strip planking
 

:D is there a math formula to figure plank shapes? like if you were to do a nacell or nose cone..

RE: strip planking
 

No, unless it is a simple shape, like a cone, cylinder, etc.

More complex shapes could be drawn using one of the softwares used for unfolding sheetmetal, but those are not cheap.

The old fashion way is manual drafting, like in the attached example.

This article describes a different approach:

http://www.raysmodels.ca/Technical%2...%20article.doc

RE: strip planking
 

I guess you're talking about sheeting and not strip planking. Actual strip planking is the best way for hard to sheet compound curves. Does take more time but can yield great results. This was my first attempt at planking a fuse that didn't have a flat spot on it.

RE: strip planking
 

Good article, but there's one thing I just don't get. He describes how to cut planks with an angle on each edge by tilting your stripper, making a cut, then "swiveling the balsa sheet 180 degrees and cutting off the other side. I just don't see how it's possible to get the shape he describes as "A" using this method. Seems to me you would get a "C" shaped piece off each time you made a cut.

Obviously I'm reading this wrong, could someone set me straight?

RE: strip planking
 

Seems to me you need to turn it around ANDflip it over to cut on the same side of the balsa plank.

RE: strip planking
 

Planking is a slow process but yields a very lightweight and strong structure. I have planked a few RC airplanes and my current one is a Yokosuka D4Y4. I have built ship models with plank on bulkhead construction and the planking is a prominent feature to say the least so accuracy is paramount. 1st- don't use CA glue- get Duco or similar. These types of glue are easily sanded. A good method is to measure the circumference at mutiple stations. Divide the largest circumference by, say 1/4"- for 1/4" wide planks. This will give you a rough estimate of the number of planks needed. At each station you will divide this number into the circumference and it will let you know the width of plank at that location. Transfer these measurements to the planks and rough cut it. Sand it to smooth the curves both sides and glue in place. Keep doing this and don't force the plank sideways. If the taper becomes too thin then cut it off at a former location but be sure a small shelf of the former shows so a 'stealer' plank can be glued to it. This is a trial fit and sand to fit process but the end result will truly amaze. Use thick enough planks that initial sanding will be no problem with flex. It's all an experience thing. If some areas are too thin just glue wood on opposite side. When satisfied join the 2 halves (after adding any 'guts'- electronics, pushrods, etc.) and final sand. Ship modeling forums will have tons of info about this process. Good luck, ARUP

RE: strip planking
 

I agree with what all above have said so far, when i had to make outer skin on the nacelles of my S Constellation this was the best way to do it, initially i tried using small widths of sheeting (1" or 3/4") wide but they would not curve and i would have gotten a flat or indented sort of a spot on the nacelles. What i did then was to cut 36"L x 1/4"W x 3/32" strips out of whole sheet and then measured the length i needed from former to former, re measure again on the model itself and then cut many strips at that length. Then depending on where i wanted to attach them, i trimmed my strip/s accordingly and glued them on with GP Aliphatic resin while used pins to hold them down. At times i had to use bit of water on the outer surface of the strip so it would easily bend grain wise and conform around the formers while maintaining true needed shape of the nacelle.

I do have to admit, strip planking is looooong, slow n boring process but in the end you get great results.



Sam

(Sorry can't find any picture showing bare planking on those nacelles w/out filler on them)

RE: strip planking
 

Maybe lofting the object in Google Sketchup?

Or maybe Solidworks, from a subsidiary of a subsidiary of Dassault Group

RE: strip planking
 

I dont understand the need for a formula. I free hand it. Like was said above, I figure on 1/4" to 3/8" wide cut to length and glue. As you get to area's you need a wedge, you still eye ball it and cut. Simple process.
Edwin

RE: strip planking
 

Ok, I finished strip planking a P-26 a couple days before reading the article that was linked to earlier, so I wasn't too concerned about the question I asked earlier about cutting angled pieces. I finally thought about it for a minute and figure out what the issue was. The quote from the article is:

After each pass of the stripper, turn the main balsa sheet 180 degrees (do not turn it over).

It just never occurred to me to do exactly what the article said NOT to do, "turn it over". After thinking it through I couldn't believe it was so obvious, so I went up and cut a couple strips. After each cut I simple "turned it over" end to end and the pieces came out just like they should. I definitely agree with the main point of the article that strip planking is so much easier than sheeting in many cases, it actually makes it enjoyable.

RE: strip planking
 

50 or so years ago, Walter Musciano had many scale models in the magazines, all of which featured strip planking, 3/32"x1/4" strips being standard.
I built his P-36, for one.
That had a skinny fuselage aft of the motor, but a serious bulge for the motor.. being a plane which really needed an inline motor rather than the radial it had... and became the P-40, with a proper motor. :)
Made for a lot of cutting and sanding.
Now, I would see where I could get away with wider strips where following a contour didn't need a lot of warping of the strip, and use the thinner strips for areas where there was a lot of contour change.