ULF-1 Discussion Archive
Anonymous static archive of the former Mailman list
Anonymous static archive of the former Mailman list
Re: [ULF-1] ULF-1 Digest, Vol 2, Issue 7
I got the reply with Dieter's second attempt. Thanks Dieter and thanks to you too Doug. Your feelings about the design and the overall project size and complexity were very helpful to me and I expect to many others too. The idea of 18:1 glide ratio, a very light wing loading, a low min sink rate and a rugged structure are still very appealing attributes. It all adds up to being able to stay aloft longer on most any lift conditions which ultimately means more flying. Being able to tow with an ultralight or a J3 is also very appealing and it don't hurt a bit that it's beautiful to look at. The only difficulty I perceive will be in trying to explain to my wife why I need two airplanes:-) Steve [email] wrote: Send ULF-1 mailing list submissions to [email] To subscribe or unsubscribe via the World Wide Web, visit http://lists.ulf-1.com/listinfo.cgi/ulf-1-ulf-1.com or, via email, send a message with subject or body 'help' to [email] You can reach the person managing the list at [email] When replying, please edit your Subject line so it is more specific than "Re: Contents of ULF-1 digest..." Today's Topics: 1. Re: ULF-1 wind limitations (Member 1) 2. Fw: wind limitations (Member 9) 3. Re: Wind limitations (from Dieter) (Member 1) ---------------------------------------------------------------------- Message: 1 Date: Sat, 31 Mar 2007 08:26:34 -0500 From: Member 1 Subject: Re: [ULF-1] ULF-1 wind limitations To: [email] Message-ID: <[email]> Content-Type: text/plain; charset=us-ascii; format=flowed Thanks for all the replies regarding your locations and areas of interest, guys. It's nice to know more about who is onboard. I haven't heard from Dieter for a while. I think he gets busy and is sometimes delayed in replying to e-mail. Regarding design complexity: It has been 2-3 months since I studied my new set of ULF-1 plans, so I'll try to not get too carried away with my recollections. The drawings are very nice and seem very thorough. There is a LOT of information presented in them, and therefore much to absorb. It is no surprise that there is an intimidation factor involved for anyone who is new to the design. I've learned that there is always some degree of fear factor or feelings of inadequacy involved when taking on a new challenge, but that these feelings always go away after I've "rolled up my sleeves" and immersed myself in the project. Since I've come to expect that, I don't let those feelings scare me as much anymore. My intimidation factor with the ULF-1 project is based primarily on knowing that the time and life energy I have available to me right now are not suficient for success (timely completion of the project). I was hoping that, in contrast to the Carbon Dragon, the ULF-1 would be kind of like a scaled-up balsa glider, as it tends to look in the photos. Alas, it is not. It is much more sophisticated than my naive hopes had given it credit for (especially aerodynamically), and of course all components are carefully designed to be as lightweight as practical. Aerodynamic sophistication, super light weight and robust strength are simply not compatible with a simple structure. Just the fact that it has tapered wings makes its fabrication more complicated than the kinds of ultralights I've accustomed to building (the ribs are all different, made in pairs). The control systems are by necessity very clever and not simple. I find the ULF-1 plans more straighforward than the Carbon Dragon plans. The CD has all those weird minimalist parts made by wrapping carbon tow and resin around molds and then somehow getting the molds out... the drawings weren't enough to convey the process sufficiently, and this left me very frustrated. Some photographs would have been very helpful. I'd encourage Dieter or one of his builders to offer a set of good quality photographs of all the systems and major component groups on aircraft that are in-process and completed; seeing everything in 3-D would really help the 2-D drawings come to life, speed up the learning process, and reduce the intimidation factor. I don't want my comments to disccourage anyone from starting a ULF-1 project, unless it would be preventing them from launching into a project that is not realistic for them to complete (I think most designers would agree with this as well). Those who have built airplanes before -- especially those who have started a project that was never completed -- know what a huge commitment it takes to see something like this through to completion. If your available resources of time and money don't allow you to complete the project within 1-2 years, there is a very good chance of failure. 2-3 years after starting you'll discover that the aircraft isn't what you really want anymore, or something else will come along that you desire more... It really helps to have a lot of time -- such as being retired -- so you can get it done before problems like this can arise. Of course, many builders take 10 years or more on a project and actually succeed in completing it, but I don't see that happening with myself. "Know thyself" is a very good maxim when considering beginning a project like this. Still, the time spent building beautiful structures such as aircraft parts can be quite rewarding even if the project is eventually abandoned. Time lapses or long breaks in work on a project like this can be deadly, too. It is very common for other commitments or life events to pull one away from the project for a couple of weeks, then it becomes a couple of months... Once you're off a project for more than a few weeks it can be VERY difficult to pick up where you left off and get back into it. I'm saying all this from experience with several aircraft projects! The ULF-1 is by no means too complicated or difficult for me to build, or for many of those who are considering it. I'd like everyone to understand that I have balked, hopefully temporarily, because I have so much going on in other areas of my life and I know from my earlier experience that it would be too much for me to try to start the project right now. So I'm keeping my foot in the door and hoping my life will un-complicate soon to the point where I can start cutting spruce and plywood. I hope we'll see some actual ULF-1 builders join this list so they can remind us that the project is just gluing a bunch of sticks together, and that big projects are nothing more than a series of little projects. I'd at least like to build a rudder or something this summer to get a better feel for the project and Dieter's construction methods. And I hope I can help encourage others to do the same -- the world needs more homemade, low-cost, foot-launch soaring machines! Doug Member 2 wrote: > Gentlemen, > > The airchair list presently has a discussion going on concerning wind > limitations of Dieter's design. I'm hoping we can get Dieter to comment > and possibly clarify what he meant when he suggested wind limitations in > the plans. Dieter, can you help us out with this? > > Also, it would appear that some people are intimitated by the design > complexity. Not having a set of plans in my possession as yet, I cannot > comment on this. How about any of you guys? Has anybody in this group > had enough time to study the plans well enough to comment on the > complexity of the design.? I'd like to suggest that it's probably a > matter of "One person's ceiling is another person's floor" when it > comes to ability and/or willingness to spend the time necessary to > complete a project as complex as an aircraft but I would still like to > hear from you guys. ------------------------------ Message: 2 Date: Sat, 31 Mar 2007 15:11:02 +0100 From: "Member 9" Subject: [ULF-1] Fw: wind limitations To: Cc: [email] Message-ID: <003401c7739e$6c93c8c0$ae022951@dieter933964n8> Content-Type: text/plain; charset="iso-8859-1" Hello Steve! Sorry, but this is the third trial to transmit! Dieter ----- Original Message ----- From: Member 9 To: [email] Sent: Tuesday, March 27, 2007 11:02 PM Subject: wind limitations second send! Dieter Hello Steve, no sweat, no worry, there are no wind limitations! The wording "No operation at wind velocities greater than 8m/s (16 kt)" is a left-over from early days and will disappear in the next issue of the flight manual. But keep in mind, that ground handling becomes more and more difficult with increasing wind velocities. To avoid a tip-over before taking off from a slope, you must apply the procedure discribed in section 3.1 of the flight manual. Doing so, you will enjoy a real, true vertical take-off at high wind speeds! You also should not be frightened by the "design complexity". I recommend to start with building the horizontal tail, because it shows basically all difficulties you encounter later on fuselage and wing. You learn to work with the material "Member 60" without risking too much. Best regards, Dieter -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ulf-1.com/private.cgi/ulf-1-ulf-1.com/attachments/[phone]/da0ba41f/attachment-0001.html ------------------------------ Message: 3 Date: Sat, 31 Mar 2007 10:23:49 -0500 From: Member 1 Subject: Re: [ULF-1] Wind limitations (from Dieter) To: [email] Message-ID: <[email]> Content-Type: text/plain; charset=us-ascii; format=flowed Hello Steve, no sweat, no worry, there are no wind limitations! The wording "No operation at wind velocities greater than 8m/s (16 kt)" is a left-over from early days and will disappear in the next issue of the flight manual. But keep in mind, that ground handling becomes more and more difficult with increasing wind velocities. To avoid a tip-over before taking off from a slope, you must apply the procedure discribed in section 3.1 of the flight manual. Doing so, you will enjoy a real, true vertical take-off at high wind speeds! You also should not be frightened by the "design complexity". I recommend to start with building the horizontal tail, because it shows basically all difficulties you encounter later on fuselage and wing. You learn to work with the material "Member 60" without risking too much. Best regards, Dieter (I'm sending this on behalf of Dieter. For some reason his attempts to post this to the list have failed. I'll check into that. Dieter, as far as I can tell you are doing everything right. --Doug) ------------------------------ _______________________________________________ ULF-1 mailing list [email] http://lists.ulf-1.com/listinfo.cgi/ulf-1-ulf-1.com End of ULF-1 Digest, Vol 2, Issue 7 *********************************** --------------------------------- Bored stiff? Loosen up... Download and play hundreds of games for free on Yahoo! Games.