airasj

Hi Guys

Does anybody remember the Classmate bipe by Ken Willard.

It was a construction article in RCM in around 1968. I build one in 1981 when I was 11 years old.

I did not have the finances to buy the full size plan and therefore enlarged it from the construction article. It was my first scratch build project and it took 3 sets of wings before I got it right. I flew the Classmate using my Dads Classic radio he built from the RCM construction articles of 1968.

I eventually crashed it but the wings and tail survived. Recently I decided to build a new fuselage and restore the wings that had been in staorage for 30 years. The Classmate is nearly completed and I will post some pics of my progress if anybody is interested. I am just trying to find the picture of the original 1981 version.

Regards
Attie

HighPlains

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That was the design that used the wings from a Schoolmaster and a Schoolgirl to build a bipe. It will be great to see your build. I think that a lot of modelers want to recreate some of the first models they owned, maybe because they didn't last as long as the should have, or to see how they actually fly with experience.

I had built the Schoolmaster around 1971, and it was the model that taught me to never trust my eyes. You know when you are watching a plan in a turn and suddenly you think it is flying the opposite direction. So I corrected for what I thought I was seeing and screwed it into the ground. I used the wing to build another airplane that was a semi-scale Cassuitt. Which I flew for awhile, but don't remember it's demise.

About the time you were building your Classmate, I moved to California and ended up in the same RC club as Ken Willard. He asked me to fly a demo at a local grade school off their playing area soon after I joined, and we also spent a lot of time training new fliers on weekends. It was a rather large club with over 400 members and a lot of active fliers.

Ken and I were instructing when our students had a mid-air (one airplane was doing a left turn, the other a right turn) and the two airplanes stuck together and kept flying. My student's airplane was an Eagle 63 and Ken's student had something smaller. Anyway, his prop stuck into the top center of the wing, killing his engine. His fuselage was parrallel to the Eagles, but his wing was vertical to the Eagles. The other airplane was short enough that it's stab was just short of the Eagles tail.

It took a minute or so to find out that the whole mess was controllable as long as Ken held full down elevator. We made a few attempts at working free, but to no avail. Finally it was time to land, even though the first thing that would make contact was the right wing of the other airplane. When it touched the ground, the wing popped free and the rest of it landed just fine, with Ken still holding full down.

airasj

Hi

Here is the pictures of the completed Classmate. I went for the traditional finish of silk and dope. Bought withe silk adn dyed it to the required blue.
The original version was covered in blue transperant Econocote and that was still good after 30 years.
The engine is an ENYA 19 i bought off ebay. The original had an Enya 15 which was just a bit marginal at 450 ft.
I hope the 19 will be OK.

Attie

airasj

Here are the pics

airasj

And one more.
I installed an old Kraft Spektrum 6 radio to keep it of about the same vintage.

Tried the Enya 19 today, but it seems to be new, because it got very hot with a 19x4 prop and I had to keep in in 4 cycle to keep it running.'
Got a bit better after the second tank alternating between 4 and 2 stroke.

Regards
Attie

HighPlains

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That looks really great! I forgot it's summer for you, so you can enjoy it now. It also looks like you have modified the wing structure to open bay, since the plans show the wings to be all sheet balsa. Can you describe how you modified it?

airasj

Yes, I almost forgot that I made some changes. The original wings took me 3 sets to get right.

The first set was a foam with paper covering ala Chuck Cunningham in RCM. It worked partly but I used too much glue and the wings were very heavy. The next set was exactly as per the plans with sheeted wing. As I was only 11 and not too skilled I did not get the sheeting perfectly smooth or got the sheets propely joined without gaps. My father was building a full size glider at the time and used a polyesther microbaloon mixture to fill holes and unevenness on the plywood covered wings. I thought this would work perfectly on my Classmate wings and applied liberal amounts of microballons to the wings. This cured very hard and was next to impossible to sand without damaging the balsa, so second set wasted.

For the last set I wend for a rethink and my dad also suggested and open structure with a sheeted D-box and capstripped ribs as per the RCM trainer of 1969. This I did with great care and the wings came out very nicely.

I covered the original in Econocote and doped and sprayed the fuselage in yellow. It flew very nicely on an Enya15 and the old Classic radio. I eventually decided to add ailerons, but the weight got a bit high with the four Orbut PS3 servos. The Enya 15 became marginal and it eventually crashed on takeoff with too little speed and a stall spin ending.

When I build the new one I decided to go for ailerons on all four wing panels and 2 ailerong servos, (one per side). I also build the fuse with 1/16 sheet balsa to decrease the weight. I did away with the rubber bands and both wings attach with a wingbolt to the fuselage and cabanes.

The turtle deck is also curved 1/16th instead on the balsa block on the plans.

Lastly I did not add the headrest and I basically forgot about it until too late.

Regards
Attie

HighPlains

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Well I can't wait for a flight report. It should be exquisite flying overhead with the sun glowing through the silk covered wings.

airasj

Hi Guys

Finally got round to flying the Classmate. Had a lot of problem with the Enya 19 overheating and not having enough power. Eventually I replaced it with an ASP 25 which has a lot of power. Made 3 flights and everything worked perfectly. A bit tricky to land. Here are some pics.

fritzke

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Here are plans
Dave

airasj

Thans a lot Dave.

Made a few more flights today and found it to be quite aerobatic with the 4 ailerons I added. The landings remain a bit difficult. You have to fly it on as little bump will result in three more, ever more violent than the previous one. Still a lot of fun to fly again after 30 years. The Kraft Spectrum 6 naturally works flawlessly.

Regards
Attie

buzzard bait

Nice project. As you may know, those old Enyas require a long break-in. Heat cycling is the way to do it, and it's good to have a lot of castor in the fuel.

Anyway, great to see you got it flying, and congrats on the pretty silk job...don't see those much nowadays.

Jim