Planking

[Mike Griffin]

Does anyone on the forum still use the planking technique on CL Models?  I would love to see a tutorial on how to do it right.  I have played around with it but really have never mastered it.

Thanks

Mike

[Jim Kraft]

I have planked several fuselage tops, and it is really pretty easy, just time consuming. I cut the strips of 1/8" balsa into 1/4" wide. I then put each strip on the table and sand a taper on each side so that they will fit together tightly. I just sand the edge to what it needs for each strip. I start on each side and work up to the top from both sides. That helps keep from warps. I use only Sig cement for gluing the strips together and to the formers as it sands so easy. After you have it all planked just sand with 220 wet or dry sand paper and it will smooth out very quickly. If you have done a good job of sanding the angles on the strips you will have no cracks to fill. I did the complete top on my Taurus and was very happy with it. I also did the top on a Yates Dragon that turned out very well. Personally, I would rather plank than hollow blocks. I hope some of this makes sense.

[Mark Scarborough]

well sure they do,, here,,

http://en.wikipedia.org/wiki/Planking_%28fad%29


oh you meant on models,, LOL

I think that Molded skins have pretty much taken a lot of the situations where planking was done in the past,, by my observation

[Randy Powell]

Mark, could it be someone else's observation.   

[jfv]

Check this out.

[Mike Griffin]

Thanks JFV   that helps a lot.

Mike

[Tim Wescott]

Will molding go around curves as sharply compound as the ones shown in that article that jfv posted?

I always figured molding for simple curves and mildly compound ones -- not radically compound curves like F7F nacells.

[Randy Cuberly]

Will molding go around curves as sharply compound as the ones shown in that article that jfv posted?

I always figured molding for simple curves and mildly compound ones -- not radically compound curves like F7F nacells.

For radical compound curves like those mentioned above it demands a combination of molded sheet and carved blocks!
I don't have any pictures immediately available but I'll look for some.
Some folks here probably have some photos of such work.

Randy Cuberly

[Avaiojet]

Here ya go Mike.

You asked for planking.

 

I do believe the planking topic IS old hat though, it's been talked about before, especially in my Threads/posts with photos.

Received well by some and not so well by others, who probably haven't used this method or who may not like it. I wouldn't say it's for everyone, but they do manufacture a "planking" making "tool." By the thousands would be my guess, so someone else, besides myself are planking, boats or model airplanes. Or anything they choose that offers this particular building method. No big deal, just another way to get something done.

I didn't invent planking, google it!, and this style or purpose of building won't go away. Still a great process to get compounds. A process or method used by many skilled modelers.

Hey! If a hack like me can do it, planking that is, so can anyone else!  

My experience goes way back to the Berkeley kits. Late 50's.

Wish those days were back.

I have this Grumman Widgeon which I'll be changing the necelles to radial, and will use planking for the purpose. This time I think 3/32" instead of 1/8".

Hope my post reply helps you Mike. Be nice if we knew your project?

Models I've used planking on, built over the years. One well over 30 years ago.

Charles

[Perry Rose]

  I think Berkley models tried planking back in the fifties on some models. I remember strips of balsa with a convex on one side and concave on the other kinda like tongue and groove or bull nose and bull butt.

[Steve Helmick]

Maybe "Griffining" will be easier to do, Mike?  Steve

Griffining [edit]Rookie Washington Redskins quarterback Robert Griffin III's (RGIII) first NFL touchdown pass was an 88-yard pass play to Pierre Garcon against the New Orleans Saints. In the process of throwing the pass, Griffin was knocked to the ground, from which position he watched the rest of the play unfold. As Garcon streaked across the goal-line, Griffin, seated on the turf, thrust his hands in the air showing a #1 with both index fingers, thereby spawning the Griffining Internet meme.[46] The Griffining movement began in earnest when Brent from @BurgundyBlog tweeted, “How has the sitting-down-arms-up posture not yet incited a ‘Griffining’ meme?" Soon afterward the Griffining pose was featured on an ESPN segment and on the front page of The Washington Post. Robert Griffin III was later asked how he felt about the new meme by ESPN's Rick Reilly and he responded with, “Who would have thought getting knocked on your butt and throwing a touchdown would start a phenomenon like that?” Griffin said. “I’m not opposed to it. It’s pretty funny to me. [47][48]

[RC Storick]

I'd skip it and go to molded parts. FWIW 

Molding is so easy once you know how. Its the lightest and strongest way to go. It been around as long as planking.

[Avaiojet]

Molding is so easy once you know how. Its the lightest and strongest way to go. It been around as long as planking.

Robert,

You mentioned an egg shaped cross section for a fuselage of your own design?

Ideas? Got anything drawn out yet? That first line? Well, in your case it won't be a straight one. 

I do have a background with other "egg" shaped models besides the Mig-3, although this is a fine example.

I'd like to see where you're headed with this?

That egg shap design concept you have for stunt, could render strength with less material, possibly permit the omittance of some solid formers, plus vent the removal of air also, and not to leave out, that tremendous advantage using less material, less weight for the build.

I believe your on to something worth pursuing. Especially with Electrics.

Exactly where my interest may be going.

Charles

 

[Dan McEntee]

   The "egg shape" type of construction is called "monocoche"  construction (and I know I don't have that spelled correctly) and has been around since Lockheed was called Loughead  and they produced the Vega and a couple of other designs with a MOLDED plywood shell for light weight and strength. The Mosquito Bomber was built the same way with a plywood inner and outer skin laminated to a balsa wood layer on the inside. Planking is and has always been a short cut to avoid hollowing blocks and making molds If Berkeley did it you know it was because it was cheaper! Molding will almost never be lighter because of the excess wood thickness that you have to include to allow for sanding, and all the weight that is added from glue and filler to fill all of the gaps. A properly hollowed out block would be a lot lighter if you start with the correct weight wood. Molding allows you to use thinner wood to start with, so it's a no brainer if you think about it.
   Type at you later,
  Dan McEntee

[Avaiojet]

Molding allows you to use thinner wood to start with, so it's a no brainer if you think about it.
  Type at you later,
  Dan McEntee

My construction thoughts on Robert's molding idea was not to use strip "planking" at all.

Thin sheet balsa, as suggested by Dan, but possibly with two layers of a suitable thickness, is my likely consideration.

Would this would allow for the application/importance of "cross graining," AND with the right choice of a laminating adheasive could add strength without adding unnecessary weight?

I trully don't believe any other material, composits that is, even when created in a female mold, would offer weight or strength advantages.

Charles

[Douglas Ames]

I think laminated balsa would add weight from the adhesive and with cross-grain layers, would be difficult to mold.
Even if you molded and applied each layer individually you would risk the chance of voids and delam.
Al Rabe uses a ply-balsa-ply laminate for his formers with finishing resin for the adhesive, but that is a structural part with minimal area.

[Paul Smith]

Doesn't a molded balsa shell start with a wood form - one wood thickness undersize?  While the finished product might potentially a bit lighter, it seems like a lot of work for a one off build. 

I've done pretty well with planking and block sanding in speed, racing, carrier, and scale.  Maybe the weight would be a factor on a big stunter, but I even plank-and-sanded my Chief and Flying Fool.

Maybe I'd feel the other way if I had a CNC mill to make the forms, but I have razor bladed, chunks of 2 x 4, 3M-77, and plenty of sandpaper.

[Mark Scarborough]

to make a buck for molding balsa, you can use foam, or hard balsa,, I have even had luck using a baseball bat ( Pat Johnstons trick)
in a lot of cases, you only need to get the shape close to make it easy enough to fit the installment,,


I believe that a molded shell is stronger than a carved block in most cases,, its also lighter and more structuraly sound than planking IMHO

[Avaiojet]

to make a buck for molding balsa, you can use foam, or hard balsa,, I have even had luck using a baseball bat ( Pat Johnstons trick)
in a lot of cases, you only need to get the shape close to make it easy enough to fit the installment,,


I believe that a molded shell is stronger than a carved block in most cases, its also lighter and more structuraly sound than planking IMHO

Mark,

I agree with you about "molded shell" being stronger than hollowed solid block, and "planking" should "not" be consided for the actual construction at all, for reasons mentioned.

BUT/however, planking "could" be used for the mock-up plug.

I've been thinking about this since Robert first mentioned the word "egg."

I did put together some considerations for the design of an egg cross section fuselage, ECSF.

Certainly I would entertain the 1/16" "cross grain" douple laminate," at 45 degrees, which I mentioned. CGDL. Application would be, one laminate at a time.

Not sure about this, but I would construct a few "test" sub structures for the foundation of this sheeting skin. I don't believe I would use a typical light ply "former with a few stringers." 

I would do testing with a full three sided structure that would attach to egg formers and run longitudionally, the entire length of the "inner" fuselage sub structure, if possible.

My guess, and I'm generally wrong  , believe this three sided or "triangle" structure may be stiffer? Engineers on this?
Certainly lighter because of less material. And yes, my stiffness test would consider holes for weight removal. A matter os size, how many and where?

I have a few other ideas also, but I would like to hear/read other modeler's comments.

Interesting method of construction/design that could possibly prove useable.

Be fun to entertain with a mock up or two.

I'm to busy, at the moment, to get physical with CAD or balsa, but I will share ideas.

Charles

[Curare]

It, monococh, (sp) was a WW1 French inovation and used on a Deperdusin (sp) monoplane.  There is a replica at Owls Head and one at Old Rhinebeck.

Acutally it's Monocoque.

[Mike Griffin]

If you are building multiple planes of one design like Tom Morris does with his Cavaliers and some other designs, it is certainly worth the time to carve foam or wood plugs but for just one Airplane of one design, it is a matter of if you want to make that form and maybe never use it again.  It is a matter of choice I suppose.  Some people like Fords others like Chevys.   

Mike

[Larry Fernandez]

Add up the glue needed for each strip and the filler to smooth it all out, a planked structure would far outweigh a molded shell.

Larry, Buttafucco Stunt Team

[Dan McEntee]

Acutally it's Monocoque.

      That's the spelling I was looking for. I thought Spell Check would bail me out, but it was fooled also! I was trying for what looked right, one of those, "I'll know it's right when I see it" moments! Itried it several ways, but I didn't have a clue about the Q!!!
   Type at you later,
   Dan McEntee

[john e. holliday]

If you go to Stuka Stunt or order one of Al Rabes CD's you will see his molds are made of wood and plaster.  Sometimes some foam.   I think the plaster makes for a better surface to work with.  I have in the past used foam for molded parts. 

[FLOYD CARTER]

Could be that the Germans were the first to use monocoque construction with the albatross biplane.  Lockheed made it famous with their Vega-series, but beginning with their little 1924 folding wing biplane.  They had a giant concrete female mold at their Santa Barbara factory.  The strips were laid in by hand- one strip at a time!  That concrete mold was later found buried when they were digging up to make a parking lot.

The little 2-cylinder engine for the 1924 biplane ended up in the garage of Monty Groves in Sunnyvale, CA.  We tried to get it running, but couldn't make it.  We think the replacement magneto that I installed on it wasn't working very well.

Floyd