RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AND FASTER!  
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RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/19/2007 11:04:43 AM   
cottp51


 

Posts: 58
Joined: 10/31/2007
From: Alta Vista, KS, USA
Status: offline 		i thank everybody who emailed me the plans and those who offered to help, i wasnt to happy about not having the plans seeing how i am taking off work today to build my plane and go to the hobby shop to buy anything i might of forgot to finish it, this thing does look badazz sitting here on the assembly table

(in reply to CrashPro)
       Post #: 126

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/24/2007 7:02:05 AM   
cottp51


 

Posts: 58
Joined: 10/31/2007
From: Alta Vista, KS, USA
Status: offline 		well she's together & ready to fly except for 1 thing, the dang actuator valve or whatever it's called ( the mechanism hooked directly to the retract servo) leaks, i pumped the system up to 100psi like the manual says and cycled the gear a time or two but started hearing a hissing of air & sure enough its this switch/valve im talking about,whats a good valve i could use for this,im going to put something else in, if this thing died that quick it must not be much

(in reply to cottp51)
       Post #: 127

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 12:35:58 AM   
Sparhawk



Posts: 391
Joined: 8/19/2002
From: Dartmouth, NS, CANADA
Status: offline 		Make sure the linkage to the air valve is not too tight to the servo. It is probably losing air due to a side load issue. If you unhook the linkage to the servo, can you manually operate it without the air escaping?
ALign the servo arm so that it does not place ony side load on the valve's plunger and you should be all right. My linkage is always a little loose and it works great!

Dan

_____________________________

Oh great are the days my landings = my take-offs....!
Revver Bro #158

(in reply to cottp51)
       Post #: 128

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 12:55:50 AM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		That control valve is pretty simple. I'd take it apart and check it for burrs around the holes and for cut o-rings. Smooth up the inside of the body, replace the o-rings, put a little silicone grease on everything, and reassemble it. Be sure to set your servo travel so that the E-clips have just a little clearance between them and the valve body.

What leaked on mine was the fill valve. To fix it, I put a one-way check valve from another brand of retracts between the fill valve and the tank. The next problem I had was a cut airline to the nose gear retract. I had run the line through one of those laser cut holes in a bulkhead and the sharp edge cut into the tubing. So make sure your airlines and servo leads are protected from those sharp-edged holes.

Lynn

(in reply to cottp51)
       Post #: 129

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 1:12:08 AM   
cottp51


 

Posts: 58
Joined: 10/31/2007
From: Alta Vista, KS, USA
Status: offline 		well i took the accuator apart and didnt really see any real issues except a couple flimsy o-rings, i did have some o-rings that worked and i used them, then i re-done the linkage between the servo and the valve to give it more play, after all this i repressurized the system and everything seems to work fine except i must have a slow leak because i loose my pressure after an hour or so of sitting, so now its time to find the leak, its still getting flown tomorrow weather permitting.

(in reply to TXKflier)
       Post #: 130

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 1:13:56 AM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		Well, use the ol' spit test on the filler valve. It's probably leaking.. ;-)

(in reply to cottp51)
       Post #: 131

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 1:28:44 AM   
cottp51


 

Posts: 58
Joined: 10/31/2007
From: Alta Vista, KS, USA
Status: offline 		yep thats exactly what im thinking to, because i have pressure on my robart air pump gauge as soon as i put the line on it to pump it up, i shouldnt get a reading until i start pumping what did you use exactly txflier?

< Message edited by cottp51 -- 11/25/2007 1:30:06 AM >

(in reply to TXKflier)
       Post #: 132

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 3:10:29 AM   
funflyerf4


 

Posts: 370
Joined: 11/8/2003
From: vernon, NJ, USA
Status: offline 		Hey Cottp51 if it holds air for an hour land after 45 min. I would keep an eye on the front retract they have pins and bushings for the trunion that likes to come out.The plane flies great.

(in reply to cottp51)
       Post #: 133

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 3:34:31 AM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		I wouldn't say great. A semi-scale Yak-54 or Extra 300 flies great. These Cermark propjets are wannabe lawn darts. They're fast and scary. They'll bite you in a New York minute. And with the weight of the engine so far ahead of the CG and the short tails, they do some awful weird things at times.

(in reply to funflyerf4)
       Post #: 134

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 12:27:59 PM   
funflyerf4


 

Posts: 370
Joined: 11/8/2003
From: vernon, NJ, USA
Status: offline
quote:

ORIGINAL: TXKflier

I wouldn't say great. A semi-scale Yak-54 or Extra 300 flies great. These Cermark propjets are wannabe lawn darts. They're fast and scary. They'll bite you in a New York minute. And with the weight of the engine so far ahead of the CG and the short tails, they do some awful weird things at times.

I dont know how you can say that I have over at least 500+ flights on both the F-16 2&3 generation and the F18 and there is no bad tendeces about eather on when set up like they should be like any plane.If they are fast and scary then fly a cub.And if you put a Jett in it than you do not worry about the engine so far ahead of the cg.They fly like a great pattern ship.

(in reply to TXKflier)
       Post #: 135

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/25/2007 2:11:53 PM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		They're not like any pattern ship I ever flew and I've been flying R/C since 1963. Are you voting for Hillary too?

(in reply to funflyerf4)
       Post #: 136

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/26/2007 11:29:14 AM   
funflyerf4


 

Posts: 370
Joined: 11/8/2003
From: vernon, NJ, USA
Status: offline
quote:

ORIGINAL: TXKflier

They're not like any pattern ship I ever flew and I've been flying R/C since 1963. Are you voting for Hillary too?

Are you voting for Hillary too I don't get it? Is that funny?

(in reply to TXKflier)
       Post #: 137

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 11/26/2007 5:21:30 PM   
cottp51


 

Posts: 58
Joined: 10/31/2007
From: Alta Vista, KS, USA
Status: offline 		I flew mine 4 times yesterday and with each flight it got better & better, i ended up using a 13x8 apc on my .100 evolution that seemed to make the plane take-off & fly better, the manual was right the best manuver this plane does is the fast low pass then point it vertical till she's a small dot in the sky!!!! My only complaint is its hard to see at times and if your not on your toes you can get dis-oriented very easy. All in all this is a good flying plane.

(in reply to funflyerf4)
       Post #: 138

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 12/2/2007 4:07:34 PM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		Here are some photos of how I balanced the flying stabs on my F-18 and F-16. On the F-16, it took a 1-7/16" inch long piece of 5/16" all-thread which weighed 0.4 ounces. I posted the text explanation here:

http://www.rcuniverse.com/forum/fb.asp?m=6434473



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(in reply to TXKflier)
       Post #: 139

RE: CERMARK F-18 HORNET, BUILT IT BETTER, STRONGER, AN... - 12/2/2007 5:29:06 PM   
TXKflier


 

Posts: 64
Joined: 1/24/2006
From: Texarkana, TX, USA
Status: offline 		You might find this interesting. I just did an Internet search for the words "Cherokee horizontal stablizer balance". One of the pages I found was about a lawsuit concerning the fatal crash of a recently serviced Piper Cherokee. If you read through it, you'll see where the stabilator was supposed to be balanced between 0 and minus 40 inch-pounds, which is nose heavy. But, the mechanic entered +20.125 inch-pounds on the worksheet, which would be tail-heavy. Read the expert's analysis of the evidence, their description of the sequence of events, and how rapidly things went wrong once the flutter started.

http://caselaw.lp.findlaw.com/cgi-bin/getcase.pl?court=6th&navby=case&no=00a0279p

The article was especially interesting to me for the following reasons:

1. My dad owned a 1972 Cherokee Arrow and I flew it for about 150 hours from 1974 to 1978.
2. Someone on RCU who didn't think R/C stabilators needed to be balanced wrote that the stab on a Cherokee would sit trailing edge low. If it did, I suspect a spring pulled it that way. Of course, when the plane's control lock is installed, the trailing edge will be low. In that position: (1) It keeps the plane from taking off if the pilot forgets to remove it. (2) It might help prevent high winds from flipping the plane over. (3) It gets the yoke out of the way for entry and exit.
3. The mechanic used an uncalibrated scale to measure the CG of the stab.
4. I'm a calibration technician in a US Army calibration lab. We calibrate scales, torque wrenches, etc.

And finally, the quote that really hit home...

"The airplane . . . flew a long time before [Plane Perfection] touched it, and it didn't last very long after . . . "

And, unfortunately, three people died.. <