I went and got a H9 US120 from my LHS and was wondering if there were any mods you guys would recommend before the constructions process begins. I will be getting a Saito 180 for the engine.

Ground, I just finished my 1.20US with a Saito 1.80. If you do a search you will see that a lot of people went totally crazy on "necessary" mods to this thing: hatches, reinforcement, replacements, etc. I have a dozen flights on my now with some pretty wild and high G stuff. It is flying great. I built mine totally stock except for the following: Sullivan & Robart control horns w/allen headed screws and Dave Brown Fiberglass pushrods. It is a trick mounting the engine without a hatch, but i did it. I wanted to build with a minimum of effort and time. I have assembled four or five H9 1/4 scale size planes. Generally they get all the bugs out of their later runs. Everything on my plane fit perfectly except for the vertical stabalizer. it's foot was about 1/8" to long.

After the above expericence with H9 planes and this US in particular, at some point in time I will probably do the following two upgrades: (1) reinforce the landing gear plate and mount with 1/4" nylon screws; (2) put a hatch in forward compartment to gain access to tank and firewall area.

Just as a matter of interest, built as above, my plane balanced perfectly at 11.8 pounds with the battery mounted directly behind the tank that was mounted as far forward as possible. the CG is at 5" from the leading edge and working out pretty good there for me currently.

Thanks for the input Splais. I was planning on putting a larger Dubro tank(20-24oz) since the 180 is pretty thirsty. Did you use the stock tank or use a different one? I also was wondering if you found the stab control surfaces to be large enough or would you increase the size?

I used the stock tank. Have not run it dry yet, but estimate 10-12 minute flight times tops, safely. (it does guzzle - about 1.5-2 oz per minute). The good thing is if you ever deadstick the thing will float down like a trainer and land easily without power. It really helps to get the low end tuned right. that will maximize your mileage.

make sure you do not mount the elevator, rudder and ailerons to tight to the trailing edges in order to maximize throw. I need to remount my elevator one of these days. the recommended throws are very conservative. I am not a "real" 3D flyer yet, but it seems to me the elevator and rudder have conservative size. I think you will notice that this plane has a little longer moment arm in the fuselage that does seem to amply what looks like insufficent rudder and elevator travel somewhat. Mine US will make very tight loops with no tendency to snap out. I have not got around to trying knifeedge yet, but all kinds of snaps and tumbles, spins, etc are really fun. with ailerons and flaps linked, this thing rolls in a blink. I have just started to mess around with the crow, but it is fun as hell to dive straight at the ground and pull out at the last minute without worrying about snapping into the ground. I'm going to be trying my first vertical dive landings this weekend. After flying Cap's, it is taking awhile to get used to the airbraking qualities of Crow.

I am planning on using a standard Futaba flight pack with the standard servos on the wing and high torque on the rudder and elevator. Should this be sufficient?

Have no idea. Think it depends on how violent you are going to fly it. I had all Hitec 605's (76#torque) on one cap that worked great. On my US I have Hitec 5625 (110oz) digitals on the wings/flaps and 5925 (103oz) digitals on the rudder and elevator just because I had them. My personal, completely unknowledgable, opinion is that a standard servo in the 40+ torque range may be pushing your luck a little. Something in the 70+ range would have a better safety factor.

Ground Zero,

One of the guys in our club stripped the gears on three of his "standard" wing servos at the same time on his US 120. Of course he flipped the crow on during a high speed dive (relatively speaking) to make it happen. He then replaced the servos with higher torque metal geared servos and has had no problems since. However, he claims that if you're not a real hot-dogger type of pilot, the standard servos may work fine. (He does highly recommend against taking the risk, though.) Based on his experience, I put metal geared, higher torque servos on mine....Have had no problems (except that I keep flying too close to the ground, which results in making the landing gear more or less retractable). Love the plane...