SA Stella G400X

[Sev Fontaine]

I got my G400X Stella kit from Steven's Aeromodel about a week ago. I really wanted to finish it for NEAT fair this coming weekend so I worked hard all of last weekend and every night this week.
I want to thank my Girlfriend for her support and understanding! :D
503
Ok... Now for the specs
AUW 18.5 Oz
Eflite Park 450 with APC-E 11x5.5 prop
CC Thunderbird 18
Electron 6 Receiver with 4 HS-55's
Thunder Power 3S1P 1320mah

This is my first plane with Pull-Pull setup on the rudder. I must say it can be frustrating to setup but I think it's worth it to save weight and improve the overall appearance.

In order to get this model ready for maiden I have to install duracollars for the wheels and glue some velcro in the battery tray. Other things I have yet to finish on this model but that are not critical for flying this weekend are... to build and paint the wheel pants, cut out and install the maple leaf on the bottom (for Canada flag) and the yellow star on top (for Acadian Flag).

I'll give my review of this model sometime next week. As for now all I have to say is that this is the best kit I have ever built. Two thumbs up for Steven's Aeromodel Balsa Kits!!

[Tom Hastie]

Lookin' forward to seeing it fly. I'm glad there's been another convert in the club. You'll feel spoiled next time you go back to a "real" kit. (What... you mean I have to sand to fit? I need to pin the part in place?)

What was the tricky part of the pull-pull? I've liked using them in the past, and haven't found it that much harder than push-pull. Just fiddley with the little threads.

Lookin' forward to seeing it fly.

One more sleep till NEAT!

Tom

[Sev Fontaine]

Well.. the tricky part was to run the thread through the fuselage and through some very small guide tubes after covering.
I had ran some thread before covering but when I installed the horizontal stabilizer I wicked some thin CA and it ran along the inside of the fulelage and jammed the entire pull-pull system. I had to then haul it out and redo it after covering. Took over an hour to redo.
If I had used a solid linkage it would have all been done in a few minutes.

I have a question about pull-pull systems.... When I set it up the first time I ran a thread from the left side of the rudder straight to the left side of the servo and the same thing on the right side. I then found out that the side that wasn't pulling was getting very loose so I tried crossing the cables. So from left side of the rudder to the right side of the servo and the same for the other side. Is this how it's supposed to be done? Crossing the cables?

[Dave Rees]

Sev, looks great, can't wait to see it fly.

Pull-Pull, yeah, can be a bit finicky to set up properly but, when done it's a great way to go. I believe that crossing the cables is quite common and have done that myself. If there is a little slack in the "pushing" side I wouldn't worry about it on the Stella. On a 40%er I'd do everything possible to eliminate the slack. Some basic tips for pull-pull (I've discovered through own experience and reading several articles and web forums) Geometry is extremely important. So, from cable attachment point to hinge line and cable attachment point to servo centre MUST be the same. The other thing to consider is whether the attachment points are in line with pivot points at both ends. If the control horns line up slightly ahead or behind the hinge line then at the servo that discrepency must be matched.

hhhmmm, don't know if that helps or not. Tough to explain in written from. Regardless, I hope that helps.

Cheers,
Dave

[Sev Fontaine]

I agree that the length of the servo horn should match the length of the rudder horn but in the case of the Stella that would only give me about 20 degrees of rudder deflection. That's not even close to what I need for 3d.
I am therefore using a much longer horn on the servo and the tension on the cables with them crossed seems to be pretty constant throughout the motion. With this setup I am getting about 40 to 45 degrees deflection (I didn't actually measure it yet)

As for the hinge line matching the control horn hole that's all taken care of by Steven's Aero. They supply the control horns so it's practically brainless to install them.

[Tom Hastie]

Well... even though Egon Spengler would tell you that crossing the cables is "unbelievably bad" (...Ghostbusters anyone?), I think alot of people do it that way. I think most of the giant scale I've noticed with pull pull setups had crossed cables. I never really thought about how it might reduce the amount of slack, but I guess the geometry would be better for the un-tensioned cable if you cross them.

That being said, I haven't crossed them in the past, and the aircraft I've flown with parallel cables (Jitterbug, Groove number 1). Both of them did have slack in one of the cables when you're at full through, but I've been hard pressed to notice and difference in flight.

I think the reason it's OK is that once you have air loads on the control surface, the tensioned cable will always be tight, and there won't be any slop as you transition from one side to the other because presumably you have both cables tight at neutral.

When I get my SA CAP 232 all hooked up I'll have to see how it works. From what I can see in the manual, Bill is suggesting you run both pull pull cables down the same pushrod tube. I'm not sure how well that's gonna work yet, but looking at examples of completed aircraft online, that's how they seem to be doing it. It'll probably be fine since at parkflyer scale, you can get away with lost of stuff that would be very bad for giant scale.

Tmo

[John Weekes]

Awesome looking mode, Sev...I like the Acadian flag idea! ...I'm glad to hear that your experience building a Stevens Aero kit was as positive as mine!!!

Have a great time at NEAT...I want to hear all about it!!!

...Now the 3 of you remember to be good boys while you're there... :cool: :cool:

John

[Tom Hastie]

...Now the 3 of you remember to be good boys while you're there... :cool: :cool:

...Yes dad :rolleyes:

[Sev Fontaine]

Yes Daddy!:D