David, et al: I'd originally intended to power my TT with my OS .20FS, but the nose-heaviness issue pretty much dictated that I'd have to run something lighter than the little four-cycle. Since my airplane is built to plan and covered with Polyspan, I suspect that at 40 oz. it's lighter than most. If I build another, I'll eliminate a lot of plywood up front, but will also strengthen the tailfeathers, which are a little frail for general sport flying. Since the thrust line is fairly high (at least when compared to many other cabin models), I think any engine in the .20--.40 range will work well, with a four-cycle being my preference.

-Mark

Originally Posted by cd_webb

Hey Chris. You are right about the plan, it is the 1938 Flying Aces one. Sometimes all you have to do is look. I get so into the details from the start that the obvious sometimes doesn't hit me until an embarrassingly long while later.

I've intended from the start to either run an O.S. 40 pre-Surpass engine, or a Saito 45. The 40 will probably be overkill from what Moeregaard has said, so I figure between the two choices I have, I'll go with it. I love my Saitos, but maybe on the next one. With either one I should have good access to all parts of the engine on the Terror. Unless I'm missing something, it should be pretty elevated and out in the open.

David

Hi David,

The 45 will certainly have more power than you will need...Ideally I reckon a Saito 30 would be ideal. But at least the engine plate gives you the possibility of changing the power plant relatively easily, so you can always experiment a bit, so dont listen to us

I'll second what Chris just said. The TT's spacious nose makes it ideal for swapping out engines. I believe Saito has discontinued the four-cycle .30, but OS still makes their .30FS, and it's very similar in weight to the old .20FS.

-Mark

I've got one of those (OS .30). It might be the best choice after all is said and done. The really sad thing for me is that I'll have to build some more airplanes now for the 40's and 45's I have! Talk about your BAD luck!

Does anyone have any opinions on the side thrust as shown on the plan. The best I can measure, it's only about 1 degree. As this one will be R/C, and run at relatively low RPMs, is it really necessary? My smallish electrics usually go with around 2 degrees of right thrust, but this is an entirely different animal here.

David

I'm running with zero side thrust and my TT will climb in a gentle left turn if left to its own devices. I usually just counter this with a couple of clicks of right trim, but adding a degree or two of right thrust would probably not be a bad idea.

Sorry to hear that you'll have to build more airplanes for your other engines! I'm thinking that a Taibi Powerhouse would make a nice home for that Saito .45!

-Mark

All you really need is 2 or 3 degrees of down thrust David.

Bill

OK, with the 2 degrees of down thrust shown on the plan, I think I should be good. If not, there are a couple of other ways to add another degree anytime without much of a problem. I've also planned for the engine to set as low as possible in it's compartment for looks and to keep the fuel tank from showing as much as I can. Hopefully lowering the engine won't really affect anything.

As usual, I've gotten well into a project and haven't thought far enough down the road to have what I need on hand to finish. Fuel tank and receiver foam, along with assorted bolts and washers and a suitable fuel tank have been ordered. As there is no such thing as a hobby shop within 120 miles, it always pays to think ahead and order everything at one time. This just doesn't happen for me. So while I'm waiting, I figured to move on gluing sticks, my favorite part!

I'm still waffling on which motor to use, but if I use the OS .30, I can lower the fuel tank another .2 inches. It's not much, but anything will help keep the fuel tank out of the windshield.

Still thinking on a color scheme. I'm partial to blue and gold with a white pinstripe separator. What I see in my head, and what I have the skill to make happen may be miles apart.

Anyway, some pictures of the progress so far.

David

Beautiful construction..

Cem

Lowering the thrust line will result in a greater trim change as power is increased, but you shouldn't have any problem with the smaller engines, David. The TT is pretty forgiving in pitch, and any excessive nose-up attitude can be corrected with some elevator trim. Once it's trimmed out you probably won't use the elevator much anyway, and it's fun to set the airplane up on final approach and let it land with the transmitter sitting on the ground.

-Mark

I appreciate that, Cem. I've gotta tell you, your Playboy is beautiful and it looks like it flies like a dream. I've watched your video at least 3 times and I love the way it floats along. The scenery ain't bad either!

Thanks for the explanation, Mark. I figured it would affect something, but had no clue what. The more I think about it, the more I think I'll cut a couple more engine bearers and mount the .30 from the get go.

David

I think you'll be happy with the .30, David, if you keep the weight to three pounds or less. As I mentioned earlier, my TT comes in just under this number, and replacing the Enya .15 with a '70s-vintage OS .20 two-cycle didn't change much.

-Mark

Well, another week and another rookie mistake (or two). Has anyone here ever built 2 right wings? And what was that stuff about "measure twice, cut once"? Thankfully nothing was unfixable, and I'm back to moving forward again.

Knowing that the wing attachment dowels will have to be set below the cabin windows, and also knowing how tightly the bands will be stretched, I decided to sheet the upper surface of the center section. I've also decided to add sheer webs between the upper and lower forward spars, hopefully to help cut down on any twist and flex. This may be unnecessary, but it makes me feel better.

I made a leading edge sanding block like one I saw on Crist Rigotti's Falcon 56 thread. I've always planed and sanded to eye before, but this was much easier. It wont be the last time I use this method of shaping. It takes the guessing out of getting identical LE's, one side to the other.

And, apparently there is some problem with uploading photos right now, so as soon as I can I'll edit some photos in.

David

Never done that, however, I can see how it would be an easy thing to do especially looking at how some of my old timer free flight plans were drawn. Kind of falls in the same category as two right hand fuselage scenario that creeps up once and awhile. Your only human.
Heck, you are doing a beautiful job on this airplane and your workmanship is something to be admired. I am glad you have overcome and are making progress.

Greg

Originally Posted by cd_webb

Well, another week and another rookie mistake (or two). Has anyone here ever built 2 right wings? And what was that stuff about "measure twice, cut once"? Thankfully nothing was unfixable, and I'm back to moving forward again.
David

Oh boy, have we David! My favourite is to build two right hand fuselage sides. A mate of mine did the wing thing when building an A/2 FF glider and didn't notice until he had covered the (plug on) wings! So he built a left wing and then couldn't stand the thought of wasting a perfectly good right wing, so built the rest of the model to go with it, ending up with two complete gliders. At the first contest he took them too he had a D/T failure and one of them disappeared upwards in a thermal, never to be seen again, so it turned out to be a good thing in the end! Welcome to the "been there done that" club, there are lots more classic screw-ups just waiting to be made!

Good idea on the shear web and surface sheeting BTW.

Your build is coming along nicely, David. I like the idea of sheeting the center section and will do that if I build another TT. Also, shear webs are an excellent idea and I carried them all the way out on the front spar. The weight gain is minimal. The 1/4" balsa spars have been more than adequate for general sport flying.

-Mark