Comment

Comment by Chumphol Sirinavin on July 3, 2011 at 9:54pm

Here is my curved roof mod.

Comment by Chumphol Sirinavin on March 20, 2011 at 6:12pm

Ken,

Try it without taking the roof off for re-work. Say, adding 2 more V's under the front half and one more under the rear. Then one curved support with notches to avoid the 4 V's could be inserted from below lengthwise in the middle of the cockpit.

Realizing that the curved roof takes more beating than any part of the upper wing skin due to the prop wash, you may consider adding not just one but a pair of the curved supports in parallel, may be, no more than 100 mm apart to keep clear of the occupants' heads. The lower edge of the said curved supports can be trimmed to parallel the upper flanged curve as Joe Spencer has shown in his Beanie Mod pictures. And if the new curved supports are made a tad taller than those on both sides, it will help out with the rattle a little better.

You can even add the new 3 V's one after each flight, The paired curved supports then can be in after another flight, or two. Doing it like this you don't have to stop flying too long, and it will be less strain for your neck, too. With the added support, the .016" roof skin does not need to be replaced with any thicker sheet.

 

Now, after the rework, if the rattle noise goes away, you only owe me posting pictures of your new roof, so that I can follow.  ;^)

All the best,

Champ

Comment by Ken Podaima on March 20, 2011 at 3:43pm

Certainly adding more bracing may work. I want to tuft the area and see what the air flow is like. This shouldn't be difficult as the most vibration occurs on the gound. To rework the roof would be a big job.

Comment by Chumphol Sirinavin on March 20, 2011 at 10:50am

Thank you for sharing.

From what you described your landing, your mod yields good result already.

To lessen vibration, may be 2 or 3 more V hat bracings span-wise, plus a curved support in the middle of the roof length-wise, can do the job for you.

 

Champ

Comment by Ken Podaima on March 19, 2011 at 10:37pm

Thanks!  Letting it vibrate is not good, one area where the cowl meets the fuselage has developed cracks after 33 hrs. of flying

I guess the color didn't come out too good in the pic. Its actually Cub yellow.

Comment by Joe Spencer on March 19, 2011 at 10:02pm

Hi Ken

Nice curved roof..that oughta help the air turn the corner. Let it vibrate and just fly it. I like the inside color...it looks like John Deere yellow dozer paint. Looks good.

Best Joe