PULL-PULL conversion on Sig Something Extra

PULL-PULL conversion on Sig Something Extra
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PULL-PULL conversion on Sig Something Extra - 2/5/2007 12:58:15 PM

CGRetired

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I just picked up my Sig Something Extra 40 size kit. I have not yet started the build process, but am planning on what I am going to do with this plane.

Is there any advantage to building this plane with a pull-pull type rudder system? The servo's are placed in the under-the-wing compartment as it is, so there will not be a weight advantage. I was just wondering if it's worth the effort or a waste of time. I don't really mind the extra work to set that up, it may be fun to do. But, was wondering if there was any advantage to doing it or not.

DS.

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RE: PULL-PULL conversion on Sig Something Extra - 2/5/2007 1:22:29 PM

mcmike

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i've got a pull-pull setup on mine. It's got a lot less slop in it than a pushrod, and I do think you're saving a few grams of weight. Try it, you might like it!

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RE: PULL-PULL conversion on Sig Something Extra - 2/5/2007 2:19:36 PM

Charlie P.

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I'd say yes. The pull-pull gives a very crisp response and stays in trim through temperature changes. Search on "Ackerman" as well as "pull-pull" for tips on how to set the linkage up.

It can get to be a "ship-in-a-bottle" rigging tighter fit planes. A jig taped to the centered rudder (and that held straight with tape or rubberbands & pencils) can be a third-hand. I use little steel bulldog clips on a piece of scrap spar to hold the cables tight while I get things rigged up at the rudder horns.

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Post #: 3

RE: PULL-PULL conversion on Sig Something Extra - 2/5/2007 2:22:04 PM

CGRetired

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Thanks, Charlie.

Mike, I will go ahead with it.

DS.

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Post #: 4

RE: PULL-PULL conversion on Sig Something Extra - 2/5/2007 5:04:09 PM

OverTheEdge

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http://www.rcuniverse.com/forum/m_5239448/tm.htm

I'm building my second SSE with pull-pull cables right now. (replacing one that I had for several years until I dumb thumbed a low knife edge pass

) Take a look at my thread and you'll see several mods that I did that you might or might not be interested in. I do recommend counter balancing the rudder... it helped my first SSE alot with rudder authority etc...
Just my .02

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RE: PULL-PULL conversion on Sig Something Extra - 2/5/2007 11:58:29 PM

CGRetired

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Thanks, Keith. I looked at your thread. Pretty impressive. A tad bit advanced for me, but I can do the rudder bit.

DS.

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Post #: 6

RE: PULL-PULL conversion on Sig Something Extra - 2/6/2007 11:37:22 AM

CGRetired

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I guess ya gotta start somewhere so I started last night. I put the spars together and looked over the kit pretty well. There were two pieces of broken balsa that I was able to mend with CA, but I may just head over to the LHS and replace them. Other than that, it looked pretty good. I can't work on it tonite, nor tomorrow night, but will get back into it on Thursday. Probably lay out the plans on my build board and start to put the wing together. I want to start when I have a couple hours to dedicate to it so that I can start something and finish it before heading for the rain locker and then rack (Navy/Coast Guard talk for the shower and the bed

).

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Post #: 7

RE: PULL-PULL conversion on Sig Something Extra - 2/7/2007 2:50:31 AM

krossk

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I did mine with pull-pull on both the rudder and elevator. Response is VERY good and there is NO slop in the control surfaces.

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RE: PULL-PULL conversion on Sig Something Extra - 2/9/2007 12:05:26 PM

CGRetired

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That looks pretty slick. I see another servo there.. Assume that's your throttle?

I was going to put the throttle closer to the front using a small servo (Hitec HS55 or Airtronics 94051Z MicroLite Servo. Don't need a lot of torque to operate a throttle, and it will fit pretty much anywhere forward of the servo tray.

I was also thinking of the elevator on pull-pull and you just made up my mind for that.

Did you consider mounting the servo's directly behind one another with the more forward one elevated by 1/4 inch blocks to put it above enough to clear? I know.. do the math... the angle does not put in differential.. or very much of it when mounted slightly off set.

Anyway, nice looking setup. Thanks for that.

DS.

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Post #: 9

RE: PULL-PULL conversion on Sig Something Extra - 2/10/2007 12:42:36 PM

krossk

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quote:

ORIGINAL: CGRetired
That looks pretty slick. I see another servo there.. Assume that's your throttle?

Yep - Throttle it is...

quote:

ORIGINAL: CGRetired
I was going to put the throttle closer to the front using a small servo (Hitec HS55 or Airtronics 94051Z MicroLite Servo. Don't need a lot of torque to operate a throttle, and it will fit pretty much anywhere forward of the servo tray.

As it turns out, the plane balanced very well - I put a full cowl and Saito.72 on the nose and a sheeted turtle deck and Sullivan Tail wheel on the rear end.

quote:

ORIGINAL: CGRetired
I was also thinking of the elevator on pull-pull and you just made up my mind for that.

I did it to mine as much just to see if I could do it. I had seen another SSE with that mod posted here a while back and felt up to the challenge. It worked out very well.

quote:

ORIGINAL: CGRetired
Did you consider mounting the servo's directly behind one another with the more forward one elevated by 1/4 inch blocks to put it above enough to clear? I know.. do the math... the angle does not put in differential.. or very much of it when mounted slightly off set.

Actually, I never gave moving the servos around any thought. I just used the stock tray and raised the elevator servo for clearance. The biggest challenge was routing the cables through the fuse formers in the tail.

quote:

ORIGINAL: CGRetired
Anyway, nice looking setup. Thanks for that.
DS.

No problem - I've got lots more pics if you need anything. Just LMK

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RE: PULL-PULL conversion on Sig Something Extra - 2/10/2007 2:41:33 PM

OverTheEdge

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quote:

ORIGINAL: krossk

As it turns out, the plane balanced very well - I put a full cowl and Saito.72 on the nose

Hi krossk.... how do you like that Saito on your SSE? Just curious as I'm putting an 82 on my new SSE that is just about finished.

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RE: PULL-PULL conversion on Sig Something Extra - 2/10/2007 7:53:18 PM

krossk

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I've only got one flight on it and it's not even close to broken in yet, but given that, I'm very pleased with it. I think the .72 is certainly adequate for any aerobatics I could throw at it right now. I can't imagine needing any more. Having said that, I've also got a barely used .82 that is going on a Tiger 60. So if I need any more power along the way, the Tiger gets a 1.00 and everything moves down a rung on the ladder. I've also got a NIB 1.50 waiting for my Sukhoi when I get it done...

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RE: PULL-PULL conversion on Sig Something Extra - 2/10/2007 10:51:42 PM

rotccapt

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From: oklahoma city, OK, USA
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i have a cowl on my saito 72 spinning an apc 13x6 on 20/20 fuel and i could not ask for more power i love it it has unlimeted vertical and also will slow down enough to land but i am going to try flaps the next time i fly to see if the landing is better.

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RE: PULL-PULL conversion on Sig Something Extra - 7/22/2008 4:20:48 AM

davidgeorge212

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From: Auburn, AL, USA
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Hi, you inspired me to go with the same setup. I have all my servos in the same way you do and I am running pull pull on both elevator and rudder. I have a couple questions though. did you notice any of the wires rubbing against each other on your plane, becuase I am pretty sure mine are. Is it ok if they do rub or should I try to separate them? I have most of my wires running as straight as I could make them going back to the tail, but as for the top elevator cable I could not get it in a straight path, did you half to curve your top elevator cable in the tail so it would line up evenly as it exited out the tail fairing block? If so, I am assuming its ok to have a curve in the pull pull set up.

Thanks, David G.

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Post #: 14

RE: PULL-PULL conversion on Sig Something Extra - 7/22/2008 11:02:11 AM