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-   -   U CAN DO 3D??? (https://www.rcuniverse.com/forum/3d-flying-82/8687650-u-can-do-3d.html)

Moki 1.8 04-16-2009 04:14 PM

U CAN DO 3D???
 
Guys I picked up a 40 size u can do, it has a saito .72 on the front and just some standard ball bearing servos in it. But I am having what heck off a problem, I cant seem to get it to balance. It's so tail heavy!!!!!!! Man have any off you guys had problems trying to get it balanced properly? I know what im doing, im folowing the manual, by there recomended cg. For it to balance, I have to add so much weight!! Fill me in guys.

Thanks,
Robert

Oh, and yes, I have the rx and battery all the way to the front.

gjeffers 04-16-2009 06:14 PM

RE: U CAN DO 3D???
 
what are you balanced at? you can go as far as 5.5 inches aft, and 6 inches if your a good pilot.

Uncas 04-16-2009 08:34 PM

RE: U CAN DO 3D???
 
I had one with an OS-50SX-H engine in it, which is a few ounces lighter than the Saito and still added weight to the tail. Have you flown it yet? Does it fly tail heavy or are you just worried about CoG before your first flight. If so just add some weight to the nose and graduallly remove it as you get comfortable with it. This plane is very gentle and predictable, it is a real floater.

rclement 04-17-2009 11:08 AM

RE: U CAN DO 3D???
 
Yeah, 5.5" is a good starting point. I bet you have the instructions without the new CG addendum in them. ??

Moki 1.8 04-17-2009 09:09 PM

RE: U CAN DO 3D???
 
guys im at 4 3/4 like the manual says. its crazy how tail heavy it is.

saintcreed 05-18-2009 10:52 PM

RE: U CAN DO 3D???
 


Moki 1.8</p>

You're on of the first that I've heard of that has come out that tail heavy....I'm on my 4th one and to get the cg back to 5.25" and more I've had too add weight to the tail...only weight I've got in front of the leading edge of the wing is the gas tank and engine...then my rx, throttle servo and then the battery...and like stated above...take the cg back to at least 5" and then proceed back from there as you get use too the plane...you'll find yourself back to almost 6" and maybe even 6+"....It'll fly great and is very forgiving....only dumb thumbs can wreck one of these planes, can land at a slow walk..it's a real floater....5mph head wind and you can elevator in for a landing..</p>

dmurf 05-19-2009 05:31 AM

RE: U CAN DO 3D???
 
Moki I just got one {46 size} 2 weeks ago and have it assembled with a YS 63s and futaba 3152 servo's all round. I had to put the battery up under the fuel tank to get it to balance at 5". The manual had a amended sheet of paper included which said that the plane could be balanced between 4" and 6" from the leading edge.

Hopes this helps

Damien

rlipsett 05-19-2009 10:56 AM

RE: U CAN DO 3D???
 
moki people have the cg further back then you do.  if you move the point back to the 5.25 or 5.5 like some people are saying the weight you need in the back will be decreased

Sierra11861 11-03-2009 03:54 PM

RE: U CAN DO 3D???
 
I have the 60 U CAN DO with a YS FZ-110 and I love it. I want to get the 40 size for my son. I was thinking of putting a OS 55 AX in the 40 U-can-do. Can anyone out there give me an idea if this is too much engine or any advise on this combination or a similar 2-cycle engine you may have to the OS 55 AX and how it performs in the U can do 40?

Uncas 11-06-2009 11:07 PM

RE: U CAN DO 3D???
 
I had an OS-50 heli engine in mine and was not satisfied with the power. The 55 might be enough but I would go with an OS-75 or bigger. Something that would turn a 13 - 14 inch prop easily. The Saito 82 might be ideal. BTW it is a UCD-46 not 40.

Sierra11861 11-08-2009 09:52 PM

RE: U CAN DO 3D???
 
How bout the .61FX?

rclement 11-09-2009 08:30 AM

RE: U CAN DO 3D???
 
I've had 4 of the 46 Do's and a Saito 82 is perfect for it.

Lightspeed1551 09-08-2010 01:51 PM

RE: U CAN DO 3D???
 
TO:Moki 1.8

<span style="font-family: Arial; font-size: 9pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">You are trying to balance the plane upside down right?I have a .60 size with a Saito 100, and it balanced just a hair nose heavy with the battery pack just aft of the main wing spar. I worked out the fine balance with1/4 ounce sticky weights after fling it a couple of times.</span>

ameyam 09-09-2010 03:14 AM

RE: U CAN DO 3D???
 
Moki,

get the latest manual from the Tower website in softcopy and have a look at the CG.

Sierra11861,

the 61FX is too heavy for the power. Instead, get the 75AX...its more powerful and almost same weight. Or if you have the money go for a FS-91SII. This is actually lighter than the 75AX and since the UCD required inverted installation (I think) its more suitable. And it has plenty of power for the UCD 46. Just note that the UCD will flutter if you fly too fast so be conservative with the throttle.

I dont have the UCD but a Phoenix Models equivalent called Topstar 60. I tried without much luck with the inverted 75AX. Then I installed a FS-91 and lowered the tank. Since then its much better

Ameyam

rclement 09-09-2010 07:25 AM

RE: U CAN DO 3D???
 
It's too bad they quit making the Hangar 9 Frenzy, I like it much better than the 46 and 60 Do's. [&o]

molokaiboy 09-10-2010 01:23 AM

RE: U CAN DO 3D???
 
<span style="font-size: small">Irecently gota UCD .46. Installed some HS 475 HB's and a S3010, 6A BECwith2 s 2000 lipo,running a OS55AX w/ pitts style muffler and a 13X4 MASK-series prop. One of the pipes came off the pitts style muffler so Ijust covered it up temporarily to see if it would work, but Ithink it has way too much back pressure as it doesn't run the same.Ihad it mounted sideways withthat muffler. Iwill be putting the stock 55AXmuffler andsee whathappens. Ihave just put on the stock mufflerand mounted the 55 upright, see if it makes a difference.

Anyway back to my thoughts on the 55AX in this UCD. Ibelieve if your just going to do sportflying it has lots of power for it.It gets kind of windy where Ifly, and Ihave difficulty locking it into a nice stable hover without it climbing or sinking. The mid range on this 55 hasproven alittle difficult to tune being it hasonly 2 needles.

There isanother club member whereIfly and he has anOS91FX and a 16x4 prop. More than enough power but then gain he doesn't do much 3d, more sport aerobatics.Being able touse a bigger prop with the 91 gets theairframe moving quicker.

My current set up has me balanced at 5.5" with just 1 3/4 oz of lead on the firewall. Inverted requires almost no input on the elevator to keep her level. Plane is reponsive yet stable, slows to a crawl, you can pretty much land anywhere you want. She lands like a helicopter hehehehe. I'll try different CG's and see which ine Ilike better.

Iam leaning to a 70-80 size 4 stroke. Ithink the ability of swinging bigger props at a lower rpm will make 3d flight better than a 2 stroke on my UCD .46. I've been flying smaller electric 3d planes, and have gotten quite used to the way electrics fly. Imay convert this sucker to electric yet.

This plane is just a blast to fly in any wind conditions. Stable and responsive, landing is fun, it just crawls in. The amount of fun you can have for this price is unbeatable.

Aloha,
Les
</span>

rclement 09-10-2010 07:23 AM

RE: U CAN DO 3D???
 


ORIGINAL: molokaiboy

<span style=''font-size: small''>I recently got a UCD .46. Installed some HS 475 HB's and a S3010, 6A BEC with 2 s 2000 lipo, running a OS55AX w/ pitts style muffler and a 13X4 MAS K-series prop. One of the pipes came off the pitts style muffler so I just covered it up temporarily to see if it would work, but I think it has way too much back pressure as it doesn't run the same. I had it mounted sideways with that muffler. I will be putting the stock 55AX muffler and see what happens. I have just put on the stock muffler and mounted the 55 upright, see if it makes a difference.

Anyway back to my thoughts on the 55AX in this UCD. I believe if your just going to do sport flying it has lots of power for it. It gets kind of windy where I fly, and I have difficulty locking it into a nice stable hover without it climbing or sinking. The mid range on this 55 has proven a little difficult to tune being it has only 2 needles.

There is another club member where I fly and he has an OS91FX and a 16x4 prop. More than enough power but then gain he doesn't do much 3d, more sport aerobatics.Being able to use a bigger prop with the 91 gets the airframe moving quicker.

My current set up has me balanced at 5.5'' with just 1 3/4 oz of lead on the firewall. Inverted requires almost no input on the elevator to keep her level. Plane is reponsive yet stable, slows to a crawl, you can pretty much land anywhere you want. She lands like a helicopter hehehehe. I'll try different CG's and see which ine I like better.

I am leaning to a 70-80 size 4 stroke. I think the ability of swinging bigger props at a lower rpm will make 3d flight better than a 2 stroke on my UCD .46. I've been flying smaller electric 3d planes, and have gotten quite used to the way electrics fly. I may convert this sucker to electric yet.

This plane is just a blast to fly in any wind conditions. Stable and responsive, landing is fun, it just crawls in. The amount of fun you can have for this price is unbeatable.

Aloha,
Les
</span>
If you can get a Saito 82 for it you'll find that to be an excellant combo. You can swing a 14 x 4 w apc prop with it and it's a perfect set up.

molokaiboy 09-10-2010 11:43 AM

RE: U CAN DO 3D???
 
<span style="font-size: small">

If you can get a Saito 82 for it you'll find that to be an excellant combo. You can swing a 14 x 4 w apc prop with it and it's a perfect set up.
Yes, Ihave been reading that the Saito 82 is the ticket for the UCD .46. My wife is due in December so Iam trying to keep my spending to a minimum as far as flying is concerned. I'll just keep scanning the classifieds and hopefully Ican get a great deal on a Saito 82.

Fellow club member have given me stuff they don't use so Ihave been finding affordable means of using them, while keeping my spending to a minimum atleast till after my daughter is born.

Thanks for the tip.

Aloha,
Les</span>

AKFireMedic 09-12-2010 02:47 AM

RE: U CAN DO 3D???
 
They are correct. I have the 82 in my do and it is a perfect combo. Honestly, the do is one of the best sport flying planes I have ever flown. It tracks well and is neutral inverted and upright. It really makes for a crappy 3d trainer and doesn't knife edge for garbage but its a great sport plane. I'm currently putting mine on floats and I think it'll be great like that!

molokaiboy 09-12-2010 04:58 AM

RE: U CAN DO 3D???
 
<span style="font-size: small">

It really makes for a crappy 3d trainer and doesn't knife edge for garbage but its a great sport plane.
Well Ibought this plane as my first glo fuel model. It has handled well in the windy conditions that frequently plague our field. It is a very stable model and you can pretty much spot land it anywhere you desire. Rolls are quick, and when you pull back hard on the elevator this sucker just snaps up to a verticalattitude almost instantly.
Iam still messing with this plane to find the right combo for me. It doesn't do KEthat well like AKsays. Ilike being able to do slow KE and Ican't with this model. Even at speed Ihave noticed it doesn't KEas well as Iwould like.
Nonetheless this model is absolutely a joy to fly especially in the windy conditions Iencounter.
Iput a OS91 FX in it and a 16x4APC. Power is unbelievable now, vertical climbs with ease. Had to put some weight on the tail to get it ballance it back on my 5.5 CG. Stilltweaking my 91 as it isstill on the rich side.Imay try a 14x6 APC and see how that flies. Iwill also be trying different CG's. Imay go to a 6" CG and see what happens.

Les</span>

rclement 09-13-2010 08:32 AM

RE: U CAN DO 3D???
 


ORIGINAL: molokaiboy

<span style=''font-size: small''>

It really makes for a crappy 3d trainer and doesn't knife edge for garbage but its a great sport plane.
Well I bought this plane as my first glo fuel model. It has handled well in the windy conditions that frequently plague our field. It is a very stable model and you can pretty much spot land it anywhere you desire. Rolls are quick, and when you pull back hard on the elevator this sucker just snaps up to a vertical attitude almost instantly.
I am still messing with this plane to find the right combo for me. It doesn't do KE that well like AK says. I like being able to do slow KE and I can't with this model. Even at speed I have noticed it doesn't KE as well as I would like.
Nonetheless this model is absolutely a joy to fly especially in the windy conditions I encounter.
I put a OS91 FX in it and a 16x4 APC. Power is unbelievable now, vertical climbs with ease. Had to put some weight on the tail to get it ballance it back on my 5.5 CG. Still tweaking my 91 as it is still on the rich side. I may try a 14x6 APC and see how that flies. I will also be trying different CG's. I may go to a 6'' CG and see what happens.

Les</span>
Keep an eye on the tail feather CA hinges, they tend to break after a while. I've had to replace them a few times. For anyone just building one, it's best to put more CA hinges in than what came with it or just use pinned hinges or robarts.

Jason 3-Danhakl 09-16-2010 02:26 PM

RE: U CAN DO 3D???
 
1 Attachment(s)
Listening to you guys a person would think the .46 needs a .95 two stroke, balanced on the LE of the wing and for some reason they won't Knife Edge.

Funny mine Knife Edges very well and flies on a .50 two stroke. Its CG is at 6" back from the LE. These airplanes fly awesome but you do have to watch the

weight. The model in the pictures weighs 6 lbs 3 oz.

rclement 09-16-2010 08:22 PM

RE: U CAN DO 3D???
 

ORIGINAL: Jason 3-Danhakl

Listening to you guys a person would think the .46 needs a .95 two stroke, balanced on the LE of the wing and for some reason they won't Knife Edge.

Funny mine Knife Edges very well and flies on a .50 two stroke. Its CG is at 6'' back from the LE. These airplanes fly awesome but you do have to watch the

weight. The model in the pictures weighs 6 lbs 3 oz.
No, the 46 doesn't need a 95 two stroke and I'm sure it flies fine on the 50. I don't use a two stroke on a plane if I don't have to, I like four strokes myself and the 82 is perfect for it. I haven't tried the plane with a 72, probably works fine. But I'd rather spend a little more $ and invest in the 82's and have more power for the same size. It's all just personal opinion and experience. [8D]

molokaiboy 09-17-2010 12:13 AM

RE: U CAN DO 3D???
 


<span style="font-size: small"><span style="font-size: small">Well mines will fly great with my 55AX, but most of the time the field Ifly at can bevery windy and so Ilike to have a little more power just for my sake. Ican knife edge this plane with my 55 and 91 but Iam trying to do some high alpha KEbut Iam having a hard time as it seems to want to fall out of the sky. I may have to move my CG to 6" or more as right now Iam at 5.5 inches.

Iam still trying different things to get this model to fly the way Ilike. This is my first glo fuel airplane, and I've always flown smaller 3d electrics and helicopters. So it will take some getting used to and Iwill just keep messing with different set ups. Imust say this plane does fly well and forthepriceof this ARF is a great value too.

Imay just swap out the glo fuel for an electric set up.

Aloha,
Les</span></span></p>


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