Did you ever have one of those days? This will tell about Day One with my new T.E.A.M. HiMax NoCal.
The History
For some reason, the HiMax is one of my favorite planes to model. This dates back to the early ’90s building and flying Peanuts with the Cleveland Free Flight Society. As far as NoCal, I know I built one that flew “pretty well” at Akron back in 2013. I may have built one before: I just can’t remember. In any case, “pretty well” was just ok – probably around 2 minutes – not bad for an outdoor guy flying indoor, but never really competitive indoors. I still have that one.
2013 version the wing markings were incorrect – there was no registration on the top of the wing
2013 version flying at Akron. A carved wood prop replaced the Ikara 6″ Indoor prop in the first picture.
The Build
Fast Forward to Fall 2024. Last year, I built a BD-4 for indoor but it didn’t fly exactly as I wanted it to, so I thought, let’s build another HiMax. I’ve learned a bit since 2013 about indoor building and flying. I redesigned the model to what I considered “minimal” structure and built it from light wood (5#, I think). I used a 7% Simplex airfoil at +2 degrees and the wing has 54 square inches of area. I located the tail hook so the rubber would come close to balancing the model. And I formed a 9″ diameter, 13.5″ pitch prop with a 1.375″ blade width. I have struggled a little with 10″x15″ props so I reduced the diameter a little bit, hoping the reduction would make it easier to trim.
Building this delicate paid off in a way: the model came out to just about 4.5 grams without rubber. Of course, there had to be “problems”. The HiMax has wing struts. This will cause problems when winding. Either I have to wind off the model (like I usually do with NoCals) or I have to wind with the rubber on the plane and the model on a stooge, much like any other Scale model. I thought for a long time how to make a stick that would allow me to wind externally, transfer to a stick and load into the model. But I felt this would be more trouble than it would be worth, so I decided to wind with the model on the stooge. This meant winding with the rubber passing through the model between the fuselage and wing and wind struts. If the rubber breaks, damage will be done. I did have to mount a small piece of aluminum tubing just in back of the tail hook to mount the model on the stooge.
One of Those Days
So, I took the model to our first Indoor contest to test it out. I had done nothing other than a small test glide in my living room to check the cg – it was close enough. I loaded up an 18″ motor of 0.085″ rubber and wound in 1000 turns. It was a little stall-y, so I adjusted the thrust and tossed again. Pretty much the same. More adjustments and a small bit of nose weight. By the time the 1,000 turns ran out, I had a fairly decent trim.
I wound in 1,500 turns and let it go. Ok, there it goes! It was climbing well (maybe a bit fast) circling to the left. Past advisors had told me to circle to the right and put is washin/washout to encourage that – but I think I got that wrong/opposite during strut installation, so I flew it left. That first flight – it turned out well. It flew to the rafters, but didn’t bump. It landed at an impressive (for me and a first flight) 2:58!
the results of the first attempted flight on 1500 turns.
I decided that maybe 0.085″ was a little too strong, since I was at 1,500 turns and knew the motor could take several hundred more. So I loaded a 20″ loop of 0.080″ and went again at 1,500. This time I got 3:06 with much the same flight pattern – a fast (but stable) climb, very near the rafters, and landing with a pretty good time! The next flight was just over 1,800 turns – 3:15 but with a couple of bangs on the rafters.
I decided to try something different. These climbs were fast – and the flights need to be longer to be competitive. I got out some 0.070″ rubber and made a 24″ loop. This was a lot less power and a lot longer. I cranked in 2,500 turns and watched the climb-out – it was a similar pattern, maybe not quite a quick to the roof. In fact, it didn’t get quite as high. It landed at a disappointing 2:44 with a bunch of turns left. Unwinding on the stooge showed 1,200 turns remained in the motor! So, while it would climb out well enough but it just couldn’t sustain the cruise.
I thought about finding some 0.075″ rubber, but wanted to try something first. I decided to chop off part of the tail end of the motor. The new motor ended up about 18″ long. I wound it up to 1,975 and watched it go up faster than before and actually cruise around. It landed at 3:25 – best of the day. But it had turns still on the motor – 350 left. One last attempt. I opened up the left circle a little bit, thinking the tight circle was holding the model back. With a wider circle on 2,000 turns, I was rewarded with a most unexpected 4:14!
I hadn’t expected flights like these on the first day. And I was very surprised I was able to use 0.070″ rubber – that’s thinner than I expected! So this little model has already surpassed my expectations! (By the way, 4:14 was good for SECOND Place today; I lost to Don Tang flying a Turbo Cessna 195 – my design – to a 4:36.)
The drawing needs to be finished (several details need to be added) and I will get the Short Kit online soon! I might even include laser-cut blades.
