Yes, thrust line is a real thing. Just as real as a 5" longitudinal C.G. envelope It needs to intersect the center of pressure (or center of drag as some may call it) at just the right place or be

With the Seawind 3000, is “thrust line” really a thing? Isn’t it really a way to get the engine to fit the cowl?

Please note the time, it is a little different. It should be a really interesting presentation. This month's Q-Tour features Matthew Curcio. I met Matthew at Oshkosh a few years ago. He was living

Hi Ian, I found the worksheet where I computed the WL of the CG for my empty A/C. My empty CG’s WL is 11.3”. Pilot and fuel were not measured but these loads are mostly higher than this WL in

Now I am curious now to see where my Crank C/L will end up, close to or not the Q-200 and your 3300. Having the C/L of the 3300 that close certainly makes anyone looking at an O-200 replacement

Hi Ian, You can do what you are describing, but simply removing the line items that I have in there for my gear and replacing with appropriate weight and moment entries for the standard wingtip

Hi Vern, I got the thrust line on the 3300 pretty close (+/- 0.2”) to that of the O200. I was able to use my original Q-200 cowling halves with not too much alteration, other than the

Hi Anthony, I think you are correct, the stock Rotax silencer will have to go! From the perspective of ear comfort during flight I had thought to keep it. I don’t think it’s a tuned exhaust so

Jay, Thank you for sharing your spreadsheet. It’s the best data source I have so far. I was hoping to do the same, but in CAD. It turns out that may be more difficult than I thought as a good

Just curious Jay.. was your 3300 also at the O-200 thrust line or did that change? I know for sure on my engine choice the supplied cowling is not a useful item. I will be hinging in 4 sections. 2 up

Hi Michael, The template of the firewall shows two small lines either side. I previously believed these were WL 15”. I now think they are WL 12.9” (fuse split line). Fortunately most of the

Hi Ian, There is a lot of good information in the files section of this group. Have a look at the folder: https://q-list.groups.io/g/main/files/Weight%20&%20Balance I just added my spreadsheet

The following files have been uploaded to the Files area of the main@Q-List.groups.io group. /Weight & Balance/Builder_W&B_by_component1.xls By: Jay Scheevel

Hi Mike, “So the Q200 is very nose heavy as built.” That the kind of information I’ve been hoping for! The Rotax is at least 50lbs lighter than the O-200 and the way I think I’m going to

Ian, if the silencer (muffler) is NOT an integral component of a sensitive tuned exhaust, I would ditch it. The Q2 is not a certified aircraft, nor is it an LSA. You can do stuff like this. I don't

FYI, I needed to place a 24 lb battery (PC925), behind the first bulkhead in the rear shell. So the Q200 is very nose heavy as built. It would be better to use a smaller battery closer to the front

Jay, Ive done vertical CofG calculations on race cars the same way. Unfortunately I don’t have a physical aircraft to work from, just some empirical data and calculations. I feel reasonably

You did indeed! And it was helpful. But there is still some doubt about the datum’s. I’m going to try some things to see if I can get some better guidance. Ian

Yes, exactly! The inconsistencies are difficult to navigate!

I just posted it a couple of days ago: Revmaster and O-200 Thrust Lines. Still an open question on the inclusive vs. exclusive of fuselage thickness until I get out to the hangar, though. The Q-200