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-   -   U Can Do 3D (https://www.rcuniverse.com/forum/3d-flying-82/226620-u-can-do-3d.html)

jrjohn 10-26-2003 08:56 PM

RE: U Can Do 3D
 
1 Attachment(s)
how do I add a picture to my post? if one doesn't show up with this message I'll need help

Rocketman_ 10-26-2003 09:19 PM

RE: U Can Do 3D
 
cum'n thru,

THANK YOU VERY MUCH.

RC Extreme power 10-26-2003 10:08 PM

RE: U Can Do 3D
 
Cut down a g23 put in in the plane it has it's own regulator
Milton

RC Extreme power 10-26-2003 10:14 PM

RE: U Can Do 3D
 
1 Attachment(s)
Picks

FlyinBlind 10-26-2003 10:29 PM

RE: U Can Do 3D
 
Milton,
sure hope you reinforced your firewall with that G26 in the front. A friend of mine pulled his firewall out with a 120 OS. There's not much gusseting behind the firewall, so be careful when landing and / ore hitting the ground hard, or you'll pull the firewall right off.
Otherwise, it's a nice fit!
Loren

rajul 10-27-2003 12:55 AM

RE: U Can Do 3D
 
DA 100 anyone ?

AcroJo 10-27-2003 08:14 AM

RE: U Can Do 3D
 
John, Thanks for the pics. Visuals go a long way. "Share the moments"
Milton, What does that monster weigh? Its obvious you have achieved the performance level you've been looking for, but doesn't that engine remove this plane from the intended parameters of a light weight 3D machine? Great job, you will redefine the word "vertical" I would like to get my hands on that one. I didn't notice a NOS canister in the pic though.

RC Extreme power 10-27-2003 05:55 PM

RE: U Can Do 3D
 
1 Attachment(s)
The plane weighs 8lb 1oz dry. there are three more at our feild with 91 in them that weigh 7lb 9 oz dry but I only have a 8oz fuel tank. so the flying weight of mine is only about 4oz more than the others. I got the engine down to 2lb 6oz with muffler and ignition. Here is a pick with cowl installed. I have about 20 flights on it with no problems so far.

AcroJo 10-27-2003 06:23 PM

RE: U Can Do 3D
 
Milton, That sh-t is bang'n!!! I often wondered about a gasser but didn't think this airframe could handle it. Hows the performance? On a vertical up line stall does it snap more than a smaller engine? Joe

FlyinBlind 10-27-2003 06:26 PM

RE: U Can Do 3D
 
What did you do to reduce the weight of the G23? Looks like if fits fine. How's the performance on the UCD?

FB

jrjohn 10-27-2003 06:29 PM

RE: U Can Do 3D
 
anybody know the Horsepower of a G23? From what I remember they are a slug

RC Extreme power 10-27-2003 06:40 PM

RE: U Can Do 3D
 
The G23 turns a 16-8 prop at 8550, I took the flywheel and magneto off and cut the back of the engine down to the crankcase, installed CH ignition and used the stock coil. pined the firewall with dowels It will do a wall with snap out at all.
Vertical is unlimited at 1/2 throttle.
Milton

rajul 10-27-2003 07:09 PM

RE: U Can Do 3D
 

ORIGINAL: Milton

pined the firewall with dowels
Milton

Hi Milton, can you post some pics of how you did the firewall pinning ? Thx

RC Extreme power 10-27-2003 08:28 PM

RE: U Can Do 3D
 
If you look at the first pics you can see them, Drill about three 1/8 holes in the side of the fuse into the bulk head and glue in 1/8 wood dowels into them.
Milton

rajul 10-27-2003 08:42 PM

RE: U Can Do 3D
 
Hi Milton, I did the same thing on mine but I doubt it really works due to the way the firewall is attached to the fuse. The dowels are not really "locking" the firewall into the fuse. They're just touching the edge of the balsa sheeting.

RC Extreme power 10-27-2003 08:46 PM

RE: U Can Do 3D
 
I think the fuse at the bulk head is light ply but not sure.
Milton

I & C Tech 10-27-2003 09:34 PM

RE: U Can Do 3D
 
Hi guys,

I'm building my first UCD and I'm confused about engine offset. The instructions refer to an embossed line on the firewall being a center reference for engine mounting. It says this line is offset to the left side of the fuse so the spinner will be on the center-line of the fuse. Two questions..... My measurements show the embossed line to be exactly centered so what gives?? The instructions don't say a thing about offsetting the engine. Is offset built into the firewall??

Thanks in advance,
Wade

rajul 10-27-2003 11:12 PM

RE: U Can Do 3D
 
Wade, the problem with the manual (at least in my version) is that it says there is some right thrust built into the firewall. Well, mine actually had a slightly negative thrust angle ! I am using a 3 deg Ernst plate to get my right thrust, some went as far as 4 deg. If you are facing the firewall, move the mount slightly to the right to minimise the offset between the cowl opening and spinner. The offset is only cosmetic and doesn't affect flight performance

AcroJo 10-28-2003 08:29 AM

RE: U Can Do 3D
 
Wade, according to the reps at GP there is no angle built in to the firewall. They're claim is that the plane does not require any????????? They said that there is an offset in the vertical stab to compensate for this?????????? Perhaps with a small engine the reaction is less but my experience with a 100 Saito with about 3 degrees dialed in it still pulls left. Right now it has a click or two of right trim on rudder. If built stock this thing will circle the field by itself under power. I think we should invite the rep to sit in on this one. Joe

rajul 10-28-2003 08:52 AM

RE: U Can Do 3D
 

ORIGINAL: cum'n thru
They said that there is an offset in the vertical stab to compensate for this?????????? Joe
So that's the reason for the fin offset. How silly of me to think that it was a manufacturing defect:eek:

jrjohn 10-28-2003 09:03 AM

RE: U Can Do 3D
 
3 deg of right thrust worked for me, and offset your engine as far to the right as you can (as your looking at it from the front) I want a U Can Do 120 somebody build it please

John

AcroJo 10-28-2003 09:15 AM

RE: U Can Do 3D
 
Rajul, I just took the remains of one of my less fortunate UCD's off my "wall of shame" and took some measurements. With the hor. stab off, looking at the plane with the engine to the front, I measured from the outside of the fuse in to the vertical stab where its glued in. On the right its 5/16" and on the left its 3/8" that would set the vert. stab with a slight right angle. Its 1/16 off on a distance of 4 1/2" (vert. stab.) Lets here from a math wiz for the degree of angle with those specs. Joe

rajul 10-28-2003 09:31 AM

RE: U Can Do 3D
 

ORIGINAL: jrjohn

I want a U Can Do 120 somebody build it please

John
U mean : Can U Do 120 .......LOL !

Dale_L 10-28-2003 10:43 AM

RE: U Can Do 3D
 
Well Joe, if the offset is 1/16" = 0.0625" over 4.5", then .0625/4.5 = sin(offset angle). So, (offset angle) = arcsin(0.0625/4.5) = 0.8°. I don't think that this offset makes a whole heck of a lot of difference.

Dale

PS: No math wiz, just simple trig.

AcroJo 10-28-2003 12:21 PM

RE: U Can Do 3D
 
Thanks Dale, Now how does that small degree play into the mix considering its app. 60" away from the engine? I know the distance dosn't change the angle but will length add leverage?


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