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May 14, 2009 - Z-21 going, going
...going. I am both pleased and a little sad to say that I have located a buyer for Walter's Z-21 project. Jim Hail, a Texan who joined up with the Flitzer group in July of 2008, had expressed interest early on when I first posted that I was going to offer it for sale. Having worked through all the inventory and valuations and reinventory and revaluations, we spoke this evening and arrived at an agreement that will put the Flitzer kit in the hands of an experienced pilot and builder--he flies an all-metal two seater that he built 15 years ago, and is now looking to build a sport plane for some REAL fun.
Jim has been a lurker for the most part thus far on the Flitzer-Builders listserve, but I expect you will hear more from him once he has the little beastie in his hands. This will be his first experience building an all wood airplane. We are looking to make the transaction sometime in early June; he plans to drive up to Albuquerque and pick up the kit, which saves me the trouble of crating everything up.
Jim noted with a laugh that several of the people on this list have a peculiar way of expressing themselves. I don't have a CLUE what he is talking about. But since we are on the topic, it is my intent to remain in contact with the group, addressing issues of aesthetic impropriety and linguistic obfuscation as time permits. Do not imagine that I have relaxed in my vigilance; the ghost of Von Schneer will not allow it in any event. You should have heard the rattling in the walls as he debriefed me on the MS Comic Sans Serif affair... suffice to say that crispness and attention to detail are always in fashion; the current infatuation with slackness and informality will run its course, but not until after it has degraded our aesthetic sensibilities to the point where one will hardly notice anymore that a 1990's Ford Taurus looks like a well-sucked, unarticulated lozenge, or may think that the blunt edges of a foam wing on a RTF model airplane really do look o.k. after all. We might even come to believe that Britney Spears can actually sing. The slippery slope shall carry us all away, though we doth claw and protest, unless we stand firm against it.
David von Schneer-Shatten, aka David WNHMN/WHYTBN
January 17, 2009 - Walter Mitchell's Z21A Flitzer project
Hi Everyone,
After a few false starts, I have finally figured out how to re-enlist on the Flitzer-builders site. Nice to see everyone's projects humming along...
As Lynn informed you a few months back, my brother Walter (aka Fabian von Schneer) passed away in October. I would first like to thank everyone for their expressions of sympathy, and for the excellent commemorative stein that I received the other day. It was, and is, a huge loss to us all, but the fine dust of comraderie and friendship is helping to fill the void.
Practical matters---I have now a partially constructed kit of a Z21a Flitzer on hand-or rather, sitting in Walter's house in New Mexico. Walter's intention was to modify the fuselage to house his 6'5" frame, thus creating a new variant of Flitzer, the Z21b "Habicht", but the project did not make it to that stage; thus, we have in effect a Z21a. You may believe that, as a professional woodworker and aviation enthusiast, NOTHING would please me (or the vaporous spirit of von Schneer, circling about in the ether) more than to complete this project myself. Alas, I have neither the hangar space, time, nor money to do so (I hear his indignant cries even now). So, in the near future I will be offering up the project for sale, in the hopes that it may yet come to fruition in the hands of some other worthy craftsman/pilot/enthusiast.
It is my task to now sort through the remaining kit pieces and provide an account of what remains. I hope to do this in the next few weeks, when I will be traveling to New Mexico to attend to further matters of his estate. In general, there are a pair of very large shipping tubes filled with assorted wing spars, fuselage longerons, etc., a box of flat metal fittings (not sure if these are from Ian Wasey or Gary Steadman) and assorted sheets of aircraft grade ply--not sure what thickness. I don't think Walter had yet purchased the metal tubing kit components, nor had he purchased an engine, wheels, cabling, etc.
Walter had finished the framework for the stabilizer, elevator, fin and rudder, and had completed the onerous task of constructing the wing ribs. He had also fabricated the wing tip laminations. I will take detailed photos of his handiwork as evidence of the quality of his work, and post some of these to the site in the near future.
I plan to offer the project for US$5000 PLUS shipping, assuming that the inventory of the remaining kit parts shows everything to be in order. Given that he had not progressed to the fuselage or wings, shipping should be a *relatively* straightforward affair, but I am not able to provide any estimate of this element of the cost, sorry. I will, however, absorb the costs of making any necessary shipping crates for the completed components.
If anyone is interested, contact me via this site, or directly at (Click for e-mail address)
Again, everyone----thanks for your support.
David Mitchell (aka David WHYTBN)
May 31, 2005
I think that I have been betrayed by the treacherous Babelfish, which has delivered the German for scoff instead of sneer. We shall agree to use schneer. The slogan is "Schneer mit uns!" (Sneer with us!)
I have allied with Baldamus, that we may jointly strive against all that is nice. In this spirit, I shall forgive his "Thomas the Tank Engine" crack, even though it must be admitted that he is correct. Attempts to undermine the Malign Alliance with clumsy propaganda will be ignored.
Regarding the PSRU, the offset is about 5.8 inches with a Valley unit, and I have been working on various combinations of cowling, engine mount, and hub extension, trying to maintain the proper appearance, thrustline, and CG. The prop shown in the CAD is 80", but appears larger due to the funny perspective of the drawing. Certainly it would make quite a mess at Rupert's unkempt field. The engine will be moved back a bit, and perhaps an aft-mounted battery installed to comphensate for the 20 lbs or so of larger prop and redrive. Attached are some later ones, including the hump-backed Z-21b for tall pilots. I'd show mounting details, but my CAD data is trapped in my old computer, which expired quite horribly, and is currently smelling bad in the corner
-Von Schneer
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June 6, 2005
Men...
Here are some pix of the new CAD model under development. Z-21B Kamelflitzer, 22 inch fuselage width, full length, 2 inch deeper firewall, rising to 3 inches deeper at the cockpit. PSRU 2/1, 80 inch prop, rough arrangement of engine mount. Also work on a tailwheel design, which really makes me wish I could use a skid! Between the PSRU, tailwheel, and brakes, there is going to be a lot of extra hardware. Depending on what carb I use, I may also need a fuel pump...I am really corrupting Lynn's beautifully simple design.
-VS
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June 13, 2005
Walter
I approve of what you are doing so far. I think that it will suit the new installation with the PSRU, and your own physical requirements very well.
However I would add one more thing. For various *reasons, I would suggest increasing the main undercarriage height on your particular aeroplane by 1.5" to 2".
*These are as follows:
1/ The basic aeroplane, even though it appears to have a steep ground angle, is quite normal in this regard, in terms of classic biplanes, with a ground angle of 15 degrees. Normal power-off three-point landings can be regularly carried out at normal loadings, without difficulty on the Z-1, but with the full permitted elevator travel on the Z-21, it is possible to achieve a still steeper angle, so that the tailslkid will strike first. Therefore it is permissible to extend the main gear slightly.
2/ The 80" propeller and the lowered engine location on the 'Z-21B', reduces the propeller clearance somewhat over the 60" propeller and the slightly higher thrustline of the Z-21. Although due to the anyway long undercarriage of the Flitzer, this is still acceptable, but with reference to (1) above, the longer gear makes more sense.
3/ The addition of brakes, and with a slightly higher 'top hamper', the tendency of an aeroplane to nose-over, although extremely unlikely on the Z-21, is slightly increased. So a longer undercarriage will help to reduce any such increased tendency.
4/ From a purely visual aspect, the deeper nose of the Z-1B will make the undercarriage 'look' shorter, and unbalance the harmonious appearance of the basic design. The useful extra fuel that can be accommodated in a deeper tank on the 'B' is another factor to commend its deeper aspect, so the undercarriage should be lengthened to restore the appearance.
5/ Aeroplanes gain much of their character with their close proximity to the individual, and when that person in is the builder/owner, it is important that the sense of scale of the machine is maintained to suit the individual's needs and physical requirements. Robert Nilsson is already doing this with the Super Goblin which also features a slightly longer undercarriage, a longer, deepened fuselage etc.
It is a very personal thing, and is part of why we do what we do, and importantly we all want to personalize everything, whilst still belonging 'to the club'. Von Schneer, you are well above average height, and you are already building into your machine certain special features unique to that aeroplane. I would suggest that, in view of the preceeding points, you extend the underacrriage to re-create a perceptably somewhat bigger Z-type to your own specification.
6/ We could at this stage talk about a bigger upper wing, based on the Stummelflitzer upper chord, of 36", which would place the leading edge about 1.5" forward of the Z-21 LE, without moving the upper TE forward at all. This would however effectively move the CP forward slightly and help accommodate the greater weight of the PSRU and propeller. The deeper spars of the Z-1S wing will also assist in carrying the greater weights at high accelerations. The lower wing can remain unchanged. The cabane can also remain unchanged, ie. the forward raked Z-1S cabane is not neceeary as it would then move the upper wing too far forward. These changes would create a distinctly new variation among Flitzer types, for a genuine new designation of Z-21B, or even Z-121 (in the Czech tradition amog Zlin and Avia types). I would prefer to retain the designation 'Z-22' to allow the Z-2 line of two-seaters room for development.
The other alternative is to build the all-round bigger Z-3, which is already perfect for your stature.
Best regards,
Lynn
June 13, 2005
Wolf-
Really, really appreciate your input!
1) Interesting... I had already noted that it looked wrong with the stock wheels, so I provisionally went up to 19" units...shown in CAD drawings.
2) Agreed, prop strikes are unpleasant....but I thought the thrustline was the "same", relative to the fuselage box...it looks lower, due to the bulkhead height increase.
3) Agreed.
4) See (1). Looks right, is right.
5) Agreed. I have learned to favor very large motorcycles for the sake of my dignity. Still have the problem with tiny women, however.
6) Aaaaah! Knock-ons! Regarding gross/operating weight, the intended pilot, though long, is, by US standards, relatively light...160 at last weigh-in. (He also has poor G tolerance!) The engine/PSRU installation should only be up about 15 lbs over direct drive, my earlier estimate somewhat pessimistic. Hope to recover most of this by jettisoning starter, alternator, accessory case, thus adding only 5 lbs or so total. The heavier prop has a long moment, however. Increased chord idea noted and considered, reluctanty. A shortened firewall bay, 2 inches, is still a possibility...most of my height is in the upper body, with semi-normal legs. Z-3? I like the Z-21, and I already have a kit for one.
And I had been annoyed with myself for spending all day doing CAD instead of building....but you know what they say....measure twice, cut once!
Baldamus, I am doing this because I have a compulsion to deviate. Yes, I had wondered if the exposed pan might enable me to forgo the exposed oil cooler... my landings are so perfect, I don't need bungees. (They are also hard to draw.) Fuel pumps would be electric, I think.
Chris, agree as to top-mounted carb...will illustrate ideas soon.
Thanks for the feedback, guys!
-VS
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Oberst von Schneer,
The CAD drawings look wonderful. If it looks like that it'll be superb. I presume that it shows the standard undercarriage leg length here, with the 19" wheel rims, although it would, look just as good with the longer legs and the 17" wheels, the latter being more Germanic (if you look at some of the Halberstadts and late Rolands). Either way you seem to have achieved the correct ground angle.
I think the design is in safe hands with you, so I won't add any more for now.
Cheers,
Wolfgang (Lynn)
Hi Walt, having said I wouldn't add any more...
It occurs to me that as you already have the Z-21 kit, you wouldn't want to order new upper spars for the Z-1S to 'Z-121' wing conversion, and that could cause complications anyway because they are shorter as well as deeper than those of the basic Z-21 - if the sawmill didn't get the precise information right to adapt then for the Z-21's upper spar length.
So why not just glue a capstrip of spruce or DF onto the existing spars, to bring them to Z-1S standard. You'll need some Z-1S drgs. to make the new (upper) ribs which have a basic 6.5" nose (instead of 5.1") dimension from the LE to the forward spar centre-line, but you'd only need to make the single rib shape not the multiple ribs that are required with the tapered outermost spar-section of the Z-1S, where this flows into the tip curvature. The upper spars are capped anyway between the ribs on the forward spars, but the Z-1S/R spars are 'full' depth on the rear.
If you are concerned about the sight lengthening of the undercarriage, you could use 1.125" OD , say, on the forward mainleg, like on the Z-3, or on both legs, as on the Z-2, but the f'wd leg should be enough, even if it's necessary at all, which it's probably not.
Best regards,
Lynn
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