I'd go with the 91!!!

Northwing.... IMO I would go with the 91 even with the added 6 to 8oz
between the two. I just like 4c's in these types of planes... And it
should balance ok by just moving the onboard equip. around.... But
with the 8oz tank you have to watch your flight times:-))

northwing, you will love the 91 in your ucando, just remember not to over speed the air frame. You will have plenty of power for any 3d move that you can think of. I have a 70 magnum 4s in mine and it works great. Just the right amount of power to get me out of trouble and plenty to get me into trouble.

Hey Ron,i dont use push pins, i just cant imagine the hinges with 30 min epoxy being pulled out without a chunk of wood with it, if you get my drift! (your in a world of hurt if they do)[X(]. but like everyone else will say:a little extra insurance wont hurt, but i have enough insurance alreadyso i guess ill be the Huckelberry!!

KAOS,good job,cant wait to get mine up!

NORTHWING, id go with the one that you feel is the most reliable runner first and then if its not the 91 it would be.good luck![sm=thumbup.gif]

The airframe appears to be very straight and the engine mount has a very obvious right offset to it. The left yaw I saw today could possibly have been due to wind. I guess one 5-minute flight isn't enough to get it fine tuned, but I'm sure happy so far!

Kaos

The 91 it is guys. Thanks for the input

Well, I wimped out and installed the CA hinges. I checked my stash of pinned hinges and only had a few and at the LHS they don't have a very good selection sometimes so the CA type will have to do. But I did make them better. I took Raideron's advice and used a crayon to mark the center but also instead of making them 3/4" wide like the directions said I made them 1" wide so being about 25% wider they'll be stronger.

The left yaw may simply be due to to little right thrust if you have a big motor. My uplines and hover had a definite left-limp until I added a 3 or 4 shims to increase the R-thrust on my OS 91 FS.
With a 15x4w prop it's a real killer. Have to tune a good low idle, otherwise it can't stay still on the pavement. I used the CA hinges. Very good instructions in the UCD manual. I pinned the hingeswith toothpicks for extra safety.

bjorngl... Hi, Some club members also used toothpicks for added
security. If I ever get to fixing my Yak with pinned hinges I'll
use push pins they go in eaiser:-) Then if the hinge still wants to
come out it has to take the whole section of the stab.. :-)

How's the weather in Iceland?? I spent a few months there on a
navy base watching Bear bombers flying down the strait, it was
cold and mostly dark while I was there... But it was good:-)

Raideron... If you don't like the weather in Iceland, just wait a few minutes, it will change :-)
You must have had some bad luck being stationed here during the "indoor period".
It's never cold in Iceland. If the outside air is too cold or wet we just go indoors and if we need more warmth we go to the nearest swimming pool. There's one within every few miles and they are warm and nice all year round thanks to geothermal energy.

They've always rotated the flight crews (fighter squadrons ?) every few months. That's really a pitty 'cause Iceland is really a nice place when you get outside the barren Keflavik area.
Most of the ground personel at the base stay for a year or two (?) and a very high percentage opt for an extra year. The Keflavik base is said to be one of the best and most popular posts outside the US homeland.
The big USSR Bear Bombers that regularly made an appearance over Iceland are no more. The base here is becoming obsolete after the fall of the USSR and the F18's are here only for the appearances nowadays.

Cheers
Björn

well the brown truck arrived and left me a near perfect ucd 46, will need minimal ironing. have the 60-120 motor mount installed for my saito 100. Have the pinned hinges installed in the control surfaces and letting dry untill tomorrow and will then install into wing and stabs.thats about it, will post some pics tomorrow

Happy Camper

Gjeffers, Glad you got your package. I like to see the pics. if you get a chance to post them.

Rob

I do love it when the Brown Truck arrives. And the FedEx truck. And the FedUp Truck...

Kaos

Yes, the UPS / FEDEX guys are far more popular than in-laws.

bjorngl... That's what most the people said about Iceland, I must admit I
found that hard to believe after the water lines froze in the hangar:-(..
I was just a "grunt" Hyd./pheumatic repair airman... We kept the "Old"
C-121.. "Connie radar planes" in the air watching the strait, Once the Bears
were picked up we would radio in and the Navy would send out the fighters
(F-102), Then the picture taking started... I guess from the planes above,
You can tell I'm an old fart:-) When I saw your location, It just got me
thinking of the "fun" times we had there.. Even tho I barely saw Day light..
Hey on your UCD/91 did you just move equip. around in the plane for your
CG or did you have to add weight??


gjeffers... Well alright!!!, sounds like your moving along really good, And she
should be in the air soon!!!..... I like it when one of those trucks arrive, I
got close to ordering something, But I'm still not sure what???? But I have
been keeping track of that Showtime plane.... I may get on the list.....

I feel stupid asking this, but how do you plumb a 4 stroke engine? Im used to 2 stroke engines, and dont know where the third line goes on the 4 stroke engine. But anywho i hopefully will have my .91 installed and ill try to fly it by next week!

Colin C

ps. Is a 14x4 a good enough prop for this plane/engine? I used a 11x7 on my .46 when it was in the nose...

Preditor, if your talking about the nipple off the crank cover, it just goes to atmosphere, at least 4"long will do!
going to build now will post pics later!

predator500.. The 14X4W is a good prop for a 91. I have a Mag 91 4c
and I run the 14X4W with good results for me:-).. My Mag will spin a
bigger prop, But spool up time lags for me, And my engine vibrates
more and always loosen my pipe/muffler with bigger props... But
most 91's should turn a 15X4W pretty good IMO... The --X6 should be
good also, But I love the "W" props for what I'm doing... Or trying too

Raideron...
F102's that's a while back :-)
You should really try to come during late july or august. You seem to have missed a lot of what Iceland has to offer.

No I did not have to add weight or mess around with the balance, it was perfect from the start. My engine is the OS.91 with a pump and the battery sits above the wing, appr. on the CG or just in front of it. The CG seems fine at 5 3/4 or so. JR DS-811 servo's all around except for a JR 8231 on rudder.
This OS is happy with the 15x4w prop and it seems to be a very good setup for the kind of flying that fits the UCD best, i.e. leisurely 3D at a docile "walking pace". I seldom throttle it over 3/4 except for quick recoveries or uplines. Haven't tested other props really. This engine is real nice, only one flame out during a gallon's worth of flying time(more time than one would expect dure to the sparse use of throttle) I have not bought an un-pumped engine since then. I got hold of a couple of YS now and fired up the .63 yesterday. It's awesome. Can't wait to test the 1.10 that's going into a 62" Edge.

The undercarriage block on the UCD separated from the fuse on the first or second harrier landing, which turned out to be necessary to get the right amount of glue in there and fix the missing pins which don't go all the way through to the front bulkhead like they should. I also broke the fuse once by hiting the ground lightly with a wing tip. The wing was unscathed but the force on the wing made the fuse separate completely behind the cockpit. Quite simple to repair and the resulting, minute extra right thrust seems to have had a good effect on the flying characteristics really :-D

I use about 30° spoilerons for impressive, rock steady harriers and elevators. Can't do rolling maneuvers myself but my 16 yr old is a wizard at it. He does not like the UCD because of the unstable knife edge but he is too skilled for his own good
I love to fool around with this plane and impress the old geezers with what little amateur 3D I can perform.

Cheers.

Björn

well ive just finished installing all my controll surfaces with pinned hinges and did a little iorning, really gonna turn out nice i think.
the picks below are the inside of the firewall after i plugged the old mount holes(the dark spots on the inside of the firewall are the plugged mount holes) and drilled and re-blindnutted for the larger mount for my 100,turned out to be pretty easy using my homemade blindnut installer tool(piece of 8-32 allthread with a nut and large washer to pull the nuts into the wood).im also going to a 11oz h9 fuel tank which fits perfect and i would reccomend(no fabbing required).
will post a couple pics tomorrow.
I need to take a nap nowwwww Gluuuuue Gooooooooood

bjorngl.... Yeah they are ancient(102's, Me)...

Hey thanks for the UCD/91 info.. I have been throwing around putting my
Mag 91 in mine... Which just may happen after today... My used YS 63 was
really down on power this morning I could not hold a hover, but kept tail
sliding.. Nice when you want to do it, But not so good while at full throttle:-(
Anyway going to check all out and readjust the valves and see how that
goes before I see what I'll do... It would have to happen now.. Wanted to
fly it for our upcoming Fly-in on the 30th:-(
Thanks again and have a Great day!!

gjeffers... Looking good!!... You wouldn't have a # on that tank??

gjeffers, Looks like you were able to take the "ramp" out to do the mods. Did that work out good for you?

Hey Ron, here is where to get the tank,or at least the # if you want to order it somwhere else
http://h1069991.hobbyshopnow.com/ser...=NOPRODUCTPAGE

CeeGee
i didnt have to remove the ramp, i really have a smooth runway so i didnt want to get to involved, enough to do already. believe it or not, i have a camera phone and the phone fit down in the fuse and took that pic, amazed me too thats why it takes me a day later to get pics posted because i have no phone service here at the house and have to go to work to send the pics to verizon and then retrieve them with my pc when i get home,whew a lot of work but you guys are worth it

im just finished getting all my carbon fiber push rods done and waiting for them to dry, also that belly pan fit like crap but its drying also.i ll have more pics tomorrow, the ones i took last night are nothing special, might post them later here tonight.

later

I think I'm going to handle the left yaw just like they do with full-size single engine aircraft and that's just dial in a little right rudder trim. I think my RD 8000 will allow some right rudder mix slaved to the throttle. And/or, keep my left thumb dancing as I change power settings.

I own on older Piper aircraft and not only does the engine have some right thrust and a little down thrust built into the engine mount, it also has some permanent, designed-in right yaw twist in the vertical stabilzer. During a full-throttle takeoff and climb, some additional right rudder input is still required to counter the torque induced left yaw tendency. The left yaw tendency becomes more noticeable as airspeed decreases. Full throttle in level flight at low altitudes actually requires a touch of left rudder to keep the ball centered (yaw indicator). During normal cruise (75% power or so) things seem to even out and the airplane flies straight, hands and feet off the controls.

Kaos

Thanks for the tank info Gary!! I may make the switch if I do
switch to my Mag 91... I'll find out tomorrow or on friday when
I go to the field.. I made my valve adjustments changed some
fuel lines and the plug... We'll see if that helped...
You seem to be moving right along on your build, Should be in
the air soon... Great work!!