I've got a Magnum .61 that (for a Magnum) runs really good and currently is sitting around doing nothing.

Badger5964,
I'd like to see what you did to the fuse and ailerons, I'll be waiting for the pics [8D]... I haven't decided what to do yet... I do know i'm going to do some lightening on the fuse and mods on the ailerons but still want to keep the lines of a contender. Did you have cut your own wing tips to match the ailerons or did you just add material to the existing tips?

Safebet,
Keep us updated when you start. [8D]

Keith,

Looks like your really moving along with the build! I like what you've done with the tail feathers. I can't say I've ever seen a Contender with counter balanced control surfaces but it looks great.

I've just got my Contender plans copied and I've begun playing with the tail configuration. Next comes the clearing of the bench and the set up for a new build.

I'd be really interested to know how your tail works out in flight. Makes me want to wait until you get yours done but I'm way to impatient for that. I've had my Contender since Christmas of last year and I'm ready to get going! Keep us posted looks great so far.

Regards
Mike

OK.

Here is my fuselage. cut slots in fuse on all four sides and drilled several lightening holes with a unibit. Fuselage is still very stiff, compared to an four star 60 and a hog bipe. Since I'm mounting a .46 I feel I need to save all the tail weight I can.

Scott,

your fuselage looks great! I think I'm going to use a 46AX for power, however it's going to be inverted. You've done a nice job with the cowl area. Looks good, keep up the good work.

Regards
Mike

The Fox .46 ABC will go on its side. I prefer to side mount my engines as I feel it makes for a better centered tank and can hardly flood. Here is a few shots of the rudder and wing tips. I did not mount any wingtips. Last rib is stiffened with a 1/32" ply peice. This should help it to avoid some of the dings and nicks. The rib was also to flimsy to resist the shrinking of the covering. Saved a little weight by leaving off the last shear web in each rib bay. I did not include a picture of the airelons. I made them slightly bigger by tapering them to 1" instead of 3/4" at the outboard end. I'll probably glue in the bottom hatch as I really do not like a hatch. I think they let in fuel, look poor, weaken the structure and I have never had to get to a tank in any model after install. However since the hatch allows access to the nose gear I may have to compromise my principles.

I'll post some pictures when I've made significant progress.

flmlm,
Thank you. I saw a contender with inverted engine and really looked excellent. The builder also made the scoop functional to provide cooling air to the inverted engine. Super Cool! Hey, a pun!

First class job, thus far. I hope I can do as well. Will begin as soon as work surface is completed, hopefully within a week. I like the way you added area to the rudder, and the elevators really look cool. Like Flmlm, I wished you would get it together so we could have a flight report before we finish ours. I am going to do the special wingtips, as per plans and I am going to use a .61 OS FX. You mentioned you would be using a .46 FX and thus you are reducing the tail weight. Gosh, what will I have to do if I use the .61? I guess I may have to use a lot of lead, huh?

Anyway, keep up the posts. I am saving this thread, for sure for future use. I may be asking both of you questions as I go along.

Thanks

Jim

Hey guys,

My Dad finished his this summer. He has a inverted Tower .46 which required no additional weight anywhere. There was plenty of room to move the battery around for balancing. His inverted engine has a removable chin cowl that has an open scoop for cooling. I will tell you, this plane "Flys" with the Tower .46. He did go with everything else standard. Though his wings are straight an true, we think the upsept tips are just off a little. Being at the tips, it really has required a fair amount of aileron offset, so much that we have talked about adding adjustable trim tabs at the wing tips. The wing tips provide a fair amount of surface area, but I don't think leaving them off would really reduce much lift, I would go without them.

I really like to mods on the rudder that I seen here.

Hello!
Me receiver battery decided it was time for me to build a new Contender, the coupling was bad on the last one so I will change the tips. Any thoughts on simply turning the stock rudder outline upside down?
I will also sheet the tail group, with the .61 I needed an ounce of tail weight, and could have used more.

Thanks
Kevin

Mike,
Thanks for the compliments... You'll probably get a chance to fly yours before I get mine to the air field. My club just moved to a new field this year and the ground is still bumpy and I'm sure as the temp keeps dropping it'll get even bumpier... so I'll most likely have to wait 'til spring. But we'll just have to see.

Badger,
Did you use the sheeting that came with the kit or did you buy wider sheeting to eliminate the edge gluing??? Like the fuse... I'm thinking of tail mounting the elevator servo and puting pull pull on the rudder (beings my rudder is just a liiiiittle bit bigger than stock).

Safebet,
Instead of putting in dead weight (lead) how 'bout moving that elevator servo to the back by the horz. stab.???

Keith

Marc,

Your dad has constructed a great looking Contender. Could you provide any detailed photos of the nose?

Regards
Mike

One of the reasons for the upswept wing tips is to get some dihedral into the wing. A flat wing on a low wing plane will produce a roll opposite to the rudder. That is, is you fly level and put in right rudder, you'll get a left roll, not something you want. Dihedral counters this effect. The upswept tips give the wing some dihedral effect.

Keith,

I used the sheeting that came with the kit. I thought it a little cheap to edge glue those strips rather then provide 4" wide material. Wood in the kit was free of warps,bows or other defects. It is however the heaviest balsa I've found in any of my kits. I lightened the fuse, it is still plenty stiff, as I just hate adding weight to balance and the Fox is a lightweight engine. This forum is motivating me to finish up my project But best I can hope for is shortly after thanksgiving. Given that your mounting a 60 for power it sounds like you won't need to bother trying for a light tail. I'd leave the fuse and tail as to counter balance. Never done pull-pull so can't help. I'd move the elevator servo back as it looks like you'll need some weight back there.

Mike,

I have will have my camera with me today. If I can stop by my Dad's after work I will snap a few detail pictures. He made a removable chin cowl from balsa. Then he strengthend it with Fiberglass mat (available at home depot, about 2 Oz wide weave great in two layers to strengthen curves -- 3 to 4 if your making just a fiberglass cowl). He used hardwood tabs on the firewall for the #2 button head screws.

If your interested in shaping and making a cowl out of fiberglass, its pretty easy and there are a couple of methods.

Caffeenman has a great website:
http://airfieldmodels.com/informatio...cowl/index.htm

Here is my attempt:
http://www.rcuniverse.com/forum/m_33...tm.htm#3310709

and installed on the plane (left-overs reassembled -- but easy enough for a 6 year old to fly)
http://www.rcuniverse.com/forum/m_34...tm.htm#3405671

Marc,

Thanks for all your effort. Any and all information is appreciated. I was thinking of carving the cowl out of balsa and then applying fiber glass on the inside for added strength.

Regards
Mike

Badger5964

For what it's worth, I built a Contender per the plans with a traditional wing and powered it with the OS-46. It came out a tad nose heavy so I had to move the battery toward the tail to achieve the proper CG. Yours will probably be similar.

DaveB

I bulit mine with 30% more rudder area, and the center of effort lower (closer the plane's axis of rotation). Followed the shape of the horizontal stabs. I did the upswept wing tips, but, doing it over, I would go with the straight. The upswept is supposed to cancel the tendency to "Dutch Roll" (a snap roll opposite the rudder input), but I think this may have been due to the original rudder having the area high on the surface. I'm no engineer.

I have talked since to pilots who left out the wing tips entirely, and one even chopped a panel out. Only drawbacl, aparantly, is a faster landing speed. I have an OS-70 II in mine and it is a bit heavy. Plenty of power, but it doesn't need the apron flap to drop plenty fast on approach.

I wouldn't worry about glassing the cowl. It's plenty solid. Mine is coated inside with thinned epoxy and even was a "functional" scoop. The OS has a down-shot rear carb and I built a 1/4" x 3/4" half-round channel into the scoop to supply the carb. from underneath.

Mike,

Here's the pictures. He's putting a little patch on the bottom hatch that came loose on Sunday.

It's probably worth mentioning that Hoerner tips are an attempt to reduce induced drag caused by the wingtip vortices.

Adverse yaw and dihedral are entirely different subjects.

Omitting the Hoerner tips does little more than effectivly reduce the wingspan by approximately double the width of the Hoerner tip.

Wind tunnel tests have shown that the Hoerner tip has little effect on aircraft of this size.
--
Merlin65

Mike, your dad's Contender looks fantastic. I have saved these pics for future use.

Merlin65, I know what you say is probably correct. I just like the looks of the curved wingtips. I may change my mind when I get into the build, but for now I plan to build them.

You guys keep up the great tips and suggestions and pics. You have given me a lot of things to think about. I don't have years of experience and it is all very helpful.

My wing jig came in today. Just waiting on the building board. Anxious to get started.

Jim
AMA 821369

Marc,

Thanks for sharing the pictures of your Dad's Contender. The photos you posted of the inverted engine will help me along the way no doubt. I also like the fueling system that has also been added, I would like to incorporated that into my build as well. Your effort is greatly appreciated.

Well, I've copied the plans and have dug out the Contender Kit from under the bed no excuses now, just do it.

Well here goes nothin, build number three for me begins....

Regards
Mike

Good Luck, Mike! I hope you are going to post as you go along, also.

Jim
AMA821369

Mike & Jim... Good luck... I'm glad to see you've joined on with the building!

Hey Jim... Where did you get your wing jig from?? I'd like to see what it looks like.

Marc... Nice plane! What did your dad use for the panel lines?


I've ran in to a little delay on my build... the build fairy came along and dropped an idea on my building bench... Decided that my contender would look nice with navigation and landing lights. However I can't find a lighting kit that I like... sooooo... I'm going to try and make my own. This will delay my build for a while but shouldn't be to hard... I hope.[&:]

OverTheEdge: The wing jig is a Great Planes, Kit # WJIG. Paid $33.00 incl. shipping from RC U ad. It will do a wing or 1/2 wing up to 48". I thought I might give one a try, although building them "on the plans" may still be the best if you have a good flat building surface.

Sometimes, I get crazy and buy stuff I probably won't use. I love this hobby. I wish I hadn't waited until I got so old to get back into it. AS a teen, some 45 years ago, I used to "scratch" build control line planes. I think breathing all those dope fumes caused me to lose a few cells. Ha, Ha.

Jim
821369

OverTheEdge,

I have a Super Sportster that I used the Great Planes 1/16th Pin Stripe tape on and it has held up pretty good. He was going to use a Top Flite Panel Pen, but you have to fuel proof that and he did not want to have to clear coat the monokote so he went with the 1/16th pin stripe tape as well. It holds up pretty good, but the great thing is, its pretty cheap so if you get a strip that peels a little, then degreaser, soap and water, then alchol and just lay down another stripe.

He thought it would be really time consuming but, the panel lines only took a couple of hours. Hes got about 15 flights on her and they still look really good. She's powered with a Tower .46 and I will tell you, this plane really fly's well on a good .45 ABC engine. A Super Tigre or a OS .46 AX or an SK 50 is plenty of power. You all looking at running .60s I would prop those using a 12x6 or 13x6 or even a 13x5 and get vertical.