JC's Planes and Projects

Horizon Hobbies Aspire EP

I purchased the Aspire EP ARF from Horizon Hobbies after reading excellent reviews of this product and the pure sailplane version (Aspire) in two hobby magazines. I then went online to read about it on the Horizon website and was convinced that this would be a relaxing and fun project that I could get into the air quickly. At the time I had absolutely no knowledge of E-flight or sailplanes. I dutifully selected the items recommended by Horizon including the Aeropeak charger and two 6-cell 1500 mah "sport" battery packs. I was pleased that this whole thing had only cost me a couple hundred bucks and eagerly awaited the delivery.

While waiting for the goods to arrive I started doing my typical post-purchase research on the Aspire EP. One of these days I will learn to do my research before the purchase! Anyway, the best I can say about what I discovered was that it was consistent. It was the opinion of many experienced E-flyers that the Aspire EP would be under-powered with the stock power package. The stock power package consists of a direct drive 550 motor, a folding 8x4 propeller, a servo operated micro switch, a spade fuse, and an external "arming" switch. I had chosen the "sport" batteries mentioned above which Horizon claimed would give me three "climbs to 500 feet in one minute thirty seconds." The estimated weight of the finished model in this stock configuration was given to be 49 to 55-oz.

Upon receipt of the package I was very impressed. The woodwork and covering was top notch. The only flaw is a slightly warped wing although I could probably cure this with a heat gun and a "twist." This was my first ARF and I really liked it. It only had a couple of small wrinkles that were easily removed with a heat gun. I assembled the wings and tail surfaces in one evening. The only thing slowing an almost immediate completion is the prudent use of 30 minute epoxy and it's required cure time.

More research and the advice of a local HS guru had me convinced that building the Aspire in its stock configuration would result in performance that would disappoint me. The capstone was a phone call to the Horizon tech department. The tech told my that the plane would climb, but "don't fly it when it is over ninety degrees outside." In other words, don't fly your glider when it is hot out. How comically ironic! The tech said that the prop will "de-pitch" with high ambient temperatures.

Here is a shot of the Aspire with the original Speed 480 setup

I originally equipped the Aspire with a Graupner Speed Gear 480 with a 3.45:1 gear ratio, 10x8 CAM folding propeller and a 8-cell, KR600AE battery pack. The system performed well for approximately 10 flights after which it dropped noticeably in power. I investigated all parts of the system and concluded it was the motor. It had dropped a full 1000 rpm off the top end. I returned the motor to the place of purchase and got another one. This motor degraded in a similar manner. I believe that, although I was running the motor with the recommended cell count, prop, and ESC, it was running way too hard. I think that a brush change would have gotten me another 10 good flights, but this was unacceptable maintenance. I decided to go with a bigger motor that would be run conservatively yet still provide good performance. I returned the 480 motor and got the following components:

Motor: Graupner Speed Gear 2.8:1, 600 size, 7.2 Volt , motor/gearbox

Propeller: Graupner 12x10 folding propeller designed specifically for this motor/gearbox

Electronic Speed Control: JETI 180

Battery:

Original: I used the 9-cell, Sanyo KR600AE packs that I had been using with the 480 motor. They are not optimal for this motor, but seem to work OK. In fact the current draw is approximately the same with the 600 compared to the 480.

New: Sanyo CP1300SCRs in a 8-cell pack. I am really impressed with these high-current cells. They charge as fast as the KR600AEs despite having twice the capacity. I no longer need three battery packs. By the time I am done with my first flight, the second pack is charged and ready to go. Duration in poor lift is usually 20 minutes. The 8-cell count gives nearly the same initial climb rate as my nine cell pack. The difference is that the CP cells can sustain the climb, where the KRs pooped-out quickly.

Servos: Hobbico CS-12 mini servos

Charger: Simprop Akku-Manager (a.k.a. Dymond Super Smart Charger)

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