It only took 3 years to fly! Pics Added!

[Brian Massey]

After 3 years on the bench, and two (Yes Two!) failed “maiden flights”, my new Chipmunk is now flying! It's a combination of scratch building and kit bashing. It is not stock, as I wanted to try some changes: equal panel wings for a span of 54 3/4”, resulting in about 575 square inches. The tail moment was lengthened; it is now 17 5/8” from hinge line to hinge line. The stab/elevator was also given more span, now 22”. I sheeted the wing and built up the tips to make them solid. It sits on the scale at 60 ounces. (More than I wanted!)

I'm powering it with a  (currently) stock LA 46; well “stock” except for the Randy Smith NVA and a Scott Dinger muffler. The first flights were done using a Brian Eather 11.5x4.5 prop, re-pitched to 4.0. It flew well, but I wasn't happy with the speed; too slow for me at 5.8 laps. I've now gone to a 12.5x4.5 B.E. prop. Stock, it measures 4.6 pitch at about 4 inches from the tip, tapering to 4.1 at the tip. I'll play with re-pitching if needed, after other trim issues are completed. With this prop my launch rpm dropped by 800 down to 9200 without touching the needle. Lap times on 63' lines is 5.4 with plenty of overhead tension and a very strong 4/2 break. With only about 8 or so flights, and only some minor trim changes, this is very close! I have high hopes for this plane.

The changes to the stock Chip seemed to have made a great model even better, but I can't take credit for them. Years ago some kid kept winning the Nats Junior title with similar mods . . . wonder what ever became of him.

I'm going to take some pics tomorrow and get them posted.

Brian

[Curare]

Pics!!!!

[Clint Ormosen]

Pics!!!!

I agree!!

What's in it that brought your weight up to 60 ounces? Seems a little porky for a chipmunk.

[Clint Ormosen]

Hey! Looks real sharp, Brian! Can't wait to fly it.
SEE IT.
  I meant see it. Really. 

[Brian Massey]

Hey! Looks real sharp, Brian! Can't wait to fly it.
SEE IT.
  I meant see it. Really. 

I think it's very porky for a Chipmunk. But the weight came on gradually over the course of two failed maiden flights. Let me explain . . . The first maiden flight (MF1) started normally enough. I took the Chip to the cage where we run engines. Once started, I held it overhead in various positions to see how it pulled fuel. It did great. I took it back over and hooked up the lines only to discover that during the previous process something in the controls had failed. that resulted in cutting into the fuse to fix. So that patch/paint added a bit of weight. Apparently I had failed to properly tighten a ball joint at the flap horn.

MF2: On roll out the lines caught a weed. The plane jerked violently up . . . and then just as violently down ripping out the landing gear about 25 feet from the launch point. That resulted in cutting into the wing and replacing/beefing up both landing gear block. More dope and more weight.

You'll be happy to know that when I emailed the club that MF3 was upon us, they showed up in droves with their cameras. But number 3 was the charm. I think some were a bit disappointed. 

Brian

[Brian Massey]

More of the repairs.

[DanielGelinas]

Brian, that is a great looking super chipmunk!
I'd love to see it fly. Not enough control line on youtube...
-Dan

[Avaiojet]

Brian,

You did a nice job with that model.

I like the accent stripes. First because they taper and because you didn't carry then to the TE.

Where did that idea come from, did you see something?

Nice!!

Charles

[Brian Massey]

Thanks Charles;

Since I changed the plane a bit, I didn't want to use the stock paint scheme. But loving the way the paint scheme looks, I wanted to keep the theme. Also, I'm a fan of the eagle on the hood of Trans Ams, so I tried to get "something" of that look using strips. As a note, the strips are the maximum size I could print on 8 1/2 x 11 decal paper. The strips are all the same size, just flipped them for right and left wing panels.

The under belly uses the stock paint scheme, except both the wing stripes are blue. I'll take a picture of the underside sometime today and post it.

Brian