Tommygun

My Feedback: (2)

I bought a Cermark F20 at a swap meet, built, and I have a couple of questions....

-Where is the CG located?

-How much should it weigh? This model weighs 4.5lbs minus engine and radio, retracts installed. Is that acceptable?

Flyboy Dave

My Feedback: (21)

A direct quote from the manual:

The optimuum CG is 4 1/2" from the leading edge at the start of the wing saddle.
Do not attempt to fly your F-20 if the CG is behind this point-the model will be
"tail heavy" and unstable. Measure the CG with the tank empty. A little nose
heavy is fine.
________________________________________________
Mine doesn't have retracts, so I can't say much to the weight of yours. As a
side note....I put a 600 ma flat battery pack up against the rear-most bulkhead
in the tail of mine for the balance.

What motor are you putting in yours ? Mine has the Rossi .45.

Dave.

Tommygun

My Feedback: (2)

I'm putting a YS .45 2 stroke side exhaust in mine. Hopefully it still works; I put one of these things in the dirt a few years back and the engine was completely buried in the ground. How much does your F20 weigh?

Flyboy Dave

My Feedback: (21)

....6 pounds ,1 ounce.... all up....no fuel. (pretty light)

Dave.

vicman

My Feedback: (10)

Sounds hot to me Like FBD I didn't have retracts on mine but it was a lot of fun!

Razor-RCU

My Feedback: (50)

Oooooooo..... YS-45? Great choice! Gonna use a Macs 7.5CC pipe?

Should be a VERY impressive combo..

Keep us posted!

Flyboy Dave

My Feedback: (21)

The side piped YS, with a proper tuned pipe should be a real winner. [sm=thumbup.gif]

Tommygun

My Feedback: (2)

Yeah, I had this combo before and that .45 really makes the F20 scream. Not sure what pipe it has; it's made by Mac. I was doing low, full throttle passes and came in about 5 feet over a line of trees. Then I noticed the plane wasn't responding. I thought it was interference at first, but then noticed the entire right wing was missing! Apparently it was sheared off at the root when I hit a small branch with no leaves. Needless to say, the plane was demolished. Never did find that wing either. Unfortunately, I don't remember any of the CG or weight info. For some reason I thought it was lighter than this one I picked up. Thanks for any input about the F20.

raven_1978

i recently bought an f20 and have an os 40 fx max...will this engine power this bird or will it not suffice?
BTW it is a 40 size ARF that has been prebuilt and flown

Flyboy Dave

My Feedback: (21)

It will do OK with the OS .40 for now....[sm=thumbup.gif]

I have one with a Master Airscrew 9-7 that turns 16,200.

I have an F-20 too, with a Rossi .45 long pipe.

FBD.

DeadAccount237939

guys, there were two version of the f-20, the .40 and .60 size. the .40 had fixed gear and was/is considerably smaller. a .40 will not fly the .60 size, assuming you could even get it in on the mounting rails. a piped ys .45 i think would fly the .60 well. I wrote the manual for the .60...seems like a long time ago!! the .60 was always my favorite, smooth and a pleasure to just rip around the sky with.

Paul

flyingmachine

My Feedback: (9)

Hi how long is the header? and what prop?


rich

raven_1978

is there anything i should be aware of with this aircraft and the os 40 (10x6 master airscrew prop and stock exhaust)....i guess what im trying to say is are there any maneuvers that i should NOT attempt with the os 40...attitudes i should not be in

vicman

My Feedback: (10)

It aint for 3D. Go fast, pull up, invert, pull out, level off 2' off the deck and do it again[>:] You will be hooked! Don't try to turn slow and banked she will drop fast. In level flight slow will work on landing.

raven_1978

Has anyone tried using flaperons with this jet and if so how well does it work?

bob27s

My Feedback: (19)

The plane looks good

Start off with the 10x6. Good choice. After some time, try a 9x6 or 9x7. Let the engine turn up a bit.

I'd suggest against flapperons. Not really needed, and you actually want to keep the speed up just a bit on landing with this.

As noted above, keep the speed (throttle) up in the turns. It bleeds energy fairly easily. On take off, let it climb out straight... get some altitude and speed before turning - and make that first turn gently.

other than that....... those giant split-S passes over the deck are a blast

raven_1978

Thanx for all the input guys i really appreciate the info and help...i am just waiting on some radio gear from eBay and then after my maiden flight i will post the results

cheerz EH !

Raven