I have a just built sopwith camel from h9 that has a serious(no major) hook to the right on the ground. it also rolls right when it gets in the air.I had gone back and balanced the model laturaly. When building the model ,I change the way the motor fits to lay sideways with a pitts muffler.If my thrust line is off a little bit, would this have a major effect like this, or could the plane be nose heavy. Its a Royal handfull on the ground and I cant get it in the air ( or is this how the plane handles on the ground and I need to be more consistant with the rudder) >>>>>>>>confused

I don't have personal experience with this model. I have seen other WW-I models and a common problem is they have small rudders compared to more modern models. On takeoff be active with the rudder and feed in throttle slowly. Abort a lot till you find the trick. Years ago I saw one do an inverted flat spin and and the pilot, our most experience pilot, could not recover it. It flat spinned all the way to the ground. The amazing thing is that there was little or no damage because it was falling vertically very slow, but spining rapidly. Sometimes a little up elevator at the start of the takeoff helps helps in tracking, but there is danger of a snap roll if held too long. Go Slow. The challenge is worth it.

Got a picture of it from directly behind the tail?

Rolling in the air is a pretty common symptom of a rather common problem.

BTW, hooking to the right as you start the takeoff roll isn't exactly a common thing with most airplanes.

It suggests a hard look at the wheel alignment.

Got a picture of the wheels/gear from directly in front?

Here are some pictures...

Models of this sort are EXTREMELY sensitive to crosswinds on both takeoff and landing. The narrow gear, high center of drag and smallish fin and rudder area all conspire to produce many a quirk if there's more than a few degrees angle to the wind.

If you have no option but to take off in cross wind conditions then you'll need to get very practiced on the use of the rudder.

In the air is different. Sounds like you're just fighting with a few trim or possible warp or misalignment issues between the panels. If you can't figure out accurate ways to test all this then get an incidence gauge and check the wings in a wide number of positions looking for angle differences of more than 0.5 degrees.

Pretty good pictures.

I think I see one problem. Your shop is too neat. And it's also too large.

The rear view pictures were to see if any obvious warps were present. They aren't bad enough to show in rear picture. But rolling is really more often a warp or trim problem than lateral balance. Do you fly with anyone who's good at eyeballing for warps? From one of the front pictures, it looks like there is a chance the lower right wing has washout compared to the lower left wing. But it's hard to see for sure. When you look at the plane, push the ailerons into alignment with the wing. They make it hard to see a warp when they're not lined up.

Looking hard at the gear, there is a suggestion of both wheels aiming at bit to the right. As Bruce has already said, there are a lot of other things to eliminate first. But rigid gear on those "tall" suckers will accentuate misalignment. I usually take my models out in the driveway and "free roll" them to see how they do on a smooth, clean, level surface. That'll tell a lot about how the wheels alignment affects the takeoff roll. Keep in mind that it really doesn't play a big part after the prop has some purchase on the air and the plane's got a bit of speed.

It takes awhile to get good at seeing twists. But it does sound like you've got one to find.

Looking at the 3rd from left pic...It looks to me like the left aileron on the bottom wing is down?
That would cause a roll to the right...All the other ailerons look like they are lined up ok though.

Hmm, the right hook on ground and right roll in the air seems too coincidental. The rudder trim would be the first thing I'd look at. Try to trim the roll out with rudder, instead of ailerons and see if the ground handling doesn't improve.

Sounds like you have some aileron and incidence issues, try banding some straight sticks under each wing panel at the aileron inner cutout position and then eyeballing from the side, that will very quickly show any differences. It also sounds like you are trying to fly it like a normal model airplane, and learning that it isn't. Full size Camels were always launched straight int the wind, anything else won't work. The rudder is your main directional control, on the ground and in the air. Use full up elevator at the start of the ground roll, this keeps the skid on the ground and the drag behind the wheels at slow speeds, helping it to stay straight. Release as the rudder bites and steer with rudder for the rest of the flight. Ailerons are there to help balance the rudder induced roll. Use the throttle carefully, rapid movements will unsettle the model. Get as much mechanical movement on rudder and elevator as you can, rudder is your directional control, and you need lots, as you have found out. Elevator is your speed control, and you also need lots of 'up' on the ground to keep the prop tips out of the dirt. If you find that you are still having problems educating your left thumb the you can try this little wheeze; put the axle through a couple of tube bearings where the bunjees are, and tie the wheels to the axle so that the wheels and axle rotate all together, this will help to keep it straight so long as both wheels are on the ground. You won't be able to taxi the thing any more, but then the real one never indulged in much taxiing anyway.
Evan, WB #12.

This was all so very helpfull, I did notice some wing warp from flying wires being loose and tight. I used lock tight on the turn buckles. I also rolled the airplane on my driveway and the right wheel was to tight. I also remember their was a heavy cross wind. This plane is also over powered with an os 91 surpass. I was really balls in it to get it of the ground. I will consider taking pimmnz flight lesson to the field. I will also finess my trims to help aid the snap roll when coming of the ground. And yes ..my shop doese looks like it has a feminine touch ( should do something about that)

Are your aileron hinge joints flush with the top of wing ? If the aileron is only slightly above the wing, at the joint, it will act like a spoiler and cause a very "heavy" wing

The hing is sealed at the bottom. but the linkage doesnt seem right to me. I get two different throws from top and bottom aileron. The botton link is more at the middle and the top link is more to the back. I said something to tec support, but they just ignored me..they say this is fine. heres some pics

You're getting the different throws because of the geometry of the lower to upper surface linkage. Ideally to produce the same throw you'd need the horns to be on the same sides of the surfaces with a hole in one of them to allow the joiner to pass thru and connect to the horn. Does that make sense to you?

It's all due to the angles and rotational arc to linear travel issues. By altering one of the horns to be closer or farther from the hinge line you could slightly minimize the issue but that would require some pretty serious mods. The other option would be to cut off the connector rod horns and re-do your connecting rod so that it attaches to the trailing edges of both surfaces with some arrangement. By having both the anchor points in the exact same spots on the lower and upper surfaces then you would be sure to get identical surface travel motion.

First picture blown up you can see the bottom linkage you can fit youre thumb their, but the top half a pinky.This gives you a wierd control throw on the top wing. I have two ultimate's biplane that have axactly the same control on top and bottom wing ,but the camel is diffrent (I know this is a totaly different airplane so im not sure) whats right.

Makes sense ...but with two different throws ,will this hinder flight!

Lots of good suggestions here regarding rolling the airplane to be sure it tracks straight, checking for warps, and taking off directly into the wind. But at best your Camel will be a lot more difficult than any typical sport plane.

I would add two more things to make the plane easier to fly. First, consider dialing in some aileron - rudder mix. The Camel has so much dihedral and such a small vertical that the adverse yaw to give you fits in the air. For starters, try about 10 degrees of rudder when the ailerons are deflected 20 degrees. (That's RIGHT rudder with RIGHT aileron.)

Second, install a yaw rate gyro in the rudder channel. You don't want a heading hold gyro, just a yaw rate gyro. The gyro should be installed such that it gives right rudder when the nose is swung left and left rudder when the nose is swung right. Check that carefully because it's really exciting if you hook it up backwards. The yaw rate gyro reacts much faster that the pilot to veering on takeoff and it will make your airplane feel like it's on rails.

Good luck,

Dick

There are a couple of threads about this kind of OEM aileron rigging. The Skybolt and 40size Ultimate both have the OEM rigging. That rigging basically violates one of R/C's most respected rules for rigging. You want the pushrod to make a right angle at the servo and at the horn. Here's what that OEM setup gives you. The attached shows a setup I made using measurements from my ARF. The setup works exactly like the model, only it's easier to measure accurately.

On that airplane, when the TX stick is moved to get 20degrees aileron deflection...... both bottom ailerons give you 20degrees. They're both driven directly from the RX after all. But the upper aileron on the side with the up-going aileron winds up being pushed 23 degrees by the lower aileron (which is going 20 degrees). At the same time, on the other side of the wing, the upper aileron on the down-going aileron winds up being pulled down 26 degrees by the lower aileron (that is going 20 degrees).

If you want to follow the "pushrod makes a right angle" rule, you'd rig your connection between the ailerons to match up with the colored lines on the attached layout.

You can move the pushrod into the wing as far as you wish, but you'll have to get it through the upper aileron. It's actually easier to do that than it seems. The 2nd attachment shows my Skybolt setup. I used the hardware the mfg supplied (no extra cost) and it actually took less time than screwing around with the horns and their backing plates and all the little screws that never seem to find the holes in the backing plates........ Cut off the base of a horn. Cut a slot in the aileron to match. Epoxy the horn in the slot. Done.

I've flown both my Ultimate and my Skybolt for over a year and am pretty familiar with 'em. Mine are definitely not sneaky flying airplanes. They don't have any bad surprises. I've had a number of flights on OEM Skybolts and maidened one Ultimate for another guy. And flown that Ultimate later on to help the guy try and find out "what was wrong with it".

The OEM Skybolts fly great. The owners have told me that I fly mine too slowly on approach and to be careful of theirs. I am. And theirs seems less accurate. What would you expect. But they fly great. I just feel mine is better. And I know it has less tendency to tip stall if you need aileron at low speed. Considering they've got one wing with it's ailerons more than 10% different and the other side with a 25% difference, all that makes sense. But keep in mind, the accuracy in flight is a subjective thing and low speed isn't usually a problem. It's lowest speed that is. So you don't see what you don't do. And the OEM Skybolts fly great. As most people fly them.

The OEM Ultimate is also a good airplane. I've got a backup in the box for when/if the first one ever bites the big one. But you can bet it'll have none of that OEM rigging when it's built. Why go to the extra work to have less?

BTW, original WWI era biplanes had aileron rigging that connected through the ailerons. They did it for a good reason. They knew about the right-angle rule. Matter of fact, they wrote it.

It's not helping that the hinges are not in the center of the surfaces. Bottom- or top-hinged surfaces will always have some degree of built-in differential.

That is exactly what I thought looking at the picture, the wings are not symetric in plane.

You can take his great rear photo load it into Photoshop and put up a ruler line. It becomes far more obvious then.

In the rear-view picture in post #6, only the lower right aileron look to be aligned with the trailing edge of the wing, the upper left aileron looks to be 1/8" down, the lower left aileron looks to be a 1/4" down, the upper right aileron appears to be 1/16" up and also warped as its trailing edge does not look parallel to the top of the wing. If these are the aileron positions that you last flew with, it is no wonder that it rolled right on you. Was the picture taken with the plane and radio turned on? If not, then you'll need to re-post a rear view picture. Also, the ailerons need to be perfectly aligned in order to help spot any wing warping so you might want to post a picture of the ailerons perfectly aligned to the wing in addition. The different throws of the upper and lower ailerons might not be a problem if the ailerons are more misaligned when they deflect upwards than they are when they deflect downwards. This situation would, for example, create more drag on the left wing in a left roll and help negate adverse yaw.

I've read somewhere in these forums that somebody had success with toe-out on their mains. I've, previously, always heard to add toe-in, but if you think about it, toe-out makes sense. For example, if you are taxiing along and add too much right rudder, the right wheel leaves the ground and the toe-out on the left wheel counters the excessive right input and steers the plane to the left. With toe-in, the plane's left wheel would have continued the right turning of the plane. Maybe even enough to cause a ground loop. It might be worth trying a couple of degrees of toe-out if you can't correct the problem of yaw stability on take-offs any other way.