Carl Goldberg Ultimate building tips needed!!!
 

Hi. I just bought Carl Goldberg Ultimate. I did the search here on RCU and found a couple of building tips. I want to set the double servos for the elevator (I am going to use Hitech 225s), but I do not see the cut offs for the servos. If you have that set up could you please post the pictures of how it should be done??? Also, I am going to use OS 120 w/ pitts muffler. Will it make it a good combo? Answers or comments will be greatly appreciated.

RE: Carl Goldberg Ultimate building tips needed!!!
 

have a look at this thread http://www.rcuniverse.com/forum/m_27...tm.htm#2798174

RE: Carl Goldberg Ultimate building tips needed!!!
 

Here's my setup, you will need to make braces for the pushrods in the fuse, you can do it all by removing the covering from the bottom of the plane. I'm using the sullivan semi-flex rods, and you need the braces to keep them from flexing, I just put a brace at every fuse former. This setup works very well and I have no slop in the linkages, you can see I moved the throttle servo forward of the stock servo mounts and used the outermost stock mounting holes for the two elevator servos.

RE: Carl Goldberg Ultimate building tips needed!!!
 

The OS should be a great combo with that plane.

Mine hovers at about 1/3 throttle with the YS.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Wow very nice and clean set up. But I was thinking to install the servos in the tail (1 servo for each half of the elevator, 1 servo on the each side of the fuselage). IMO I hope it will help me to balance the plane. I know a couple of people did that and I just want to see some pictures before I start slicing and dicing fuselage...I do not want to make wrong decision. Thanks a bunch for the replies

RE: Carl Goldberg Ultimate building tips needed!!!
 

Unless you're putting a gas engine in there (NOT advisable) the model will balance fine with one elevator servo up in the radio compartment.

I have done two of these; one an ARF, the other a kit I built over ten years ago. The kit had an OS 120, the ARF (which I still have) totes a Laser 150 when it is in commission. The model wil handle a 30-35 ounce engine/muffler combo with no balance problems.

To be brutally frank, you're just causing yourself more work with the two elevator servo idea. Its simply not necessary. The single split pushrod supplied works fine, although it does need a bit of tweaking to eliminate any differential in the elevator halves. You would need to do the same thing with two servos.

RE: Carl Goldberg Ultimate building tips needed!!!
 

I also originally wanted to mount the servos in the tail, but there wasn't enough wood to mount them, unless I added some braces to the fuse side. I didn't want to cut the covering on the sides but didn't mind the bottom.

I wasn't able to get the split pushrod to give me even deflection on both sides. I also didn't like the amount of slop and springee feeling you get with the split pushrod.

I also lost one elevator side due to flutter in my first kit built ultimate which is why I decided to come up with something better for my ARF version.

I did have to add weight to the tail, I think it ended up being less than two ounces. I think my YS 1.20 is pretty much overkill this is not meant to be a fast flying airplane, and I never usually get above 1/2 throttle unless I want to accelerate going strait up (which looks pretty cool) IF I was to do it again I would put in something smaller and lighter (engine) so I wouldn't have to add weight to the tail and I could use my throttle above 1/3-1/2.

RE: Carl Goldberg Ultimate building tips needed!!!
 

The reason most folks who have trouble with elevator differential on this type of installation is because they don't realize that a split pushrod which is not centered in the fuse at the servo automatically induces a bit of differential. The manual tells you to use one of the side slots for the elevator servo, reserving the center one for the rudder servo so the pull-pull will be centered. Assuming the elevator pushrod is even on both sides, a quick look at the geometry will show that, with a non-centered servo, one side of the split pushrod is moving farther than the other; instant differential. One can tweak and bend the pushrod to eliminate this, but it is a tedious trial-and-effect exercise. It was easier for me just to make an alternate set-up and glue that puppy in place, so i could center the elevator servo.

What I did is fabricate a bellcrank for the rudder from a DuBro h/d servo horn and two tiny bearings from my stash of heli junk, on a plywood platform. This is centered in the fuselage, driven by an off-set servo. This allows me to use the center slot for my elevator servo; the pushrod is centered and not introducing any differential. There's a photo of this floating around somewhere, in an OLD thread where this was being discussed.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Thanks a lot for the replies. As far as I understood, setting up the elevator on this plane is going to be a challenge. Well, I did not decided yet what set up I am going to use, so I guess I will make something up when I will get to it. Making the bellcrank it seems for me more complicated than two servos in the tail. Also, the reason why I want this type of set up it’s because I have Extreme Flight Yak and it has two servos in the tail and I just love it. Guys if you have a pictures of the plane with OS 120 please post it here, I will use it as a reference when I start mounting the engine and cutting cowl. Thank a bunch to all of you. :D

RE: Carl Goldberg Ultimate building tips needed!!!
 

Well, I've done it both ways. I had to fabricate a two servo elevator installation in a Goldberg Matrix when that bizarre through-the-fuselage bellcrank arrangement it comes with would not smooth up.

YMMV, but I find it difficult to see how building a simple bellcrank on a platform is more involved than cutting into the bottom of the fuselage, adding holes in the side of the fuselage, building sufficiently sturdy servo mounts, routing the servo wires, and closing it all back up with care so it looks halfway decent.

Good luck with whatever you decide to do.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Hi Steve,

That's why I like the setup I used, I used the stock servo mounting holes. (with exception of the throttle which only took two blocks) I removed the covering on the bottom of the plane where it's open and was able to fit the braces inside the fuse through the existing holes. The holes for the pushrod exits are the stock holes also. My setup only cost you the pushrods and some scrap 1/8 plywood.

I just can't see using the stock setup though.

To each his own I guess...

Take it easy..

RE: Carl Goldberg Ultimate building tips needed!!!
 

Yes, your method would be the way to do it with the least amount of fuss.

How are you matching your servos; with a Matchbox, or radio program?

RE: Carl Goldberg Ultimate building tips needed!!!
 

I've posted this elsewhere but you guys have the Ultimate too so,

Engines:
I have a new Saito 120 for a Corsair that needs the nose weight bad!
I have a buddy selling some new (discontinued) YS engines:
YS 120 (non air chamber) $250 (I'm sure the others will be close to this price)
YS 120 AC
YS 91 AC
I'm just not sure which would give me the power to do any maneuvers it's capable of without the extra weight.
I could use the Saito on the Ultimate and save the YS choice for the Corsair unless someone thinks the YS would be better for the Ultimate.
I know the best choice would be the Saito 125 or the YS 110 but they are an extra $100 or more and I would have to wait and possibly miss the "Christmas giving spirit" ;)

Covering:
I know I can do a great job with typical covering but I was thinking about painting it because of the endless possibilities and the ease of painting. I would rather mask and paint than cut and iron.

Guys, and maybe gals, could you post some more of your plane pictures. I thought about mounting the engine out of the bottom of the cowl but that would destroy the looks more than out the side but man would it stay cool.

Thanks, Tim.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Cam, which YS are you using. Having unlimited vertical would convince me that I had enough power! :)

RE: Carl Goldberg Ultimate building tips needed!!!
 

I was using the YS120 SF the first and least powerful version I'm told, although mine does have a newer head on it. (I have since sold the plane, going BIGGER!)
I was swingin an APC 16x6 and was hovering around 1/3 throttle.
You could accelerate strait up out of a hover and accelerate on any vertical line whenever you wanted, vertical was definately unlimited.
Any of the YS 120's (and 110's) would give you at least this much power.

I like the idea of mounting the enigne inverted.

I was using a the raido to match the two elevator servos, it worked fine and I didn't want to spend the $$ on the matchboxes.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Agreed, an inverted mount is best cosmetically for this airplane. Both of mine were/are side-mounts, because I'm basically lazy... and the Laser's carb would be too low to work without a pump or regulator.

IMO, an OS 1.20 four stroke is just the right amount of power for the CG Ultimate (my Laser 150 approximates this power level). YS are a lot stronger; I had an old 120N in a GP Super Aeromaster that was absolutely insane on 30% heli fuel.

Given your choices, I would grab the non-air chamber version (its probably a 120N). Its the only YS I have owned that didn't eventually give me problems. While it may not be quite as strong as the AC, it is a solid brute of an engine.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Ya know now that I'm thinking about it, unless you like flying below half throttle the whole time you may want to consider something a little smaller. I was talking to a guy at the field the other day and really with an overpowered plane you have to make the whole flight using only half the throw on the throttle stick. I find it kind of annoying to be honest, I like having a plane that if you want you can use full throttle and now worry about the wings comming apart. I've noticed I have more fun with planes I use the entire throttle range than ones I'm flying 1/2 and below the whole time.

RE: Carl Goldberg Ultimate building tips needed!!!
 

Steve I agree if I went with the non Air Chambered it would have less parts. What is the air chamber on the back, if they all use the crank for "supercharging"?
I think I'll use the YS for the Corsair because we had to add 3 oz of weight to my brothers just to balance it with the OS 120 fs!!! That way I can use the Saito in the Ultimate and maybe mount the servos in the back.

Cam, on a side note, I have a friend with two Camero SS. One is a '69 and one is a bit older...I love them, they are both stock but one is under a tree in bad shape...NO, SHE DOESN'T WANT TO GET RID OF THEM hehehe. Anyway, I fly mostly warbirds with big engines so I am use to flying at low throttle most of the time for scale looks so it doesn't bother me. My pet peeve is adding balast when you don't have to. But isn't it nice when someone jumps on the field without telling you and all of the sudden he's taking off and you can just pull up and go vertical, man, that just gives me goose bumps :). Besides, I want something I can "wring out" and not fly scale all the time.:D

Thanks guys, I'll try some post about the paint issue in some other fuorums . If someone has some inverted engine installations I would like to see them.