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Building Tips and technical articles. => ARF'S => Topic started by: Ironbomb on April 19, 2009, 06:51:45 PM

Title: ARF Cardinal
Post by: Ironbomb on April 19, 2009, 06:51:45 PM
Hi gang, its been a while since I last posted. I have finally made time available to get a couple planes airworthy again, and decided to use this opportunity to fix my favorite Cardinal. This arf is about 4 years old, had maybe slightly more than two hundred flights on it, and several crashes.

I have just replaced the leadouts. There was no wear on the bellcrank, I just dont trust crimps. (lost more than one plane to a failed crimp). I am happy to replace the original covering. the edges were lifting badly as of its last flights. The film was a nightmare to remove. There is still pigmented goo in the corners, its hard to remove.

But my questions are,  1, what is the fues made of? its really sorta heavy. Sturdy, but heavy. it seems harder than hard balsa and softer than plywood. If I remember right, my arf weighed 50oz with a LA40 installed. And 2, will the remaing glue from the original covering make it impossible to apply new film? I have had no luck removing the old stuff with MEK, acetone or even dope thinner. Any thoughts, anyone been down this road before?

It sure is good to be back at my workbench again. After this I will be finishing a plane I started three years ago  #^

Greg

Title: Re: ARF Cardinal
Post by: Leester on April 20, 2009, 03:18:23 AM
I've never had the glue stay after using acetone  ??? ??? How about heating with your heat gun, then trying to clean it  ??? ??? None the less as long as the surface is smooth I'd think the new covering would stick. Good Luck
Title: Re: ARF Cardinal
Post by: Bob Reeves on April 20, 2009, 08:18:28 AM
If you are going to use a covering darker or the same color I wouldn't worry about left over glue, I would be more concirned with oil soaked wood. Tip, next time use a heat gun to remove the covering. Balsarite or foam friendly CA can be used over oil to help the covering stick. See the "Undressing My Score" thread..
Title: Re: ARF Cardinal
Post by: Paul Taylor on April 20, 2009, 07:31:05 PM
Hey Greg,
About time you got your butt back here and on the end of a handle. I have my Cardinal almost finished with the foam wing.

Watch the main page for a picture in a few days.
Title: Re: ARF Cardinal
Post by: Ironbomb on April 21, 2009, 09:38:40 AM
Hi Bob, I just read your "Score" thread. I wish I read that first, or at least asked before I started peeling. Its all good tho, I got lots of time eye-balling the structure while I was removing the old stuff. I didnt have any noticable oil soaked wood. I kept the seams pretty well stuck down with epoxy. Not very pretty, but effective. I'll put some pics up when I can, maybe this weekend.

happy to have glue on my fingers again

Greg
Title: Re: ARF Cardinal
Post by: Ironbomb on April 21, 2009, 09:42:55 AM
Hey Greg,
About time you got your butt back here and on the end of a handle. I have my Cardinal almost finished with the foam wing.

Watch the main page for a picture in a few days.

Hey Paul, yea, it is about time. I missed it plenty. I'll have to shoot you a pic of what I DID build last winter. The wood was heavy.
I cant wait to se your foamie Card. I hope yours is as durable as mine was. I smacked the ground plenty with it. It got me to learn the pattern. I might build another, who knows. I'll be watching for your pics, later man

G
Title: Re: ARF Cardinal
Post by: Dennis Moritz on May 02, 2009, 09:03:05 AM
Yeah I stripped a Cardinal ARF. The fues wood was indeed a mystery. Sweet smelling, some kind of ply laminated to balsa. Hung it up to dry for a month or so. I think the "seasoning" did it good. The huge cut outs keep it light enough. Get as much glue off as you can. If I can ever get wing straight (so far I've tried this and that "trick," but it's a STUBBORN warp of 1/4" at the trailing edge) I'll cover the wing with monokote and do the fues in silkspan and dope. That way I won't be fighting delaminating covering. I fiberglassed the nose and sunk in 1/8" thick aluminum plates to back up the mounting bolts. All this to help with the DREADED PROFILE BAD VIBES. It was a shock tho, seeing the fues construction with the china kote stripped off. (How do you like those big pliers, file and so forth, fixing an ARF Profile must be a serious business.)
Title: Re: ARF Cardinal
Post by: Jim Oliver on May 03, 2009, 06:16:27 AM
The fuse is very carefully crafted from an "exotic oriental hardwood"............. ::)

Cheers,
Jim
Title: Re: ARF Cardinal
Post by: peabody on May 03, 2009, 01:37:45 PM
I know several that are involved in the prototyping of Brodak's ARF/ARCs, and have learned that the Chinese seem incapable (or uncaring) of choosing wood or wood grains for particular applications...they seem to use the piece that is the closest in size to their requirement.

It is some wierd wood though...
Title: Re: ARF Cardinal
Post by: Dennis Adamisin on May 03, 2009, 07:02:58 PM
I know several that are involved in the prototyping of Brodak's ARF/ARCs, and have learned that the Chinese seem incapable (or uncaring) of choosing wood or wood grains for particular applications...they seem to use the piece that is the closest in size to their requirement.

It is some wierd wood though...

Despite it all the Cardinals are pretty darned good ARF's.  My only knock on Dad's was the too-heavy o/b tip, and that is more of a nuisance than a real problem...

Title: Re: ARF Cardinal
Post by: Paul Taylor on May 03, 2009, 07:24:12 PM
http://stunthanger.com/smf/index.php?action=dlattach;topic=12154.0;attach=40616;image

And the wood is also patched.

Look at my thread on patched wood on Tut2
Title: Re: ARF Cardinal
Post by: Brett Buck on May 04, 2009, 10:44:27 PM
I know several that are involved in the prototyping of Brodak's ARF/ARCs, and have learned that the Chinese seem incapable (or uncaring) of choosing wood or wood grains for particular applications...

   But I know ARF manufacturers at least do some sorting of the wood, and reject some. I have a bunch of the reject wood that Elliot Scott bought. It's all that crummy straight-grained stuff that only weighs 4.2 lb/cu ft. Real weak.

     Brett
Title: Re: ARF Cardinal
Post by: Dennis Adamisin on May 05, 2009, 01:33:43 PM
   But I know ARF manufacturers at least do some sorting of the wood, and reject some. I have a bunch of the reject wood that Elliot Scott bought. It's all that crummy straight-grained stuff that only weighs 4.2 lb/cu ft. Real weak.

     Brett

Hmmmm, this is where I should say something I'll have to apologize for later....  LL~  LL~  LL~  VD~
Title: Re: ARF Cardinal
Post by: Steve Helmick on May 12, 2009, 06:46:39 PM
In '83, the Chinese showed up in Australia for the World Free Flight Champs. I wuz there. One of the Chinese guys won F1A glider, and I was kinda invited by my Ozzie friend Peter Lloyd to check out the model during official post-contest processing. When it was being given back, some questions were asked: "Wot kind of wood?" "Chinese wood."  "What is the covering?" "Chinese tissue."  Kinda funny???

I wouldn't be surprised if the plywood is bamboo. You see bamboo flooring on sale here, these days.  I suppose it's stripped and laminated into sheets, but maybe not. It's a pretty cool wood...tough, and grows faster than about anything... but dandelions at River View Park!   >:( Steve
Title: Re: ARF Cardinal
Post by: Ironbomb on September 29, 2009, 01:06:44 PM
Its been a while since I did an update, so here it is,.... the plane is done.  it took a while to finish, but its done. It was at 50oz when I crashed it last, and its at 50oz all done and balanced. I removed the fues gear, a total of 5oz (wheel pants, Dubro tires and aluminum struts). I added a bit of lite ply to the wing to make a good (I hope) wing mounted gear atachment. I put two sections of aluminum arrow shafts in the fues to add some integrity to the fues. I had routered the balsa between the nose doublers and layed the arrow shafts in with gorilla glue. The fues had broke three times in the same place in my years of flying the plane. So I wanted to beef up the thin section of the fues over the wing. I also installed a OS46LA instead of my trusty OS40LA. And I put some really light balsa in the open holes of the fues. I doped the fues and tail feathers, and only ultra coted the wing and flap.

cant wait to fly it. it was fun fixing it up again.

Greg
Title: Re: ARF Cardinal
Post by: Leester on October 01, 2009, 07:02:04 PM
Hey Greg, That really looks nice!! Hope the weather lets you fly it soon.