I am a ways off before my skills are good enough to approach an "actual" or "real" interest in this, by this I mean "ready to buy". I have been around these boards for a long while as with several other forums. I guess I am one of the "idiots", as some describe, that always want bigger, bigger, bigger! I am curious as to why there are no large scale EDFs, by this I mean 10-30lbs aircraft. If we have electric helicopters with 3 meter rotor diameters, 40% electric planes, etc, why is it we only have 45" EDF jets? I can't seem to find anything greater than 90mm which from looking around doesn't seem to push a whole hell of a lot of weight.

Is the issue that once you get the fans large enough to be used for larger jets that all of a sudden your motor/fan/batteries now outway the application? Are they just not efficient enough? Has no one bothered to care and build one that big? Just curious. Of course the other side I am seeing is that once you put together everything required for such a project you can have just strapped real turbines to your model and been done with a lot less pain, is that actually the issue. With turbines coming further and further under $3,000 by the day and the cost of the huge LiPo packs still over $800 is it just not reasonable to build a large scale EDF?

Like I said, I am just curious is all. If anyone wouldn't mind I would love a set of links to several of the different manufactures of both EDF supplies and model kits. I found one on here the other day for an F-14 I think it was than ran dual 90mm fans with a 60"+ wingspan but now I can't find it again, that kit looked like a hell of a lot of fun.

In the UK we have a large model association, and yes we have large EDFs. My A10 which we are developing this year has a 3.3m wing span weights 25lbs and has 17lbs thrust from 2 Turbo4000 120mm fans driven by Plettenburgh motors and 10S lipo each. We have designed and currently having built the worlds largest electric ducted fans which will be flown in the A10 at the Aspach show in Germany in september. THese will have 50N thrust on each with a high exit velocity. We will publish the on board data results on the forum when tests are completed. Such large models are usually designed and built by their owners as it is not a commercial proposition to make them into kits. There are a number of people on the forum pushing the boundaries of EDF in particular the use of the Lenher motors. I believe over the next 12 months the equivalent power to weight ratio of the 14lb turbines will be met.

How did I know it would be someone from Europe to pop in first.

You guys simply amaze the hell out of me over there. I have been in the scale helicopter realm for a few years now and here in the states we barely dent the surface of what is coming out of Europe. I don't know if it is the generalization of the "lazy american" or the "american way of life", referring to our hectic lives or what but I just don't see that many american engineers that are building to the same level that y'all are. Here in the states we build kits, there you create them and then sell them to us. I wish I had half the engineering might that some of the guys over in Germany are showing us day after day over in scale helicopters. Well enough of my arse kissing for now, you get the point, I respect your ingenuity.

I can't wait to see pics and more info. I would like to see models like the Yellow Aircraft F-18 running on dual EDFs for the Bobcat running off a single. I know it can be done. Since you are building one of the larger units, do you consider the cost on par with a 14lbs thrust turbine option, more, less? I realize that the battery purchase is a one time expense but you get the general point of my interest.

Daniael

There are several being done in EDF now over on www.rcgroups.com right now.
Bob is doing a YA F-4 http://www.rcgroups.com/forums/showthread.php?t=332845
Phil Lin is doing a JHH F-4 http://www.rcgroups.com/forums/showthread.php?t=325806
Ralpf has done a BVM F-86
And several others have done large scale EDF's
I'm doing a F-4 as well as a very old ETA F-89 Scorpion for 2 HW-730 fans

Just head on over to RC Groups and do a few searchs in the EDF forum.

HTH's

Awesome Mark, thanks. I will head over there now, it's all about knowing where to go to find what you happen to be looking for at the time right