hi everyone.
i want to buy the GP UCD 3D and i need help in choosing the engine.(only 2 stroke engines)
what should i go in the ucd?
O.S 91FX
O.S 1.08 FSR (BX-1)
SUPER TIGRE 90
any recommends on the muffler?
what prop should i use? apc 15x4 or 16x4?

we got one we about to put a OS 91 heli motor in. hoping it works better there than it did in the heli. no it is not the new cspec.

i had a 108 on mine and id was way to much but it flew perfict

3d

HI TOOLY!!!

why not to buy saito 100 ???

maybe i get it in good price.

u can come to the field and to see my UCD with the saito 100.

My UCD has a ST 90. It has good power, but it also has throttling and reliability problems.......which gives you an uneasy feeling when flying near the ground.

The OS 108 is way too heavy for a UCD. It's still too nose heavy with the ST 90.

The OS 91FX has a mixed reputation in the UCD threads. Some liked it.......some cussed it.

I would suspect the OS 91 heli engine would be one of the best choices for a UCD due to the better carb, and the lack of a remote needle valve. But this is only a guess since no one around here has one yet.

I'd like to see how a Saito 100 performed in a UCD, but I'm not willing to spend $300 just to test it against my ST 90.

hi meeko.
i sent you a message in the FLYHI forum.

I have a 91 FX for sale. Includes tru-turn spinner a props. PM if interested!

well, i think i will buy the 91 fx but new.
i don't think that will want to sell it to me, i'm from israel.

91 FX all the way

what prop to use on fx91?
apc 15x4 or 16x4???
also, shat HITEC or futaba servos to use?
i want to put in my 6V pack.

I use a 14 x 6 APC on mine with a 91fx, and it pulls great. I tried a 15 x 4 W, but it was too much for the engine. It was very slow to spool up with that prop.

what servo hitec i should use?
should i use micro on throttle?

Saw one today at the field and it had an RCS 1.40 gas......Awesome! Hovered at 1/4 throttle, 2 foot take offs, and still floats like a profile fun fly.

I used the new Hitec 5475 (digital) on my ailerons and elevator. I used a Hitec 5645 on the rudder.

As for the throttle I used a small hobbico CS12MG (similar to Hitec HS81MG). The metal gear isn't really needed but I had one laying around.

The servos perform very well and they center A LOT better then the 605s I had in the UCD before.

Hope this helps.............Mark

thanks for the info mark!
the hitec digital servo are too expensive to me.
i'm planning to use my home made 6V 1800MA nimh in it.
i thought to use these:

HS-81 - throttle
HS-525MG - ailerons
HS-605BB or HS-77BB - elevator
HS-645MG - rudder

should i use 4-40 rods ?

Yes.......definately use 4-40 rods and ends. Throw all the 2-56 stuff in your spare parts drawer. Also keep the slop as little as possible on the control surfaces to reduce the chance of flutter. I used ballinks on the servo arm on all my controls.

Also the new 5475 digital servos are "value priced digitals" they're only about $5 more than the HS525MGs and $8 more than the 605BB's.

Best of luck...............Mark

tooly- where do you fly

hi
my frienf who have the flip with saito 72 fly it in rishon.

yep we know the place. we used to fly at enshemmer and hod ha sharon but now will go to the new field at ha hogen,