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Building Tips and technical articles. => ARF'S => Topic started by: John Rakes on November 04, 2007, 04:12:48 PM
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Been working on this Cardinal today. Covered with Ulatra Coat white and carbon fibre print. The carbon print works really well. I thought it would strech its shape but it didnt. I will change the flap tp elevator pushrod
with carbon tube and ball links. I will use a LA 46 and 4.5 oz profile tank. Usually go with APC 11/5 prop and aluminum spinner. See Ya
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(Pssttt, try an APC 12.25 x 3.75 at about 9700 rpm,, ) H^^
Cardinal looks nice, are you planning other trim?
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That is a nice look. For the uninitiated, what exactly is the carbon print??? (never heard of it before)
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I think it is/was Ultracote that has/had faux carbonfiber cloth trimsheet. It looks very real, but is useless for anything except for D-Bats. It really gets Mel Lyne excited, or at least, it usta. Technology isn't allowed, but film covering is, you see. I don't think it's available anymore, sadly. It would be great to cover the hood of the "Hated Honda" with it, while Da Dirt wasn't looking. It would be a very spendy prank, tho. LL~ Steve
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The carbon print film could be obsulete. He had a high price of $23 and gave it to me for the price of white, he may have just wanted to get rid of it, and it was the last roll. I have some more trim work to do, I just loose fit together to see what I had. Got to do something to match up thiose blue wheel pants.
As far as the LA 46, I will try that set up, but so far the Dixon modified 46 likes the 11/5 set up at wet 2 with that slight break. Thanks I will try it.
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Hi John,
Lustrecoat white should paint the wheel pants for you after a coat of primer.
If the LA 46 is one of Tom's reworks, I would strongly vote against trying the 12.25-3.75 APC. It won't like it.
Bill <><
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A word of warning on the Cardinal ARC. If the bell crank and lead outs are the same as mine, DO change them. My up leadout broke at the bellcrank just as I finished a four leaf clover on it's 12th flight. Not a lot of flights for a wire to break. n1 y1 H^^
After looking mine over I traded it to a fellow flyer. The leadout broke on the second flight. When he informed Brodak they said they were really, really sorry to hear that.
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I have a Brodak Cardinal ARF and a Brodak Oriental ARF. Do you know if the Oriental has the same problem of weak leadouts? What about the Top Flite Nobler, Flite Streak, and Tutor II?
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All of the Top Flite "models" come with metal bellcranks--at least every one that I have seen; Score, Tutor II, Nobler and F.S. The control horns included in the Score, Tutor II (don't know about the Nobler) are too springy. I could deflect inboard flap to it's limit while holding outboard flap at the limit in the oposite direction. The elevator horn solder joint on my Score failed.
All the Brodak arf/arc models that I have seen have usable nylon bellcranks. The Brodak control horns are usable but not great.
The pushrods in most Top Flite kits should NOT be used ( the Flite Streak pushrod is usable, but not really good.)
Some of the Brodak pushrods are fair, some use a cheap clevis which must be replaced---may as well replace the pushrod with something that will last, and use a Z bend or ball link for the connections. There are a very few clevis connectors which could be used, but not the ones in the kits in question.
If you expect your ARF/ARC (of either brand) to last very long, replace the leadouts and the metal bellcrank and bush the bellcrank at the leadout attach points.
Cheers,
Jim
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Thanks for all of that helpful info!
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I agree with the above and change out the controls on any ARF/ARC I own. Even though these are supposedly "disposable", I still prefer to build them so I can use them a long time. ALL of the leadouts are too wimpy for me. The TF metal bellcranks are junk from the sixties era; the Brodak nylon bellcranks are fine, just install new leadouts with brass bushings and forget them forever.
I recently picked up a Strega and it has a "Gen You Whine" Tom Morris bellcrank and leadouts already installed. If you want to change this one, please wrap it carefully and send it to me. LL~ LL~
Aside from the fact that the Strega has more plywood than a Georgia Pacific warehouse, it looks like a very good creation and I think you could build it as is with no problems (other than weight). n~
Ron
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Ron,
My Strega ARF airframe/hardware weighed 46.75 oz.---probably lighter than I could build/cover.
The Brodak covering, while not premium grade, is very light.
Jim
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My Strega ARF airframe/hardware weighed 46.75 oz.---probably lighter than I could build/cover.
Jim,
You might be right about the weight, especially if you are planning to use the film covering.
I was a little surprised by all the plywood up in the front end - shades of the Big Jim Super Tiger Patternmaster. n~
If you plan to use a traditional covering and finish, your model may end up heavy. I always estimate 10 ounces minimum, plus another 16 ounces for my engine, tank, spinner, and pipe. That estimate just put me in the 70 - 75 ounce range. That's not bad for a wing with 740 squares. The loading is still very reasonable, but I am now thinking about simply using the wing and tail, then building a new, much lighter, fuselage. So much for quick and dirty ARCs. It's now a long winter project. :## :##
Take care,
Ron
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I think the Strega ARF (and most other Windy designs) reflects Windy's concerns about vibration from engines like the ST 60. For smoother engines, some redesign of the structure could save lots of weight.
I decided to not assemble the Strega ARF, but do have a Strega kit to build. Ronnie Thompson's Strega seems to fly very well; even better after the Nats crash and rebuild.
Jim
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Hi Jim,
Thanks for all your great info on this forum, it has been helpful to us retreads. y1
You wrote:
"Ron,
My Strega ARF airframe/hardware weighed 46.75 oz.---probably lighter than I could build/cover.
The Brodak covering, while not premium grade, is very light.
Jim Oliver"
When you refer to the "Brodak covering" above, are you referring to the covering on the ARFs or the covering we can buy from Brodak? Do you think the one we buy is nearly as light as the ARFs covering? I agree that this is very light covering. I "Uncovered" one of their ARFs and the covering felt lighter, but I did not weigh it.
I ordered some covering from Brodak to match my P-40 ARFs covering (Pls don't ask why? ;-) and I found it to be EXCELLENT. I think it is Orcover?, which is like Ultrakote. It was easy to apply, and matched perfectly. Unlike the ARF covering, this covering stayed down, and sealed well. I am a 30+ yr. fan of Monokote, but I was very impressed with Brodaks covering.
I just did not want people out there to think that the ARF covering (AKA, Chinakote?) was the same as the excellent covering Brodak sells to match the ARF colors.
Again, thank you for all your help.
Regards, H^^
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Rudy,
I was referring to the covering on the Brodak ARFs. I have not tried any of the covering that is sold by Brodak on rolls, so I don't know what it is.
In another life (RC) I found that recent production Monocote seemed less usable (erratic shrink/adhesion) than the Monocote of the earlier years. Usability seems to vary with color, for some reason. Anyway, I switched to Ultracote (Orocover) with relative satisfaction. Very uniform adhesion/shrink, the ability to lift and reposition if needed, etc. The finish on U.C. is not as glossy as M.C.; U.C. looks more like paint. I have found a few rolls of U.C. that have very light lines (like scratches) on the surface--not really a problem for most uses, but would not be acceptable for a really first class covering job.
I have a few rolls of U.C. and M.C. left in the shop, but don't plan to buy any more. I am rediscovering the fun of dope and colored tissue and colored silkspan. Sig still sells light weight colored tissue and heavier weight colored silkspan---they call it something else, maybe "plyspan". Tom Morris (and possibably others) sell something called Polyspan that is a white polyester material that seems very good when properly applied and finished with dope.
I think some of the guys use the Polyspan and finish with auto paint.
Cheers,
Jim
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You must check all controls on arcs or arfs I have seen several failures including my cardinal. The lead outs failed after at least 15 flights including two pull tests at contests (did a lot of outside loops until it hit).
by the way your plane look good. HH%%
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(snip)
Tom Morris (and possibably others) sell something called Polyspan that is a white polyester material that seems very good when properly applied and finished with dope.
I think some of the guys use the Polyspan and finish with auto paint.
Cheers,
Jim
Hi Jim,
I have really found polyspan to be the best of two worlds in my experiences. It is a lightweight polyester coat lining. Apply with dope exactly like silkspan, silk or tissue, but it heat shrinks! And you can drop a glo plug on it, and it won't go through! LL~
Downsides are inability to go around tight corners, and it fizzes if saded too soon. Thin CA takes care of the fuzzies but they are still a pain! ;D
I would never suggest covering a fuselage or things like that with it, but it has become my covering of choice for a built up wing!
(disclaimer: I only used enough $cote to get to know how to put it on......)
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I have covered one wing with Polyspan and can state with confidence: you DON'T want to sand into it!!
Other than that and the fact that it doesn't like compound curves, it great stuff.
Jim
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I have covered one wing with Polyspan and can state with confidence: you DON'T want to sand into it!!
Other than that and the fact that it doesn't like compound curves, it great stuff.
Jim
Tom has always recommended covering tough wing tips and such with silkspan, or suitable, material. Just make sure that the material is filled (and hardened/saturated) before sanding. Thin CA does harden the fuzzies where you can get rid of them, but that is ALL I have found to work once you get a case of fuzzies. ;D