized pattern metal work. Somehow I missed that before posting question!

abufletcher

The EII looks a little stubby in my opinion..and the EIV a bit chubby! The EIII is just right! While for the most part Fokker's design was just a rip off of the Morane-Saulnier Type H, he added some clever refinements, such as the all-steel framework and the "bungees on top" UC. Still, the EIII was never a great aircraft and perhaps it's only real claim to fame is an initial mount for a fixed forward firing machine gun.

It's a shame that we don't see more careful scale models of the EIII. I understand that most modelers find the idea of including functioning wing-warping a little daunting. But even barn-door style ailerons on thin wing would look pretty close. Of course, that thin wing would require functional flying and landing wires, but really that should be a requirement for all good WWI models. BTW, a clubmate came up with a novel approach to wing-warping on his sport scale own-designed EIII (which was still far more scale than the BUSA kit). He actually included a mechanism that rotated the entire right and left wing halves in opposite directions...sort of like turning them in large full-flying elevators. It worked, but it was a little odd to see the LE go down as the TE went up. Perhaps it would have been better to pivot the wing on the LE. In the end, it probably would have been easy to do proper wing-warping.

BTW, it seems like a good way to practice for wing-warping flying would be to set very low throws on the ailerons.

abufletcher

The UC cross-bracing is done, using 0.6mm stainless music wire instead of cable. This is similar to the technique I've used on all my other models. It looks like rigging but is rock solid. I also finished the four (top) landing wires and what would have been two cable runs through two pulleys for the wing-warping. On my model they're just an additional set of flying wires in approximately the right locations. Tomorrow, I'll work on the (bottom) flying wires and mock warping cables (i.e. additional flying wires).

TFF

Make it a flier. If you build a warper, do another. I say a big one for the Seidel.

abufletcher

That's the initial plan. But if it does fly well, I might, down the line, replace the fat BUSA wing with ailerons with a Proctor style wing with warping. But first I plan to fly it a while. If it survives, then I might upgrade it. Actually building a new pair of wing panels wouldn't be that much work. That's ultimately the easiest part of build. And I've already got functional pulleys on the top pylon and a functional warping lever on the UC. All I'd have to do is install a warping servo in the fuselage. No big deal really. But we'll see.

I'm not sure I'll have it ready to fly by this weekend, but if not for sure by the following weekend. (We are now only allowed to fly on weekends.)

abufletcher

Things yet to do:

1. Complete the rigging
2. Beef up the inside of the dummy engine cylinders to deal with vibration
3. Build a battery box on the firewall
4. Decide on the initial incidence of the elevator
5. Finalize the balance
6. Test run the engine
7. Fine tune the servo settings/set the throws
8. Replace the windscreen

Teus

Don, great restoration. Nice to follow.

But you forgot number 9 in your to do list:

9. When finished, grab a beer and enjoy the plane [8D]