Rebellion

My Feedback: (2)

Hi All,

I plan on starting a 108" Dallaire Sportster build next weekend. All the goodies should be in by then, I hope. I plan on using either Solartex or Nelson Color Fab for covering. Power will be an OS 55AX. Not exactly a vintage engine, but it's what I have and in this economy it'll have to do. Before I start I have a few questions.

First of all, I measured the stock dihedral at 17 degrees. I've been advised to reduce it somewhat and am planning on going with ten degrees. Any comments? Also, considering the power fo the OS 55 would it be a good idea to use lite ply doublers in the front of the fuselage, say back to mid way of the cabin or so? Finally, what would be a good target weight for the Dallaire?

That's about it for now.

Thanks,

Dave

squeakalong

My Feedback: (8)

Hi, Dave.

I'd go with lite-ply doublers on both fuselage sides from the firewall to the rear cabin former; this catches the entire wing/fuselage area too. 10 degrees sounds reasonable and as for weight...just build clean and light for a nice flying model. I've flown the Dallaire in the past and it sure is a nice floater and looks nice in the sky against the clouds. Are you building yours from plans or a kit?

Soft landings.

Joe

Rebellion

My Feedback: (2)

Thanks Joe, I appreciate your advice.

I'm building the Dallaire from plans and a short kit from Bob Holman Plans. This will be my first cut and glue build in a couple of decades and frankly, I can't wait to get started. Kinda sick of bARFs.

Thanks again,

Dave

squeakalong

My Feedback: (8)

You know, Dave, having fun building your own flying model can become habit forming...especially when it takes off for the first time and you realize that YOU built it. That's what I enjoy most.

Soft landings.

Joe

Rebellion

My Feedback: (2)

Yup, I remember enjoying building C/L and F/F kits in my younger days, and the thrill of seeing them fly once they were finished. A stint in the service and a full time job put my hobby on the back burner for a number of years and when I decided to get back into it around six years ago the realities of adulthood made ARFs seem like the way to go. I've had enough of correcting someone else's work for a while though. Time to build my own again.


A flying bud of mine brought his Dallaire to the field a year or so ago and I fell in love with it. Such a beautiful and graceful thing in the air! Been wanting one ever since and I finally decided now is the time.

I've added a couple of pics of my friend's Dallaire below. It's been through a major crash ( wing came off in flight ) and isn't quite as pristine as it once was, but is still a delight to see in the air.

Take care and good luck on your builds,

Dave

beppeVRCS

Dave, the OS 55 on the Dallaire will look strange, to say the least... I may have an engine for you and we can swap them, if you like the idea. What would you like to have? I may have it...
Beppe

squeakalong

My Feedback: (8)

I don't know, Beppe, that color scheme on his friends Dallaire looks mighty "sporty" and I'd think the .55 would be all right to use. Now, if you're going for the Old Timer look, in the strict sence, well...that would be a different consideration. I kind of like that red and white look. Whatever you decide..HAVE FUN !

Soft landings.

Joe

John 38

Dave,
is 17 deg the angle between the 2 wing halves? if so then this will give approx 8" dihedral under each tip.

for a vintage model of 108" span - this is about right and I would suggest staying with the plan if you intend to fly it vintage style.

I reduced the dihedral on another vintage model and it did not fly as nice and furthermore it just did not look right

john

Strat2003

My Feedback: (1)

I have a little Dallaire for the SAM Speed 400 event and it flies just fine with the stock dihedral. I use it for both climb-and-glide type flying and general flying around and I'm not sure why you'd want to change the angle, although I often hear that recommendation as well as the one about reducing the incidence in the wing.
I'd build it stock.

Rebellion

My Feedback: (2)

Guys, thanks for all the advice and offers.

Bepe, I do appreciate the engine swop offer, but truthfully, it may look odd but the OS is as reliable as a rock. I think I'll stick with it. Something I'm doing that will improve the look a bit is using an extra long side exhaust [link=http://www.macspro.com/headers_side.asp]header pipe[/link] with a muffler insert from Jett. It'll get rid of the ugly muffler at least.

John 38 and Strat, yes, the dihedral is 17 degrees total, approximately. The plans call for 9" under each wing tip, so my measurement may be a bit off. If it'll fly nicer then I'll stick with the stock dihedral. The one in the pics above, however, had half the dihedral removed during the after-crash repairs. He likes the way it flies better, but then he is doing wierd stuff like barrell rolls with it.

As for the look at this time I haven't quite decided. I'm thinking a PT-19ish scheme might be OK, but I'll probably change my mind a dozen times or so between now and the time I cover it.

Joe, I'll pass along your compliments to my friend. His is covered in Monokote and, though not a true vintage look, it's still gorgeous in the air.

Ahh, decisions, decisions. Tons of fun ain't it?

Thanks again folks,

Dave

PS, there is a double Dallaire build thread going on on another forum. Unfortunately, there is some bad blood between that forum and RCU so I can't provide a link. If anyone here is intrerested, PM me and I'll provide the info.

timfarrar

Hi Dave !!

I am glad you decided to do get opinions here too !!

It will be interesting getting thoughts from you guy's here at RCU also !!

I am building the Dallaire with Dave Guy's
My own that is... We both got short kits from Bob Holman.

Hi John, the reason we were thinking of taking some Dihedral out is the Dallaire is actually a free flight plane isn't it ?
We were thinking it may float even better being a little less dihedral ...
Or at least that is what I was thinking...but I dont know, I am no expert but it just seams it would to me ...

Maybe you guy's could stop us from making a mistake !!!
What do you guy's think ?

Dave, how does your friends turn now that he has less dihedral ?
That was my only concern of changing anything.
Also Dave,
That front view picture you posted of your friends Dallaire is before he took dihedral out right ?
Well, the reason I ask is it actually looks pretty good to me like that !!!
If that picture is the recommended dihedral I may stay with it and not change nothing...lol lol lol...

I know I sound like a idiot guy's going back and forth like this but I am thinking and I am wondering what you think and what you might have exsperianced...

Lets build Dave !!!!...lol lol lol...


Seeya, Tim

Strat2003

My Feedback: (1)

SAM rules require the original dihedral on everything flown in competetion, so there might be some advantage if it were reduced somewhat. However, reduced dihedral can lead to spiral instability in certain cases. For an airplane to be spirally stable the dihedral and fin area must be correctly proportioned. One of my friends had a Lanzo Airborn with less than original dihedral and it had a nasty habit of entering a spiral dive on its own, sometimes from great height! Not desirable in an easy-flying airplane, lol. He corrected the dihedral and it's now a sweetheart. The Airborn has an especially big fin while the Dallaire looks more conventional, but I'd proceed with caution.

timfarrar

Thanks, After seeing the picture of Dave's friend's Dallaire above, I may just keep the original dihedral.

I like the looks of that plane !!


Seeya, Tim

Sky Dart1

My Feedback: (6)

Dave and Tim;

I built a Dallaire Sportster from a Penn Valley Hobby kit last summer, and built it with the full 9" of dihedral under each wing tip. Powered with an OS 70 four-stroke, it is a wonderful flying machine. With the dihedral as called for in the plans, it floats forever after the engine run. I can't imagine doing anything that would cause me to need more time in the sky - it will stay up on a summer evening as long as I want. My only complaint is waiting for the engine to run out of fuel so I can begin the 'silent' portion of my flight.

Good luck with your builds.

Ron

timfarrar

Thanks Ron !!

What does your weigh if you know, I was curriouse about that.

I am really thinking I will go with the original dihedral for sure !!
I need to let Dave know ...lol lol lol...

Also, I am doing the two piece wing, which did you do ?

What color did you do ?

If you have pictures that would be great too !!!


Thanks again
Seeya, Tim

Rebellion

My Feedback: (2)

Tim, Dave's watching too, and I've been thinking of staying with the original dihedral myself.

Ron, thanks for the info. If you, or anyone else, has pics of your Dallaire Id love to see 'em.

Dave

w8ye

My Feedback: (16)

I have a friend in Opelika, AL that built a Dallaire from the Holman plans with a ASP 65 four stroke about 4 years ago. He used the prescribed dihedral and it floats around very nice. He goes up as high as he can see to control it then floats around until it gets low and then he goes up again. He does this until it runs out of fuel and he lands dead stick.

timfarrar

Thanks for the information !!

I think that just about does it for me Dave !!...

I am going with the original Dihedral...lol lol lol...

Are you still starting Sunday ?

I am so close with my DH 89 that I might just finnish it ...
All I have left now is putting the Cowl's on and rigging it with the wires or strings I should say...lol lol lol...

I do have the Cowl's made, I just got to get them on...
They were a pain in the butt too !!!!
The had six pieces on each Cowl !!!!




Seeya guy's, Tim

w8ye

My Feedback: (16)

This gentleman with the Dallaire first built a Ben Buckle kit of the Record Breaker and had a Saito 45 engine. The Record Breaker had Polyhedral and was made according to the plans.

Of the two planes, it was my observation that flying them as 3 channel with no ailerons, the dihedral is needed. However, and particularly with polyhedral, all that wing sticking up in the air makes the plane more prone to problems with crosswinds on the runway. In a comparison of the Record Breaker with the Dallaire, the Dallaire was far superior as far as the cross wind effect goes. I attribute this to the straight wing versus polyhedral.

The Record Breaker had to be taken off and landed directly into the wind no matter what.

w8ye

My Feedback: (16)

With no ailerons a good measure whether your dihedral is about right is how much it banks in the turns.

If you don't have enough it will sorta skid around.

My friends Dallaire banked correctly with rudder/elevator in a turn

I think the Dallaire is one of the best radio assisted gas free flight planes out there.

Rebellion

My Feedback: (2)

OK, stock dihedral it is. That'll save the work of cutting several new parts too.[8D]

timfarrar

Thanks, I am not putting ailerons eather...

I thought about it and I at first was putting them and Dave said he wasnt ...

I was pretty much decided to go with Dave on that and I am ...lol lol lol...

Thanks for the advice w8ye !!




Seeya, Tim

Lomcevak Duck

My Feedback: (14)

Keep in mind that if you decrease the dihedral you run the risk of decreasing the rudder authority. I have flown a Dallaire Sportster with the stock dihedral and it flys great, part of what makes it such a great flyer in my opinion is the rudder authority, which can get to be a problem with a 108" wingspan and a high aspect ratio.

I much prefer the flying characteristics of the Dallaire to my big Westerner because my Westerner has less dihedral and you really have to stand on the rudder to make a turn.

w8ye

My Feedback: (16)

I always considered the Westerner to be another great RC assist gas free flight model along with the Dallaire

Rebellion

My Feedback: (2)

Some of you old pros at building will get a snicker out of this. I spent the better part of the weekend building the two fuselage sides. They looked great! Straight, warp free, and evenly matched. Problem is, the Titebond III glue I used didn't stick to the spruce worth a crap. A bit of flexing would pop the joints loose. A close inspection showed that the glue didn't penetrate the surface into the wood. Lesson learned. They'll be trashed and this time I'll use CA and epoxy. Heck, I even plan on using Hysol 9462 to glue the wing spars and joiners in. It's a little heavy but it's as strong as it gets.

Thanks again guys!

Dave