Ultimate Bipe servo question
 

I have a Goldberg Ultimate Bipe that is ready for radio installation. I have two questions you may be able to help with:

1.) What is the right aileron servo (Futaba or Futaba compatible) for a single servo setup driving 4 ailerons? I stupidly :( didn't put servos in the wings so I'm sure I need a high torque servo. Space is limited so a servo equal to the size of a S148/S3003/S3001 would be best.

2.) Do I need high torque in the rudder (pull-pull) and elevator also?

Your help is greatly appreciated!

Mike

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i highly recommend putting one servo in each wing....you still can do it. just a little surgery is all. i thought that plane called for 1 in each wing ? kit or arf?

Ultimate Bipe servo question
 

I have an Ultimate with the ASP 108 that is about nine years old. I have two aileron servos driving the four ailerons. They are JR 4031, coreless, and as I recall, 60-70 oz. inches of torque. Same servos on the rudder, and elevator. Cheap servo on throttle. Only one needed on elevator if you use a decent one.

Hope this helps you. It is a fine flying airplane.

Clair Sieverling

more info
 

It's the 60 size kit. I built it to the plans which show a single servo/bellcrank setup. when I was done I found goldberg's "secret" optional dual servo loose direction page folded and shoved into the end of directions book #2 (Goldberg's generic radio installation/set up guide). I can't blame them ... I didn't find it when I read through the directions before starting to build. Also, the quality of the kit & directions was first rate.

Looks like surgery may be the best solution though I hate to tear up the nice covering job ... I'll have to take a look at the directions & see what can be done.

I bought a Thunder Tiger Pro .61 ABC for it ... that should haul it around pretty good.

I will look for high torque servos in the range Clair suggests for rudder & elevator at a minimum. I need Futaba gear though ...

Ultimate Bipe servo question
 

I think you will be disappointed with a 60 two cycle in the plane. I would go with at least a 90.

And JR servos will work with Futaba if you can't find what you want in the Futaba line.

Clair

Ultimate Bipe servo question
 

Mike,

Go with Futaba 9202 servos on the control surfaces. This is an old (as in long-standing excellent reputation), reliable "mule" of a servo that is probably, along with the afore-mentioned JR 4131/8101 series, the best all-around class of servo for anything
less than giant-scale models.

They hold up well in 60-size helos, so a comparably-sized airplane won't cause them any strain. You can find them for around $55 a piece; JR is a bit more proud of theirs.

Modifying your wing for separate servos will involve a bit of work; but the result will be worth it, believe me. I built that kit over ten years ago, and foolishly sold it. Great model; and the ARF is sitting on the floor of my shop, waiting its turn after I finish my current project.

Just make sure your engine is broken-in and reliable. The Ultimate has the gliding characteristics of a cinder block; no problem with maintaining control as long as you keep the nose pointed down, but it is coming down right NOW. Never try to stretch a dead-stick.

If you decide NOT to modify the wing, then I would acquire a JR 4721 or 2721 servo for the wing. This bad boy has 120 or so oz./in. of torque and will handle those four ailerons with no sweat.

Steve

Ultimate Bipe servo question
 

I have the Goldberg Ultimate kit and fly it with two aileron servos in the wing and all servos are Airtronics Ball Bearing type - 94322's I think is the correct number. The engine is an OS 120 Pumped version and it flys great. Someone else in the club owned this plane and flew it with a 91 and was disappointed with performance. Other upgrades to the kit were FG Specialties wheel pants, cowl and TNT landing gear.

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i had a YS91 inverted in mine and it was awesome... :D

Ultimate Bipe servo question
 

OK. Out with the .61 and in with something else ... no problem. I have a warbird I can put the .61 in. Thanks for the heads up.

I'll check on the surgery required tonight ... if too much I'll buy a mega torque servo (>120 oz./in.)

Ultimate Bipe servo question
 

Steve--"the gliding characteristics of a cinder block"--naw, Steve, not with Monokote finish.....then they glide like a "polished rock"!

Good advice on the JR 4721 mule....JR used to show it lifting a bowling ball off the floor. I would still slice open the bottom Monokote and put a servo in each lower wing panel though.

Clair

Ultimate Bipe servo question
 

One Futaba 9202 in each wing sounds like a good idea. I will just have to open the black bag and get out the scalpel. With these higher torque servos I'll need to do more than mount to the underside of the lite ply wing skin. "Paging Dr. Mike to the E.R. stat"

Now I just have to find the right engine!

harry higley's bipes book
 

I guess you haven't seen harry higley's book on bipes. It's very good, and it focuses primarily on the goldberg ultimate. It illustrates some good improvements, including a couple of ways to mount the aileron servos.

Ultimate Bipe servo question
 

No I haven't seen that book ... too bad for me.

Looked at the x-section last night. Surgery is not going to be fun. I may try the single servo setup Futaba 9202 with a 6V up pack which should get me ~ 100 oz-in. If this doesn't seem to be enough strength then I'll cut her open.

Ultimate Bipe servo question
 

One fellow at our field encountered flutter problems with the single servo setup. I think it was accumulated wear and wouldn'd be surprised if he just had a 148 and they get sloppy at the top pretty quick. Just something to keep in mind. I don't think flutter is a particular problem if the linage is kept tight.

Ultimate Bipe servo question
 

I still have concerns with the single servo set-up on this airplane. Even if you put a real mule of a servo in the center, driving four ailerons, you are still putting a lot of stresses on the torque rods out to the lower ailerons. And they can twist, wear the bearings, loosen the bearings in the wood, etc.

You can mount your servos on a plate made of 1/16" aircraft ply which fits between two ribs in the servo bay, with only the servo arm sticking out of the airplane. Screw the plates into hard points in the four corners and you can remove the plate and the servo anytime you need to service anything. As I recall, the ribs already had lightening holes in them, so you can get the servo leads into the center of the wing by dropping a string with a weight (fishing sinker is good) through from the servo bay, and use it to pull the servo lead through. Only one rib bay would have to be uncovered this way.

Give it some thought, but good luck however you do it!

Clair Sieverling

Ultimate Bipe servo question
 

John, are you saying he had a S148 driving 4 ailerons? Yikes!

The sysyem is tight at the moment but I will keep a close eye on it. Thanks for the heads up.

Ultimate Bipe servo question
 

Here's a picture to illustrate just that. In this case I mounted the servos on the top of the wing but some mount them underneath. In that case the surgery would be out of sight.

John

Ultimate Bipe servo question
 

John, is that the plate that came with the kit? Mine is obviously already glued in & covered but that can be remedied. I would think you need ply and strong screws for the hatch or it would flex.

I'm buying 4 9202s so I'll have enough for 2 wing, elevator & rudder no matter what I decide.

Also, the .032 elevator wire that came with the kit is so wimpy. I built the pushrod per plan & installed it but I don't trust it. I'm thinking about beefier wire in the same set up or soldering on stiffeners. Any hints that may be better?

I apreciate all the help ...

Ultimate Bipe servo question
 

That's 1/16 aircraft ply and the strips are the same. There are little squares of 1/8 ply at the screw holes. It's plenty strong. Screws are #2 socket heads.

Not sure if the guy with flutter used a 148 or not. He generally uses standard servos but has some better ones too. I think it was just accumulated slop.

Good idea to stiffen the elevator linkage I think.

Ultimate Bipe servo question
 

A few Ultimates: The pink one use a YS120; the blue one ,mine, a YS91FZ (when it works!) The yellow one a Saito 150. I'm resurrecting the one shown in the servo illustration. In its first life it had an OS1.08 in it. Today I ran in a GMS120 to put in it.

Ultimate Bipe servo question
 

Good job, John.....your pictures show the system I described perfectly.

Clair Sieverling

Ultimate Bipe servo question
 

Thanks guys ... just returned from the basement fixing a hurt fin & rudder from a landing flip in my Corsair (today was a bit more windy than I like). I looked again at the Ultimate wing and think I can make the needed mods. Cutting up the covering will hurt me more than the plane.

Sweet Ultimates, John ...

Now to find an engine at a reasonable price ... got any leads?

Ultimate Bipe servo question
 

Here's a picture of my first Ultimate taken at the Halifax club field. I hadn't noticed before but the clouds are reflected in the covering. I pancaked this in a year ago due to lack of elevator authority but have it just about rebuilt now. That's the new wing in the servo illustration. I had a wimp servo on the elevator and a long battery lead with an extension. Won't go there again. The pumped OS1.08 hauled it pretty well but this time I am going with a GMS 120. I just ran in it yesterday and am quite pleased with it. It looks promising and the price of these engines can't be beat right now. This one cost me $190Cdn without a muffler (about US137).
http://www.rcuniverse.com/gallery/da...Ultimate_1.jpg

Ultimate Bipe servo question
 

Another beautiful 10-100, John. Good luck getting her flight ready. I need to visit the local hobby store to pick up my new 9C and do-dads to get mine a bit closer to flight ready. Not sure when my 9202s will show up either.

I looked for the GMS 120 but couldn't find a shop selling it near the $140 figure you mentioned. Where did you buy yours from??

Ultimate Bipe servo question
 

I got mine here:
http://www.rcwings.com/listings/engines.htm
It is shown in his engine listings at that price.

I see it advertised in the current Model Aviation Canada at $195Cdn From HobbyHobby but not on their web site
http://www.hobbyhobby.com/index1.html

The box indicated that it was distributed by Richmond R/C

That's a pretty decent price.

John