GP Ultimate Bipe Setup
 

I'm building the Great Planes Ultimate Bipe. I have heard a few reports of control-surface fultter in this model on this forum and at my club. What should I be doing to assure that I don't have this problem?

Are CA hinges OK?
Are the linkeages supplied with the kit OK?
Are 'standard' servos OK or should I use high torque?

Any thoughts /comments will be appreciated!

RE: GP Ultimate Bipe Setup
 

I put a Saito 91 on mine.It flies full bore with no flutter.
I don't use CA hinges.
I used high torque servos.
I sealed the hinge gaps.

RE: GP Ultimate Bipe Setup
 

I'm in the process of building the same plane. Just finished sheeting the bottom wing, going to start on the ailerons tomorrow. No CA hinges though. I will probably use robart hinges. I can't wait till this thing starts to come together. Just bought an os70 surpass for it. I am also in the process of making a mold of the cowl so I can lay up a fiberglass one or two. I've read the horror stories about the abs cowl and I dont want to put that much work into something and have it be junk in a couple of weeks. I'll post pictures of my progress if you would like.

happy building
Tim

RE: GP Ultimate Bipe Setup
 

I used an OS 70 in mine and it was a great combo. I also used CA hinges with no problem (As long as they are installed properly - read this: [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=55]Installing CA Hinges[/link] )

And I used standard servo - also no problem

RE: GP Ultimate Bipe Setup
 

Thanks for the responses. Yes, Tim, please post pictures of your build. I will do the same. I'm about to start covering. I'm a slow builder - took 3 months to build the wings, fuse, and tail feathers. I found the construction easy and straightforward aside from joing the fuse sides. That was tricky. I will use a Saito 72 since it is sitting around without a home.

Hope to have it ready for our club's building contest in May.

I've used CA hinges on several planes without any problem, but I'll go with Dubro hinges for the Ultimate just to be extra safe. I'm thinking of using ball links on the aileron linkeages to reduce slop. I built it with a single aileron servo.

I guess I'll use the stock cowl for now and replace it with a fiberglass cowl when it cracks. I won't bother with the wheel pants - they never hold up at our rough grass field.

RE: GP Ultimate Bipe Setup
 

JPMacG,
Just curious what was tricky about the fuse sides. I am just to that point and plan on starting in on the fuse tonight. The tail feathers amd bottom wing went together pretty smoothly (minimal sanding and filler required.) I finally recieved my engine for this thing. I decided on the OS70 Surpass II. I have a Saito 65 in the cabinet and a saito 91 in my hog bipe and love those engines, but I have heard a lot of good things about O.S. so I decided to try one.
I recieved my fiberglass today so I am going to try to make a glass cowl. I got some good tips on another web site on making custom cowls so we will see.
I will try to post picts later tonight.

Good luck on covering. What colors did you decide on?
Tim

RE: GP Ultimate Bipe Setup
 

Here are some pictures of what I have done so far. This is about 5 nights of working till midnight or one in the morning. I see what you meant about the fuse sides being tricky. The firewall is not epoxied in yet. My father-in-law borrowed my quick clamps and has not returned them yet.
Post some progress on your covering job and maybe some picts if you could. I have never covered a complete plane before, so this should be an experience. I have a friend that is experienced in covering, so maybe i'll recruit his help in the department.

Have fun.[img][/img][img][/img][img][/img]

RE: GP Ultimate Bipe Setup
 

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[img][/img][img][/img]
Maybe I will post some pictures if I could just figure out how. If anyone can give some advise of posting images that would be awesome.
Thanks

I will give it 1 moe try

RE: GP Ultimate Bipe Setup
 

Your work looks nice Tim.

I'll post some pictures of mine tonight from home.

I ran into trouble getting the fuse to fit together. The tabs didn't line up very well and I had to modify the slots a bit. I used every clamp I had (about a dozen) together with several string tourniquets and eastic bands to force the fuse sides into the tapered shape. I also had trouble with the fuse plywood delaminating. I had to break apart some areas and reglue them. I worked through the problems and the end result is decent enough. A more experienced builder would probably have had no trouble.

I have three rolls of white ultracoat left over from a previous build, so I'll first cover everyting in white. Then I'll add some design to the fuse and wing top surfaces in missile red. I plan to cover alternating bays of the underside of the wings with a dark color. I want the bottom to be obvious to help me keep orientation in flight.

I trial mounted the Saito 72 last night. It fit the stock engine mount perfectly. I drilled and tapped the holes - don't like self-threading screws. I'm wondering though how well the stock mount will hold up to a 4-stroke. I'd like to hear from anyone else who has used the stock mount.

Let me know how your fiberglass cowl works out.

Jon

RE: GP Ultimate Bipe Setup
 

ive got one of these on the bench right now...im at about the same as loganjoel's pics....epoxied the firewall last night. I also did not find joining the sides all that difficult...just took time that could have been avoided. i love gp kits though. there is just no way to get the fuse crooked, it all snaps together so tight. was anyone else supprised at how small the wings are? its not a bad thing, it just seems small...this is my first bibe though. Can't wait to strap a 70 FS on it. i hope it is everything hoped for.

RE: GP Ultimate Bipe Setup
 

Hi Mark.
I am gluing in my firewall tonight. I was hoping to finish up the fuse tonight or get as close as I can. Does anyone plan on using an in cowl muffler or just going with the stock muffler?

Jon, I plan on using the stock mount also. I have a Hog Bipe with a Saito 91 in it with stock mounts and I have not had a problem with them. I guess we will see. I also plan on doctoring up the landing gear a little bit by making glass strut covers, but not sure how i will do it yet.

RE: GP Ultimate Bipe Setup
 

Here it is, ARC (almost ready to cover).

RE: GP Ultimate Bipe Setup
 

JPMacG,
Very nice! I noticed in your pictures that there is not an 1/8" balsa strip on yor wing struts. Is this on purpose? I have read on a review that this area when used with the strips became very hard to cover so the person doing the review left them off. Also, the plans called for balsa strips to be cut and glued to enclose the sides of the cockpit. The way I am looking at the pictures appears that these strips are missing. I'm not cutting apart your work, I am just curious because if you found a better way of doing some things then it would be great to know. Otherwise, your build looks awesome and I can only hope mine turns out just as good.

Keep up the good work.
Tim:D

RE: GP Ultimate Bipe Setup
 

LOL.... you have a good eye. Actually I was planning to work on both of those tonight. I also need to add filler where the vertical stab meets the fuse. Now that you mention the covering difficulty I may think twice about adding the balsa strips to the wing struts. I wonder if the strips are just decorative or if they add stiffness to the struts. Don't see how they could do much for stiffness.

Thanks

RE: GP Ultimate Bipe Setup
 

They do quite a bit for stiffness. Don't leave them off.

And covering them is not too tough, but a heat gun is a big help

RE: GP Ultimate Bipe Setup
 

Thanks for the info minnflyer. I figured they put them on for a reason so better follow the plans I guess.

RE: GP Ultimate Bipe Setup
 

This is what I got acomplished this weekend. Everything was pretty simple except when I got ahead of myself and sheeted the top of the fuse before cutting the slots for the metal cabanes.[:@]
I also started on the top wing. Spars were warped pretty bad. I hope it turns out ok. I set them so the counter react with each other. Also found time to assemble the abs cowl to start my fiberglass project. My wing ,stab, and fin alignment came out perfectly.:D and the wing seam is pretty tight with no gaps. All in all, I am very happy with this build so far. GP has made a very nice and easy to build airplane.

Send some picts of your planes, especially anyone who used a four stroke with a stock muffler.
I have an os 70 and my initial mock up of the engine seemed to pose a problem with the original muffler. It seemed to hit the bottom of the firewall and i could not rotate it in a manner that would allow the cowl to cover it. It either hit the firewall or it would have to stick out of the side of the cowl. I am going to try to use the stock engine mount.[img][/img]

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RE: GP Ultimate Bipe Setup
 

loganjoel:

That looks really nice! Keep the pictures coming.

Can't wait to get mine started. :D

-tychoc

RE: GP Ultimate Bipe Setup
 

I finished framing the top wing last night and mounted it on the cabanes to check for alignment. This thing lined up perfectly. I put the cockpit sides on also. Modified them a tad to make them look more appealing. Hopefully I will be able to start covering it this weekend. I think I am going to cover it in ultracote. Either pearl blue or purple over magic yellow/red with a pearl white base. I have the graphics done so tonight maybe I will post the for some feedback. I will also post my progress to see if anyone likes my very small modifications.

Keep them picts coming.
Tim

RE: GP Ultimate Bipe Setup
 

Here are the pictures of what I got done last night. I pretty much have the top wing done tonight. I just have to sheet the bottom TE and cap the ends.
[img][/img][img][/img]

RE: GP Ultimate Bipe Setup
 

Hi all - I also have one of these on the bench right now - just finished the bottom wing. I've looked through the instructions to find out how the struts are attached to the wings and don't see anything on it. When assembling the plane at the flying field, will these struts just slip into their respective slots, or will there be some way of holding or locking them in place? Thanks for everybody's input on this thread.

==Mike==

RE: GP Ultimate Bipe Setup
 

They just slip in. It seems like they would need to lock, but they don't. And although it seems like an over-simplified way of doing it, it works very well

RE: GP Ultimate Bipe Setup
 

Just finished the top wing on mine. I also finished bonding my cowl together and filling and sanding the seams. Everything fits great. Some final filling and sanding and I should be able to start covering it this weekend. I think I am going to build the wheel pants.I am going to make them so they clip on and off easily because we have a grass field that loves to eat wheel pants.
My fiberglass cowl seemed to be working ok, but I decided to scrap the thing when I discovered the cost of making it myself would exceed the cost of just ordering one. I am going to try to use what i have done to make a cowl for my hog bipe though.
I will post pictures tomorrow of the thing totally framed up and this wekend when I start covering it.
Please post pictures of your builds.
Have fun.
Tim:D