This happened to mine about 10 flights also, the metal is bent to sharp for the thickness or it is to brittle for the vibration. I replaced it with another piece from Lanier and it held up even through the crash.

When tooling gets old and worn it will pull the metal to a 90 degree bend creating heat that will make the metal brittle. Also using too much pressure on a press will result in the bend being thin at the bend. Its hard to see but almost looks like the ear was only holding by 1/2 its thickness.

Was that Aluminum or cheap steel? I checked mine out and so far it looks ok. I may fabricate a stainless replacement anyway. Thanks for the heads up.

Chasbuff

RC-Sport I noticed that you have sheeted your fuse all the way back to the TE, is that a change in the kit or your personal EC (engineering change)?

I've read this entire thread so far.

Couple mentions of a DA50. General concensis is that it will tear the plane apart.

I'm flying at high altitude--8000' and don't think this will perform on a 40cc engine.

I have a 54cc conversion engine that I was thinking about bolting to this plane.

Could this plane be beefed up enough to handle the 54cc engine? My engine is no powerhouse. It will only turn a 20-10 at this altitude. I could go with a 3-blade to help smooth out engine pulses??

Any suggestions?

A Brison 2.4 (40cc) is absolutely the top end power-wise on this airframe.
I have had all sorts of wood & metal parts break on me because of excessive power on mine.
(And I know how to use the throttle, BTW) These were not crash related failures.

Going to this much power results in a high maintenance aircraft.
I've parked it for now - Tired of messing with it. (Not a sucessful project because of this)

I was turning a 20x8 at the low 7000's. (600ft MSL)
Out-of-sight verticals with this setup.

In hindsight, a lightweight 25 would have been a better choice.
Keep the weight below 12lb, whatever you do.

A 50cc at any altitude would be insane IMO.
If you really want a biplane for this size motor, I would suggest another airframe.
Have a look at the Procraft Ultimate or the Miles Reed Weeks Solution.

Good luck, whatever direction you choose. Post some pics!

Insane--hhmmmmmmm. Thats right up my alley

Heck with it--against all the good advice--I'm gonna do it. Will post pics of the crash.

OK, now that we have crosed that hurdle,
a couple of things to watch out overpowering this beast, based on my experience.

1. Replace cabane strut assemblies in the kit with 1/8in T6 or steel.
Make sure where it bolts in the fuselage is reinforced with 1/8in aircraft ply.
Make sure you build a way to easily go back in there once the plane is finished.
2. Throw the supplied landing gear in the trash. Have TNT bend you a one-piece. (Check prop clearance)
The Midwest gear is a two-piece assembly, and will tear out of the airplane in real nasty ways.
3. Flying wires are structural. Do not make them by bending clevises as shown on the plans.
Bend yourself some aluminum brackets and use straight #2 pushrods with clevises at both ends.
Use nylon clevises on the fin and at fuse bottom to prevent forming a RF ground plane.
5. Replace the motor box lite ply parts with aircraft ply. Use lots of triangles throughout.
6. Incidence is critical - zero - zero - zero. Plan on 3+ degrees right thrust.
7. Initial balance is on the spar at the tips of the top wing, as shown in the plans.
8. Fiberglass the motor box and the landing gear area.
9. The tail post and rudder spine are weak points. Use extra-hard balsa or basswood.

Post a follow-up if you need more info. Plan on investing 100 hours building this thing.

Have fun with it!

Sorry chasrb, I never saw your question. It was a personal EC, I didn't like hoe the open frame work looked.

Marty:
Thanks a bunch for those tips. I've already built a couple Lanier kits--so I'm used to how they build.
I'm glad you told me about those weak spots in the tail.

I've read just about every post I can find here on RCU about this plane--must be close to 300 posts. Eyes are buggin' out.[sm=spinnyeyes.gif]

I'd read about the weak cabane struts--but had no idea how to fix problem. I haven't even seen the kit yet--just ordered it from Tower. They had one on the Scratch & Dent page for $112. Said it had damaged balsa. No problem--I got a wheelbarrel full of that stuff in the shop.

Definetly replace the motor box with hard ply--no way lite ply is gonna hold up to this engine. I'm guilty of using TOO MUCH triangle stock in motor boxes. I usually put tri-stock everywhere I can get it. Both sides of everything. Maybe overkill--but I've never ripped a FW out of a kit that I've built--yet.........

I did try and fnd the Super Stinker LG on the TH website--but couldn't locate it. Just as well--I'd be happier with a 1-piece unit from TNT.

I'm planning on using JR8231 digitals on all 4 ailerons and both elevator halves. I'll be using a JR Matchbox to get the aileron servos all synchronized properly. And another Matchbox on the elevators. JR8411 on the rudder. JR4721 on the choke and an Airtronics 94145 MG coreless on the throttle. Jeez- thats 9 servos.[X(]

I also got some monkeykote yellow. My eyes like that color in the sky--easy to see.

I'd be tickled to get the wings framed in 100 hours.[:-] I build pretty slow.

Thanks for the help.

I had my FW come off in mid-air the last time I flew the UP. I was fortunate that I was on a downwind heading into the finals or I would have had a pile of balsa! I had made my engine box per the plans and had even glassed in the tri-stock in the corners, my saito 180 still pulled the FW off. I went back in and put 4 right angle alum. brackets on the FW and reglued with tri-stock to make sure this does not happen again. If the weather would clear for a while I might get to fly it to test the repairs...it'll hold.

Since the following pics were taken, I changed out all the tail wires and replaced them with CF rods, I put nylon clevis' on the mouting plate on the bottom. Saved a lot of weight!

Here's a few pics of my U-Pitts

Boy, I spent a lot of time agonizing over that part of the engineering. [sm=tired.gif]

Keeping the weight down will be critical on this project. Especially since you'll be flying at altitude.
I would suggest you go with 1 digital per side for ailerons, and fabricate a CF rod interplane linkage. (Save 5oz)
There is very little surface area on these ailerons.

Also, I would use a 8-channel receiver, mix in the transmitter, and dump the matchboxes. (Save more oz and complexity)

I had (4) HS-5625 (Ail/Ele), (1) HS-5945 (Rud), (1) HS-425 (Thr) on mine. (Sorry, not familiar with JR p/n)
5-cell 1650 AA NiMH on Rx (135g) and 4-cell KAN1050 on Ign (90g)

I haven't even flown mine yet and you guys have me nervous already. Mine came in at a whopping 14 lbs. I think I may swap out my Roto 35 for a Saito 180 to save some weight.

Did you pin the firewall also? My 2.4 never pulled mine loose and it was glassed and pinned. Youre fix should hold it that's for sure.

rc-sport 14lbs is heavy, are your servos in the tail? If you swap to the 1.8 those may have to come foward into the fuse for balance purposes. I would check over the plane and see where the weight is then fly it first. You may be surprised.

V-snap, I do have the servos in the tail and I thought about moving the Rudder servo in to the fuse and moving the battery pack to the firewall, it's at the trailing edge now. I think my weight issues stem from the fact that I have a 1400mah pack and 3000mah pack (8oz), I also have servo for the choke.

My radio won't mix all those aileron servos properly. Thats why I've gotta use the Matchboxes. The JR8231 servos will pump out real close to 100oz.in. at 6V I'm not sure thats enough to only use 2 on the ailerons and link them with CF rods. If 100oz.in. is enough to run 2 ailerons--then I can dump 1 of the Matchboxes. What do you think?

RCpilet, I think you'll be fine, 100oz is alot of torque.

100oz is more than enough to run ailerons on one side of this plane.

I would like to know if a Super Tigre G-4500 would be to much for this plane! I know it would be over kill But I need to pull out of a hover with authority!!!
Thanks
Baker

I'm building one of these over this winter (well maybe part of next summer too - it's a big job and I have little ones at home to help take care of…!)

This is my first non-ARF build. Probably not super smart to take on such a complex build first time out but I can get lots of help from the Pro's at our club... 1/4 of our members scratch build from plans so they know LOTS. They had me convinced to do a scratch-build of something from plans only… but once I saw this kit and did some reading it seemed like a great project and a really great flying bipe at the end. Something I can be proud of at the end… Also it’s big, but not too big…

Just as a sanity check - here are my current plans:
1. Saito 180 w/Slimline muffler
2. Hitec HS-6975HB digitals on Ailerons and rudder (ailerons will be joined with CF tubes so only 2 servos will be used)
3. Hitec HS-6635HB digitals on Elevator 1/2's, some smaller servo mounted up by the engine for throttle
4. Elevator and rudder servos mounted in the fuse (not in the rear)
5. I plan to sheet back to the cockpit with thin balsa (I’ll sand carefully – I want this plane to be as light-weight as possible but still strong and smooth looking)
6. TNT Gear, glass the LG area
7. Stan’s fibertech cowl and pants
8. Lots of re-enforcing on the motor box, tri-stick and maybe some glassing too
9. Use bass-wood for the rudder post and tail spine weak spots
10. I was thinking to start with 0-0-0 incidences, or should the top wing be –1?

Questions:
I was thinking to sheet the elevators and rudder – at least the leading edges. What about aero-foiling these slightly too?

If sheeting the rudder/elevators is a good idea should I still use flying wires?

What should I do about the cabane struts that have failed for some people? Should I make new ones with a thicker material? Alternatively I was thinking I could solder some brass tube into the bend area where they have been breaking to re-enforce them?

Thanks for any help / suggestions!
Chris

Chris, I built this plane last winter and have been flying it over the summer, if I had to build it again I wouldn't. I thought the kit was hard to build and the quality of the wood was poor, I had to replace alot of the balsa. The plane is a pig weight wise, mine came in at almost 14lbs with a Roto 35 motor for power. I tried to keep it as light as possible. The plane looks great in the air and flies good, not great, just good. If I had known this before hand I would have chosen another kit. If I were you I would try to find a Midwest Super Stinker. The set up you have planned sounds great, save it for a better plane.

Okay, this is one nice looking bipe, I bought it based on that alone. It is a very heavy kit. I had a FEMA on-board starter in mine so I added another 20 oz. and it flew like it. Since my last post my UP went in after what seemed to be a very light touch and go where the mains folder back and into the lower wing casuing a major control issue. I did what I could to belly it in but on the final it flipped and went straight in. Was not even worth the rebuild so I stripped it and and using them elssewhere.


Cermark or Aeroworks may be your better choice.

I have two other Lainer kits a 1/4 scale Laser 200 and the 1/3, for it's size the 1/3 is lighter than the 1/4 relativly speaking 1/3 20-22 lbs with a Brisson 4.2 the 1/4 about 12-14 with saito 150.


[link]http://webpages.charter.net/rcfu/KitReviews/CermarkS2B.html[/link]

Any one wanting a Lanier Ultimate Bipe kit I have one NIB for sale $140 shipped.

I was going to buy one of these bipes, good thing I read this thread, I don't need the hassles, but I do have the 1/4 Laser 200 which I intend to build this winter, power will be the OS 160 FX.

Joe

Joe, I really like my 1/4 scale Laser flys like it is on rails and is a reat handleing plane, I have the saito 150 in it and it does power it well.