Estes Mini A Heli #007272, Build, Part 5, Optimized and Lighter Parts

The launch lugs are short at 3/8" long.
They say if you cut the ends off at an angle that drag is reduced.

Use a new, sharp knife, this is one of the rare times I'll use an X-Acto #11 instead of my break-off blade knife.

Both the lugs got the front ends trimmed at a 45 degree angle.

I might reduce more drag by trimming the back end, but the lugs are very short.

The engine block was lightened by peeling a few layers from the inside.










The red coupler is probably longer than it needs to be.
1/4" was trimmed off.

Maybe all the little weight reductions could give a longer duration flight. Years back, Estes recommended  hollowing out the balsa nose cone on the Streak rocket. The instructions claimed it would add 20 feet to the altitude.

Maybe I should have hollowed out the balsa nose cone.

Estes Mini A Heli #007272, Build, Part 4, Lighter Parts

I was going to use the kit supplied plastic nose cone at first.
The shoulder on this nose cone always seemed a little long so about 1/8" was cut off the bottom with a razor saw.

The plastic kit nose cone weighs .04 oz. with the shortened shoulder.







For comparison I weighed a balsa Mosquito style nose cone from the spare parts drawer. It weighs half of what the plastic nose cone did, at .02 oz.

When the plastic nose cone was fitted, there was a small body tube "step".

The balsa nose cone was a little wider at the shoulder and could be sanded to the outside diameter of the body tube. The joint will be an easy fill and less drag.

Estes Mini A Heli #007272, Build, Part 3, Fin Substitution

On the top is the kit supplied 3/32" thick fin, it should actually be flipped over. The leading edge is the diagonal.

On the bottom is the shape I came up with for the 1/32" thick plywood fin. I've read where this is a more efficient shape, like the old Estes Sprint fins.

This time (maybe a different fin?) the kit fin weighed in at .02 oz. Again, the fin is flipped over.






After the thin plywood fin was shaped, it weighs in the same as the kit fin.

Estes Mini A Heli #007272, Build, Part 2, Fins?

Here's something I don't get -
The wood grain on the supplied fins doesn't run down the leading edge. On the right is the picture on the first page of the instructions.

I probably won't use them anyway. I thought the 3/32" thick fins were a little thick for a competition model. Recently I bought some 1/32" thick plywood from BMS.


Competition flying is all about reducing weight and drag. I'll be doing some adjustments to hopefully have a more efficient model.

On the left is the kit fin, weighing .01 oz.
On the right is the 1/32" thick plywood copy. It's double the weight at .02 oz.




The kit fin is on the left, thin plywood fin on the right.
When I get finished with the replacement fin, it should weigh less.

Just comparing the root edge widths, the thinner ply fin will have much less drag.