swk550

My Feedback: (76)

[size=3]I have been trying to trim a red Sebart Wind S Pro 2m pattern plane. When I installed the rudder, I didn't notice the rudder is warped. As it turns out the rudder is warped between 1/4" to 3/8". I have attached some pictures. The rudder is fiberglass. I was thinking about removing the rudder and making a clamping jig to straighten the rudder. Then I would put the rudder in the oven at 200 deg F for a few hours. After it cools I could check if I got it straight. Has anyone ever done a similar procedure? I will call Thunder Power tomorrow and see if they have a spare part for the rudder.

Ricardo M.

Maybe you could try to make a new rudder with foam sheeted with balsa. I think this will be easy than try to fix the fiberglass one.

Just my opinion.

woodie

Or, ask the manufacturer to replace the defective rudder. Or, maybe someone has 'lost' a Wind S Pro and could give/sell you the straight rudder.

I would be surprised if the baking approach will work since the resin was probably baked as it was laid up and probably took a set during the curing process, but what the heck, worth a try.

Woodie

Malcolm H

I have fixed warped control surfaces on composite turbine powered models in the past (F18 flap and L39 aileron) using nothing more than a heat gun and a wet towel. The epoxy used in cold layups is different to heat cured stuff which is autoclaved to cure. The stuff used in our models becomes very flexible when heated to relatively low temperatures typically less than 40 C (100F).

If that rudder was mine I wouldn't even remove it from the model. Wear a pair of thick gloves and have a cold wet towel handy. A spare pair of hands helps. Warm the whole rudder using the heat gun, being careful not to let the gun sit in one place and burn the paint. When the temp is just getting too hot to keep your hand on comfortably hold the warped part just past the straight point for a few seconds and then let go. Eyeball the result and if still warped heat again and hold but this time with a little more deflection. Once you have it straight hold in this position and have your helper apply the cold towel until whole rudder is cold.

Darrol Cady the pylon racing guy fixes whole wings like this. Here's a link to his site where he describes the process. http://www.darrolcady.com/Racing_Inf...tips-tech.html

Hope this helps.

Malcolm

Jason Arnold

I think you'll find it's the vertical fin that is warped not the actual rudder. It has been noted on a number of these models downunder.

Cheers,
Jason.

swk550

My Feedback: (76)

Before I try and straighten the rudder, I'd be interested in buying a salvage rudder from the red color scheme airframe. This way I could get a match from the painted in mold. PM me if you have one from a no longer useable airframe.

woodie

The fin may be twisted, hard to tell from the pictures, but the pictures of the rudder sure like it has a serious twist....

Woodie