Carl Goldberg Endurance 400 (Part 2: Building and Flying)

Carl Goldberg Endurance 400 (Part 2: Building and Flying)

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Recently I wrote my early impressions on the new electric 400 class model produced by Goldberg Models named Endurance 400. My final review was waiting for my annual trip to Toledo to look for a receiver, speed control, and a battery. Unplanned, but a good deal, I also bought a new Airtronics RD-8000 radio system that I have used on this plane also.

If you haven’t already, read Carl Goldberg Endurance 400 Part 1: First Impressions.

Read on for Part 2: Building and Flying


What I bought

ReceiverKennedy Composites was selling the new Shadow 3 programmable receiver. This thumb size receiver uses a plug in module to set it to a channel thus no crystal is needed. Also you only need one programmer for as many receivers you need. This is the direction the whole R/C hobby is going. The Shadow 3 is a really first rate receiver.

Speed Control – I bought a thumb nail size 25 amp unit made by Castle Creations. Noted for being reliable and the small size was very important in this usage I thought $25 was a good deal.

Batteries – From Batteries America I picked up an assembled 8 cell pack of Sanyos. The pack rating was only 500ma the cell length is only 1/3 the size of a normal A size battery and it fit into the model easily. Flight test will show if this will be enough capacity for our August contest. Batteries America has larger capacity batteries, in the 1/3 cell length listed in their catalog, should I need more capacity.

How I assembled

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The fuselage has a preinstalled servo/battery tray. Now this tray has a vertical keel piece to absorb the impact of landings. This reduces the distortion the fuselage would take on a harder than meant to landing. Repeated fuselage distortions and the servo/battery tray would pop loose from the glue holding it in. The tray shows some forethought as there is already a servo mount in place and a vertical stop in the rear to stop NiCad packs from sliding aft.

I used a Hitec HS-85 servo to drive the V-tail elevator because it fit the servo mount, and because I had one extra on hand. The tiny Castle Creations speed control just did fit into the small cavity under the elevator servo mount that the keel created.

One thing I think there is room for improvement is there are no pictures or drawings to suggest how to install the electronics so I would be very concerned for a beginner correctly setting up this plane from this point onward. Looking at the battery tray it is easy to see that a NiCad pack was thought about when the plane was designed and that is how I plan on using it. The problem is the instructions talk about using a two cell lit-poly pack ONLY! The real problem becomes where to mount the receiver? There is enough room to set the receiver on the servo/battery tray in front of the NiCad battery. I personally don’t want to turn my new Shadow 3 receiver into scrap when (not if) the battery comes loose on a firm landing and tries to take out everything in front of it. For the Lit-Poly user there is no mention where to mount the receiver. Although it may be possible to stick it right on top of the poly pack. Maybe not if your receiver has plugs coming out the top and not on the ends.

My solution was to Velcro the receiver vertically on the side of the fuselage right near the servo arm with part of it sticking up into the canopy area. This way if the battery ever tries to escape, the receiver will not get a solid blow and the Velcro will let the receiver come loose also.

I put a pair of JR 241 micro servos in the wings. I mounted these with contact cement. When done the plane balanced 1/4 inch behind the rear most recommended CG point. I added a 1/2 ounce of nose weight. That hurt my feelings, especially on an electric model and I was still somewhat tail heavy.

Flying

Sunday at the field I prepped the Endurance 400 for its maiden flight. A range check with my Airtronics RD8000 radio with the motor off and again with it on and found no problems. The Shadow 3 was working well with my Airtronics radio. A hand toss found the trim close enough to try it again with power. Applying half throttle I tossed the Endurance 400 for its first flight. Going to full throttle the plane shot off across the field. Three clicks of up trim and I had a steady rate of climb. It was clear I had too much roll rate and the elevator was touchy. Yes I know it is still a little tail heavy. Otherwise the first flight to feel the plane out went without incident.

With some throw adjustments made to my transmitter and the battery recharged I went for another flight. This was much better although a mite still tail heavy the Endurance 400 climbed steadily to normal winch height on a one minute motor run. I proceeded to test the planes legs. Cruising around the field I saw the tail kick up and I sensed a thermal. Rolling the plane into the lift I climbed right out until I was loosing sight of it. I cursed the white bottoms on the wings. With plenty of juice still in the battery I brought the plane down for an 8:30 min flight which easily could have been much longer.

Some flight notes – Circling required a slight opposite stick to keep the 400 from ‘spiraling up’ in the turns. Landings will take some practice as the landings are flat but fast. Some radio mixing to make spoilers out of the ailerons will be tried later. I was able to detect lift easily. I will be recovering my model for better visibility at distance and altitude.

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