Still to do: Reseal engine compartment after trimming the wood, remount the engine, realign the hi and low needle access holes (which are now off since I moved he engine), reconsider whether there's any way to use a larger tank (currently there's only a 6oz tank), redo the hardwood supports for the top cowl mounting screws (they've gotten stripped out) and review the balancing.

Jack,
it just so happened when I pulled the engine picture into a new tab, the wings center section was perfect align with the top screen edge.
( agree one in a million). It was also nice to see MerlinV's felt it just looked off ( my words) Good eye or intuition based on the first few posts and flight info is my guess how he new. Point is he mentioned it and Abu was not afraid to check.

So I ran the picture to the bottom edge and noticed port side prop was a little more aft. Thus I mentioned this and the only sure way was to measure it. I'm glad we try to teach and learn from each other.

In fact I 'm redoing my 1/3 pup now. last weekend I had the landing wires snug to set the dihedral first. Abu did not do that and the light bulb went on. Incidence first, then the dihedral. 5 hours on the garage floor and almost all done. Got to love scale.

Jack, your N-28 is more scale than Lou Proctors. I especially love the starboard side and the auxiliary fuel tank you made. A high standard for us all to aspire to.
You know the story how Lufberry fell out of his barrowed N-28 as he was hit in the right thumb and shell ignited the starboard aux tank?

Actually, that's exactly what I did: Incidence (strut bracing) wires first, then dihedral. I also did the rear dihedral wires first since one of the rigging documents posted here suggested that incidence was set both with the strut wires AND the rear landing wire.

Yep, I learned that from you and this thread. cool.

It can be tricky on a large model like your 1/3 scale Pup since the wing panels are really just hanging off the fuse and center section (as on the original). So the wires not only control incidence and dihedral, they actually hold the plane together! If a wire (or a couple of wires) comes off on a large Pup, there's a very good chance of one (or more) wings coming off also.

Scroll about 2/3 down this page from Mick Reeve's website showing how he does the field setup for his Pup. As you can see he "hangs" the wing panels first with the landing wires and then slips in the struts as a fixed unit. Obviously, this method depends of getting the length of the landing wires perfect to start with.

http://www.mickreevesmodels.co.uk/~m...es/p2bipe.html

I think if you can manage to set the model on it's sides with the centerline secured in a level position you can use the robart inc. meter to check and adjust the engine thrust line. I haven't felt the need to do this in a long time and as I recall the "jigging" the models' centerline level was the part where a little creativity was needed.

Thanks Mike. That is one of four N28s that I have scratched from my own plans over the past few years and yes it is more scale than the proctor N28. No desrespect intended to the guys at proctor or lou. They are a great bunch and I have met them a few times at events over the years. I know one of the partners retired a few years ago.

I had posted that the engine thrust line did not look right but when I saw how the kit was constructed, I have one, I wondered how the engine thrust could be off. Dave Platt never addresses engine thrust line at all in the manual or plans. Live and learn. I just started a scratch build of a Boeing P12 so I won't be getting to the SE5 for some time but when I do I will certainly remember this thread. There certainly has been some creative advice.

yes gotta love those scale models...they are never finished even when they are finished ! I know this............ what Abu did certainly straightened that great looking SE5 out.

Jack

No kit can EVER be scale as a one-off scratch-built model. The realities of turning a model into a kit require compromises. Some of these compromises are made for the sake of cost/efficiency, but others are made simply because most customers probably don't want (or can't afford) a 100% museum quality model. And that's all perfectly OK.

Mike, I almost forgot about Lufberrys' demise. When researching the N28 I read most of the combat reports and maintenance reports when the 94th was flying N28s. I find the history and the stories of the pilots both before and after the war to be one of the most facinating parts of scale modeling. When I was deep into my research I could look at photo of 94th pilots and know their names and a little about who they were and where they would end up. I built Lufberrys' #2 and also nos 1, Huffers and Rickenbackers, # 5 of John Wentworths and #8 of James Meisners'. I'll attach a few more photos of the last N28 no.8. It had a good layer of dust when I took the photos and was not quite done....Then again it never realy will be "done" I just finished it in early fall and have not had it out yet......bitter winter up north here.

I know it's comparing eggs with apples (or chalk with cheese) but we maiden-ed my 1/6 scale BUSA Pup yesterday.
In accordance with the instructions (and with my engineers mark one eyeball hurting terribly) I dutifully installed the OS 52 Surpass with 2 degrees down and right thrust. In fact it's as plain as anything to see when looking down from above the fuselage just how much right thrust there is.

Jon (My test pilot) said that it tracked beautifully and needed no trim whatsoever on the Ailerons. Given how slap dash I felt that the rigging and alignment was, I was pleasantly surprised at this assessment.

I do however have to add some more weight to the nose. Although I followed the Kit instructions to the letter regarding engine setup, I thought the CoG looked very far forward on the plan and using the standard Biplane CoG calcs, put it 1/8th of an inch further back... I'll be pushing it forward again to where it should be.



Good luck with the next test flight!

Cheers,

Hugh

Yes it is perfectly OK. It has to be as even the National Air and Space Museumss' restoration is missing some things. That is why some of us like to design our own...it is not for everybody only folks with an obsessive compulsive dissorder. Lou Proctor designed his N28 around a museum N28 that had been to Hollywood, had it's wings clipped and I struts replaced the wing struts. In the US back then most museums were not concerned about real accuracy either and i imagine when they restored that N28 they only wanted to get it close. The Navy version, that they restored it to, had differnces from the N28s used in WW1. Not knocking kits or arfs of scale models I love em all without prejudice.

Congratulations on your Pup's maiden! It looks really nice in the air...despite the ghost pilot. Of course with the BUSA Pup (and a few others) technically no rigging is needed since the wings are designed to support the load (with the thick leading edge, double spars, and spar webs). The Flair Puppeteer is the same way. Still, I think the sturdy functional rigging (music wires) on my Puppeteer saved its bacon on several crashes into the trees...not to mention a few "less than perfect" landings.

Jack, I didn't mean to imply that your N28 was "just OK." It's fantastic! Rather I meant that it's OK that kits, even the ones from Proctor, GTM, and MR, aren't perfect. They just can't be. It's in the nature of kits.

*****

Merlin, here's a bit of photo editing on you Pup shot. Lets us see more of your great model! BTW, it looks like you've done some scale mods on it.

Merlin since your model is also 1/6 scale, just how much would you say the center of end of the engine crankshaft is off-set from dead-center? This should give me an idea of what 2 degrees looks like.

I agree it is OK that kits are not 100% scale I designed some scale kits back in the late 80s and just from a manufaturing stand point it's almost impossible if you want to have a product that is affordable and as you say most folks don't care. That is the last N28 I built. The intention was to have a model that could compete in world competition. Due to health issues I had to put those thoughts on the back burner for a while. No worries now ! This is the first time I have ever participated in a thread on any forum and I must say it is intersting. The pleasure is meeting modelers from all over. Good luck on your next shake down with the SE5. Jackson

Hmmm... good question that Don.

I would say (from memory) that at the firewall (which is 110-115 mm back from the front of the cowl) i had the mounting holes about 4mm offset (up and to the left) so that the prop would be dead centre at the front of the cowl.

I have actually just come back in from the shed having just re-fitted the cowl after adding another 6 or so ounces (she is still 20% lighter than a club members 48" Camel). I took the opportunity to Eyeball the right thrust and I'd say that the starboard prop tip a good 5mm closer to the plane of the front of the cowl than the Port tip (12 x 6 APC).

To my eye, 2-2.5 degrees is slap in the face obvious. If you can't see the side thrust with your naked eye, you probably don't have quite enough.

And yes, I know that my rigging is purely cosmetic. But I cannot stand to see WWI subjects that are lacking flying and landing wires.

Cheers,

Hugh

It's a good thing that I did "unbutton the hood" since it turned out that the fuel tank has some serious gunk from a half tank of fuel left sitting for over a year. This would definitely have led to a dead-stick. Some spray-on parts cleaner got rid of that.

Now, I'm waiting for the 2-part urethane to cure in the engine compartment before putting it all back together.

[QUOTE=MerlinV;11721175]To my eye, 2-2.5 degrees is slap in the face obvious. If you can't see the side thrust with your naked eye, you probably don't have quite enough.
[/QUOTE}

With the way the engine is wedged into my model (no "firewall" per se), there's no way to get more than the perhaps 1 degree I have now. It is just barely discernible. The main thing is that I've gotten rid of any left thrust and gotten just a tad of right thrust. That should be enough.

Oh, absolutely. A WWI model without rigging is just a WWII model with an extra wing!!! Are your wires actually load-bearing...at least partially. Personally, I think that's a good idea even on the BUSA/Flair. It makes the model much sturdier. (And gets modelers used to doing rigging so they move on to other scale projects. )

Hi Don,

Yes, I have double flying wires and single landing wires using 20 Lb nylon coated trace.

To say that they are "Load Bearing" might be being generous. But they are certainly there and under load during flight.

1 degree right thrust is certainly better than any left thrust.

Cheers,

Hugh

Even after all my work, the starboard side measure is still only 1-2mm shorter. It's sort of annoying. I suppose it's gotten maybe 4mm shorter when you remember than it used to be +2mm (not degrees) on the port side. Given the way the engine is mounted between two ply "shelves" I'm hesitant to enlarge the bolt holes an further to allow more movement.

I didn't read through all the posts, and maybe someone already mentioned this, but I recommend to anyone who is building a biplane to go out and get a copy of Harry Higleys book called BIPES. My first two biplanes barely flew for @&$%, then I got this and every bipe since then has maidened with only a click or two of trim (if that.) if you plan to build one, I STRONGLY recommend it. You can even apply a lot of it to mono wing planes as well.just my opinion. Steve.

The question that truly interests me is not how we can alter the design of our models to make them fly "better" but rather is it possible to use scale airfoils, scale incidences, scale dihedrals, scale empennage and still have a flyable model. I'm not necessarily talking about an "easy flyer" but one that flies pretty much like the original.

My SE5a is a good case in point. While it doesn't use a scale RAF airfoil, it does have a "scale-ish" airfoil. The wings are mounted at the same AoA as on the original (about 5 degrees) and use the same amount of dihedral (also about 5 degrees). The engine is mounted parallel with the main longerons as per the original. The main aerodynamic difference is that the stab on the model is at +3 to the center line, while the tail on the original (which was adjustable) was also level with the longerons. I'm hoping that now that I've gotten all the kinks straightened out my SE5a will fly as it was intended to fly. And if it can't...well...then I will have learned something.

I trust the original WWI designers and don't feel it's necessary to "re-design" models of WWI aircraft. I especially don't feel it's necessary (or desirable) to "improve" the design. Would we improve on the Mona Lisa? Sure there are inevitable differences. But I believe that the wonderful WWI scale models that have been built and flown in top competitions show that completely flying scale WWI models are indeed possible.

I'm using Mick Reeves, flat flying wires for my BUSA Pup as test bed for my Tripehound. Seen his site and how to silver solder them.

They are slick and look great. I found you need to be very close to final measurement as clevis only has about 1/4 inch travel on the threads. Word is the flat wire also stretches slightly after a few break in flights. I was also advised to upgrading size from his 3mm to 4-40 size clevis to be more robust based on three others who use them on their 1/3 Albatross or Camels.

Perhaps we just like to fly more aggressive or have heavier models. Will see.

MerlinV, Congrats on your maiden. A very nice looking Pup. You will have en exciting yet easy flying plane to take on those Fokker's.

FYI: our club has mostly switched to: 1/4 scale using 40 or 60 lb stainless steel 7 or 9 strand fishing line and crimps and 2-56 Clevis for elev/rudder pul/pull cables and the wing rigging. For 1/3 we are using 90 lb. they have held up on many models over past 5 years.

Sorry to,do this but PM's not showing up.

Jack Steward350: sent you PM on N-28 question.
CafeenMan: Sent PM. Yes. Send me email