Justin

Hi Jeff, Go to the UL Power website, and on the 'manuals' page for each engine there are STP file downloads. The installation manuals are there too, and well worth reading. https://ulpower.com/en/engines/ul390/ul390i#downloads Justin

The engine mounts always need to be engineered for the job. It is likely that the torque reaction of the UL390i is similar to the O-235, because it revs slightly higher. Other higher torque engines are already used in EZs. You just design the mount for the job. In any case the Lycoming mounts are not used with UL engines. BTW, the UL390i is 140hp. The UL390iS makes 160hp. I think propeller design issues are more of a concern. These are things we can investigate in simulation.

Hello Kent, The UL390i is not bigger than an O-235, but is a little more powerful at 140hp. It is 4kg lighter, has a slightly smaller frontal area, and the starter ring is at the opposite end to the prop drive, so the engine cowl can fair better to a prop spinner. In my model the firewall is bog standard EZ, and I have now extended the upper engine blisters to make them fairer. I think this reduces the pinched in zone. I prefer not to affect the standard firewall. This might preserve a faster airflow over the cooling outlets (not modeled yet). I will model armpit intakes. I read about them in one of the CP leaflets. I prefer not to affect the standard firewall. The canopy is sleeker than the standard one. It has the same height and width at the canopy frame. It fairs to the standard firewall, and at the front I took some volume out with a more sloping profile. It does have a circular section at the pilot's head, and would be a little wider there then most, but not much. If I ever really build one I would mock up the cockpit first, to see if I would like it wider, but I used to enjoy the secure feeling of being strapped in tight fitting seats in my glider flying days. This is a 'paper plane' that will most likely only exist in the X-Plane simulator world. Cheers, Justin

I think I will not build an EZ anytime soon, except for X-Plane. I will make a bog standard one first, just to benchmark it with known performance. Then I will make an adaption with the UL 390i engine and retractable main gear. Anyway, all these kind of projects start with CAD models.

Hi Jon. Yeah. ´Makes good sense. CAD stuff can be presented as impressive even when it is complete rubbish. Crap in = Crap out. We see it too often in my day job. It is just good sense to be suspicious of it. With old, manually drawn projects, what CAD can do is fill in gaps, where the 'power of the pencil' gets away with ridiculous inaccuracy, or some error has been made, or there is simply missing data. I have to say that my view of RAF drawings is that they are pretty dismal, but good enough for skilled people to make perfectly good aircraft. The 3D models I received were treated with my normal suspicion, and failed. I am using data now from Open EZ, and I suspect there is little worth having the CD from TERF. I hope that provokes some informative responses that might change my view. One discrepancy I have found more recently is that the RAF drawing of the centre spar, when modelled in 3D, goes slightly through the internal wing core skins, as modelled from the Open EZ drawing scans. It is a small amount, but notable. The RAF drawing of the centre spar makes some approximations of the lofted wing skin inside surface. I know there was no CAD lofting when Long EZ was made, but you don't see so much error in Spitfire drawings from the 1930s. As far as I have explored the Canard Pusher newsletters now, there seems to be good laminate build data there, so laminate thicknesses can be determined. There are an awful lot of CP newsletters, and I have a lot more to learn from exploring them. Cheers, Justin

Hi Jon, Thanks for your replies. Skills?.... I am an automotive designer with aerospace and defence industry experience. I have been using CAD since 1980. I am afraid I am impaired in some way.... I just cannot leave 3D geometric challenges alone, and end up in all sorts of projects. I also design boats, mainly sailing craft. There are about 100 boats afloat today that I have designed. The Spitfire work started in a purely geometric wing lofting challenge I fell into, but now I help a little on a restoration project over here, Well, I have latched on to Open EZ now. I am considering building a Sonex B. A long range touring aircraft could be quite a good thing for me. I like working with epoxy and glass, and an EZ is pretty unmatched when it comes to long range, speed and economy. I am an ex-glider pilot, and really like being in the front on any tandem seater, with very good fields of view. I will probably model an EZ in X-Plane 11, if I can find accurate airfoil performance curves. I did ask a question in an earlier post on this thread.... Is there really anything more on the TERF CD. than already published in Open EZ, and all the CP publications, pertinent to the EZ build? It is the only Rutan aircraft I will find time to play with, although the Q1 is quite fascinating. I will try attaching a high resolution rendering now.... Nope.. it didn't work. It was only a 3.3Mb PNG file. Cheers, Justin

Hi Jon, Ary linked the very same page to me. Sheets A2, A7 and A10 are shown with scaling errors. It easy to cross check in CAD, because you overlay the drawings on the stations, waterplanes and but lines that are dimensioned by RAF. What is difficult to know is which axis on A2, A7 and A10 is incorrect, but the information in the linked page clarifies this. I am sure this is all Ary did his in Catia. I use Rhino for this kind of correction; sometimes even in Spitfire work I do.

Hi Jeff, Well, it started when someone sent me another CAD model to help them with a modification. There were errors when compared to the Rutan drawings that were on the Open EZ site. Both the IP and the little frame (F28, I think) just aft of the canard were in the wrong position. I have all the CP publications from somewhere, probably Open EZ too. Ary Glantz kindly pointed me to some info to correct some of the scaling issues in the drawings. Can anyone tell me, is there anything pertinent to the Long EZ on the TERF CD that is not in the Open EZ information ? I have not found much information on the main gear legs. Cheers, Justin

Hi Jon, I use Rhino for surface lofting, and a combination of Rhino and Catia for detail and assembly work. Catia renders pictures well enough for me, and is fairly quick at it. I don't know if I will build an EZ, but was helping with some modifications on another one, and just continued modelling.

Ahaa.... JPG format works better

Hello EZ people, I made some surfaces from Open EZ data I downloaded ages ago. 'Thought I would share them. I am going further with the modeling, making a sleeker canopy, and a slightly less drooped nose, along with packaging the UL390i engine. It is almost as heavy as the O-235, is slightly smaller, very likely less expensive, fuel injected, and has FADEC. I will add a few WIP pictures. Cheers, Justin ps I think there is a file size limit on uploading images. I tried some just over 3mb and they failed. OpenEZ.zip