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Jun 13, 2016, 03:07 PM
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yeh the stock sig hinges are especially terrible unfortunately. I was able to install them in the elevator and rudder, but they seems to come loose easily, i've already re-glued them a few times since it doesnt wick in well, and they are much stiffer than the hinge material i used on the ailerons. I'm still considering cutting the sig hinges and replacing them with the other stuff despite the hassle....

Quote:
Originally Posted by Nergall
Making the 'pull' movement drive the up elevator would mean placing the control horn on top. So, for ascetic reasons, it's normally done the other way around. Of course, sometimes being able to input down elevator is just as critical, so really, it just needs to work well in both directions anyway.

A good pre-flight test is to push lightly against the surface with your finger while moving the sticks on the transmitter. The amount of force you use, of course, proportional to the size and speed of the aircraft - in your case, maybe just the weight of your finger alone. Also, with maybe twice that force, tug directly backward on the surface to make sure the hinges are still solid. IMHO, you should do this second test at least once a month because hinges do wear - especially CA hinges.
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Jun 13, 2016, 03:30 PM
FlyBilly
wkener2's Avatar
Radio South makes CA hinges that most of us on the aerobatic side agree are the best hinges out there... you can get them at Atlanta Hobby

http://www.radiosouthrc.com/pro-hinge.htm
Jun 13, 2016, 04:39 PM
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Nergall's Avatar
The SIG ones used to be fine as well, but yeah, the Radio South ones are in another category.
Jun 14, 2016, 08:16 AM
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Quote:
Originally Posted by wkener2
radio south makes ca hinges that most of us on the aerobatic side agree are the best hinges out there... You can get them at atlanta hobby

http://www.radiosouthrc.com/pro-hinge.htm
+1 !!!
Jun 14, 2016, 09:57 AM
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Thread OP
The servos and pushrods for the ailerons are installed, but not entirely without incident. One of them just broke while I was making my z-bend in it, so I used the other end that broke off, and z-bent both ends, since the bit with the threads was now too short to be of use. So now my one wing has a threaded plastic link, the other end 2 z-bends with a v bend in the middle to make it adjustable. It will work, but part of me wants them to match! Maybe I just ditch the stock aileron pushrods entirely and use some of my own music wire. I dunno, this and the tail hinges....room for refinement.
Also laminated together the plywood motor mount spacers. Tonight I'll glue them onto the firewall. I drilled the cowl for it's screws first, checked the length of my motor with it and decided the stock 1/2" of spacers should probably do the trick. epoxy the spacers to the firewall, then screw the motor to those. should be simple enough. I'll have to check the build threads on here and see if there is a solid recommendation for down or right thrust.
Once the motor is on I can install my ESC and RX and check the balance and weight. :-)
Jun 14, 2016, 10:16 AM
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Nergall's Avatar
I keep 2-56 and 4-40 end threaded rod on hand if you need one.

I wouldn't trust a rod that snapped on a Z bend. This is aviation, so I just throw out anything dodgy.
Jun 15, 2016, 10:39 AM
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last night I put the checkerboard decals on the bottom of the wingtips, and a triangle of it on the bottom of the tail end of the fuselage. I'll put it on the tail fin too, but that has to wait a bit, because I also installed some additional support for the fin, using some spare balsa sticks I reinforced the mounting of the fin to the stabilizer. Those have to be covered with the red covering, and then the checkerboard decals can go on the fin.
I also tried to epoxy on the spacers, and then mount the motor once that had set for an hour. I ran up the motor and the spacers popped right off! Immediately had a flashback to the poor cub motor mount coming apart in flight. I guess either the epoxy hadn't set up long enough, or the surfaces weren't sufficiently sticky, who knows. I sanded off as much of the dried epoxy as I could manage, replaced it with kind of a lot of wood glue, and taped it in place to dry overnight. I have no confidence now in glue to hold this on, so additionally i'll be running a pair of long bolts through the firewall to ensure it stays on mechanically.
Jun 16, 2016, 09:30 AM
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last night I ran the two long bolts through the firewall, and re-attached the motor. I ran it up to full power (pretty impressive amount of power really I thought) and it held nicely at full throttle for about a minute, seemed sound. For now i'm going to fly it without the cowling, so that I can more easily check on the motor mount and have generally easier access to things.
I've also applied the decals, I used the classic four star star decals on the fuselage sides and wings, and the lightning bolts on the top of the stabilizer. The fin, and bottom of the stabilizer got some more checkerboard.
Jun 19, 2016, 02:33 AM
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Thread OP
I think the 4 star is ready for it's maiden flight now, the motor seems to run well, little vibration, the controls all answer properly, and with the plan-specified amount of deflection, and she taxis around just fine, so I think its basically all set. I'm going to leave the cowl off, since honestly i kinda like my planes that way, and also it makes getting to the motor or changing props harder. The cowl is little more than sort of a tapered tube anyway, it's the spinner that would make it sleek, but I've left off any spinner at the moment. Mostly to make sure I'm getting good motor cooling for now.
I've gotten 2 new kits just today, so i'll probably begin one of those while i await some excellent weather to fly the 4 star :-)
Jul 02, 2016, 09:08 PM
Registered User
Thread OP
had a false start today, got the 4 star out and the wing warp had come back enough that it was a pretty poor flyer. Took it home and straightened it as bit, headed back out and had a great flight on it. It's still warped definitely, but less so, such that its now a pretty nice flyer.
I'll have to keep an eye on it. I'm tempted to order a new wing and give it another go at building it straight. Once you have a warp apparently it will often come back.
Ill have to see what SIG wants for another wing kit.
Jul 02, 2016, 09:47 PM
Registered User
Nergall's Avatar
Before building another whole wing, you could always remove the covering, pin it back onto the building board and add a few diagonal pieces to hold it straight.

But, as is right now, it seems great. Also, it looks great!
Jul 02, 2016, 11:20 PM
Registered User
Thread OP
yeh I guess in fact I'ts just the one half of the wing that's warped, maybe i could avoid recovering the whole wing...otoh, adding some weight to one wing and not the other isn't great. good idea and ill give it some thought.
Jul 03, 2016, 07:57 AM
T-Squared
I didn't get to see her fly but she does look great.
Mar 03, 2019, 10:55 PM
f-80 driver
Interesting color scheme. Looks like my Four Star I built in 1990. I like using fluorescent red ultracote these days, it has a nice glow to it. I like your red plane, good job with the covering.


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