prgonzalez

Continue the building by installing rudder and pull-pull system...

prgonzalez

I have found the elevator servo mounting I initially built was too weak. I made a new mounting with light ply with keyed parts. Now it's holding strong. Will post pics later.

I have also decided that I will redo the DEPS to eliminate the friction and stress it has. After a second thought about taking so much time on building this model (over 100 hours in more than one year), it is just slopy to leave an important control not worting at its best.

I have completed the lateral balance with adding 0.5-oz of lead at left wing tip. Now, wing is ready for final touchups and covering.

Another quick weight check gave me 5-lbs 13.5-oz. I still need to add wing covering material, prop, spinner, and ailerons/flaps controls. At this time, I estimate the final weight will be around 6.5-lbs. Definitively less than 7.0 pounds.

prgonzalez

I have continued with covering of the wing. I will be done by next Friday with all covering and hardware installation. Then, I will start breaking in the engine, a TH-0.75.

prgonzalez

Today's progress:

1. I finished the covering of the wing.
2. Installed all servos to wing.
3. Total weight as of now: 5 pounds 15.2 oz.

I am waiting for the new battery pack to arrive 2200mA Ni-Mh.

Additional work to do:

1. Install canopy.
2. Install break-in prop 12x6 APC and spinner.
3. Complete rework of DEPS.
4. Install receiver.
5. Install ailerons and flaps.
6. C.G. balance.
7. Break-in engine.

I am targetting this coming weekend for maiden flight.

prgonzalez

I could not finish the US for this part weekend. It was too windy anyways.

Now, I am getting closer and closer to finishing.

Work done this past week:

1. Installed flaps and ailerons.
2. Completed new DEPS system with 4-40 ends.
3. Installed break-in prop 12x6 and spinner.
4. Forming and recycling new TX batteries. Old one was giving only 1300mAh out of 2200mAh.

To be performed:

1. Form and recycle new RX battery.
2. Install aileron control links.
3. Install canopy.
4. C.G.
5. Break-In engine.

prgonzalez

Here is how it looks like right now...

Overall weight as of today: 6 pounds 11.4-oz. I still need to add the weight of the canopy and aileron control linkages. Deninitively reaching the 7.0 pounds but I believe it will not go over 7.0 pounds. Weight adds up very quickly with the hardware.

I will set the C.G. tomorrow evening.

prgonzalez

Weather was not good today for maiden the US 60. So, probably will be tomorow.

As a final report is approaching, I completed the installation of airleron controls. The C.G. fall within range after placing the battery and receiver between the rudder servo and the turtle deck. No extra weight has been necessary at this time. I will see if C.G. needs to change after initial flights.

Weight? Final weight is 7 pounds even. I am very happy with this final weight.

I started engine break-in today at home. I added some SIG castor oil to 1/4 gal of fuel for this purpose. I follow the procedure and the engine accumulated 30 mins on ground. Next step, idle adjustment with normal 10% nitro fuel, will be at the field tomorrow.

Flight report will follow.

prgonzalez

Flight Report ... After arriving and assembling the plane, I proceeded to tune the LSN for idle and transition of the engine. After a few minutes tuning the LSN, it was ready for maiden flight.

Takeoff was smooth and the plane took off after rolling about 30 feet. I set it for a shallow ascending rate while watching for any unexpected tendencies. Made first turn at about 100 feet of altitude and kept the model climbing. I had to change ailerons from low to high rate because it needed more aileron throws. After turning, I started to cut throttle when passing in front of me. Then I let it fly level and kept watching any tendencies while the US was going away from me. Then a second turn to the left for another pass. Again, straight level passes. At this time, I could not say anything more than WOW, NO TRIMMING (left, right, up, or down) NEEDED. Then, I started to continue circling around while cruising at half throttle. I notice the model is still a tad nose heavy for my liking. C.G. was within range while empty. But, at maiden, it had full 14-oz tank. A big adder to nose weight. After a few circles, I gained attitude for flap testing. After applying flaps, I had another WOW. The plane just went UP and UP to almost 60° vertical. Then, I set flaps to normal and resumed normal flight.

Then, landing for checkup...I announced LANDING, first attempt ... it was a surprise seeing the model floating forever. I had to abort landing because ran out of runway at 3-feet from ground. Second attempt...slowed airplane down and set for lower altitude. Again, floated for half runway but it touched ground at 3/4 of runway and slowed down quickly. While taxing back to the pits, the left tire found a small rock on its way and after seeing the small bump, the left block that holds the retract broke and the wing went down; one BIG disappointment for me. So, this was the end of the day for the Ultra Sport.

So, after about seven minutes of flight, information collected pointed to the following changes: move C.G. 1/8" aft, increase aileron throw, lean engine a bit more.

Lesson learned: I need to redo and improve the blocks that hold the retracts. This is my first retract installation. So, I have learned a big lesson about forces that affect retracts.

Overall, it is an amazing model!!!

dash008

My Feedback: (1)

Thanks for the flight report. Hope mine flies as well as yours! It has been way too windy here for the past week. I'm hoping for calm weather this weekend. Hope you get your retract fixed so you can get it back in the air!

prgonzalez

I made a second flight with the US60 this past Saturday. The repair and reinforcement of the retracts held pretty good and was solid throughout all bumps on the runway. Then I found another problem and could not continue flying.

Because I used light-soft balsa, the balsa ply of the rudder compressed at the pull-pull screw washers and the rudder is loose with a 1/4" throw play left and right. Now, I need to reinforce that section of the rudder.. First, I am planning on making a 1/2 inch hole and insert a basswood dowel with cross grain (grain aligned with screw). Then, glue one piece of approx 1 inch diameter 1/32 thickness aircraft ply at each side of the rudder with a center at the pull-pull screw. This will help to distribute out the torque of the pull-pull screw and maybe I do not have to make up a new rudder of harder wood.

I hope this to be the last fix I need to do to the plane and that I can start fully enjoying my Ultra Sport.

cpeisher

My Feedback: (13)

I just read the whole thread, i'm really inspired to scratch build my own US 60 now, after i build the one in the kit....
How is your plane flying now?  Any video of it flying or final assembly shots with the canopy etc?

prgonzalez

I am glad you got inspired by this thread. I know it lacks of detailed explanations about the building process. But, I think that all pictures captured every step.

I have a video of the mainden flight. I am not sure how to post videos here, I will try. Next time I go to the field, I will take good pictures of the airplane.

I am sure you will enjoy the Ultra Sport.

prgonzalez

Here is the link of the maiden flight video. (I just hope I am posting it correctly)

[link=http://rcuvideos.com/video/RCM-Ultra-Sport-60-Maiden-Fligh]Maiden Fligth video[/link]

You will see the failure of one of the retract supports. As I explained before, I have reinforced both retracts since the video was made.