Hello everyone,

I am new to these forums but have read the other threads posted here. Tons of great information, a very valuable resource indeed!

I currently fly a raptor 30 with the JR8103 and have just recently purchased a ultra stick 40 with Saito 72 that will also be controlled with the 8103. I have read many mods and tid bits of advice on various techniques involved with the US40 scattered about the threads. Does anyone have a list of what I need to do to make my US40 iron clad out of the gate?

Should I reinforce the firewall? If so, how? If I don't use the stock tank(I am using a low profile sullivan 11 oz.) what is the best way to seal the hole in the firewall around the fuel lines? Should I go ahead and purchase the nylon motor mount? Did anyone cross the cable guides going back to the rudder and elevator to create less friction for the metal pushrods? Install the servos in the tail? Use nylon screws in the gear mount? Also, any other thoughts, suggestions, or ideas would be greatly appreciated!

Sorry so many questions, but i have tried to throw out lots of ideas for comments. Thank you in advance for your kind responses and your expert advice. I am sure this will generate a good read for all US40 pilots and prospects.

Tricky T

One thing.
If you are using the Saito 72 go with a bigger tank at least a 14oz.
When I had a 11oz I was always running out of fuel.

Here's what I did to mine....don't read it as the Gospel, however...

Should I reinforce the firewall?
I did. Drill 3 or 4 holes in each side of the firewall and epoxy in toothpicks.

f I don't use the stock tank(I am using a low profile sullivan 11 oz.) what is the best way to seal the hole in the firewall around the fuel lines?
I used the stock tank. Just seal the fuel line holes with silicon.

Should I go ahead and purchase the nylon motor mount?
I did. Used a Dave Brown, but think the one they supply is fine.

Did anyone cross the cable guides going back to the rudder and elevator to create less friction for the metal p
I didn't, left them stock.

The only other things I did was to pin the control surface hinges (toothpicks, again) and seal all the control surface gaps.

I know there are some other mods but mine flies fine with an Enya 50CX.

I think you'll like this plane and it will fly just fine with no mods, I'm sure.

I have a OS .46FX on mine and it flies well. Good vertical, but not unlimited. For the type of flying I do the .46FX is well suited to this plane.

One thing I would caution you about is to reinforce/CA/Epoxy the landing gear plate better to the fuselage. Mine popped out after a harder than normal landing, so I repaired with a new plywood plate and tri stock. Works great now.

Everything else on the plane is completely stock and I have about 80 flights on it.

On my first one (Saito .72 powered) I drilled a series of .050" holes through the fuselage side into the firewall. I then pinned the firewall in place with toothpicks and thin CA. On my current one (YS .63 powered) I peeled back the covering around the nose, added a few strips of pantyhose with extra-thin finishing epoxy, the reapplied the covering. More work than just pinning the firewall in place, but this distributes the load a bit more evenly.

12oz. standard Sullivan tank in mine. I have left the hole in the firewall open with no ill effect (plus it makes a cool howl when the plane is at speed )

Up to you. I used the supplied mount on my first Stick with no problems. On my current one I switched to a GP adjustable mount which helped in balancing the slightly heavier YS engine versus the lightweight Saito.


No, no and yes. I had the gear plate pop out on my first one when my Saito backfired during a full-throttle full-flap takeoff... replaced the supplied blind nuts and bolts with 1/4-20 hardware. Overkill, but I had them on hand.

Quote:

Also, any other thoughts, suggestions, or ideas would be greatly appreciated!

It's a good idea to pin the horizontal stab in place, as the tail does take a beating if you fly from an inimproved surface. A couple of toothpicks at the LE adds a lot of strength and very little weight.

Replace the stock wheels in the kit with Sullivan lightweight 3" or 3.5" ones. Just a little extra ground clearance for 13"-14" props.

If your Stick comes out nose-heavy, don't add weight! Cut a hole in the top rear sheeting and velcro your battery pack back there. CA some sticks in place to keep it from shifting, then cover the hole with a bit of white Ultracote. I've done this on my Sticks and the battery has not moved.

I'm using an OS.46 on my UltraStik. Things I've done on mine:

1. strengthened firewall on inside with fiberglass cloth.

2. replaced mount with a DaveBrown mount. I've seen other mounts from other fliers in our club break on a hard landing. Purpose of replacing it for me was to save weight.

3. I tossed out the rudder pushrod, and installed kevlar pull-pulls.

If you are installing a big 4-stroke, you may not be as interested as I in saving weight...

I have a Ultra Stick 40 mod for ya, my stepson has one and he well lawn darted it slightly, and in the repair process we flipped it over and made a low wing stick. Very easy to do especially if ya are still in the assembly stage. Since he popped the V stab off anyway we just mounted it on the bottom (as well as the control rods), swapped places with the tailwheel. Then relocated the main landing gear to the top of the fuse in the same location just on the top. Left the wing in its original location no need to change a thing it thinks it is flying inverted. Color scheme was a little weird since we had flown it previously in the right side up configuration. The only thing that needs attention is the Rudder is less effective now, but no big deal just extend the bottom portion to match the now bottom of the fuse. It is a scream to see this thing.
I would advocate the firewall reinforcement, mount change, landing gear beefup, and better wheel. All in all a fun bird.

Yes! I only used epoxy but some of the other ideas here sound good. Also reinforce the landing gear area with epoxy.

While you're at it reinforce the holes that the wing dowels fit into. I've had to redo mine two times already because they seem to widen after several flights which causes the wing to have play in it. I did this by removing the ultracoat covering on the top of the fuse in front of the wing saddle (only a few inches back) and epoxying a fiberglass strip around the top and down over the dowel holes.

I used a 12 oz. Sulivan (I think) tank whose neck fit perfectly into the hole in the firewall. I run an OS 70 four stoke and can easily fly 15 to 20 minutes (your mileage may vary).

I just used the stock one, with your engine the weight won't hurt other than making it nose heavy.

I suggest putting the servos in the rear with your engine. I would do this if I had to do it over again. Since I didn't do this I had to cut a hatch in the rear of the fuse and place my battery and about 3+ ounces of lead in the tail. By changing the motor mount this could be reduced, but why bother? The Saito 72 will yank this plane out of sight even with the motor mount and extra lead in the tail!

I didn't, but it's up to you (depends on how well you land )

Definitely do the quad flaps, it's really cool!

To do a knife edge without a lot of control coupling you'll need to add some mixes to your radio (if you have a computer radio). Start off with the following:

5 point mixes:

Rudder to Aileron: 18, 8, 0, -10, -19 (opposite aileron from rudder)
Rudder to Elevator: 18, 12, 0, 12, 18 (this is down elevator)

Have fun!
Keith

Thank you guys for giving me some advice on my US40. I am definitely going to reinforce the firewall, probably with toothpicks; go with the nylon motor mount so I don't end up adding weight to the tail; beefing up the gear and thinking about mounting the servos in the tail with Kevlar pull-pulls. If anyone has done this please send me details or pics.

Thanks a ton,
T

In addition to the other responses, I've read previously that the tail wheel should be replaced. I replaced mine with the Sullivan.

I used the stock motor mount, beefed up the firewall and landing gear with epoxy, used the enclosed hardware and with using four servos in the wings and the OS 46FX I didn't have to add any weight, just moved the battery and receiver back.

You will love it

Great point Denjones. I'd forgotten about that but totally agree.

Here's the one I used. Notice the raised section that the wheel is on. I placed thin plywood on the tail to strengthen the gear mount since the existing balsa is fairly weak in that location.

This type of tail wheel handles bumps better and won't dislodge your rudder if it catches on something.

I also changed the main gear wheels to 3" ultra-light Dubro's. Since I fly off of somewhat bumpy grass the larger wheels help prevent tipping forward.

Another thing nobody has said is to drip some thin CA on the piece where the wing screws in. I was flying someones US 40 one day and the whole wing just came off clean almost no glue on the piece which H9 had glued in. Fuse went down like dart, not a pretty sight.