Hey you experienced Hog Bipe builders.

I'm about to commence covering my Hog Bipe (I have a build thread that's been suspended since June - 2009). I have these very hard (and heavy)balsa control surfaces (4 ailerons, 2 elevators, 1 rudder and a partridge in a pear tree). Should I or should I NOT put a bunch of holes in these surfaces?

As always - thanks for your candid input!

I know what yer talking about. I'm building a gb ulti and the solid ailerons are quite heavy too. I'm making my ailerons larger and making them from 1/16th sheeting/ribs with a leading edge. I'll make mine solid where the horns go but it shoud save a lot of weight.

I don't know about punching holes but the ailerons on my original sse was 1/4" sheeting with holes...

If you dont like the pieces I would hit the hobby shop and see if they have acceptable replacements first. Holes should be ok too; it is done all the time, even with light balsa. I would be inclined to keep the tail light and not worry with the ailerons.

Thx TFF,

Having just finished a tail heavy LT-40 I understand the priority to keep the backside on the liteside. Also, the ailerons are pretty narrow.

Since these are all pre-shaped pieces I'm likely to save my money.

It will be fine as is.

Brian

My elevators were medium and the rudder very soft. I didn't lighten them and mine balances just fine with a Saito 100 and a 2150ma 4.8v pack under the fuel tank. My ailerons were a different story. I had 2 soft, one medium and 1 hickory. I cut the medium and hickory in half an biscuitted them back together to make two equal weight ailerons and installed them on the bottom wing. When I trimmed them to length, I made sure to cut off more hickory than medium to lighten them further.

Ailerons are small and near enough to the CG to be fine as is. They might actually be better on the heavy side to resist twisting in flight. Tail feathers your choice but do not get carried away if you decide to put some holes in them. I'd rather see you build some new ones out of stick stock. But that said I agree with Brian, it will be fine as is.

Well, I have this set of hole saw blades. There they were just looking forlornly up at me from my drill tool box. Couldn't help myself.

Pic 1 - layout of 4 holes on each elevator (saved .6 oz)
Pic 2 - finished lightened elevators
Pic 3 - layout of 3 holes on rudder (saved .4 oz)
Pic 4 - finished lightened rudder

Total weight savings is 1.0 oz. (using digital postal scale). Should reduce firewall weight by 3 oz.

Can't hurt. Hey, everything is a learning opportunity.

I did this recently on another biplane with heavy tail material and saved 1 1/2 ounces at the tail. Since the tail is so long compared to the nose I figured the nose would need to be 6 ounces lighter to balance the tail weight saving. That's almost 1/2-pound from an 8-pound airplane. It allowed my Jungmeister to balance without nose ballast. Anyone would notice that much difference in performance so yes, it's well worth it. I'd just make sure the holes aren't too close to the joiner wire or control horn(s).

Unless your rudder and elevator are rock hard, I think lightening holes are a waste of time on the Hog Bipe. I even made my rud and ele bigger and mine still balances just fine with no additional ballast...