Cermark F-20 ARF Winter Project question
09-02-2002, 01:01 PM
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Cermark F-20 ARF Winter Project question
If you had a Cermark F-20 60 size and wanted to make a winter project of it. Would you strip the covering, glass the whole plane and put a JETT 90L engine on it. And Robart #604 pneumatic gear under it? Use Hitec 605's for the Rudder and Elevator. JR High Torque Low Profile for Ailerons. Does this sound like I'm on the right track so far? 
09-02-2002, 11:25 PM
#2
Cermark F-20 ARF Winter Project question
Here is mine about a month ago. It is now about 95% done. Just need to install the receiver, hook stuff up and adjust. It is also home to the Jett .90L. As far as retracts. I have always had good luck with simple Hobbico Mechanicals in my Warbirds. These greenies seem to be clones and seem to work well so far on the bench. I am going with them. I recovered only because I did not like the red scheme. I also glassed the entire inside of the engine area and the inside of the main wheel mounts. If you glass the whole plane you will have to paint and that will rack up some weight. Recovering was no problem. One thing I did not do which may be a plus which either "Airgar or Flyboy " did was to shorten the alierons. I have no regrets on this plane unlike the GSP P-51 I have. Later 
09-04-2002, 11:49 PM
#4
No need to glass and paint......
......too much weight, and too much work. 
I would say go for it, if the structure was weak, but it's plenty strong.
BTW, Cyclic....the aileron mod cured the flutter....and I covered the seams on the wing. My torque rods seemed "soft", and I wonder now if just doing the seams would have cured it.
But i had my mind made up....
Next one will have aileron servos in the wings, and smaller than stock ailerons. Got the Robarts this week, and they sent the darn 85 degree ones...shoot-poop-heckydarn !!!! I have to check and see if theres enough dihedral to get by with them. Your gonna hate those stock retracts .....
I think I have a big-block Rossi .90 comin' , with a Macs long tuned pipe ...heh heh heh. ( the ol' man is gonna try and show them wippersnappers a thing or two ). :stupid:
I would say go for it, if the structure was weak, but it's plenty strong.
BTW, Cyclic....the aileron mod cured the flutter....and I covered the seams on the wing. My torque rods seemed "soft", and I wonder now if just doing the seams would have cured it.
But i had my mind made up....
Next one will have aileron servos in the wings, and smaller than stock ailerons. Got the Robarts this week, and they sent the darn 85 degree ones...shoot-poop-heckydarn !!!! I have to check and see if theres enough dihedral to get by with them. Your gonna hate those stock retracts .....
I think I have a big-block Rossi .90 comin' , with a Macs long tuned pipe ...heh heh heh. ( the ol' man is gonna try and show them wippersnappers a thing or two ). :stupid:
09-05-2002, 12:41 AM
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Big Block Rossi 90..
I got a few of the big block RIRE Rossi 90's..they are studs. I won't get into a brand war, but they will turn better than the posted Jett 90 R's on the Jett website...but I was using the "aluminum baseball bat" Rossi 90 pipe..just parted the muffler portion off the end LOL
I really want to mount one in a plane...my test stand will only fast taxi with these on it
I really want to mount one in a plane...my test stand will only fast taxi with these on it
09-05-2002, 01:26 AM
#6
I hear ya'....
I don't want to start a brand war either....I just wanna smoke my buddy Gary's jett .90 butt off....heh heh heh....this one is justa' front intake, side exhaust one....with a Macs pipe.
I don't know if I can out-rev him with it....but I think I can out-HP him and run more prop.
But first things first.....here's the next one up...K&B Q-500 motor.
Not much, but It's all I got for now. Air-Gar's commin' out with a Sport Jett .50, I think, same type plane....front carb, side exhaust. I think propped right I can stay with him....
Have you ever seen one of these K&B's run ? I haven't .
Dave.
I don't know if I can out-rev him with it....but I think I can out-HP him and run more prop.
But first things first.....here's the next one up...K&B Q-500 motor.
Not much, but It's all I got for now. Air-Gar's commin' out with a Sport Jett .50, I think, same type plane....front carb, side exhaust. I think propped right I can stay with him....
Have you ever seen one of these K&B's run ? I haven't .
Dave.
09-05-2002, 01:36 AM
#7
Cermark F-20 ARF Winter Project question
Hopefully some pictures by the end of the week. BTW "Flyboy" If you want the edge use some 30% heli fuel. Two guys here run Jett .50 in their DC Tigersharks. Both were even. One switched to that fuel and was smokin the other guy.
09-05-2002, 01:45 AM
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No Dave..never have..
Seen the K&B Q500 engine...not a clue...
As far as out propping AirGar..Get something like an 11X 10 or such..I was getting 15.5K with a 12X8 Zinger...14.2K with a 14X6 Rev Up. I bet you can crack 13K with an 11 X 10..that will get his attention. But a 10" prop would fly the plane, only problem I had was the prop shaft boss is .400" I think..I didn't have much hub left with the 10X10....the 11" pattern props had larger hubs.
As far as out propping AirGar..Get something like an 11X 10 or such..I was getting 15.5K with a 12X8 Zinger...14.2K with a 14X6 Rev Up. I bet you can crack 13K with an 11 X 10..that will get his attention. But a 10" prop would fly the plane, only problem I had was the prop shaft boss is .400" I think..I didn't have much hub left with the 10X10....the 11" pattern props had larger hubs.
09-05-2002, 02:08 PM
#10
Gittin back to AMTdude......
Yes, your on the right track. My observations (about a years worth)
1. You absolutely have to modify the elevator servo mounting.
2. Save the retracts for a smaller plane, get the Robart HD's.
3. Double-up on all the hinges, and tape the seams.
4. Jett .90, good choice.
5. Recover as you like....forget the glass.
6. Get a different canopy, or make a wood one, yours will melt.
I glued the rudder solid, and trimmed the tail feathers searching for a flutter...pay no attn. to the funny tail....
We need to start a F-20 Lover's Club.
I Just did a "trim-job" on mine, liked the missle red....Dave.
( ooops....pic got "digital" )
1. You absolutely have to modify the elevator servo mounting.
2. Save the retracts for a smaller plane, get the Robart HD's.
3. Double-up on all the hinges, and tape the seams.
4. Jett .90, good choice.
5. Recover as you like....forget the glass.
6. Get a different canopy, or make a wood one, yours will melt.
I glued the rudder solid, and trimmed the tail feathers searching for a flutter...pay no attn. to the funny tail....
We need to start a F-20 Lover's Club.
I Just did a "trim-job" on mine, liked the missle red....Dave.
( ooops....pic got "digital" )
09-06-2002, 11:49 PM
#13
Cermark F-20 ARF Winter Project question
Actually I rigged the hinges in the rudder so they are very stiff. I don't use rudder much anyways. I am a tad concerned on the ailerons though. The missles tubes are "Estes" and the fins are bass wood. They are held on with velcro (removable)
*Actually I took a good look at your rear end It is entirely different from mine. You have an earlier version of this plane. I read about it in my directions. They did not change my booklet, they just gave me a few extra pages explaining what is going on.
*Actually I took a good look at your rear end
It is entirely different from mine. You have an earlier version of this plane. I read about it in my directions. They did not change my booklet, they just gave me a few extra pages explaining what is going on.
09-07-2002, 12:44 AM
#14
Cyclic....negateevo....
Mine was the same as yours, I modified that verticle stabilize "adapter" piece....it looked like a sailboat. LOL.
And I trimmed off the trailing end of the rudder, and the outboard edges of the elevators....chasing after that flutter. Also I left off that "cap piece" on the top of the verticle stab.
I recall reading in the directions....somthing about the tail had been modified from ealier designs to reduce flutter. Is that what you mean ?
And I trimmed off the trailing end of the rudder, and the outboard edges of the elevators....chasing after that flutter. Also I left off that "cap piece" on the top of the verticle stab.
I recall reading in the directions....somthing about the tail had been modified from ealier designs to reduce flutter. Is that what you mean ?
09-14-2002, 02:40 AM
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Retracts?
Has anybody used the Dave Brown mech. retracts?
I have a Cermark F20 coming(NIB kit bought on RCU)and a Cermark F16 in hand and the retracts that came with it have a LOT of slop.I ordered a set of Dave Brown's from Quantum hobbies ($70).
I have a Cermark F20 coming(NIB kit bought on RCU)and a Cermark F16 in hand and the retracts that came with it have a LOT of slop.I ordered a set of Dave Brown's from Quantum hobbies ($70).
09-14-2002, 04:56 AM
#16
GeeBee....no, not I.....
....I'm putting the Robart's in my F-16.
IMHO....put as much power in the "16" as you can. I'm running an O.S. 1.08 FSR in mine.
The F-20 goes fine with a good running .75....but if you want to "schweed" the fellas ( read: BLOW 'EM IN THE WEEDS ) a Jett .90, or a big block Rossi .90, with the long pipe....will pretty much get their attention ! Heh Heh Heh.
Economy Style.....I wonder how the new Magnum .90 XLS runs.
IMHO....put as much power in the "16" as you can. I'm running an O.S. 1.08 FSR in mine.
The F-20 goes fine with a good running .75....but if you want to "schweed" the fellas ( read: BLOW 'EM IN THE WEEDS ) a Jett .90, or a big block Rossi .90, with the long pipe....will pretty much get their attention ! Heh Heh Heh.
Economy Style.....I wonder how the new Magnum .90 XLS runs.
09-14-2002, 02:10 PM
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Engine
I have a Jet90L for one of them,probably the F16,will do the same for the F20 if the funds are available at "build Time"
I like mech.retracts cause they dont leak.Might try Spring Airs on one of them,where is a good place to buy them mail order?Haven't seen them advertised.
I like mech.retracts cause they dont leak.Might try Spring Airs on one of them,where is a good place to buy them mail order?Haven't seen them advertised.
09-15-2002, 12:26 AM
#18
Re: Retracts?
Originally posted by GeeBee
Has anybody used the Dave Brown mech. retracts?
I have a Cermark F20 coming(NIB kit bought on RCU)and a Cermark F16 in hand and the retracts that came with it have a LOT of slop.I ordered a set of Dave Brown's from Quantum hobbies ($70).
Has anybody used the Dave Brown mech. retracts?
I have a Cermark F20 coming(NIB kit bought on RCU)and a Cermark F16 in hand and the retracts that came with it have a LOT of slop.I ordered a set of Dave Brown's from Quantum hobbies ($70).
09-15-2002, 12:28 AM
#19
Re: Engine
Originally posted by GeeBee
I have a Jet90L for one of them,probably the F16,will do the same for the F20 if the funds are available at "build Time"
I like mech.retracts cause they dont leak.Might try Spring Airs on one of them,where is a good place to buy them mail order?Haven't seen them advertised.
I have a Jet90L for one of them,probably the F16,will do the same for the F20 if the funds are available at "build Time"
I like mech.retracts cause they dont leak.Might try Spring Airs on one of them,where is a good place to buy them mail order?Haven't seen them advertised.
